![Sasha Levin](/assets/img/avatar_default.png)
Link: http://lkml.kernel.org/r/1357772960-4436-5-git-send-email-sasha.levin@oracle.com Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
5246 lines
118 KiB
C
5246 lines
118 KiB
C
/*
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* Infrastructure for profiling code inserted by 'gcc -pg'.
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*
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* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
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* Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
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*
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* Originally ported from the -rt patch by:
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* Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
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*
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* Based on code in the latency_tracer, that is:
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*
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* Copyright (C) 2004-2006 Ingo Molnar
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* Copyright (C) 2004 Nadia Yvette Chambers
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*/
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#include <linux/stop_machine.h>
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#include <linux/clocksource.h>
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#include <linux/kallsyms.h>
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#include <linux/seq_file.h>
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#include <linux/suspend.h>
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#include <linux/debugfs.h>
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#include <linux/hardirq.h>
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#include <linux/kthread.h>
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#include <linux/uaccess.h>
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#include <linux/bsearch.h>
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#include <linux/module.h>
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#include <linux/ftrace.h>
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#include <linux/sysctl.h>
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#include <linux/slab.h>
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#include <linux/ctype.h>
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#include <linux/sort.h>
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#include <linux/list.h>
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#include <linux/hash.h>
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#include <linux/rcupdate.h>
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#include <trace/events/sched.h>
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#include <asm/setup.h>
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#include "trace_output.h"
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#include "trace_stat.h"
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#define FTRACE_WARN_ON(cond) \
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({ \
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int ___r = cond; \
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if (WARN_ON(___r)) \
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ftrace_kill(); \
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___r; \
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})
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#define FTRACE_WARN_ON_ONCE(cond) \
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({ \
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int ___r = cond; \
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if (WARN_ON_ONCE(___r)) \
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ftrace_kill(); \
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___r; \
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})
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/* hash bits for specific function selection */
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#define FTRACE_HASH_BITS 7
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#define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
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#define FTRACE_HASH_DEFAULT_BITS 10
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#define FTRACE_HASH_MAX_BITS 12
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#define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_CONTROL)
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#ifdef CONFIG_DYNAMIC_FTRACE
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#define INIT_REGEX_LOCK(opsname) \
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.regex_lock = __MUTEX_INITIALIZER(opsname.regex_lock),
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#else
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#define INIT_REGEX_LOCK(opsname)
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#endif
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static struct ftrace_ops ftrace_list_end __read_mostly = {
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.func = ftrace_stub,
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.flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB,
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};
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/* ftrace_enabled is a method to turn ftrace on or off */
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int ftrace_enabled __read_mostly;
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static int last_ftrace_enabled;
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/* Quick disabling of function tracer. */
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int function_trace_stop __read_mostly;
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/* Current function tracing op */
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struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
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/* What to set function_trace_op to */
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static struct ftrace_ops *set_function_trace_op;
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/* List for set_ftrace_pid's pids. */
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LIST_HEAD(ftrace_pids);
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struct ftrace_pid {
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struct list_head list;
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struct pid *pid;
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};
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/*
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* ftrace_disabled is set when an anomaly is discovered.
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* ftrace_disabled is much stronger than ftrace_enabled.
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*/
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static int ftrace_disabled __read_mostly;
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static DEFINE_MUTEX(ftrace_lock);
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static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end;
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static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end;
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static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
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ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
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ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
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static struct ftrace_ops global_ops;
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static struct ftrace_ops control_ops;
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#if ARCH_SUPPORTS_FTRACE_OPS
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static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
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struct ftrace_ops *op, struct pt_regs *regs);
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#else
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/* See comment below, where ftrace_ops_list_func is defined */
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static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
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#define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
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#endif
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/*
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* Traverse the ftrace_global_list, invoking all entries. The reason that we
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* can use rcu_dereference_raw_notrace() is that elements removed from this list
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* are simply leaked, so there is no need to interact with a grace-period
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* mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
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* concurrent insertions into the ftrace_global_list.
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*
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* Silly Alpha and silly pointer-speculation compiler optimizations!
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*/
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#define do_for_each_ftrace_op(op, list) \
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op = rcu_dereference_raw_notrace(list); \
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do
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/*
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* Optimized for just a single item in the list (as that is the normal case).
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*/
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#define while_for_each_ftrace_op(op) \
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while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
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unlikely((op) != &ftrace_list_end))
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static inline void ftrace_ops_init(struct ftrace_ops *ops)
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{
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#ifdef CONFIG_DYNAMIC_FTRACE
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if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
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mutex_init(&ops->regex_lock);
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ops->flags |= FTRACE_OPS_FL_INITIALIZED;
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}
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#endif
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}
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/**
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* ftrace_nr_registered_ops - return number of ops registered
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*
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* Returns the number of ftrace_ops registered and tracing functions
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*/
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int ftrace_nr_registered_ops(void)
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{
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struct ftrace_ops *ops;
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int cnt = 0;
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mutex_lock(&ftrace_lock);
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for (ops = ftrace_ops_list;
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ops != &ftrace_list_end; ops = ops->next)
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cnt++;
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mutex_unlock(&ftrace_lock);
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return cnt;
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}
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static void
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ftrace_global_list_func(unsigned long ip, unsigned long parent_ip,
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struct ftrace_ops *op, struct pt_regs *regs)
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{
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int bit;
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bit = trace_test_and_set_recursion(TRACE_GLOBAL_START, TRACE_GLOBAL_MAX);
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if (bit < 0)
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return;
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do_for_each_ftrace_op(op, ftrace_global_list) {
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op->func(ip, parent_ip, op, regs);
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} while_for_each_ftrace_op(op);
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trace_clear_recursion(bit);
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}
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static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
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struct ftrace_ops *op, struct pt_regs *regs)
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{
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if (!test_tsk_trace_trace(current))
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return;
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ftrace_pid_function(ip, parent_ip, op, regs);
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}
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static void set_ftrace_pid_function(ftrace_func_t func)
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{
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/* do not set ftrace_pid_function to itself! */
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if (func != ftrace_pid_func)
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ftrace_pid_function = func;
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}
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/**
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* clear_ftrace_function - reset the ftrace function
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*
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* This NULLs the ftrace function and in essence stops
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* tracing. There may be lag
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*/
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void clear_ftrace_function(void)
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{
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ftrace_trace_function = ftrace_stub;
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ftrace_pid_function = ftrace_stub;
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}
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static void control_ops_disable_all(struct ftrace_ops *ops)
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{
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int cpu;
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for_each_possible_cpu(cpu)
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*per_cpu_ptr(ops->disabled, cpu) = 1;
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}
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static int control_ops_alloc(struct ftrace_ops *ops)
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{
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int __percpu *disabled;
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disabled = alloc_percpu(int);
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if (!disabled)
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return -ENOMEM;
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ops->disabled = disabled;
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control_ops_disable_all(ops);
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return 0;
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}
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static void update_global_ops(void)
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{
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ftrace_func_t func = ftrace_global_list_func;
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void *private = NULL;
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/* The list has its own recursion protection. */
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global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE;
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/*
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* If there's only one function registered, then call that
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* function directly. Otherwise, we need to iterate over the
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* registered callers.
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*/
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if (ftrace_global_list == &ftrace_list_end ||
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ftrace_global_list->next == &ftrace_list_end) {
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func = ftrace_global_list->func;
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private = ftrace_global_list->private;
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/*
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* As we are calling the function directly.
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* If it does not have recursion protection,
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* the function_trace_op needs to be updated
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* accordingly.
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*/
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if (!(ftrace_global_list->flags & FTRACE_OPS_FL_RECURSION_SAFE))
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global_ops.flags &= ~FTRACE_OPS_FL_RECURSION_SAFE;
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}
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/* If we filter on pids, update to use the pid function */
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if (!list_empty(&ftrace_pids)) {
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set_ftrace_pid_function(func);
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func = ftrace_pid_func;
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}
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global_ops.func = func;
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global_ops.private = private;
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}
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static void ftrace_sync(struct work_struct *work)
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{
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/*
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* This function is just a stub to implement a hard force
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* of synchronize_sched(). This requires synchronizing
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* tasks even in userspace and idle.
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*
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* Yes, function tracing is rude.
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*/
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}
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static void ftrace_sync_ipi(void *data)
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{
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/* Probably not needed, but do it anyway */
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smp_rmb();
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}
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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static void update_function_graph_func(void);
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#else
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static inline void update_function_graph_func(void) { }
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#endif
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static void update_ftrace_function(void)
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{
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ftrace_func_t func;
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update_global_ops();
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/*
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* If we are at the end of the list and this ops is
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* recursion safe and not dynamic and the arch supports passing ops,
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* then have the mcount trampoline call the function directly.
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*/
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if (ftrace_ops_list == &ftrace_list_end ||
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(ftrace_ops_list->next == &ftrace_list_end &&
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!(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) &&
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(ftrace_ops_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) &&
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!FTRACE_FORCE_LIST_FUNC)) {
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/* Set the ftrace_ops that the arch callback uses */
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if (ftrace_ops_list == &global_ops)
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set_function_trace_op = ftrace_global_list;
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else
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set_function_trace_op = ftrace_ops_list;
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func = ftrace_ops_list->func;
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} else {
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/* Just use the default ftrace_ops */
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set_function_trace_op = &ftrace_list_end;
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func = ftrace_ops_list_func;
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}
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/* If there's no change, then do nothing more here */
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if (ftrace_trace_function == func)
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return;
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update_function_graph_func();
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/*
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* If we are using the list function, it doesn't care
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* about the function_trace_ops.
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*/
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if (func == ftrace_ops_list_func) {
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ftrace_trace_function = func;
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/*
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* Don't even bother setting function_trace_ops,
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* it would be racy to do so anyway.
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*/
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return;
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}
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#ifndef CONFIG_DYNAMIC_FTRACE
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/*
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* For static tracing, we need to be a bit more careful.
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* The function change takes affect immediately. Thus,
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* we need to coorditate the setting of the function_trace_ops
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* with the setting of the ftrace_trace_function.
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*
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* Set the function to the list ops, which will call the
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* function we want, albeit indirectly, but it handles the
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* ftrace_ops and doesn't depend on function_trace_op.
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*/
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ftrace_trace_function = ftrace_ops_list_func;
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/*
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* Make sure all CPUs see this. Yes this is slow, but static
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* tracing is slow and nasty to have enabled.
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*/
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schedule_on_each_cpu(ftrace_sync);
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/* Now all cpus are using the list ops. */
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function_trace_op = set_function_trace_op;
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/* Make sure the function_trace_op is visible on all CPUs */
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smp_wmb();
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/* Nasty way to force a rmb on all cpus */
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smp_call_function(ftrace_sync_ipi, NULL, 1);
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/* OK, we are all set to update the ftrace_trace_function now! */
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#endif /* !CONFIG_DYNAMIC_FTRACE */
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ftrace_trace_function = func;
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}
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static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
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{
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ops->next = *list;
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/*
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* We are entering ops into the list but another
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* CPU might be walking that list. We need to make sure
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* the ops->next pointer is valid before another CPU sees
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* the ops pointer included into the list.
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*/
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rcu_assign_pointer(*list, ops);
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}
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static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
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{
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struct ftrace_ops **p;
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/*
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* If we are removing the last function, then simply point
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* to the ftrace_stub.
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*/
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if (*list == ops && ops->next == &ftrace_list_end) {
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*list = &ftrace_list_end;
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return 0;
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}
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for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
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if (*p == ops)
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break;
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if (*p != ops)
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return -1;
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*p = (*p)->next;
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return 0;
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}
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static void add_ftrace_list_ops(struct ftrace_ops **list,
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struct ftrace_ops *main_ops,
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struct ftrace_ops *ops)
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{
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int first = *list == &ftrace_list_end;
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add_ftrace_ops(list, ops);
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if (first)
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add_ftrace_ops(&ftrace_ops_list, main_ops);
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}
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static int remove_ftrace_list_ops(struct ftrace_ops **list,
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struct ftrace_ops *main_ops,
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struct ftrace_ops *ops)
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{
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int ret = remove_ftrace_ops(list, ops);
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if (!ret && *list == &ftrace_list_end)
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ret = remove_ftrace_ops(&ftrace_ops_list, main_ops);
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return ret;
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}
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static int __register_ftrace_function(struct ftrace_ops *ops)
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{
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if (ops->flags & FTRACE_OPS_FL_DELETED)
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return -EINVAL;
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if (FTRACE_WARN_ON(ops == &global_ops))
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return -EINVAL;
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if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
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return -EBUSY;
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/* We don't support both control and global flags set. */
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if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK)
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return -EINVAL;
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#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
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/*
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* If the ftrace_ops specifies SAVE_REGS, then it only can be used
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* if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
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* Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
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*/
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if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
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!(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
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return -EINVAL;
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if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
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ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
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#endif
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if (!core_kernel_data((unsigned long)ops))
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ops->flags |= FTRACE_OPS_FL_DYNAMIC;
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if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
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add_ftrace_list_ops(&ftrace_global_list, &global_ops, ops);
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ops->flags |= FTRACE_OPS_FL_ENABLED;
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} else if (ops->flags & FTRACE_OPS_FL_CONTROL) {
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if (control_ops_alloc(ops))
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return -ENOMEM;
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add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops);
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} else
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add_ftrace_ops(&ftrace_ops_list, ops);
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if (ftrace_enabled)
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update_ftrace_function();
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return 0;
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}
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static int __unregister_ftrace_function(struct ftrace_ops *ops)
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{
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int ret;
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if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
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return -EBUSY;
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if (FTRACE_WARN_ON(ops == &global_ops))
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return -EINVAL;
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if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
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ret = remove_ftrace_list_ops(&ftrace_global_list,
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&global_ops, ops);
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if (!ret)
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ops->flags &= ~FTRACE_OPS_FL_ENABLED;
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} else if (ops->flags & FTRACE_OPS_FL_CONTROL) {
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ret = remove_ftrace_list_ops(&ftrace_control_list,
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&control_ops, ops);
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} else
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ret = remove_ftrace_ops(&ftrace_ops_list, ops);
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if (ret < 0)
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return ret;
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if (ftrace_enabled)
|
|
update_ftrace_function();
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void ftrace_update_pid_func(void)
|
|
{
|
|
/* Only do something if we are tracing something */
|
|
if (ftrace_trace_function == ftrace_stub)
|
|
return;
|
|
|
|
update_ftrace_function();
|
|
}
|
|
|
|
#ifdef CONFIG_FUNCTION_PROFILER
|
|
struct ftrace_profile {
|
|
struct hlist_node node;
|
|
unsigned long ip;
|
|
unsigned long counter;
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
unsigned long long time;
|
|
unsigned long long time_squared;
|
|
#endif
|
|
};
|
|
|
|
struct ftrace_profile_page {
|
|
struct ftrace_profile_page *next;
|
|
unsigned long index;
|
|
struct ftrace_profile records[];
|
|
};
|
|
|
|
struct ftrace_profile_stat {
|
|
atomic_t disabled;
|
|
struct hlist_head *hash;
|
|
struct ftrace_profile_page *pages;
|
|
struct ftrace_profile_page *start;
|
|
struct tracer_stat stat;
|
|
};
|
|
|
|
#define PROFILE_RECORDS_SIZE \
|
|
(PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
|
|
|
|
#define PROFILES_PER_PAGE \
|
|
(PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
|
|
|
|
static int ftrace_profile_enabled __read_mostly;
|
|
|
|
/* ftrace_profile_lock - synchronize the enable and disable of the profiler */
|
|
static DEFINE_MUTEX(ftrace_profile_lock);
|
|
|
|
static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
|
|
|
|
#define FTRACE_PROFILE_HASH_BITS 10
|
|
#define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
|
|
|
|
static void *
|
|
function_stat_next(void *v, int idx)
|
|
{
|
|
struct ftrace_profile *rec = v;
|
|
struct ftrace_profile_page *pg;
|
|
|
|
pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
|
|
|
|
again:
|
|
if (idx != 0)
|
|
rec++;
|
|
|
|
if ((void *)rec >= (void *)&pg->records[pg->index]) {
|
|
pg = pg->next;
|
|
if (!pg)
|
|
return NULL;
|
|
rec = &pg->records[0];
|
|
if (!rec->counter)
|
|
goto again;
|
|
}
|
|
|
|
return rec;
|
|
}
|
|
|
|
static void *function_stat_start(struct tracer_stat *trace)
|
|
{
|
|
struct ftrace_profile_stat *stat =
|
|
container_of(trace, struct ftrace_profile_stat, stat);
|
|
|
|
if (!stat || !stat->start)
|
|
return NULL;
|
|
|
|
return function_stat_next(&stat->start->records[0], 0);
|
|
}
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
/* function graph compares on total time */
|
|
static int function_stat_cmp(void *p1, void *p2)
|
|
{
|
|
struct ftrace_profile *a = p1;
|
|
struct ftrace_profile *b = p2;
|
|
|
|
if (a->time < b->time)
|
|
return -1;
|
|
if (a->time > b->time)
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
#else
|
|
/* not function graph compares against hits */
|
|
static int function_stat_cmp(void *p1, void *p2)
|
|
{
|
|
struct ftrace_profile *a = p1;
|
|
struct ftrace_profile *b = p2;
|
|
|
|
if (a->counter < b->counter)
|
|
return -1;
|
|
if (a->counter > b->counter)
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static int function_stat_headers(struct seq_file *m)
|
|
{
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
seq_printf(m, " Function "
|
|
"Hit Time Avg s^2\n"
|
|
" -------- "
|
|
"--- ---- --- ---\n");
|
|
#else
|
|
seq_printf(m, " Function Hit\n"
|
|
" -------- ---\n");
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
static int function_stat_show(struct seq_file *m, void *v)
|
|
{
|
|
struct ftrace_profile *rec = v;
|
|
char str[KSYM_SYMBOL_LEN];
|
|
int ret = 0;
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
static struct trace_seq s;
|
|
unsigned long long avg;
|
|
unsigned long long stddev;
|
|
#endif
|
|
mutex_lock(&ftrace_profile_lock);
|
|
|
|
/* we raced with function_profile_reset() */
|
|
if (unlikely(rec->counter == 0)) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
|
|
seq_printf(m, " %-30.30s %10lu", str, rec->counter);
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
seq_printf(m, " ");
|
|
avg = rec->time;
|
|
do_div(avg, rec->counter);
|
|
|
|
/* Sample standard deviation (s^2) */
|
|
if (rec->counter <= 1)
|
|
stddev = 0;
|
|
else {
|
|
/*
|
|
* Apply Welford's method:
|
|
* s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
|
|
*/
|
|
stddev = rec->counter * rec->time_squared -
|
|
rec->time * rec->time;
|
|
|
|
/*
|
|
* Divide only 1000 for ns^2 -> us^2 conversion.
|
|
* trace_print_graph_duration will divide 1000 again.
|
|
*/
|
|
do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
|
|
}
|
|
|
|
trace_seq_init(&s);
|
|
trace_print_graph_duration(rec->time, &s);
|
|
trace_seq_puts(&s, " ");
|
|
trace_print_graph_duration(avg, &s);
|
|
trace_seq_puts(&s, " ");
|
|
trace_print_graph_duration(stddev, &s);
|
|
trace_print_seq(m, &s);
|
|
#endif
|
|
seq_putc(m, '\n');
|
|
out:
|
|
mutex_unlock(&ftrace_profile_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
|
|
{
|
|
struct ftrace_profile_page *pg;
|
|
|
|
pg = stat->pages = stat->start;
|
|
|
|
while (pg) {
|
|
memset(pg->records, 0, PROFILE_RECORDS_SIZE);
|
|
pg->index = 0;
|
|
pg = pg->next;
|
|
}
|
|
|
|
memset(stat->hash, 0,
|
|
FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
|
|
}
|
|
|
|
int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
|
|
{
|
|
struct ftrace_profile_page *pg;
|
|
int functions;
|
|
int pages;
|
|
int i;
|
|
|
|
/* If we already allocated, do nothing */
|
|
if (stat->pages)
|
|
return 0;
|
|
|
|
stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
|
|
if (!stat->pages)
|
|
return -ENOMEM;
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
functions = ftrace_update_tot_cnt;
|
|
#else
|
|
/*
|
|
* We do not know the number of functions that exist because
|
|
* dynamic tracing is what counts them. With past experience
|
|
* we have around 20K functions. That should be more than enough.
|
|
* It is highly unlikely we will execute every function in
|
|
* the kernel.
|
|
*/
|
|
functions = 20000;
|
|
#endif
|
|
|
|
pg = stat->start = stat->pages;
|
|
|
|
pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
|
|
|
|
for (i = 1; i < pages; i++) {
|
|
pg->next = (void *)get_zeroed_page(GFP_KERNEL);
|
|
if (!pg->next)
|
|
goto out_free;
|
|
pg = pg->next;
|
|
}
|
|
|
|
return 0;
|
|
|
|
out_free:
|
|
pg = stat->start;
|
|
while (pg) {
|
|
unsigned long tmp = (unsigned long)pg;
|
|
|
|
pg = pg->next;
|
|
free_page(tmp);
|
|
}
|
|
|
|
stat->pages = NULL;
|
|
stat->start = NULL;
|
|
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int ftrace_profile_init_cpu(int cpu)
|
|
{
|
|
struct ftrace_profile_stat *stat;
|
|
int size;
|
|
|
|
stat = &per_cpu(ftrace_profile_stats, cpu);
|
|
|
|
if (stat->hash) {
|
|
/* If the profile is already created, simply reset it */
|
|
ftrace_profile_reset(stat);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* We are profiling all functions, but usually only a few thousand
|
|
* functions are hit. We'll make a hash of 1024 items.
|
|
*/
|
|
size = FTRACE_PROFILE_HASH_SIZE;
|
|
|
|
stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
|
|
|
|
if (!stat->hash)
|
|
return -ENOMEM;
|
|
|
|
/* Preallocate the function profiling pages */
|
|
if (ftrace_profile_pages_init(stat) < 0) {
|
|
kfree(stat->hash);
|
|
stat->hash = NULL;
|
|
return -ENOMEM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ftrace_profile_init(void)
|
|
{
|
|
int cpu;
|
|
int ret = 0;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
ret = ftrace_profile_init_cpu(cpu);
|
|
if (ret)
|
|
break;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* interrupts must be disabled */
|
|
static struct ftrace_profile *
|
|
ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
|
|
{
|
|
struct ftrace_profile *rec;
|
|
struct hlist_head *hhd;
|
|
unsigned long key;
|
|
|
|
key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
|
|
hhd = &stat->hash[key];
|
|
|
|
if (hlist_empty(hhd))
|
|
return NULL;
|
|
|
|
hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
|
|
if (rec->ip == ip)
|
|
return rec;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void ftrace_add_profile(struct ftrace_profile_stat *stat,
|
|
struct ftrace_profile *rec)
|
|
{
|
|
unsigned long key;
|
|
|
|
key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
|
|
hlist_add_head_rcu(&rec->node, &stat->hash[key]);
|
|
}
|
|
|
|
/*
|
|
* The memory is already allocated, this simply finds a new record to use.
|
|
*/
|
|
static struct ftrace_profile *
|
|
ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
|
|
{
|
|
struct ftrace_profile *rec = NULL;
|
|
|
|
/* prevent recursion (from NMIs) */
|
|
if (atomic_inc_return(&stat->disabled) != 1)
|
|
goto out;
|
|
|
|
/*
|
|
* Try to find the function again since an NMI
|
|
* could have added it
|
|
*/
|
|
rec = ftrace_find_profiled_func(stat, ip);
|
|
if (rec)
|
|
goto out;
|
|
|
|
if (stat->pages->index == PROFILES_PER_PAGE) {
|
|
if (!stat->pages->next)
|
|
goto out;
|
|
stat->pages = stat->pages->next;
|
|
}
|
|
|
|
rec = &stat->pages->records[stat->pages->index++];
|
|
rec->ip = ip;
|
|
ftrace_add_profile(stat, rec);
|
|
|
|
out:
|
|
atomic_dec(&stat->disabled);
|
|
|
|
return rec;
|
|
}
|
|
|
|
static void
|
|
function_profile_call(unsigned long ip, unsigned long parent_ip,
|
|
struct ftrace_ops *ops, struct pt_regs *regs)
|
|
{
|
|
struct ftrace_profile_stat *stat;
|
|
struct ftrace_profile *rec;
|
|
unsigned long flags;
|
|
|
|
if (!ftrace_profile_enabled)
|
|
return;
|
|
|
|
local_irq_save(flags);
|
|
|
|
stat = &__get_cpu_var(ftrace_profile_stats);
|
|
if (!stat->hash || !ftrace_profile_enabled)
|
|
goto out;
|
|
|
|
rec = ftrace_find_profiled_func(stat, ip);
|
|
if (!rec) {
|
|
rec = ftrace_profile_alloc(stat, ip);
|
|
if (!rec)
|
|
goto out;
|
|
}
|
|
|
|
rec->counter++;
|
|
out:
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
static int profile_graph_entry(struct ftrace_graph_ent *trace)
|
|
{
|
|
function_profile_call(trace->func, 0, NULL, NULL);
|
|
return 1;
|
|
}
|
|
|
|
static void profile_graph_return(struct ftrace_graph_ret *trace)
|
|
{
|
|
struct ftrace_profile_stat *stat;
|
|
unsigned long long calltime;
|
|
struct ftrace_profile *rec;
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
stat = &__get_cpu_var(ftrace_profile_stats);
|
|
if (!stat->hash || !ftrace_profile_enabled)
|
|
goto out;
|
|
|
|
/* If the calltime was zero'd ignore it */
|
|
if (!trace->calltime)
|
|
goto out;
|
|
|
|
calltime = trace->rettime - trace->calltime;
|
|
|
|
if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
|
|
int index;
|
|
|
|
index = trace->depth;
|
|
|
|
/* Append this call time to the parent time to subtract */
|
|
if (index)
|
|
current->ret_stack[index - 1].subtime += calltime;
|
|
|
|
if (current->ret_stack[index].subtime < calltime)
|
|
calltime -= current->ret_stack[index].subtime;
|
|
else
|
|
calltime = 0;
|
|
}
|
|
|
|
rec = ftrace_find_profiled_func(stat, trace->func);
|
|
if (rec) {
|
|
rec->time += calltime;
|
|
rec->time_squared += calltime * calltime;
|
|
}
|
|
|
|
out:
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
static int register_ftrace_profiler(void)
|
|
{
|
|
return register_ftrace_graph(&profile_graph_return,
|
|
&profile_graph_entry);
|
|
}
|
|
|
|
static void unregister_ftrace_profiler(void)
|
|
{
|
|
unregister_ftrace_graph();
|
|
}
|
|
#else
|
|
static struct ftrace_ops ftrace_profile_ops __read_mostly = {
|
|
.func = function_profile_call,
|
|
.flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
|
|
INIT_REGEX_LOCK(ftrace_profile_ops)
|
|
};
|
|
|
|
static int register_ftrace_profiler(void)
|
|
{
|
|
return register_ftrace_function(&ftrace_profile_ops);
|
|
}
|
|
|
|
static void unregister_ftrace_profiler(void)
|
|
{
|
|
unregister_ftrace_function(&ftrace_profile_ops);
|
|
}
|
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
|
|
|
|
static ssize_t
|
|
ftrace_profile_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
unsigned long val;
|
|
int ret;
|
|
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
|
|
if (ret)
|
|
return ret;
|
|
|
|
val = !!val;
|
|
|
|
mutex_lock(&ftrace_profile_lock);
|
|
if (ftrace_profile_enabled ^ val) {
|
|
if (val) {
|
|
ret = ftrace_profile_init();
|
|
if (ret < 0) {
|
|
cnt = ret;
|
|
goto out;
|
|
}
|
|
|
|
ret = register_ftrace_profiler();
|
|
if (ret < 0) {
|
|
cnt = ret;
|
|
goto out;
|
|
}
|
|
ftrace_profile_enabled = 1;
|
|
} else {
|
|
ftrace_profile_enabled = 0;
|
|
/*
|
|
* unregister_ftrace_profiler calls stop_machine
|
|
* so this acts like an synchronize_sched.
|
|
*/
|
|
unregister_ftrace_profiler();
|
|
}
|
|
}
|
|
out:
|
|
mutex_unlock(&ftrace_profile_lock);
|
|
|
|
*ppos += cnt;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static ssize_t
|
|
ftrace_profile_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
char buf[64]; /* big enough to hold a number */
|
|
int r;
|
|
|
|
r = sprintf(buf, "%u\n", ftrace_profile_enabled);
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
}
|
|
|
|
static const struct file_operations ftrace_profile_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = ftrace_profile_read,
|
|
.write = ftrace_profile_write,
|
|
.llseek = default_llseek,
|
|
};
|
|
|
|
/* used to initialize the real stat files */
|
|
static struct tracer_stat function_stats __initdata = {
|
|
.name = "functions",
|
|
.stat_start = function_stat_start,
|
|
.stat_next = function_stat_next,
|
|
.stat_cmp = function_stat_cmp,
|
|
.stat_headers = function_stat_headers,
|
|
.stat_show = function_stat_show
|
|
};
|
|
|
|
static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
|
|
{
|
|
struct ftrace_profile_stat *stat;
|
|
struct dentry *entry;
|
|
char *name;
|
|
int ret;
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
stat = &per_cpu(ftrace_profile_stats, cpu);
|
|
|
|
/* allocate enough for function name + cpu number */
|
|
name = kmalloc(32, GFP_KERNEL);
|
|
if (!name) {
|
|
/*
|
|
* The files created are permanent, if something happens
|
|
* we still do not free memory.
|
|
*/
|
|
WARN(1,
|
|
"Could not allocate stat file for cpu %d\n",
|
|
cpu);
|
|
return;
|
|
}
|
|
stat->stat = function_stats;
|
|
snprintf(name, 32, "function%d", cpu);
|
|
stat->stat.name = name;
|
|
ret = register_stat_tracer(&stat->stat);
|
|
if (ret) {
|
|
WARN(1,
|
|
"Could not register function stat for cpu %d\n",
|
|
cpu);
|
|
kfree(name);
|
|
return;
|
|
}
|
|
}
|
|
|
|
entry = debugfs_create_file("function_profile_enabled", 0644,
|
|
d_tracer, NULL, &ftrace_profile_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'function_profile_enabled' entry\n");
|
|
}
|
|
|
|
#else /* CONFIG_FUNCTION_PROFILER */
|
|
static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
|
|
{
|
|
}
|
|
#endif /* CONFIG_FUNCTION_PROFILER */
|
|
|
|
static struct pid * const ftrace_swapper_pid = &init_struct_pid;
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
|
|
#ifndef CONFIG_FTRACE_MCOUNT_RECORD
|
|
# error Dynamic ftrace depends on MCOUNT_RECORD
|
|
#endif
|
|
|
|
static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
|
|
|
|
struct ftrace_func_probe {
|
|
struct hlist_node node;
|
|
struct ftrace_probe_ops *ops;
|
|
unsigned long flags;
|
|
unsigned long ip;
|
|
void *data;
|
|
struct list_head free_list;
|
|
};
|
|
|
|
struct ftrace_func_entry {
|
|
struct hlist_node hlist;
|
|
unsigned long ip;
|
|
};
|
|
|
|
struct ftrace_hash {
|
|
unsigned long size_bits;
|
|
struct hlist_head *buckets;
|
|
unsigned long count;
|
|
struct rcu_head rcu;
|
|
};
|
|
|
|
/*
|
|
* We make these constant because no one should touch them,
|
|
* but they are used as the default "empty hash", to avoid allocating
|
|
* it all the time. These are in a read only section such that if
|
|
* anyone does try to modify it, it will cause an exception.
|
|
*/
|
|
static const struct hlist_head empty_buckets[1];
|
|
static const struct ftrace_hash empty_hash = {
|
|
.buckets = (struct hlist_head *)empty_buckets,
|
|
};
|
|
#define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
|
|
|
|
static struct ftrace_ops global_ops = {
|
|
.func = ftrace_stub,
|
|
.notrace_hash = EMPTY_HASH,
|
|
.filter_hash = EMPTY_HASH,
|
|
.flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
|
|
INIT_REGEX_LOCK(global_ops)
|
|
};
|
|
|
|
struct ftrace_page {
|
|
struct ftrace_page *next;
|
|
struct dyn_ftrace *records;
|
|
int index;
|
|
int size;
|
|
};
|
|
|
|
#define ENTRY_SIZE sizeof(struct dyn_ftrace)
|
|
#define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
|
|
|
|
/* estimate from running different kernels */
|
|
#define NR_TO_INIT 10000
|
|
|
|
static struct ftrace_page *ftrace_pages_start;
|
|
static struct ftrace_page *ftrace_pages;
|
|
|
|
static bool ftrace_hash_empty(struct ftrace_hash *hash)
|
|
{
|
|
return !hash || !hash->count;
|
|
}
|
|
|
|
static struct ftrace_func_entry *
|
|
ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
|
|
{
|
|
unsigned long key;
|
|
struct ftrace_func_entry *entry;
|
|
struct hlist_head *hhd;
|
|
|
|
if (ftrace_hash_empty(hash))
|
|
return NULL;
|
|
|
|
if (hash->size_bits > 0)
|
|
key = hash_long(ip, hash->size_bits);
|
|
else
|
|
key = 0;
|
|
|
|
hhd = &hash->buckets[key];
|
|
|
|
hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
|
|
if (entry->ip == ip)
|
|
return entry;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static void __add_hash_entry(struct ftrace_hash *hash,
|
|
struct ftrace_func_entry *entry)
|
|
{
|
|
struct hlist_head *hhd;
|
|
unsigned long key;
|
|
|
|
if (hash->size_bits)
|
|
key = hash_long(entry->ip, hash->size_bits);
|
|
else
|
|
key = 0;
|
|
|
|
hhd = &hash->buckets[key];
|
|
hlist_add_head(&entry->hlist, hhd);
|
|
hash->count++;
|
|
}
|
|
|
|
static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
|
|
{
|
|
struct ftrace_func_entry *entry;
|
|
|
|
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
|
|
if (!entry)
|
|
return -ENOMEM;
|
|
|
|
entry->ip = ip;
|
|
__add_hash_entry(hash, entry);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
free_hash_entry(struct ftrace_hash *hash,
|
|
struct ftrace_func_entry *entry)
|
|
{
|
|
hlist_del(&entry->hlist);
|
|
kfree(entry);
|
|
hash->count--;
|
|
}
|
|
|
|
static void
|
|
remove_hash_entry(struct ftrace_hash *hash,
|
|
struct ftrace_func_entry *entry)
|
|
{
|
|
hlist_del(&entry->hlist);
|
|
hash->count--;
|
|
}
|
|
|
|
static void ftrace_hash_clear(struct ftrace_hash *hash)
|
|
{
|
|
struct hlist_head *hhd;
|
|
struct hlist_node *tn;
|
|
struct ftrace_func_entry *entry;
|
|
int size = 1 << hash->size_bits;
|
|
int i;
|
|
|
|
if (!hash->count)
|
|
return;
|
|
|
|
for (i = 0; i < size; i++) {
|
|
hhd = &hash->buckets[i];
|
|
hlist_for_each_entry_safe(entry, tn, hhd, hlist)
|
|
free_hash_entry(hash, entry);
|
|
}
|
|
FTRACE_WARN_ON(hash->count);
|
|
}
|
|
|
|
static void free_ftrace_hash(struct ftrace_hash *hash)
|
|
{
|
|
if (!hash || hash == EMPTY_HASH)
|
|
return;
|
|
ftrace_hash_clear(hash);
|
|
kfree(hash->buckets);
|
|
kfree(hash);
|
|
}
|
|
|
|
static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
|
|
{
|
|
struct ftrace_hash *hash;
|
|
|
|
hash = container_of(rcu, struct ftrace_hash, rcu);
|
|
free_ftrace_hash(hash);
|
|
}
|
|
|
|
static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
|
|
{
|
|
if (!hash || hash == EMPTY_HASH)
|
|
return;
|
|
call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
|
|
}
|
|
|
|
void ftrace_free_filter(struct ftrace_ops *ops)
|
|
{
|
|
ftrace_ops_init(ops);
|
|
free_ftrace_hash(ops->filter_hash);
|
|
free_ftrace_hash(ops->notrace_hash);
|
|
}
|
|
|
|
static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
|
|
{
|
|
struct ftrace_hash *hash;
|
|
int size;
|
|
|
|
hash = kzalloc(sizeof(*hash), GFP_KERNEL);
|
|
if (!hash)
|
|
return NULL;
|
|
|
|
size = 1 << size_bits;
|
|
hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
|
|
|
|
if (!hash->buckets) {
|
|
kfree(hash);
|
|
return NULL;
|
|
}
|
|
|
|
hash->size_bits = size_bits;
|
|
|
|
return hash;
|
|
}
|
|
|
|
static struct ftrace_hash *
|
|
alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
|
|
{
|
|
struct ftrace_func_entry *entry;
|
|
struct ftrace_hash *new_hash;
|
|
int size;
|
|
int ret;
|
|
int i;
|
|
|
|
new_hash = alloc_ftrace_hash(size_bits);
|
|
if (!new_hash)
|
|
return NULL;
|
|
|
|
/* Empty hash? */
|
|
if (ftrace_hash_empty(hash))
|
|
return new_hash;
|
|
|
|
size = 1 << hash->size_bits;
|
|
for (i = 0; i < size; i++) {
|
|
hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
|
|
ret = add_hash_entry(new_hash, entry->ip);
|
|
if (ret < 0)
|
|
goto free_hash;
|
|
}
|
|
}
|
|
|
|
FTRACE_WARN_ON(new_hash->count != hash->count);
|
|
|
|
return new_hash;
|
|
|
|
free_hash:
|
|
free_ftrace_hash(new_hash);
|
|
return NULL;
|
|
}
|
|
|
|
static void
|
|
ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash);
|
|
static void
|
|
ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash);
|
|
|
|
static int
|
|
ftrace_hash_move(struct ftrace_ops *ops, int enable,
|
|
struct ftrace_hash **dst, struct ftrace_hash *src)
|
|
{
|
|
struct ftrace_func_entry *entry;
|
|
struct hlist_node *tn;
|
|
struct hlist_head *hhd;
|
|
struct ftrace_hash *old_hash;
|
|
struct ftrace_hash *new_hash;
|
|
int size = src->count;
|
|
int bits = 0;
|
|
int ret;
|
|
int i;
|
|
|
|
/*
|
|
* Remove the current set, update the hash and add
|
|
* them back.
|
|
*/
|
|
ftrace_hash_rec_disable(ops, enable);
|
|
|
|
/*
|
|
* If the new source is empty, just free dst and assign it
|
|
* the empty_hash.
|
|
*/
|
|
if (!src->count) {
|
|
free_ftrace_hash_rcu(*dst);
|
|
rcu_assign_pointer(*dst, EMPTY_HASH);
|
|
/* still need to update the function records */
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Make the hash size about 1/2 the # found
|
|
*/
|
|
for (size /= 2; size; size >>= 1)
|
|
bits++;
|
|
|
|
/* Don't allocate too much */
|
|
if (bits > FTRACE_HASH_MAX_BITS)
|
|
bits = FTRACE_HASH_MAX_BITS;
|
|
|
|
ret = -ENOMEM;
|
|
new_hash = alloc_ftrace_hash(bits);
|
|
if (!new_hash)
|
|
goto out;
|
|
|
|
size = 1 << src->size_bits;
|
|
for (i = 0; i < size; i++) {
|
|
hhd = &src->buckets[i];
|
|
hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
|
|
remove_hash_entry(src, entry);
|
|
__add_hash_entry(new_hash, entry);
|
|
}
|
|
}
|
|
|
|
old_hash = *dst;
|
|
rcu_assign_pointer(*dst, new_hash);
|
|
free_ftrace_hash_rcu(old_hash);
|
|
|
|
ret = 0;
|
|
out:
|
|
/*
|
|
* Enable regardless of ret:
|
|
* On success, we enable the new hash.
|
|
* On failure, we re-enable the original hash.
|
|
*/
|
|
ftrace_hash_rec_enable(ops, enable);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Test the hashes for this ops to see if we want to call
|
|
* the ops->func or not.
|
|
*
|
|
* It's a match if the ip is in the ops->filter_hash or
|
|
* the filter_hash does not exist or is empty,
|
|
* AND
|
|
* the ip is not in the ops->notrace_hash.
|
|
*
|
|
* This needs to be called with preemption disabled as
|
|
* the hashes are freed with call_rcu_sched().
|
|
*/
|
|
static int
|
|
ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
|
|
{
|
|
struct ftrace_hash *filter_hash;
|
|
struct ftrace_hash *notrace_hash;
|
|
int ret;
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
|
|
/*
|
|
* There's a small race when adding ops that the ftrace handler
|
|
* that wants regs, may be called without them. We can not
|
|
* allow that handler to be called if regs is NULL.
|
|
*/
|
|
if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
|
|
return 0;
|
|
#endif
|
|
|
|
filter_hash = rcu_dereference_raw_notrace(ops->filter_hash);
|
|
notrace_hash = rcu_dereference_raw_notrace(ops->notrace_hash);
|
|
|
|
if ((ftrace_hash_empty(filter_hash) ||
|
|
ftrace_lookup_ip(filter_hash, ip)) &&
|
|
(ftrace_hash_empty(notrace_hash) ||
|
|
!ftrace_lookup_ip(notrace_hash, ip)))
|
|
ret = 1;
|
|
else
|
|
ret = 0;
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* This is a double for. Do not use 'break' to break out of the loop,
|
|
* you must use a goto.
|
|
*/
|
|
#define do_for_each_ftrace_rec(pg, rec) \
|
|
for (pg = ftrace_pages_start; pg; pg = pg->next) { \
|
|
int _____i; \
|
|
for (_____i = 0; _____i < pg->index; _____i++) { \
|
|
rec = &pg->records[_____i];
|
|
|
|
#define while_for_each_ftrace_rec() \
|
|
} \
|
|
}
|
|
|
|
|
|
static int ftrace_cmp_recs(const void *a, const void *b)
|
|
{
|
|
const struct dyn_ftrace *key = a;
|
|
const struct dyn_ftrace *rec = b;
|
|
|
|
if (key->flags < rec->ip)
|
|
return -1;
|
|
if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static unsigned long ftrace_location_range(unsigned long start, unsigned long end)
|
|
{
|
|
struct ftrace_page *pg;
|
|
struct dyn_ftrace *rec;
|
|
struct dyn_ftrace key;
|
|
|
|
key.ip = start;
|
|
key.flags = end; /* overload flags, as it is unsigned long */
|
|
|
|
for (pg = ftrace_pages_start; pg; pg = pg->next) {
|
|
if (end < pg->records[0].ip ||
|
|
start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
|
|
continue;
|
|
rec = bsearch(&key, pg->records, pg->index,
|
|
sizeof(struct dyn_ftrace),
|
|
ftrace_cmp_recs);
|
|
if (rec)
|
|
return rec->ip;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* ftrace_location - return true if the ip giving is a traced location
|
|
* @ip: the instruction pointer to check
|
|
*
|
|
* Returns rec->ip if @ip given is a pointer to a ftrace location.
|
|
* That is, the instruction that is either a NOP or call to
|
|
* the function tracer. It checks the ftrace internal tables to
|
|
* determine if the address belongs or not.
|
|
*/
|
|
unsigned long ftrace_location(unsigned long ip)
|
|
{
|
|
return ftrace_location_range(ip, ip);
|
|
}
|
|
|
|
/**
|
|
* ftrace_text_reserved - return true if range contains an ftrace location
|
|
* @start: start of range to search
|
|
* @end: end of range to search (inclusive). @end points to the last byte to check.
|
|
*
|
|
* Returns 1 if @start and @end contains a ftrace location.
|
|
* That is, the instruction that is either a NOP or call to
|
|
* the function tracer. It checks the ftrace internal tables to
|
|
* determine if the address belongs or not.
|
|
*/
|
|
int ftrace_text_reserved(const void *start, const void *end)
|
|
{
|
|
unsigned long ret;
|
|
|
|
ret = ftrace_location_range((unsigned long)start,
|
|
(unsigned long)end);
|
|
|
|
return (int)!!ret;
|
|
}
|
|
|
|
static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
|
|
int filter_hash,
|
|
bool inc)
|
|
{
|
|
struct ftrace_hash *hash;
|
|
struct ftrace_hash *other_hash;
|
|
struct ftrace_page *pg;
|
|
struct dyn_ftrace *rec;
|
|
int count = 0;
|
|
int all = 0;
|
|
|
|
/* Only update if the ops has been registered */
|
|
if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
|
|
return;
|
|
|
|
/*
|
|
* In the filter_hash case:
|
|
* If the count is zero, we update all records.
|
|
* Otherwise we just update the items in the hash.
|
|
*
|
|
* In the notrace_hash case:
|
|
* We enable the update in the hash.
|
|
* As disabling notrace means enabling the tracing,
|
|
* and enabling notrace means disabling, the inc variable
|
|
* gets inversed.
|
|
*/
|
|
if (filter_hash) {
|
|
hash = ops->filter_hash;
|
|
other_hash = ops->notrace_hash;
|
|
if (ftrace_hash_empty(hash))
|
|
all = 1;
|
|
} else {
|
|
inc = !inc;
|
|
hash = ops->notrace_hash;
|
|
other_hash = ops->filter_hash;
|
|
/*
|
|
* If the notrace hash has no items,
|
|
* then there's nothing to do.
|
|
*/
|
|
if (ftrace_hash_empty(hash))
|
|
return;
|
|
}
|
|
|
|
do_for_each_ftrace_rec(pg, rec) {
|
|
int in_other_hash = 0;
|
|
int in_hash = 0;
|
|
int match = 0;
|
|
|
|
if (all) {
|
|
/*
|
|
* Only the filter_hash affects all records.
|
|
* Update if the record is not in the notrace hash.
|
|
*/
|
|
if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
|
|
match = 1;
|
|
} else {
|
|
in_hash = !!ftrace_lookup_ip(hash, rec->ip);
|
|
in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
|
|
|
|
/*
|
|
*
|
|
*/
|
|
if (filter_hash && in_hash && !in_other_hash)
|
|
match = 1;
|
|
else if (!filter_hash && in_hash &&
|
|
(in_other_hash || ftrace_hash_empty(other_hash)))
|
|
match = 1;
|
|
}
|
|
if (!match)
|
|
continue;
|
|
|
|
if (inc) {
|
|
rec->flags++;
|
|
if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX))
|
|
return;
|
|
/*
|
|
* If any ops wants regs saved for this function
|
|
* then all ops will get saved regs.
|
|
*/
|
|
if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
|
|
rec->flags |= FTRACE_FL_REGS;
|
|
} else {
|
|
if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0))
|
|
return;
|
|
rec->flags--;
|
|
}
|
|
count++;
|
|
/* Shortcut, if we handled all records, we are done. */
|
|
if (!all && count == hash->count)
|
|
return;
|
|
} while_for_each_ftrace_rec();
|
|
}
|
|
|
|
static void ftrace_hash_rec_disable(struct ftrace_ops *ops,
|
|
int filter_hash)
|
|
{
|
|
__ftrace_hash_rec_update(ops, filter_hash, 0);
|
|
}
|
|
|
|
static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
|
|
int filter_hash)
|
|
{
|
|
__ftrace_hash_rec_update(ops, filter_hash, 1);
|
|
}
|
|
|
|
static void print_ip_ins(const char *fmt, unsigned char *p)
|
|
{
|
|
int i;
|
|
|
|
printk(KERN_CONT "%s", fmt);
|
|
|
|
for (i = 0; i < MCOUNT_INSN_SIZE; i++)
|
|
printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
|
|
}
|
|
|
|
/**
|
|
* ftrace_bug - report and shutdown function tracer
|
|
* @failed: The failed type (EFAULT, EINVAL, EPERM)
|
|
* @ip: The address that failed
|
|
*
|
|
* The arch code that enables or disables the function tracing
|
|
* can call ftrace_bug() when it has detected a problem in
|
|
* modifying the code. @failed should be one of either:
|
|
* EFAULT - if the problem happens on reading the @ip address
|
|
* EINVAL - if what is read at @ip is not what was expected
|
|
* EPERM - if the problem happens on writting to the @ip address
|
|
*/
|
|
void ftrace_bug(int failed, unsigned long ip)
|
|
{
|
|
switch (failed) {
|
|
case -EFAULT:
|
|
FTRACE_WARN_ON_ONCE(1);
|
|
pr_info("ftrace faulted on modifying ");
|
|
print_ip_sym(ip);
|
|
break;
|
|
case -EINVAL:
|
|
FTRACE_WARN_ON_ONCE(1);
|
|
pr_info("ftrace failed to modify ");
|
|
print_ip_sym(ip);
|
|
print_ip_ins(" actual: ", (unsigned char *)ip);
|
|
printk(KERN_CONT "\n");
|
|
break;
|
|
case -EPERM:
|
|
FTRACE_WARN_ON_ONCE(1);
|
|
pr_info("ftrace faulted on writing ");
|
|
print_ip_sym(ip);
|
|
break;
|
|
default:
|
|
FTRACE_WARN_ON_ONCE(1);
|
|
pr_info("ftrace faulted on unknown error ");
|
|
print_ip_sym(ip);
|
|
}
|
|
}
|
|
|
|
static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
|
|
{
|
|
unsigned long flag = 0UL;
|
|
|
|
/*
|
|
* If we are updating calls:
|
|
*
|
|
* If the record has a ref count, then we need to enable it
|
|
* because someone is using it.
|
|
*
|
|
* Otherwise we make sure its disabled.
|
|
*
|
|
* If we are disabling calls, then disable all records that
|
|
* are enabled.
|
|
*/
|
|
if (enable && (rec->flags & ~FTRACE_FL_MASK))
|
|
flag = FTRACE_FL_ENABLED;
|
|
|
|
/*
|
|
* If enabling and the REGS flag does not match the REGS_EN, then
|
|
* do not ignore this record. Set flags to fail the compare against
|
|
* ENABLED.
|
|
*/
|
|
if (flag &&
|
|
(!(rec->flags & FTRACE_FL_REGS) != !(rec->flags & FTRACE_FL_REGS_EN)))
|
|
flag |= FTRACE_FL_REGS;
|
|
|
|
/* If the state of this record hasn't changed, then do nothing */
|
|
if ((rec->flags & FTRACE_FL_ENABLED) == flag)
|
|
return FTRACE_UPDATE_IGNORE;
|
|
|
|
if (flag) {
|
|
/* Save off if rec is being enabled (for return value) */
|
|
flag ^= rec->flags & FTRACE_FL_ENABLED;
|
|
|
|
if (update) {
|
|
rec->flags |= FTRACE_FL_ENABLED;
|
|
if (flag & FTRACE_FL_REGS) {
|
|
if (rec->flags & FTRACE_FL_REGS)
|
|
rec->flags |= FTRACE_FL_REGS_EN;
|
|
else
|
|
rec->flags &= ~FTRACE_FL_REGS_EN;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If this record is being updated from a nop, then
|
|
* return UPDATE_MAKE_CALL.
|
|
* Otherwise, if the EN flag is set, then return
|
|
* UPDATE_MODIFY_CALL_REGS to tell the caller to convert
|
|
* from the non-save regs, to a save regs function.
|
|
* Otherwise,
|
|
* return UPDATE_MODIFY_CALL to tell the caller to convert
|
|
* from the save regs, to a non-save regs function.
|
|
*/
|
|
if (flag & FTRACE_FL_ENABLED)
|
|
return FTRACE_UPDATE_MAKE_CALL;
|
|
else if (rec->flags & FTRACE_FL_REGS_EN)
|
|
return FTRACE_UPDATE_MODIFY_CALL_REGS;
|
|
else
|
|
return FTRACE_UPDATE_MODIFY_CALL;
|
|
}
|
|
|
|
if (update) {
|
|
/* If there's no more users, clear all flags */
|
|
if (!(rec->flags & ~FTRACE_FL_MASK))
|
|
rec->flags = 0;
|
|
else
|
|
/* Just disable the record (keep REGS state) */
|
|
rec->flags &= ~FTRACE_FL_ENABLED;
|
|
}
|
|
|
|
return FTRACE_UPDATE_MAKE_NOP;
|
|
}
|
|
|
|
/**
|
|
* ftrace_update_record, set a record that now is tracing or not
|
|
* @rec: the record to update
|
|
* @enable: set to 1 if the record is tracing, zero to force disable
|
|
*
|
|
* The records that represent all functions that can be traced need
|
|
* to be updated when tracing has been enabled.
|
|
*/
|
|
int ftrace_update_record(struct dyn_ftrace *rec, int enable)
|
|
{
|
|
return ftrace_check_record(rec, enable, 1);
|
|
}
|
|
|
|
/**
|
|
* ftrace_test_record, check if the record has been enabled or not
|
|
* @rec: the record to test
|
|
* @enable: set to 1 to check if enabled, 0 if it is disabled
|
|
*
|
|
* The arch code may need to test if a record is already set to
|
|
* tracing to determine how to modify the function code that it
|
|
* represents.
|
|
*/
|
|
int ftrace_test_record(struct dyn_ftrace *rec, int enable)
|
|
{
|
|
return ftrace_check_record(rec, enable, 0);
|
|
}
|
|
|
|
static int
|
|
__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
|
|
{
|
|
unsigned long ftrace_old_addr;
|
|
unsigned long ftrace_addr;
|
|
int ret;
|
|
|
|
ret = ftrace_update_record(rec, enable);
|
|
|
|
if (rec->flags & FTRACE_FL_REGS)
|
|
ftrace_addr = (unsigned long)FTRACE_REGS_ADDR;
|
|
else
|
|
ftrace_addr = (unsigned long)FTRACE_ADDR;
|
|
|
|
switch (ret) {
|
|
case FTRACE_UPDATE_IGNORE:
|
|
return 0;
|
|
|
|
case FTRACE_UPDATE_MAKE_CALL:
|
|
return ftrace_make_call(rec, ftrace_addr);
|
|
|
|
case FTRACE_UPDATE_MAKE_NOP:
|
|
return ftrace_make_nop(NULL, rec, ftrace_addr);
|
|
|
|
case FTRACE_UPDATE_MODIFY_CALL_REGS:
|
|
case FTRACE_UPDATE_MODIFY_CALL:
|
|
if (rec->flags & FTRACE_FL_REGS)
|
|
ftrace_old_addr = (unsigned long)FTRACE_ADDR;
|
|
else
|
|
ftrace_old_addr = (unsigned long)FTRACE_REGS_ADDR;
|
|
|
|
return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
|
|
}
|
|
|
|
return -1; /* unknow ftrace bug */
|
|
}
|
|
|
|
void __weak ftrace_replace_code(int enable)
|
|
{
|
|
struct dyn_ftrace *rec;
|
|
struct ftrace_page *pg;
|
|
int failed;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return;
|
|
|
|
do_for_each_ftrace_rec(pg, rec) {
|
|
failed = __ftrace_replace_code(rec, enable);
|
|
if (failed) {
|
|
ftrace_bug(failed, rec->ip);
|
|
/* Stop processing */
|
|
return;
|
|
}
|
|
} while_for_each_ftrace_rec();
|
|
}
|
|
|
|
struct ftrace_rec_iter {
|
|
struct ftrace_page *pg;
|
|
int index;
|
|
};
|
|
|
|
/**
|
|
* ftrace_rec_iter_start, start up iterating over traced functions
|
|
*
|
|
* Returns an iterator handle that is used to iterate over all
|
|
* the records that represent address locations where functions
|
|
* are traced.
|
|
*
|
|
* May return NULL if no records are available.
|
|
*/
|
|
struct ftrace_rec_iter *ftrace_rec_iter_start(void)
|
|
{
|
|
/*
|
|
* We only use a single iterator.
|
|
* Protected by the ftrace_lock mutex.
|
|
*/
|
|
static struct ftrace_rec_iter ftrace_rec_iter;
|
|
struct ftrace_rec_iter *iter = &ftrace_rec_iter;
|
|
|
|
iter->pg = ftrace_pages_start;
|
|
iter->index = 0;
|
|
|
|
/* Could have empty pages */
|
|
while (iter->pg && !iter->pg->index)
|
|
iter->pg = iter->pg->next;
|
|
|
|
if (!iter->pg)
|
|
return NULL;
|
|
|
|
return iter;
|
|
}
|
|
|
|
/**
|
|
* ftrace_rec_iter_next, get the next record to process.
|
|
* @iter: The handle to the iterator.
|
|
*
|
|
* Returns the next iterator after the given iterator @iter.
|
|
*/
|
|
struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
|
|
{
|
|
iter->index++;
|
|
|
|
if (iter->index >= iter->pg->index) {
|
|
iter->pg = iter->pg->next;
|
|
iter->index = 0;
|
|
|
|
/* Could have empty pages */
|
|
while (iter->pg && !iter->pg->index)
|
|
iter->pg = iter->pg->next;
|
|
}
|
|
|
|
if (!iter->pg)
|
|
return NULL;
|
|
|
|
return iter;
|
|
}
|
|
|
|
/**
|
|
* ftrace_rec_iter_record, get the record at the iterator location
|
|
* @iter: The current iterator location
|
|
*
|
|
* Returns the record that the current @iter is at.
|
|
*/
|
|
struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
|
|
{
|
|
return &iter->pg->records[iter->index];
|
|
}
|
|
|
|
static int
|
|
ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
|
|
{
|
|
unsigned long ip;
|
|
int ret;
|
|
|
|
ip = rec->ip;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return 0;
|
|
|
|
ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
|
|
if (ret) {
|
|
ftrace_bug(ret, ip);
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* archs can override this function if they must do something
|
|
* before the modifying code is performed.
|
|
*/
|
|
int __weak ftrace_arch_code_modify_prepare(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* archs can override this function if they must do something
|
|
* after the modifying code is performed.
|
|
*/
|
|
int __weak ftrace_arch_code_modify_post_process(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
void ftrace_modify_all_code(int command)
|
|
{
|
|
int update = command & FTRACE_UPDATE_TRACE_FUNC;
|
|
int err = 0;
|
|
|
|
/*
|
|
* If the ftrace_caller calls a ftrace_ops func directly,
|
|
* we need to make sure that it only traces functions it
|
|
* expects to trace. When doing the switch of functions,
|
|
* we need to update to the ftrace_ops_list_func first
|
|
* before the transition between old and new calls are set,
|
|
* as the ftrace_ops_list_func will check the ops hashes
|
|
* to make sure the ops are having the right functions
|
|
* traced.
|
|
*/
|
|
if (update) {
|
|
err = ftrace_update_ftrace_func(ftrace_ops_list_func);
|
|
if (FTRACE_WARN_ON(err))
|
|
return;
|
|
}
|
|
|
|
if (command & FTRACE_UPDATE_CALLS)
|
|
ftrace_replace_code(1);
|
|
else if (command & FTRACE_DISABLE_CALLS)
|
|
ftrace_replace_code(0);
|
|
|
|
if (update && ftrace_trace_function != ftrace_ops_list_func) {
|
|
function_trace_op = set_function_trace_op;
|
|
smp_wmb();
|
|
/* If irqs are disabled, we are in stop machine */
|
|
if (!irqs_disabled())
|
|
smp_call_function(ftrace_sync_ipi, NULL, 1);
|
|
err = ftrace_update_ftrace_func(ftrace_trace_function);
|
|
if (FTRACE_WARN_ON(err))
|
|
return;
|
|
}
|
|
|
|
if (command & FTRACE_START_FUNC_RET)
|
|
err = ftrace_enable_ftrace_graph_caller();
|
|
else if (command & FTRACE_STOP_FUNC_RET)
|
|
err = ftrace_disable_ftrace_graph_caller();
|
|
FTRACE_WARN_ON(err);
|
|
}
|
|
|
|
static int __ftrace_modify_code(void *data)
|
|
{
|
|
int *command = data;
|
|
|
|
ftrace_modify_all_code(*command);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* ftrace_run_stop_machine, go back to the stop machine method
|
|
* @command: The command to tell ftrace what to do
|
|
*
|
|
* If an arch needs to fall back to the stop machine method, the
|
|
* it can call this function.
|
|
*/
|
|
void ftrace_run_stop_machine(int command)
|
|
{
|
|
stop_machine(__ftrace_modify_code, &command, NULL);
|
|
}
|
|
|
|
/**
|
|
* arch_ftrace_update_code, modify the code to trace or not trace
|
|
* @command: The command that needs to be done
|
|
*
|
|
* Archs can override this function if it does not need to
|
|
* run stop_machine() to modify code.
|
|
*/
|
|
void __weak arch_ftrace_update_code(int command)
|
|
{
|
|
ftrace_run_stop_machine(command);
|
|
}
|
|
|
|
static void ftrace_run_update_code(int command)
|
|
{
|
|
int ret;
|
|
|
|
ret = ftrace_arch_code_modify_prepare();
|
|
FTRACE_WARN_ON(ret);
|
|
if (ret)
|
|
return;
|
|
/*
|
|
* Do not call function tracer while we update the code.
|
|
* We are in stop machine.
|
|
*/
|
|
function_trace_stop++;
|
|
|
|
/*
|
|
* By default we use stop_machine() to modify the code.
|
|
* But archs can do what ever they want as long as it
|
|
* is safe. The stop_machine() is the safest, but also
|
|
* produces the most overhead.
|
|
*/
|
|
arch_ftrace_update_code(command);
|
|
|
|
function_trace_stop--;
|
|
|
|
ret = ftrace_arch_code_modify_post_process();
|
|
FTRACE_WARN_ON(ret);
|
|
}
|
|
|
|
static ftrace_func_t saved_ftrace_func;
|
|
static int ftrace_start_up;
|
|
static int global_start_up;
|
|
|
|
static void control_ops_free(struct ftrace_ops *ops)
|
|
{
|
|
free_percpu(ops->disabled);
|
|
}
|
|
|
|
static void ftrace_startup_enable(int command)
|
|
{
|
|
if (saved_ftrace_func != ftrace_trace_function) {
|
|
saved_ftrace_func = ftrace_trace_function;
|
|
command |= FTRACE_UPDATE_TRACE_FUNC;
|
|
}
|
|
|
|
if (!command || !ftrace_enabled)
|
|
return;
|
|
|
|
ftrace_run_update_code(command);
|
|
}
|
|
|
|
static int ftrace_startup(struct ftrace_ops *ops, int command)
|
|
{
|
|
bool hash_enable = true;
|
|
int ret;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return -ENODEV;
|
|
|
|
ret = __register_ftrace_function(ops);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ftrace_start_up++;
|
|
command |= FTRACE_UPDATE_CALLS;
|
|
|
|
/* ops marked global share the filter hashes */
|
|
if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
|
|
ops = &global_ops;
|
|
/* Don't update hash if global is already set */
|
|
if (global_start_up)
|
|
hash_enable = false;
|
|
global_start_up++;
|
|
}
|
|
|
|
ops->flags |= FTRACE_OPS_FL_ENABLED;
|
|
if (hash_enable)
|
|
ftrace_hash_rec_enable(ops, 1);
|
|
|
|
ftrace_startup_enable(command);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ftrace_shutdown(struct ftrace_ops *ops, int command)
|
|
{
|
|
bool hash_disable = true;
|
|
int ret;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return -ENODEV;
|
|
|
|
ret = __unregister_ftrace_function(ops);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ftrace_start_up--;
|
|
/*
|
|
* Just warn in case of unbalance, no need to kill ftrace, it's not
|
|
* critical but the ftrace_call callers may be never nopped again after
|
|
* further ftrace uses.
|
|
*/
|
|
WARN_ON_ONCE(ftrace_start_up < 0);
|
|
|
|
if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
|
|
ops = &global_ops;
|
|
global_start_up--;
|
|
WARN_ON_ONCE(global_start_up < 0);
|
|
/* Don't update hash if global still has users */
|
|
if (global_start_up) {
|
|
WARN_ON_ONCE(!ftrace_start_up);
|
|
hash_disable = false;
|
|
}
|
|
}
|
|
|
|
if (hash_disable)
|
|
ftrace_hash_rec_disable(ops, 1);
|
|
|
|
if (ops != &global_ops || !global_start_up)
|
|
ops->flags &= ~FTRACE_OPS_FL_ENABLED;
|
|
|
|
command |= FTRACE_UPDATE_CALLS;
|
|
|
|
if (saved_ftrace_func != ftrace_trace_function) {
|
|
saved_ftrace_func = ftrace_trace_function;
|
|
command |= FTRACE_UPDATE_TRACE_FUNC;
|
|
}
|
|
|
|
if (!command || !ftrace_enabled) {
|
|
/*
|
|
* If these are control ops, they still need their
|
|
* per_cpu field freed. Since, function tracing is
|
|
* not currently active, we can just free them
|
|
* without synchronizing all CPUs.
|
|
*/
|
|
if (ops->flags & FTRACE_OPS_FL_CONTROL)
|
|
control_ops_free(ops);
|
|
return 0;
|
|
}
|
|
|
|
ftrace_run_update_code(command);
|
|
|
|
/*
|
|
* Dynamic ops may be freed, we must make sure that all
|
|
* callers are done before leaving this function.
|
|
* The same goes for freeing the per_cpu data of the control
|
|
* ops.
|
|
*
|
|
* Again, normal synchronize_sched() is not good enough.
|
|
* We need to do a hard force of sched synchronization.
|
|
* This is because we use preempt_disable() to do RCU, but
|
|
* the function tracers can be called where RCU is not watching
|
|
* (like before user_exit()). We can not rely on the RCU
|
|
* infrastructure to do the synchronization, thus we must do it
|
|
* ourselves.
|
|
*/
|
|
if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_CONTROL)) {
|
|
schedule_on_each_cpu(ftrace_sync);
|
|
|
|
if (ops->flags & FTRACE_OPS_FL_CONTROL)
|
|
control_ops_free(ops);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void ftrace_startup_sysctl(void)
|
|
{
|
|
if (unlikely(ftrace_disabled))
|
|
return;
|
|
|
|
/* Force update next time */
|
|
saved_ftrace_func = NULL;
|
|
/* ftrace_start_up is true if we want ftrace running */
|
|
if (ftrace_start_up)
|
|
ftrace_run_update_code(FTRACE_UPDATE_CALLS);
|
|
}
|
|
|
|
static void ftrace_shutdown_sysctl(void)
|
|
{
|
|
if (unlikely(ftrace_disabled))
|
|
return;
|
|
|
|
/* ftrace_start_up is true if ftrace is running */
|
|
if (ftrace_start_up)
|
|
ftrace_run_update_code(FTRACE_DISABLE_CALLS);
|
|
}
|
|
|
|
static cycle_t ftrace_update_time;
|
|
unsigned long ftrace_update_tot_cnt;
|
|
|
|
static inline int ops_traces_mod(struct ftrace_ops *ops)
|
|
{
|
|
/*
|
|
* Filter_hash being empty will default to trace module.
|
|
* But notrace hash requires a test of individual module functions.
|
|
*/
|
|
return ftrace_hash_empty(ops->filter_hash) &&
|
|
ftrace_hash_empty(ops->notrace_hash);
|
|
}
|
|
|
|
/*
|
|
* Check if the current ops references the record.
|
|
*
|
|
* If the ops traces all functions, then it was already accounted for.
|
|
* If the ops does not trace the current record function, skip it.
|
|
* If the ops ignores the function via notrace filter, skip it.
|
|
*/
|
|
static inline bool
|
|
ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
|
|
{
|
|
/* If ops isn't enabled, ignore it */
|
|
if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
|
|
return 0;
|
|
|
|
/* If ops traces all mods, we already accounted for it */
|
|
if (ops_traces_mod(ops))
|
|
return 0;
|
|
|
|
/* The function must be in the filter */
|
|
if (!ftrace_hash_empty(ops->filter_hash) &&
|
|
!ftrace_lookup_ip(ops->filter_hash, rec->ip))
|
|
return 0;
|
|
|
|
/* If in notrace hash, we ignore it too */
|
|
if (ftrace_lookup_ip(ops->notrace_hash, rec->ip))
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int referenced_filters(struct dyn_ftrace *rec)
|
|
{
|
|
struct ftrace_ops *ops;
|
|
int cnt = 0;
|
|
|
|
for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
|
|
if (ops_references_rec(ops, rec))
|
|
cnt++;
|
|
}
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
|
|
{
|
|
struct ftrace_page *pg;
|
|
struct dyn_ftrace *p;
|
|
cycle_t start, stop;
|
|
unsigned long update_cnt = 0;
|
|
unsigned long ref = 0;
|
|
bool test = false;
|
|
int i;
|
|
|
|
/*
|
|
* When adding a module, we need to check if tracers are
|
|
* currently enabled and if they are set to trace all functions.
|
|
* If they are, we need to enable the module functions as well
|
|
* as update the reference counts for those function records.
|
|
*/
|
|
if (mod) {
|
|
struct ftrace_ops *ops;
|
|
|
|
for (ops = ftrace_ops_list;
|
|
ops != &ftrace_list_end; ops = ops->next) {
|
|
if (ops->flags & FTRACE_OPS_FL_ENABLED) {
|
|
if (ops_traces_mod(ops))
|
|
ref++;
|
|
else
|
|
test = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
start = ftrace_now(raw_smp_processor_id());
|
|
|
|
for (pg = new_pgs; pg; pg = pg->next) {
|
|
|
|
for (i = 0; i < pg->index; i++) {
|
|
int cnt = ref;
|
|
|
|
/* If something went wrong, bail without enabling anything */
|
|
if (unlikely(ftrace_disabled))
|
|
return -1;
|
|
|
|
p = &pg->records[i];
|
|
if (test)
|
|
cnt += referenced_filters(p);
|
|
p->flags = cnt;
|
|
|
|
/*
|
|
* Do the initial record conversion from mcount jump
|
|
* to the NOP instructions.
|
|
*/
|
|
if (!ftrace_code_disable(mod, p))
|
|
break;
|
|
|
|
update_cnt++;
|
|
|
|
/*
|
|
* If the tracing is enabled, go ahead and enable the record.
|
|
*
|
|
* The reason not to enable the record immediatelly is the
|
|
* inherent check of ftrace_make_nop/ftrace_make_call for
|
|
* correct previous instructions. Making first the NOP
|
|
* conversion puts the module to the correct state, thus
|
|
* passing the ftrace_make_call check.
|
|
*/
|
|
if (ftrace_start_up && cnt) {
|
|
int failed = __ftrace_replace_code(p, 1);
|
|
if (failed)
|
|
ftrace_bug(failed, p->ip);
|
|
}
|
|
}
|
|
}
|
|
|
|
stop = ftrace_now(raw_smp_processor_id());
|
|
ftrace_update_time = stop - start;
|
|
ftrace_update_tot_cnt += update_cnt;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ftrace_allocate_records(struct ftrace_page *pg, int count)
|
|
{
|
|
int order;
|
|
int cnt;
|
|
|
|
if (WARN_ON(!count))
|
|
return -EINVAL;
|
|
|
|
order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
|
|
|
|
/*
|
|
* We want to fill as much as possible. No more than a page
|
|
* may be empty.
|
|
*/
|
|
while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
|
|
order--;
|
|
|
|
again:
|
|
pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
|
|
|
|
if (!pg->records) {
|
|
/* if we can't allocate this size, try something smaller */
|
|
if (!order)
|
|
return -ENOMEM;
|
|
order >>= 1;
|
|
goto again;
|
|
}
|
|
|
|
cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
|
|
pg->size = cnt;
|
|
|
|
if (cnt > count)
|
|
cnt = count;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static struct ftrace_page *
|
|
ftrace_allocate_pages(unsigned long num_to_init)
|
|
{
|
|
struct ftrace_page *start_pg;
|
|
struct ftrace_page *pg;
|
|
int order;
|
|
int cnt;
|
|
|
|
if (!num_to_init)
|
|
return 0;
|
|
|
|
start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
|
|
if (!pg)
|
|
return NULL;
|
|
|
|
/*
|
|
* Try to allocate as much as possible in one continues
|
|
* location that fills in all of the space. We want to
|
|
* waste as little space as possible.
|
|
*/
|
|
for (;;) {
|
|
cnt = ftrace_allocate_records(pg, num_to_init);
|
|
if (cnt < 0)
|
|
goto free_pages;
|
|
|
|
num_to_init -= cnt;
|
|
if (!num_to_init)
|
|
break;
|
|
|
|
pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
|
|
if (!pg->next)
|
|
goto free_pages;
|
|
|
|
pg = pg->next;
|
|
}
|
|
|
|
return start_pg;
|
|
|
|
free_pages:
|
|
while (start_pg) {
|
|
order = get_count_order(pg->size / ENTRIES_PER_PAGE);
|
|
free_pages((unsigned long)pg->records, order);
|
|
start_pg = pg->next;
|
|
kfree(pg);
|
|
pg = start_pg;
|
|
}
|
|
pr_info("ftrace: FAILED to allocate memory for functions\n");
|
|
return NULL;
|
|
}
|
|
|
|
#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
|
|
|
|
struct ftrace_iterator {
|
|
loff_t pos;
|
|
loff_t func_pos;
|
|
struct ftrace_page *pg;
|
|
struct dyn_ftrace *func;
|
|
struct ftrace_func_probe *probe;
|
|
struct trace_parser parser;
|
|
struct ftrace_hash *hash;
|
|
struct ftrace_ops *ops;
|
|
int hidx;
|
|
int idx;
|
|
unsigned flags;
|
|
};
|
|
|
|
static void *
|
|
t_hash_next(struct seq_file *m, loff_t *pos)
|
|
{
|
|
struct ftrace_iterator *iter = m->private;
|
|
struct hlist_node *hnd = NULL;
|
|
struct hlist_head *hhd;
|
|
|
|
(*pos)++;
|
|
iter->pos = *pos;
|
|
|
|
if (iter->probe)
|
|
hnd = &iter->probe->node;
|
|
retry:
|
|
if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
|
|
return NULL;
|
|
|
|
hhd = &ftrace_func_hash[iter->hidx];
|
|
|
|
if (hlist_empty(hhd)) {
|
|
iter->hidx++;
|
|
hnd = NULL;
|
|
goto retry;
|
|
}
|
|
|
|
if (!hnd)
|
|
hnd = hhd->first;
|
|
else {
|
|
hnd = hnd->next;
|
|
if (!hnd) {
|
|
iter->hidx++;
|
|
goto retry;
|
|
}
|
|
}
|
|
|
|
if (WARN_ON_ONCE(!hnd))
|
|
return NULL;
|
|
|
|
iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node);
|
|
|
|
return iter;
|
|
}
|
|
|
|
static void *t_hash_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
struct ftrace_iterator *iter = m->private;
|
|
void *p = NULL;
|
|
loff_t l;
|
|
|
|
if (!(iter->flags & FTRACE_ITER_DO_HASH))
|
|
return NULL;
|
|
|
|
if (iter->func_pos > *pos)
|
|
return NULL;
|
|
|
|
iter->hidx = 0;
|
|
for (l = 0; l <= (*pos - iter->func_pos); ) {
|
|
p = t_hash_next(m, &l);
|
|
if (!p)
|
|
break;
|
|
}
|
|
if (!p)
|
|
return NULL;
|
|
|
|
/* Only set this if we have an item */
|
|
iter->flags |= FTRACE_ITER_HASH;
|
|
|
|
return iter;
|
|
}
|
|
|
|
static int
|
|
t_hash_show(struct seq_file *m, struct ftrace_iterator *iter)
|
|
{
|
|
struct ftrace_func_probe *rec;
|
|
|
|
rec = iter->probe;
|
|
if (WARN_ON_ONCE(!rec))
|
|
return -EIO;
|
|
|
|
if (rec->ops->print)
|
|
return rec->ops->print(m, rec->ip, rec->ops, rec->data);
|
|
|
|
seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func);
|
|
|
|
if (rec->data)
|
|
seq_printf(m, ":%p", rec->data);
|
|
seq_putc(m, '\n');
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void *
|
|
t_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
struct ftrace_iterator *iter = m->private;
|
|
struct ftrace_ops *ops = iter->ops;
|
|
struct dyn_ftrace *rec = NULL;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return NULL;
|
|
|
|
if (iter->flags & FTRACE_ITER_HASH)
|
|
return t_hash_next(m, pos);
|
|
|
|
(*pos)++;
|
|
iter->pos = iter->func_pos = *pos;
|
|
|
|
if (iter->flags & FTRACE_ITER_PRINTALL)
|
|
return t_hash_start(m, pos);
|
|
|
|
retry:
|
|
if (iter->idx >= iter->pg->index) {
|
|
if (iter->pg->next) {
|
|
iter->pg = iter->pg->next;
|
|
iter->idx = 0;
|
|
goto retry;
|
|
}
|
|
} else {
|
|
rec = &iter->pg->records[iter->idx++];
|
|
if (((iter->flags & FTRACE_ITER_FILTER) &&
|
|
!(ftrace_lookup_ip(ops->filter_hash, rec->ip))) ||
|
|
|
|
((iter->flags & FTRACE_ITER_NOTRACE) &&
|
|
!ftrace_lookup_ip(ops->notrace_hash, rec->ip)) ||
|
|
|
|
((iter->flags & FTRACE_ITER_ENABLED) &&
|
|
!(rec->flags & FTRACE_FL_ENABLED))) {
|
|
|
|
rec = NULL;
|
|
goto retry;
|
|
}
|
|
}
|
|
|
|
if (!rec)
|
|
return t_hash_start(m, pos);
|
|
|
|
iter->func = rec;
|
|
|
|
return iter;
|
|
}
|
|
|
|
static void reset_iter_read(struct ftrace_iterator *iter)
|
|
{
|
|
iter->pos = 0;
|
|
iter->func_pos = 0;
|
|
iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH);
|
|
}
|
|
|
|
static void *t_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
struct ftrace_iterator *iter = m->private;
|
|
struct ftrace_ops *ops = iter->ops;
|
|
void *p = NULL;
|
|
loff_t l;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return NULL;
|
|
|
|
/*
|
|
* If an lseek was done, then reset and start from beginning.
|
|
*/
|
|
if (*pos < iter->pos)
|
|
reset_iter_read(iter);
|
|
|
|
/*
|
|
* For set_ftrace_filter reading, if we have the filter
|
|
* off, we can short cut and just print out that all
|
|
* functions are enabled.
|
|
*/
|
|
if (iter->flags & FTRACE_ITER_FILTER &&
|
|
ftrace_hash_empty(ops->filter_hash)) {
|
|
if (*pos > 0)
|
|
return t_hash_start(m, pos);
|
|
iter->flags |= FTRACE_ITER_PRINTALL;
|
|
/* reset in case of seek/pread */
|
|
iter->flags &= ~FTRACE_ITER_HASH;
|
|
return iter;
|
|
}
|
|
|
|
if (iter->flags & FTRACE_ITER_HASH)
|
|
return t_hash_start(m, pos);
|
|
|
|
/*
|
|
* Unfortunately, we need to restart at ftrace_pages_start
|
|
* every time we let go of the ftrace_mutex. This is because
|
|
* those pointers can change without the lock.
|
|
*/
|
|
iter->pg = ftrace_pages_start;
|
|
iter->idx = 0;
|
|
for (l = 0; l <= *pos; ) {
|
|
p = t_next(m, p, &l);
|
|
if (!p)
|
|
break;
|
|
}
|
|
|
|
if (!p)
|
|
return t_hash_start(m, pos);
|
|
|
|
return iter;
|
|
}
|
|
|
|
static void t_stop(struct seq_file *m, void *p)
|
|
{
|
|
mutex_unlock(&ftrace_lock);
|
|
}
|
|
|
|
static int t_show(struct seq_file *m, void *v)
|
|
{
|
|
struct ftrace_iterator *iter = m->private;
|
|
struct dyn_ftrace *rec;
|
|
|
|
if (iter->flags & FTRACE_ITER_HASH)
|
|
return t_hash_show(m, iter);
|
|
|
|
if (iter->flags & FTRACE_ITER_PRINTALL) {
|
|
seq_printf(m, "#### all functions enabled ####\n");
|
|
return 0;
|
|
}
|
|
|
|
rec = iter->func;
|
|
|
|
if (!rec)
|
|
return 0;
|
|
|
|
seq_printf(m, "%ps", (void *)rec->ip);
|
|
if (iter->flags & FTRACE_ITER_ENABLED)
|
|
seq_printf(m, " (%ld)%s",
|
|
rec->flags & ~FTRACE_FL_MASK,
|
|
rec->flags & FTRACE_FL_REGS ? " R" : "");
|
|
seq_printf(m, "\n");
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations show_ftrace_seq_ops = {
|
|
.start = t_start,
|
|
.next = t_next,
|
|
.stop = t_stop,
|
|
.show = t_show,
|
|
};
|
|
|
|
static int
|
|
ftrace_avail_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct ftrace_iterator *iter;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return -ENODEV;
|
|
|
|
iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
|
|
if (iter) {
|
|
iter->pg = ftrace_pages_start;
|
|
iter->ops = &global_ops;
|
|
}
|
|
|
|
return iter ? 0 : -ENOMEM;
|
|
}
|
|
|
|
static int
|
|
ftrace_enabled_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct ftrace_iterator *iter;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return -ENODEV;
|
|
|
|
iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
|
|
if (iter) {
|
|
iter->pg = ftrace_pages_start;
|
|
iter->flags = FTRACE_ITER_ENABLED;
|
|
iter->ops = &global_ops;
|
|
}
|
|
|
|
return iter ? 0 : -ENOMEM;
|
|
}
|
|
|
|
static void ftrace_filter_reset(struct ftrace_hash *hash)
|
|
{
|
|
mutex_lock(&ftrace_lock);
|
|
ftrace_hash_clear(hash);
|
|
mutex_unlock(&ftrace_lock);
|
|
}
|
|
|
|
/**
|
|
* ftrace_regex_open - initialize function tracer filter files
|
|
* @ops: The ftrace_ops that hold the hash filters
|
|
* @flag: The type of filter to process
|
|
* @inode: The inode, usually passed in to your open routine
|
|
* @file: The file, usually passed in to your open routine
|
|
*
|
|
* ftrace_regex_open() initializes the filter files for the
|
|
* @ops. Depending on @flag it may process the filter hash or
|
|
* the notrace hash of @ops. With this called from the open
|
|
* routine, you can use ftrace_filter_write() for the write
|
|
* routine if @flag has FTRACE_ITER_FILTER set, or
|
|
* ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
|
|
* tracing_lseek() should be used as the lseek routine, and
|
|
* release must call ftrace_regex_release().
|
|
*/
|
|
int
|
|
ftrace_regex_open(struct ftrace_ops *ops, int flag,
|
|
struct inode *inode, struct file *file)
|
|
{
|
|
struct ftrace_iterator *iter;
|
|
struct ftrace_hash *hash;
|
|
int ret = 0;
|
|
|
|
ftrace_ops_init(ops);
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return -ENODEV;
|
|
|
|
iter = kzalloc(sizeof(*iter), GFP_KERNEL);
|
|
if (!iter)
|
|
return -ENOMEM;
|
|
|
|
if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
|
|
kfree(iter);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
iter->ops = ops;
|
|
iter->flags = flag;
|
|
|
|
mutex_lock(&ops->regex_lock);
|
|
|
|
if (flag & FTRACE_ITER_NOTRACE)
|
|
hash = ops->notrace_hash;
|
|
else
|
|
hash = ops->filter_hash;
|
|
|
|
if (file->f_mode & FMODE_WRITE) {
|
|
iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash);
|
|
if (!iter->hash) {
|
|
trace_parser_put(&iter->parser);
|
|
kfree(iter);
|
|
ret = -ENOMEM;
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
|
|
if ((file->f_mode & FMODE_WRITE) &&
|
|
(file->f_flags & O_TRUNC))
|
|
ftrace_filter_reset(iter->hash);
|
|
|
|
if (file->f_mode & FMODE_READ) {
|
|
iter->pg = ftrace_pages_start;
|
|
|
|
ret = seq_open(file, &show_ftrace_seq_ops);
|
|
if (!ret) {
|
|
struct seq_file *m = file->private_data;
|
|
m->private = iter;
|
|
} else {
|
|
/* Failed */
|
|
free_ftrace_hash(iter->hash);
|
|
trace_parser_put(&iter->parser);
|
|
kfree(iter);
|
|
}
|
|
} else
|
|
file->private_data = iter;
|
|
|
|
out_unlock:
|
|
mutex_unlock(&ops->regex_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
ftrace_filter_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct ftrace_ops *ops = inode->i_private;
|
|
|
|
return ftrace_regex_open(ops,
|
|
FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH,
|
|
inode, file);
|
|
}
|
|
|
|
static int
|
|
ftrace_notrace_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct ftrace_ops *ops = inode->i_private;
|
|
|
|
return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
|
|
inode, file);
|
|
}
|
|
|
|
static int ftrace_match(char *str, char *regex, int len, int type)
|
|
{
|
|
int matched = 0;
|
|
int slen;
|
|
|
|
switch (type) {
|
|
case MATCH_FULL:
|
|
if (strcmp(str, regex) == 0)
|
|
matched = 1;
|
|
break;
|
|
case MATCH_FRONT_ONLY:
|
|
if (strncmp(str, regex, len) == 0)
|
|
matched = 1;
|
|
break;
|
|
case MATCH_MIDDLE_ONLY:
|
|
if (strstr(str, regex))
|
|
matched = 1;
|
|
break;
|
|
case MATCH_END_ONLY:
|
|
slen = strlen(str);
|
|
if (slen >= len && memcmp(str + slen - len, regex, len) == 0)
|
|
matched = 1;
|
|
break;
|
|
}
|
|
|
|
return matched;
|
|
}
|
|
|
|
static int
|
|
enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not)
|
|
{
|
|
struct ftrace_func_entry *entry;
|
|
int ret = 0;
|
|
|
|
entry = ftrace_lookup_ip(hash, rec->ip);
|
|
if (not) {
|
|
/* Do nothing if it doesn't exist */
|
|
if (!entry)
|
|
return 0;
|
|
|
|
free_hash_entry(hash, entry);
|
|
} else {
|
|
/* Do nothing if it exists */
|
|
if (entry)
|
|
return 0;
|
|
|
|
ret = add_hash_entry(hash, rec->ip);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
ftrace_match_record(struct dyn_ftrace *rec, char *mod,
|
|
char *regex, int len, int type)
|
|
{
|
|
char str[KSYM_SYMBOL_LEN];
|
|
char *modname;
|
|
|
|
kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
|
|
|
|
if (mod) {
|
|
/* module lookup requires matching the module */
|
|
if (!modname || strcmp(modname, mod))
|
|
return 0;
|
|
|
|
/* blank search means to match all funcs in the mod */
|
|
if (!len)
|
|
return 1;
|
|
}
|
|
|
|
return ftrace_match(str, regex, len, type);
|
|
}
|
|
|
|
static int
|
|
match_records(struct ftrace_hash *hash, char *buff,
|
|
int len, char *mod, int not)
|
|
{
|
|
unsigned search_len = 0;
|
|
struct ftrace_page *pg;
|
|
struct dyn_ftrace *rec;
|
|
int type = MATCH_FULL;
|
|
char *search = buff;
|
|
int found = 0;
|
|
int ret;
|
|
|
|
if (len) {
|
|
type = filter_parse_regex(buff, len, &search, ¬);
|
|
search_len = strlen(search);
|
|
}
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
goto out_unlock;
|
|
|
|
do_for_each_ftrace_rec(pg, rec) {
|
|
if (ftrace_match_record(rec, mod, search, search_len, type)) {
|
|
ret = enter_record(hash, rec, not);
|
|
if (ret < 0) {
|
|
found = ret;
|
|
goto out_unlock;
|
|
}
|
|
found = 1;
|
|
}
|
|
} while_for_each_ftrace_rec();
|
|
out_unlock:
|
|
mutex_unlock(&ftrace_lock);
|
|
|
|
return found;
|
|
}
|
|
|
|
static int
|
|
ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
|
|
{
|
|
return match_records(hash, buff, len, NULL, 0);
|
|
}
|
|
|
|
static int
|
|
ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
|
|
{
|
|
int not = 0;
|
|
|
|
/* blank or '*' mean the same */
|
|
if (strcmp(buff, "*") == 0)
|
|
buff[0] = 0;
|
|
|
|
/* handle the case of 'dont filter this module' */
|
|
if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
|
|
buff[0] = 0;
|
|
not = 1;
|
|
}
|
|
|
|
return match_records(hash, buff, strlen(buff), mod, not);
|
|
}
|
|
|
|
/*
|
|
* We register the module command as a template to show others how
|
|
* to register the a command as well.
|
|
*/
|
|
|
|
static int
|
|
ftrace_mod_callback(struct ftrace_hash *hash,
|
|
char *func, char *cmd, char *param, int enable)
|
|
{
|
|
char *mod;
|
|
int ret = -EINVAL;
|
|
|
|
/*
|
|
* cmd == 'mod' because we only registered this func
|
|
* for the 'mod' ftrace_func_command.
|
|
* But if you register one func with multiple commands,
|
|
* you can tell which command was used by the cmd
|
|
* parameter.
|
|
*/
|
|
|
|
/* we must have a module name */
|
|
if (!param)
|
|
return ret;
|
|
|
|
mod = strsep(¶m, ":");
|
|
if (!strlen(mod))
|
|
return ret;
|
|
|
|
ret = ftrace_match_module_records(hash, func, mod);
|
|
if (!ret)
|
|
ret = -EINVAL;
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct ftrace_func_command ftrace_mod_cmd = {
|
|
.name = "mod",
|
|
.func = ftrace_mod_callback,
|
|
};
|
|
|
|
static int __init ftrace_mod_cmd_init(void)
|
|
{
|
|
return register_ftrace_command(&ftrace_mod_cmd);
|
|
}
|
|
core_initcall(ftrace_mod_cmd_init);
|
|
|
|
static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
|
|
struct ftrace_ops *op, struct pt_regs *pt_regs)
|
|
{
|
|
struct ftrace_func_probe *entry;
|
|
struct hlist_head *hhd;
|
|
unsigned long key;
|
|
|
|
key = hash_long(ip, FTRACE_HASH_BITS);
|
|
|
|
hhd = &ftrace_func_hash[key];
|
|
|
|
if (hlist_empty(hhd))
|
|
return;
|
|
|
|
/*
|
|
* Disable preemption for these calls to prevent a RCU grace
|
|
* period. This syncs the hash iteration and freeing of items
|
|
* on the hash. rcu_read_lock is too dangerous here.
|
|
*/
|
|
preempt_disable_notrace();
|
|
hlist_for_each_entry_rcu_notrace(entry, hhd, node) {
|
|
if (entry->ip == ip)
|
|
entry->ops->func(ip, parent_ip, &entry->data);
|
|
}
|
|
preempt_enable_notrace();
|
|
}
|
|
|
|
static struct ftrace_ops trace_probe_ops __read_mostly =
|
|
{
|
|
.func = function_trace_probe_call,
|
|
.flags = FTRACE_OPS_FL_INITIALIZED,
|
|
INIT_REGEX_LOCK(trace_probe_ops)
|
|
};
|
|
|
|
static int ftrace_probe_registered;
|
|
|
|
static void __enable_ftrace_function_probe(void)
|
|
{
|
|
int ret;
|
|
int i;
|
|
|
|
if (ftrace_probe_registered) {
|
|
/* still need to update the function call sites */
|
|
if (ftrace_enabled)
|
|
ftrace_run_update_code(FTRACE_UPDATE_CALLS);
|
|
return;
|
|
}
|
|
|
|
for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
|
|
struct hlist_head *hhd = &ftrace_func_hash[i];
|
|
if (hhd->first)
|
|
break;
|
|
}
|
|
/* Nothing registered? */
|
|
if (i == FTRACE_FUNC_HASHSIZE)
|
|
return;
|
|
|
|
ret = ftrace_startup(&trace_probe_ops, 0);
|
|
|
|
ftrace_probe_registered = 1;
|
|
}
|
|
|
|
static void __disable_ftrace_function_probe(void)
|
|
{
|
|
int i;
|
|
|
|
if (!ftrace_probe_registered)
|
|
return;
|
|
|
|
for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
|
|
struct hlist_head *hhd = &ftrace_func_hash[i];
|
|
if (hhd->first)
|
|
return;
|
|
}
|
|
|
|
/* no more funcs left */
|
|
ftrace_shutdown(&trace_probe_ops, 0);
|
|
|
|
ftrace_probe_registered = 0;
|
|
}
|
|
|
|
|
|
static void ftrace_free_entry(struct ftrace_func_probe *entry)
|
|
{
|
|
if (entry->ops->free)
|
|
entry->ops->free(entry->ops, entry->ip, &entry->data);
|
|
kfree(entry);
|
|
}
|
|
|
|
int
|
|
register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
|
|
void *data)
|
|
{
|
|
struct ftrace_func_probe *entry;
|
|
struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash;
|
|
struct ftrace_hash *hash;
|
|
struct ftrace_page *pg;
|
|
struct dyn_ftrace *rec;
|
|
int type, len, not;
|
|
unsigned long key;
|
|
int count = 0;
|
|
char *search;
|
|
int ret;
|
|
|
|
type = filter_parse_regex(glob, strlen(glob), &search, ¬);
|
|
len = strlen(search);
|
|
|
|
/* we do not support '!' for function probes */
|
|
if (WARN_ON(not))
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&trace_probe_ops.regex_lock);
|
|
|
|
hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
|
|
if (!hash) {
|
|
count = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
if (unlikely(ftrace_disabled)) {
|
|
count = -ENODEV;
|
|
goto out;
|
|
}
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
|
|
do_for_each_ftrace_rec(pg, rec) {
|
|
|
|
if (!ftrace_match_record(rec, NULL, search, len, type))
|
|
continue;
|
|
|
|
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
|
|
if (!entry) {
|
|
/* If we did not process any, then return error */
|
|
if (!count)
|
|
count = -ENOMEM;
|
|
goto out_unlock;
|
|
}
|
|
|
|
count++;
|
|
|
|
entry->data = data;
|
|
|
|
/*
|
|
* The caller might want to do something special
|
|
* for each function we find. We call the callback
|
|
* to give the caller an opportunity to do so.
|
|
*/
|
|
if (ops->init) {
|
|
if (ops->init(ops, rec->ip, &entry->data) < 0) {
|
|
/* caller does not like this func */
|
|
kfree(entry);
|
|
continue;
|
|
}
|
|
}
|
|
|
|
ret = enter_record(hash, rec, 0);
|
|
if (ret < 0) {
|
|
kfree(entry);
|
|
count = ret;
|
|
goto out_unlock;
|
|
}
|
|
|
|
entry->ops = ops;
|
|
entry->ip = rec->ip;
|
|
|
|
key = hash_long(entry->ip, FTRACE_HASH_BITS);
|
|
hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
|
|
|
|
} while_for_each_ftrace_rec();
|
|
|
|
ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
|
|
if (ret < 0)
|
|
count = ret;
|
|
|
|
__enable_ftrace_function_probe();
|
|
|
|
out_unlock:
|
|
mutex_unlock(&ftrace_lock);
|
|
out:
|
|
mutex_unlock(&trace_probe_ops.regex_lock);
|
|
free_ftrace_hash(hash);
|
|
|
|
return count;
|
|
}
|
|
|
|
enum {
|
|
PROBE_TEST_FUNC = 1,
|
|
PROBE_TEST_DATA = 2
|
|
};
|
|
|
|
static void
|
|
__unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
|
|
void *data, int flags)
|
|
{
|
|
struct ftrace_func_entry *rec_entry;
|
|
struct ftrace_func_probe *entry;
|
|
struct ftrace_func_probe *p;
|
|
struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash;
|
|
struct list_head free_list;
|
|
struct ftrace_hash *hash;
|
|
struct hlist_node *tmp;
|
|
char str[KSYM_SYMBOL_LEN];
|
|
int type = MATCH_FULL;
|
|
int i, len = 0;
|
|
char *search;
|
|
|
|
if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
|
|
glob = NULL;
|
|
else if (glob) {
|
|
int not;
|
|
|
|
type = filter_parse_regex(glob, strlen(glob), &search, ¬);
|
|
len = strlen(search);
|
|
|
|
/* we do not support '!' for function probes */
|
|
if (WARN_ON(not))
|
|
return;
|
|
}
|
|
|
|
mutex_lock(&trace_probe_ops.regex_lock);
|
|
|
|
hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
|
|
if (!hash)
|
|
/* Hmm, should report this somehow */
|
|
goto out_unlock;
|
|
|
|
INIT_LIST_HEAD(&free_list);
|
|
|
|
for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
|
|
struct hlist_head *hhd = &ftrace_func_hash[i];
|
|
|
|
hlist_for_each_entry_safe(entry, tmp, hhd, node) {
|
|
|
|
/* break up if statements for readability */
|
|
if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
|
|
continue;
|
|
|
|
if ((flags & PROBE_TEST_DATA) && entry->data != data)
|
|
continue;
|
|
|
|
/* do this last, since it is the most expensive */
|
|
if (glob) {
|
|
kallsyms_lookup(entry->ip, NULL, NULL,
|
|
NULL, str);
|
|
if (!ftrace_match(str, glob, len, type))
|
|
continue;
|
|
}
|
|
|
|
rec_entry = ftrace_lookup_ip(hash, entry->ip);
|
|
/* It is possible more than one entry had this ip */
|
|
if (rec_entry)
|
|
free_hash_entry(hash, rec_entry);
|
|
|
|
hlist_del_rcu(&entry->node);
|
|
list_add(&entry->free_list, &free_list);
|
|
}
|
|
}
|
|
mutex_lock(&ftrace_lock);
|
|
__disable_ftrace_function_probe();
|
|
/*
|
|
* Remove after the disable is called. Otherwise, if the last
|
|
* probe is removed, a null hash means *all enabled*.
|
|
*/
|
|
ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
|
|
synchronize_sched();
|
|
list_for_each_entry_safe(entry, p, &free_list, free_list) {
|
|
list_del(&entry->free_list);
|
|
ftrace_free_entry(entry);
|
|
}
|
|
mutex_unlock(&ftrace_lock);
|
|
|
|
out_unlock:
|
|
mutex_unlock(&trace_probe_ops.regex_lock);
|
|
free_ftrace_hash(hash);
|
|
}
|
|
|
|
void
|
|
unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
|
|
void *data)
|
|
{
|
|
__unregister_ftrace_function_probe(glob, ops, data,
|
|
PROBE_TEST_FUNC | PROBE_TEST_DATA);
|
|
}
|
|
|
|
void
|
|
unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
|
|
{
|
|
__unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
|
|
}
|
|
|
|
void unregister_ftrace_function_probe_all(char *glob)
|
|
{
|
|
__unregister_ftrace_function_probe(glob, NULL, NULL, 0);
|
|
}
|
|
|
|
static LIST_HEAD(ftrace_commands);
|
|
static DEFINE_MUTEX(ftrace_cmd_mutex);
|
|
|
|
/*
|
|
* Currently we only register ftrace commands from __init, so mark this
|
|
* __init too.
|
|
*/
|
|
__init int register_ftrace_command(struct ftrace_func_command *cmd)
|
|
{
|
|
struct ftrace_func_command *p;
|
|
int ret = 0;
|
|
|
|
mutex_lock(&ftrace_cmd_mutex);
|
|
list_for_each_entry(p, &ftrace_commands, list) {
|
|
if (strcmp(cmd->name, p->name) == 0) {
|
|
ret = -EBUSY;
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
list_add(&cmd->list, &ftrace_commands);
|
|
out_unlock:
|
|
mutex_unlock(&ftrace_cmd_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Currently we only unregister ftrace commands from __init, so mark
|
|
* this __init too.
|
|
*/
|
|
__init int unregister_ftrace_command(struct ftrace_func_command *cmd)
|
|
{
|
|
struct ftrace_func_command *p, *n;
|
|
int ret = -ENODEV;
|
|
|
|
mutex_lock(&ftrace_cmd_mutex);
|
|
list_for_each_entry_safe(p, n, &ftrace_commands, list) {
|
|
if (strcmp(cmd->name, p->name) == 0) {
|
|
ret = 0;
|
|
list_del_init(&p->list);
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
out_unlock:
|
|
mutex_unlock(&ftrace_cmd_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int ftrace_process_regex(struct ftrace_hash *hash,
|
|
char *buff, int len, int enable)
|
|
{
|
|
char *func, *command, *next = buff;
|
|
struct ftrace_func_command *p;
|
|
int ret = -EINVAL;
|
|
|
|
func = strsep(&next, ":");
|
|
|
|
if (!next) {
|
|
ret = ftrace_match_records(hash, func, len);
|
|
if (!ret)
|
|
ret = -EINVAL;
|
|
if (ret < 0)
|
|
return ret;
|
|
return 0;
|
|
}
|
|
|
|
/* command found */
|
|
|
|
command = strsep(&next, ":");
|
|
|
|
mutex_lock(&ftrace_cmd_mutex);
|
|
list_for_each_entry(p, &ftrace_commands, list) {
|
|
if (strcmp(p->name, command) == 0) {
|
|
ret = p->func(hash, func, command, next, enable);
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
out_unlock:
|
|
mutex_unlock(&ftrace_cmd_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t
|
|
ftrace_regex_write(struct file *file, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos, int enable)
|
|
{
|
|
struct ftrace_iterator *iter;
|
|
struct trace_parser *parser;
|
|
ssize_t ret, read;
|
|
|
|
if (!cnt)
|
|
return 0;
|
|
|
|
if (file->f_mode & FMODE_READ) {
|
|
struct seq_file *m = file->private_data;
|
|
iter = m->private;
|
|
} else
|
|
iter = file->private_data;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return -ENODEV;
|
|
|
|
/* iter->hash is a local copy, so we don't need regex_lock */
|
|
|
|
parser = &iter->parser;
|
|
read = trace_get_user(parser, ubuf, cnt, ppos);
|
|
|
|
if (read >= 0 && trace_parser_loaded(parser) &&
|
|
!trace_parser_cont(parser)) {
|
|
ret = ftrace_process_regex(iter->hash, parser->buffer,
|
|
parser->idx, enable);
|
|
trace_parser_clear(parser);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
|
|
ret = read;
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
ssize_t
|
|
ftrace_filter_write(struct file *file, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
|
|
}
|
|
|
|
ssize_t
|
|
ftrace_notrace_write(struct file *file, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
|
|
}
|
|
|
|
static int
|
|
ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
|
|
{
|
|
struct ftrace_func_entry *entry;
|
|
|
|
if (!ftrace_location(ip))
|
|
return -EINVAL;
|
|
|
|
if (remove) {
|
|
entry = ftrace_lookup_ip(hash, ip);
|
|
if (!entry)
|
|
return -ENOENT;
|
|
free_hash_entry(hash, entry);
|
|
return 0;
|
|
}
|
|
|
|
return add_hash_entry(hash, ip);
|
|
}
|
|
|
|
static void ftrace_ops_update_code(struct ftrace_ops *ops)
|
|
{
|
|
if (ops->flags & FTRACE_OPS_FL_ENABLED && ftrace_enabled)
|
|
ftrace_run_update_code(FTRACE_UPDATE_CALLS);
|
|
}
|
|
|
|
static int
|
|
ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
|
|
unsigned long ip, int remove, int reset, int enable)
|
|
{
|
|
struct ftrace_hash **orig_hash;
|
|
struct ftrace_hash *hash;
|
|
int ret;
|
|
|
|
/* All global ops uses the global ops filters */
|
|
if (ops->flags & FTRACE_OPS_FL_GLOBAL)
|
|
ops = &global_ops;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return -ENODEV;
|
|
|
|
mutex_lock(&ops->regex_lock);
|
|
|
|
if (enable)
|
|
orig_hash = &ops->filter_hash;
|
|
else
|
|
orig_hash = &ops->notrace_hash;
|
|
|
|
hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
|
|
if (!hash) {
|
|
ret = -ENOMEM;
|
|
goto out_regex_unlock;
|
|
}
|
|
|
|
if (reset)
|
|
ftrace_filter_reset(hash);
|
|
if (buf && !ftrace_match_records(hash, buf, len)) {
|
|
ret = -EINVAL;
|
|
goto out_regex_unlock;
|
|
}
|
|
if (ip) {
|
|
ret = ftrace_match_addr(hash, ip, remove);
|
|
if (ret < 0)
|
|
goto out_regex_unlock;
|
|
}
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
ret = ftrace_hash_move(ops, enable, orig_hash, hash);
|
|
if (!ret)
|
|
ftrace_ops_update_code(ops);
|
|
|
|
mutex_unlock(&ftrace_lock);
|
|
|
|
out_regex_unlock:
|
|
mutex_unlock(&ops->regex_lock);
|
|
|
|
free_ftrace_hash(hash);
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
|
|
int reset, int enable)
|
|
{
|
|
return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
|
|
}
|
|
|
|
/**
|
|
* ftrace_set_filter_ip - set a function to filter on in ftrace by address
|
|
* @ops - the ops to set the filter with
|
|
* @ip - the address to add to or remove from the filter.
|
|
* @remove - non zero to remove the ip from the filter
|
|
* @reset - non zero to reset all filters before applying this filter.
|
|
*
|
|
* Filters denote which functions should be enabled when tracing is enabled
|
|
* If @ip is NULL, it failes to update filter.
|
|
*/
|
|
int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
|
|
int remove, int reset)
|
|
{
|
|
ftrace_ops_init(ops);
|
|
return ftrace_set_addr(ops, ip, remove, reset, 1);
|
|
}
|
|
EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
|
|
|
|
static int
|
|
ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
|
|
int reset, int enable)
|
|
{
|
|
return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
|
|
}
|
|
|
|
/**
|
|
* ftrace_set_filter - set a function to filter on in ftrace
|
|
* @ops - the ops to set the filter with
|
|
* @buf - the string that holds the function filter text.
|
|
* @len - the length of the string.
|
|
* @reset - non zero to reset all filters before applying this filter.
|
|
*
|
|
* Filters denote which functions should be enabled when tracing is enabled.
|
|
* If @buf is NULL and reset is set, all functions will be enabled for tracing.
|
|
*/
|
|
int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
|
|
int len, int reset)
|
|
{
|
|
ftrace_ops_init(ops);
|
|
return ftrace_set_regex(ops, buf, len, reset, 1);
|
|
}
|
|
EXPORT_SYMBOL_GPL(ftrace_set_filter);
|
|
|
|
/**
|
|
* ftrace_set_notrace - set a function to not trace in ftrace
|
|
* @ops - the ops to set the notrace filter with
|
|
* @buf - the string that holds the function notrace text.
|
|
* @len - the length of the string.
|
|
* @reset - non zero to reset all filters before applying this filter.
|
|
*
|
|
* Notrace Filters denote which functions should not be enabled when tracing
|
|
* is enabled. If @buf is NULL and reset is set, all functions will be enabled
|
|
* for tracing.
|
|
*/
|
|
int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
|
|
int len, int reset)
|
|
{
|
|
ftrace_ops_init(ops);
|
|
return ftrace_set_regex(ops, buf, len, reset, 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(ftrace_set_notrace);
|
|
/**
|
|
* ftrace_set_filter - set a function to filter on in ftrace
|
|
* @ops - the ops to set the filter with
|
|
* @buf - the string that holds the function filter text.
|
|
* @len - the length of the string.
|
|
* @reset - non zero to reset all filters before applying this filter.
|
|
*
|
|
* Filters denote which functions should be enabled when tracing is enabled.
|
|
* If @buf is NULL and reset is set, all functions will be enabled for tracing.
|
|
*/
|
|
void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
|
|
{
|
|
ftrace_set_regex(&global_ops, buf, len, reset, 1);
|
|
}
|
|
EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
|
|
|
|
/**
|
|
* ftrace_set_notrace - set a function to not trace in ftrace
|
|
* @ops - the ops to set the notrace filter with
|
|
* @buf - the string that holds the function notrace text.
|
|
* @len - the length of the string.
|
|
* @reset - non zero to reset all filters before applying this filter.
|
|
*
|
|
* Notrace Filters denote which functions should not be enabled when tracing
|
|
* is enabled. If @buf is NULL and reset is set, all functions will be enabled
|
|
* for tracing.
|
|
*/
|
|
void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
|
|
{
|
|
ftrace_set_regex(&global_ops, buf, len, reset, 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
|
|
|
|
/*
|
|
* command line interface to allow users to set filters on boot up.
|
|
*/
|
|
#define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
|
|
static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
|
|
static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
|
|
|
|
/* Used by function selftest to not test if filter is set */
|
|
bool ftrace_filter_param __initdata;
|
|
|
|
static int __init set_ftrace_notrace(char *str)
|
|
{
|
|
ftrace_filter_param = true;
|
|
strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
|
|
return 1;
|
|
}
|
|
__setup("ftrace_notrace=", set_ftrace_notrace);
|
|
|
|
static int __init set_ftrace_filter(char *str)
|
|
{
|
|
ftrace_filter_param = true;
|
|
strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
|
|
return 1;
|
|
}
|
|
__setup("ftrace_filter=", set_ftrace_filter);
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
|
|
static int ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer);
|
|
|
|
static int __init set_graph_function(char *str)
|
|
{
|
|
strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
|
|
return 1;
|
|
}
|
|
__setup("ftrace_graph_filter=", set_graph_function);
|
|
|
|
static void __init set_ftrace_early_graph(char *buf)
|
|
{
|
|
int ret;
|
|
char *func;
|
|
|
|
while (buf) {
|
|
func = strsep(&buf, ",");
|
|
/* we allow only one expression at a time */
|
|
ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
|
|
FTRACE_GRAPH_MAX_FUNCS, func);
|
|
if (ret)
|
|
printk(KERN_DEBUG "ftrace: function %s not "
|
|
"traceable\n", func);
|
|
}
|
|
}
|
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
|
|
|
|
void __init
|
|
ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
|
|
{
|
|
char *func;
|
|
|
|
ftrace_ops_init(ops);
|
|
|
|
while (buf) {
|
|
func = strsep(&buf, ",");
|
|
ftrace_set_regex(ops, func, strlen(func), 0, enable);
|
|
}
|
|
}
|
|
|
|
static void __init set_ftrace_early_filters(void)
|
|
{
|
|
if (ftrace_filter_buf[0])
|
|
ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
|
|
if (ftrace_notrace_buf[0])
|
|
ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
if (ftrace_graph_buf[0])
|
|
set_ftrace_early_graph(ftrace_graph_buf);
|
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
|
|
}
|
|
|
|
int ftrace_regex_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct seq_file *m = (struct seq_file *)file->private_data;
|
|
struct ftrace_iterator *iter;
|
|
struct ftrace_hash **orig_hash;
|
|
struct trace_parser *parser;
|
|
int filter_hash;
|
|
int ret;
|
|
|
|
if (file->f_mode & FMODE_READ) {
|
|
iter = m->private;
|
|
seq_release(inode, file);
|
|
} else
|
|
iter = file->private_data;
|
|
|
|
parser = &iter->parser;
|
|
if (trace_parser_loaded(parser)) {
|
|
parser->buffer[parser->idx] = 0;
|
|
ftrace_match_records(iter->hash, parser->buffer, parser->idx);
|
|
}
|
|
|
|
trace_parser_put(parser);
|
|
|
|
mutex_lock(&iter->ops->regex_lock);
|
|
|
|
if (file->f_mode & FMODE_WRITE) {
|
|
filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
|
|
|
|
if (filter_hash)
|
|
orig_hash = &iter->ops->filter_hash;
|
|
else
|
|
orig_hash = &iter->ops->notrace_hash;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
ret = ftrace_hash_move(iter->ops, filter_hash,
|
|
orig_hash, iter->hash);
|
|
if (!ret)
|
|
ftrace_ops_update_code(iter->ops);
|
|
|
|
mutex_unlock(&ftrace_lock);
|
|
}
|
|
|
|
mutex_unlock(&iter->ops->regex_lock);
|
|
free_ftrace_hash(iter->hash);
|
|
kfree(iter);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations ftrace_avail_fops = {
|
|
.open = ftrace_avail_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release_private,
|
|
};
|
|
|
|
static const struct file_operations ftrace_enabled_fops = {
|
|
.open = ftrace_enabled_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release_private,
|
|
};
|
|
|
|
static const struct file_operations ftrace_filter_fops = {
|
|
.open = ftrace_filter_open,
|
|
.read = seq_read,
|
|
.write = ftrace_filter_write,
|
|
.llseek = tracing_lseek,
|
|
.release = ftrace_regex_release,
|
|
};
|
|
|
|
static const struct file_operations ftrace_notrace_fops = {
|
|
.open = ftrace_notrace_open,
|
|
.read = seq_read,
|
|
.write = ftrace_notrace_write,
|
|
.llseek = tracing_lseek,
|
|
.release = ftrace_regex_release,
|
|
};
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
|
|
static DEFINE_MUTEX(graph_lock);
|
|
|
|
int ftrace_graph_count;
|
|
int ftrace_graph_notrace_count;
|
|
unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
|
|
unsigned long ftrace_graph_notrace_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
|
|
|
|
struct ftrace_graph_data {
|
|
unsigned long *table;
|
|
size_t size;
|
|
int *count;
|
|
const struct seq_operations *seq_ops;
|
|
};
|
|
|
|
static void *
|
|
__g_next(struct seq_file *m, loff_t *pos)
|
|
{
|
|
struct ftrace_graph_data *fgd = m->private;
|
|
|
|
if (*pos >= *fgd->count)
|
|
return NULL;
|
|
return &fgd->table[*pos];
|
|
}
|
|
|
|
static void *
|
|
g_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
(*pos)++;
|
|
return __g_next(m, pos);
|
|
}
|
|
|
|
static void *g_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
struct ftrace_graph_data *fgd = m->private;
|
|
|
|
mutex_lock(&graph_lock);
|
|
|
|
/* Nothing, tell g_show to print all functions are enabled */
|
|
if (!*fgd->count && !*pos)
|
|
return (void *)1;
|
|
|
|
return __g_next(m, pos);
|
|
}
|
|
|
|
static void g_stop(struct seq_file *m, void *p)
|
|
{
|
|
mutex_unlock(&graph_lock);
|
|
}
|
|
|
|
static int g_show(struct seq_file *m, void *v)
|
|
{
|
|
unsigned long *ptr = v;
|
|
|
|
if (!ptr)
|
|
return 0;
|
|
|
|
if (ptr == (unsigned long *)1) {
|
|
seq_printf(m, "#### all functions enabled ####\n");
|
|
return 0;
|
|
}
|
|
|
|
seq_printf(m, "%ps\n", (void *)*ptr);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations ftrace_graph_seq_ops = {
|
|
.start = g_start,
|
|
.next = g_next,
|
|
.stop = g_stop,
|
|
.show = g_show,
|
|
};
|
|
|
|
static int
|
|
__ftrace_graph_open(struct inode *inode, struct file *file,
|
|
struct ftrace_graph_data *fgd)
|
|
{
|
|
int ret = 0;
|
|
|
|
mutex_lock(&graph_lock);
|
|
if ((file->f_mode & FMODE_WRITE) &&
|
|
(file->f_flags & O_TRUNC)) {
|
|
*fgd->count = 0;
|
|
memset(fgd->table, 0, fgd->size * sizeof(*fgd->table));
|
|
}
|
|
mutex_unlock(&graph_lock);
|
|
|
|
if (file->f_mode & FMODE_READ) {
|
|
ret = seq_open(file, fgd->seq_ops);
|
|
if (!ret) {
|
|
struct seq_file *m = file->private_data;
|
|
m->private = fgd;
|
|
}
|
|
} else
|
|
file->private_data = fgd;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
ftrace_graph_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct ftrace_graph_data *fgd;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return -ENODEV;
|
|
|
|
fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
|
|
if (fgd == NULL)
|
|
return -ENOMEM;
|
|
|
|
fgd->table = ftrace_graph_funcs;
|
|
fgd->size = FTRACE_GRAPH_MAX_FUNCS;
|
|
fgd->count = &ftrace_graph_count;
|
|
fgd->seq_ops = &ftrace_graph_seq_ops;
|
|
|
|
return __ftrace_graph_open(inode, file, fgd);
|
|
}
|
|
|
|
static int
|
|
ftrace_graph_notrace_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct ftrace_graph_data *fgd;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return -ENODEV;
|
|
|
|
fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
|
|
if (fgd == NULL)
|
|
return -ENOMEM;
|
|
|
|
fgd->table = ftrace_graph_notrace_funcs;
|
|
fgd->size = FTRACE_GRAPH_MAX_FUNCS;
|
|
fgd->count = &ftrace_graph_notrace_count;
|
|
fgd->seq_ops = &ftrace_graph_seq_ops;
|
|
|
|
return __ftrace_graph_open(inode, file, fgd);
|
|
}
|
|
|
|
static int
|
|
ftrace_graph_release(struct inode *inode, struct file *file)
|
|
{
|
|
if (file->f_mode & FMODE_READ) {
|
|
struct seq_file *m = file->private_data;
|
|
|
|
kfree(m->private);
|
|
seq_release(inode, file);
|
|
} else {
|
|
kfree(file->private_data);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer)
|
|
{
|
|
struct dyn_ftrace *rec;
|
|
struct ftrace_page *pg;
|
|
int search_len;
|
|
int fail = 1;
|
|
int type, not;
|
|
char *search;
|
|
bool exists;
|
|
int i;
|
|
|
|
/* decode regex */
|
|
type = filter_parse_regex(buffer, strlen(buffer), &search, ¬);
|
|
if (!not && *idx >= size)
|
|
return -EBUSY;
|
|
|
|
search_len = strlen(search);
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
|
|
if (unlikely(ftrace_disabled)) {
|
|
mutex_unlock(&ftrace_lock);
|
|
return -ENODEV;
|
|
}
|
|
|
|
do_for_each_ftrace_rec(pg, rec) {
|
|
|
|
if (ftrace_match_record(rec, NULL, search, search_len, type)) {
|
|
/* if it is in the array */
|
|
exists = false;
|
|
for (i = 0; i < *idx; i++) {
|
|
if (array[i] == rec->ip) {
|
|
exists = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!not) {
|
|
fail = 0;
|
|
if (!exists) {
|
|
array[(*idx)++] = rec->ip;
|
|
if (*idx >= size)
|
|
goto out;
|
|
}
|
|
} else {
|
|
if (exists) {
|
|
array[i] = array[--(*idx)];
|
|
array[*idx] = 0;
|
|
fail = 0;
|
|
}
|
|
}
|
|
}
|
|
} while_for_each_ftrace_rec();
|
|
out:
|
|
mutex_unlock(&ftrace_lock);
|
|
|
|
if (fail)
|
|
return -EINVAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t
|
|
ftrace_graph_write(struct file *file, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
struct trace_parser parser;
|
|
ssize_t read, ret = 0;
|
|
struct ftrace_graph_data *fgd = file->private_data;
|
|
|
|
if (!cnt)
|
|
return 0;
|
|
|
|
if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX))
|
|
return -ENOMEM;
|
|
|
|
read = trace_get_user(&parser, ubuf, cnt, ppos);
|
|
|
|
if (read >= 0 && trace_parser_loaded((&parser))) {
|
|
parser.buffer[parser.idx] = 0;
|
|
|
|
mutex_lock(&graph_lock);
|
|
|
|
/* we allow only one expression at a time */
|
|
ret = ftrace_set_func(fgd->table, fgd->count, fgd->size,
|
|
parser.buffer);
|
|
|
|
mutex_unlock(&graph_lock);
|
|
}
|
|
|
|
if (!ret)
|
|
ret = read;
|
|
|
|
trace_parser_put(&parser);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static const struct file_operations ftrace_graph_fops = {
|
|
.open = ftrace_graph_open,
|
|
.read = seq_read,
|
|
.write = ftrace_graph_write,
|
|
.llseek = tracing_lseek,
|
|
.release = ftrace_graph_release,
|
|
};
|
|
|
|
static const struct file_operations ftrace_graph_notrace_fops = {
|
|
.open = ftrace_graph_notrace_open,
|
|
.read = seq_read,
|
|
.write = ftrace_graph_write,
|
|
.llseek = tracing_lseek,
|
|
.release = ftrace_graph_release,
|
|
};
|
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
|
|
|
|
void ftrace_create_filter_files(struct ftrace_ops *ops,
|
|
struct dentry *parent)
|
|
{
|
|
|
|
trace_create_file("set_ftrace_filter", 0644, parent,
|
|
ops, &ftrace_filter_fops);
|
|
|
|
trace_create_file("set_ftrace_notrace", 0644, parent,
|
|
ops, &ftrace_notrace_fops);
|
|
}
|
|
|
|
/*
|
|
* The name "destroy_filter_files" is really a misnomer. Although
|
|
* in the future, it may actualy delete the files, but this is
|
|
* really intended to make sure the ops passed in are disabled
|
|
* and that when this function returns, the caller is free to
|
|
* free the ops.
|
|
*
|
|
* The "destroy" name is only to match the "create" name that this
|
|
* should be paired with.
|
|
*/
|
|
void ftrace_destroy_filter_files(struct ftrace_ops *ops)
|
|
{
|
|
mutex_lock(&ftrace_lock);
|
|
if (ops->flags & FTRACE_OPS_FL_ENABLED)
|
|
ftrace_shutdown(ops, 0);
|
|
ops->flags |= FTRACE_OPS_FL_DELETED;
|
|
mutex_unlock(&ftrace_lock);
|
|
}
|
|
|
|
static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
|
|
{
|
|
|
|
trace_create_file("available_filter_functions", 0444,
|
|
d_tracer, NULL, &ftrace_avail_fops);
|
|
|
|
trace_create_file("enabled_functions", 0444,
|
|
d_tracer, NULL, &ftrace_enabled_fops);
|
|
|
|
ftrace_create_filter_files(&global_ops, d_tracer);
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
trace_create_file("set_graph_function", 0444, d_tracer,
|
|
NULL,
|
|
&ftrace_graph_fops);
|
|
trace_create_file("set_graph_notrace", 0444, d_tracer,
|
|
NULL,
|
|
&ftrace_graph_notrace_fops);
|
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ftrace_cmp_ips(const void *a, const void *b)
|
|
{
|
|
const unsigned long *ipa = a;
|
|
const unsigned long *ipb = b;
|
|
|
|
if (*ipa > *ipb)
|
|
return 1;
|
|
if (*ipa < *ipb)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
static void ftrace_swap_ips(void *a, void *b, int size)
|
|
{
|
|
unsigned long *ipa = a;
|
|
unsigned long *ipb = b;
|
|
unsigned long t;
|
|
|
|
t = *ipa;
|
|
*ipa = *ipb;
|
|
*ipb = t;
|
|
}
|
|
|
|
static int ftrace_process_locs(struct module *mod,
|
|
unsigned long *start,
|
|
unsigned long *end)
|
|
{
|
|
struct ftrace_page *start_pg;
|
|
struct ftrace_page *pg;
|
|
struct dyn_ftrace *rec;
|
|
unsigned long count;
|
|
unsigned long *p;
|
|
unsigned long addr;
|
|
unsigned long flags = 0; /* Shut up gcc */
|
|
int ret = -ENOMEM;
|
|
|
|
count = end - start;
|
|
|
|
if (!count)
|
|
return 0;
|
|
|
|
sort(start, count, sizeof(*start),
|
|
ftrace_cmp_ips, ftrace_swap_ips);
|
|
|
|
start_pg = ftrace_allocate_pages(count);
|
|
if (!start_pg)
|
|
return -ENOMEM;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
|
|
/*
|
|
* Core and each module needs their own pages, as
|
|
* modules will free them when they are removed.
|
|
* Force a new page to be allocated for modules.
|
|
*/
|
|
if (!mod) {
|
|
WARN_ON(ftrace_pages || ftrace_pages_start);
|
|
/* First initialization */
|
|
ftrace_pages = ftrace_pages_start = start_pg;
|
|
} else {
|
|
if (!ftrace_pages)
|
|
goto out;
|
|
|
|
if (WARN_ON(ftrace_pages->next)) {
|
|
/* Hmm, we have free pages? */
|
|
while (ftrace_pages->next)
|
|
ftrace_pages = ftrace_pages->next;
|
|
}
|
|
|
|
ftrace_pages->next = start_pg;
|
|
}
|
|
|
|
p = start;
|
|
pg = start_pg;
|
|
while (p < end) {
|
|
addr = ftrace_call_adjust(*p++);
|
|
/*
|
|
* Some architecture linkers will pad between
|
|
* the different mcount_loc sections of different
|
|
* object files to satisfy alignments.
|
|
* Skip any NULL pointers.
|
|
*/
|
|
if (!addr)
|
|
continue;
|
|
|
|
if (pg->index == pg->size) {
|
|
/* We should have allocated enough */
|
|
if (WARN_ON(!pg->next))
|
|
break;
|
|
pg = pg->next;
|
|
}
|
|
|
|
rec = &pg->records[pg->index++];
|
|
rec->ip = addr;
|
|
}
|
|
|
|
/* We should have used all pages */
|
|
WARN_ON(pg->next);
|
|
|
|
/* Assign the last page to ftrace_pages */
|
|
ftrace_pages = pg;
|
|
|
|
/*
|
|
* We only need to disable interrupts on start up
|
|
* because we are modifying code that an interrupt
|
|
* may execute, and the modification is not atomic.
|
|
* But for modules, nothing runs the code we modify
|
|
* until we are finished with it, and there's no
|
|
* reason to cause large interrupt latencies while we do it.
|
|
*/
|
|
if (!mod)
|
|
local_irq_save(flags);
|
|
ftrace_update_code(mod, start_pg);
|
|
if (!mod)
|
|
local_irq_restore(flags);
|
|
ret = 0;
|
|
out:
|
|
mutex_unlock(&ftrace_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_MODULES
|
|
|
|
#define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
|
|
|
|
void ftrace_release_mod(struct module *mod)
|
|
{
|
|
struct dyn_ftrace *rec;
|
|
struct ftrace_page **last_pg;
|
|
struct ftrace_page *pg;
|
|
int order;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
|
|
if (ftrace_disabled)
|
|
goto out_unlock;
|
|
|
|
/*
|
|
* Each module has its own ftrace_pages, remove
|
|
* them from the list.
|
|
*/
|
|
last_pg = &ftrace_pages_start;
|
|
for (pg = ftrace_pages_start; pg; pg = *last_pg) {
|
|
rec = &pg->records[0];
|
|
if (within_module_core(rec->ip, mod)) {
|
|
/*
|
|
* As core pages are first, the first
|
|
* page should never be a module page.
|
|
*/
|
|
if (WARN_ON(pg == ftrace_pages_start))
|
|
goto out_unlock;
|
|
|
|
/* Check if we are deleting the last page */
|
|
if (pg == ftrace_pages)
|
|
ftrace_pages = next_to_ftrace_page(last_pg);
|
|
|
|
*last_pg = pg->next;
|
|
order = get_count_order(pg->size / ENTRIES_PER_PAGE);
|
|
free_pages((unsigned long)pg->records, order);
|
|
kfree(pg);
|
|
} else
|
|
last_pg = &pg->next;
|
|
}
|
|
out_unlock:
|
|
mutex_unlock(&ftrace_lock);
|
|
}
|
|
|
|
static void ftrace_init_module(struct module *mod,
|
|
unsigned long *start, unsigned long *end)
|
|
{
|
|
if (ftrace_disabled || start == end)
|
|
return;
|
|
ftrace_process_locs(mod, start, end);
|
|
}
|
|
|
|
static int ftrace_module_notify_enter(struct notifier_block *self,
|
|
unsigned long val, void *data)
|
|
{
|
|
struct module *mod = data;
|
|
|
|
if (val == MODULE_STATE_COMING)
|
|
ftrace_init_module(mod, mod->ftrace_callsites,
|
|
mod->ftrace_callsites +
|
|
mod->num_ftrace_callsites);
|
|
return 0;
|
|
}
|
|
|
|
static int ftrace_module_notify_exit(struct notifier_block *self,
|
|
unsigned long val, void *data)
|
|
{
|
|
struct module *mod = data;
|
|
|
|
if (val == MODULE_STATE_GOING)
|
|
ftrace_release_mod(mod);
|
|
|
|
return 0;
|
|
}
|
|
#else
|
|
static int ftrace_module_notify_enter(struct notifier_block *self,
|
|
unsigned long val, void *data)
|
|
{
|
|
return 0;
|
|
}
|
|
static int ftrace_module_notify_exit(struct notifier_block *self,
|
|
unsigned long val, void *data)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_MODULES */
|
|
|
|
struct notifier_block ftrace_module_enter_nb = {
|
|
.notifier_call = ftrace_module_notify_enter,
|
|
.priority = INT_MAX, /* Run before anything that can use kprobes */
|
|
};
|
|
|
|
struct notifier_block ftrace_module_exit_nb = {
|
|
.notifier_call = ftrace_module_notify_exit,
|
|
.priority = INT_MIN, /* Run after anything that can remove kprobes */
|
|
};
|
|
|
|
void __init ftrace_init(void)
|
|
{
|
|
extern unsigned long __start_mcount_loc[];
|
|
extern unsigned long __stop_mcount_loc[];
|
|
unsigned long count, flags;
|
|
int ret;
|
|
|
|
local_irq_save(flags);
|
|
ret = ftrace_dyn_arch_init();
|
|
local_irq_restore(flags);
|
|
if (ret)
|
|
goto failed;
|
|
|
|
count = __stop_mcount_loc - __start_mcount_loc;
|
|
if (!count) {
|
|
pr_info("ftrace: No functions to be traced?\n");
|
|
goto failed;
|
|
}
|
|
|
|
pr_info("ftrace: allocating %ld entries in %ld pages\n",
|
|
count, count / ENTRIES_PER_PAGE + 1);
|
|
|
|
last_ftrace_enabled = ftrace_enabled = 1;
|
|
|
|
ret = ftrace_process_locs(NULL,
|
|
__start_mcount_loc,
|
|
__stop_mcount_loc);
|
|
|
|
ret = register_module_notifier(&ftrace_module_enter_nb);
|
|
if (ret)
|
|
pr_warning("Failed to register trace ftrace module enter notifier\n");
|
|
|
|
ret = register_module_notifier(&ftrace_module_exit_nb);
|
|
if (ret)
|
|
pr_warning("Failed to register trace ftrace module exit notifier\n");
|
|
|
|
set_ftrace_early_filters();
|
|
|
|
return;
|
|
failed:
|
|
ftrace_disabled = 1;
|
|
}
|
|
|
|
#else
|
|
|
|
static struct ftrace_ops global_ops = {
|
|
.func = ftrace_stub,
|
|
.flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
|
|
INIT_REGEX_LOCK(global_ops)
|
|
};
|
|
|
|
static int __init ftrace_nodyn_init(void)
|
|
{
|
|
ftrace_enabled = 1;
|
|
return 0;
|
|
}
|
|
core_initcall(ftrace_nodyn_init);
|
|
|
|
static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
|
|
static inline void ftrace_startup_enable(int command) { }
|
|
/* Keep as macros so we do not need to define the commands */
|
|
# define ftrace_startup(ops, command) \
|
|
({ \
|
|
int ___ret = __register_ftrace_function(ops); \
|
|
if (!___ret) \
|
|
(ops)->flags |= FTRACE_OPS_FL_ENABLED; \
|
|
___ret; \
|
|
})
|
|
# define ftrace_shutdown(ops, command) \
|
|
({ \
|
|
int ___ret = __unregister_ftrace_function(ops); \
|
|
if (!___ret) \
|
|
(ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
|
|
___ret; \
|
|
})
|
|
|
|
# define ftrace_startup_sysctl() do { } while (0)
|
|
# define ftrace_shutdown_sysctl() do { } while (0)
|
|
|
|
static inline int
|
|
ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
#endif /* CONFIG_DYNAMIC_FTRACE */
|
|
|
|
static void
|
|
ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
|
|
struct ftrace_ops *op, struct pt_regs *regs)
|
|
{
|
|
if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT)))
|
|
return;
|
|
|
|
/*
|
|
* Some of the ops may be dynamically allocated,
|
|
* they must be freed after a synchronize_sched().
|
|
*/
|
|
preempt_disable_notrace();
|
|
trace_recursion_set(TRACE_CONTROL_BIT);
|
|
|
|
/*
|
|
* Control funcs (perf) uses RCU. Only trace if
|
|
* RCU is currently active.
|
|
*/
|
|
if (!rcu_is_watching())
|
|
goto out;
|
|
|
|
do_for_each_ftrace_op(op, ftrace_control_list) {
|
|
if (!(op->flags & FTRACE_OPS_FL_STUB) &&
|
|
!ftrace_function_local_disabled(op) &&
|
|
ftrace_ops_test(op, ip, regs))
|
|
op->func(ip, parent_ip, op, regs);
|
|
} while_for_each_ftrace_op(op);
|
|
out:
|
|
trace_recursion_clear(TRACE_CONTROL_BIT);
|
|
preempt_enable_notrace();
|
|
}
|
|
|
|
static struct ftrace_ops control_ops = {
|
|
.func = ftrace_ops_control_func,
|
|
.flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
|
|
INIT_REGEX_LOCK(control_ops)
|
|
};
|
|
|
|
static inline void
|
|
__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
|
|
struct ftrace_ops *ignored, struct pt_regs *regs)
|
|
{
|
|
struct ftrace_ops *op;
|
|
int bit;
|
|
|
|
if (function_trace_stop)
|
|
return;
|
|
|
|
bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
|
|
if (bit < 0)
|
|
return;
|
|
|
|
/*
|
|
* Some of the ops may be dynamically allocated,
|
|
* they must be freed after a synchronize_sched().
|
|
*/
|
|
preempt_disable_notrace();
|
|
do_for_each_ftrace_op(op, ftrace_ops_list) {
|
|
if (ftrace_ops_test(op, ip, regs))
|
|
op->func(ip, parent_ip, op, regs);
|
|
} while_for_each_ftrace_op(op);
|
|
preempt_enable_notrace();
|
|
trace_clear_recursion(bit);
|
|
}
|
|
|
|
/*
|
|
* Some archs only support passing ip and parent_ip. Even though
|
|
* the list function ignores the op parameter, we do not want any
|
|
* C side effects, where a function is called without the caller
|
|
* sending a third parameter.
|
|
* Archs are to support both the regs and ftrace_ops at the same time.
|
|
* If they support ftrace_ops, it is assumed they support regs.
|
|
* If call backs want to use regs, they must either check for regs
|
|
* being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
|
|
* Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
|
|
* An architecture can pass partial regs with ftrace_ops and still
|
|
* set the ARCH_SUPPORT_FTARCE_OPS.
|
|
*/
|
|
#if ARCH_SUPPORTS_FTRACE_OPS
|
|
static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
|
|
struct ftrace_ops *op, struct pt_regs *regs)
|
|
{
|
|
__ftrace_ops_list_func(ip, parent_ip, NULL, regs);
|
|
}
|
|
#else
|
|
static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
|
|
{
|
|
__ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
|
|
}
|
|
#endif
|
|
|
|
static void clear_ftrace_swapper(void)
|
|
{
|
|
struct task_struct *p;
|
|
int cpu;
|
|
|
|
get_online_cpus();
|
|
for_each_online_cpu(cpu) {
|
|
p = idle_task(cpu);
|
|
clear_tsk_trace_trace(p);
|
|
}
|
|
put_online_cpus();
|
|
}
|
|
|
|
static void set_ftrace_swapper(void)
|
|
{
|
|
struct task_struct *p;
|
|
int cpu;
|
|
|
|
get_online_cpus();
|
|
for_each_online_cpu(cpu) {
|
|
p = idle_task(cpu);
|
|
set_tsk_trace_trace(p);
|
|
}
|
|
put_online_cpus();
|
|
}
|
|
|
|
static void clear_ftrace_pid(struct pid *pid)
|
|
{
|
|
struct task_struct *p;
|
|
|
|
rcu_read_lock();
|
|
do_each_pid_task(pid, PIDTYPE_PID, p) {
|
|
clear_tsk_trace_trace(p);
|
|
} while_each_pid_task(pid, PIDTYPE_PID, p);
|
|
rcu_read_unlock();
|
|
|
|
put_pid(pid);
|
|
}
|
|
|
|
static void set_ftrace_pid(struct pid *pid)
|
|
{
|
|
struct task_struct *p;
|
|
|
|
rcu_read_lock();
|
|
do_each_pid_task(pid, PIDTYPE_PID, p) {
|
|
set_tsk_trace_trace(p);
|
|
} while_each_pid_task(pid, PIDTYPE_PID, p);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void clear_ftrace_pid_task(struct pid *pid)
|
|
{
|
|
if (pid == ftrace_swapper_pid)
|
|
clear_ftrace_swapper();
|
|
else
|
|
clear_ftrace_pid(pid);
|
|
}
|
|
|
|
static void set_ftrace_pid_task(struct pid *pid)
|
|
{
|
|
if (pid == ftrace_swapper_pid)
|
|
set_ftrace_swapper();
|
|
else
|
|
set_ftrace_pid(pid);
|
|
}
|
|
|
|
static int ftrace_pid_add(int p)
|
|
{
|
|
struct pid *pid;
|
|
struct ftrace_pid *fpid;
|
|
int ret = -EINVAL;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
|
|
if (!p)
|
|
pid = ftrace_swapper_pid;
|
|
else
|
|
pid = find_get_pid(p);
|
|
|
|
if (!pid)
|
|
goto out;
|
|
|
|
ret = 0;
|
|
|
|
list_for_each_entry(fpid, &ftrace_pids, list)
|
|
if (fpid->pid == pid)
|
|
goto out_put;
|
|
|
|
ret = -ENOMEM;
|
|
|
|
fpid = kmalloc(sizeof(*fpid), GFP_KERNEL);
|
|
if (!fpid)
|
|
goto out_put;
|
|
|
|
list_add(&fpid->list, &ftrace_pids);
|
|
fpid->pid = pid;
|
|
|
|
set_ftrace_pid_task(pid);
|
|
|
|
ftrace_update_pid_func();
|
|
ftrace_startup_enable(0);
|
|
|
|
mutex_unlock(&ftrace_lock);
|
|
return 0;
|
|
|
|
out_put:
|
|
if (pid != ftrace_swapper_pid)
|
|
put_pid(pid);
|
|
|
|
out:
|
|
mutex_unlock(&ftrace_lock);
|
|
return ret;
|
|
}
|
|
|
|
static void ftrace_pid_reset(void)
|
|
{
|
|
struct ftrace_pid *fpid, *safe;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) {
|
|
struct pid *pid = fpid->pid;
|
|
|
|
clear_ftrace_pid_task(pid);
|
|
|
|
list_del(&fpid->list);
|
|
kfree(fpid);
|
|
}
|
|
|
|
ftrace_update_pid_func();
|
|
ftrace_startup_enable(0);
|
|
|
|
mutex_unlock(&ftrace_lock);
|
|
}
|
|
|
|
static void *fpid_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
mutex_lock(&ftrace_lock);
|
|
|
|
if (list_empty(&ftrace_pids) && (!*pos))
|
|
return (void *) 1;
|
|
|
|
return seq_list_start(&ftrace_pids, *pos);
|
|
}
|
|
|
|
static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
if (v == (void *)1)
|
|
return NULL;
|
|
|
|
return seq_list_next(v, &ftrace_pids, pos);
|
|
}
|
|
|
|
static void fpid_stop(struct seq_file *m, void *p)
|
|
{
|
|
mutex_unlock(&ftrace_lock);
|
|
}
|
|
|
|
static int fpid_show(struct seq_file *m, void *v)
|
|
{
|
|
const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);
|
|
|
|
if (v == (void *)1) {
|
|
seq_printf(m, "no pid\n");
|
|
return 0;
|
|
}
|
|
|
|
if (fpid->pid == ftrace_swapper_pid)
|
|
seq_printf(m, "swapper tasks\n");
|
|
else
|
|
seq_printf(m, "%u\n", pid_vnr(fpid->pid));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations ftrace_pid_sops = {
|
|
.start = fpid_start,
|
|
.next = fpid_next,
|
|
.stop = fpid_stop,
|
|
.show = fpid_show,
|
|
};
|
|
|
|
static int
|
|
ftrace_pid_open(struct inode *inode, struct file *file)
|
|
{
|
|
int ret = 0;
|
|
|
|
if ((file->f_mode & FMODE_WRITE) &&
|
|
(file->f_flags & O_TRUNC))
|
|
ftrace_pid_reset();
|
|
|
|
if (file->f_mode & FMODE_READ)
|
|
ret = seq_open(file, &ftrace_pid_sops);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t
|
|
ftrace_pid_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
char buf[64], *tmp;
|
|
long val;
|
|
int ret;
|
|
|
|
if (cnt >= sizeof(buf))
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(&buf, ubuf, cnt))
|
|
return -EFAULT;
|
|
|
|
buf[cnt] = 0;
|
|
|
|
/*
|
|
* Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
|
|
* to clean the filter quietly.
|
|
*/
|
|
tmp = strstrip(buf);
|
|
if (strlen(tmp) == 0)
|
|
return 1;
|
|
|
|
ret = kstrtol(tmp, 10, &val);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = ftrace_pid_add(val);
|
|
|
|
return ret ? ret : cnt;
|
|
}
|
|
|
|
static int
|
|
ftrace_pid_release(struct inode *inode, struct file *file)
|
|
{
|
|
if (file->f_mode & FMODE_READ)
|
|
seq_release(inode, file);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations ftrace_pid_fops = {
|
|
.open = ftrace_pid_open,
|
|
.write = ftrace_pid_write,
|
|
.read = seq_read,
|
|
.llseek = tracing_lseek,
|
|
.release = ftrace_pid_release,
|
|
};
|
|
|
|
static __init int ftrace_init_debugfs(void)
|
|
{
|
|
struct dentry *d_tracer;
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
if (!d_tracer)
|
|
return 0;
|
|
|
|
ftrace_init_dyn_debugfs(d_tracer);
|
|
|
|
trace_create_file("set_ftrace_pid", 0644, d_tracer,
|
|
NULL, &ftrace_pid_fops);
|
|
|
|
ftrace_profile_debugfs(d_tracer);
|
|
|
|
return 0;
|
|
}
|
|
fs_initcall(ftrace_init_debugfs);
|
|
|
|
/**
|
|
* ftrace_kill - kill ftrace
|
|
*
|
|
* This function should be used by panic code. It stops ftrace
|
|
* but in a not so nice way. If you need to simply kill ftrace
|
|
* from a non-atomic section, use ftrace_kill.
|
|
*/
|
|
void ftrace_kill(void)
|
|
{
|
|
ftrace_disabled = 1;
|
|
ftrace_enabled = 0;
|
|
clear_ftrace_function();
|
|
}
|
|
|
|
/**
|
|
* Test if ftrace is dead or not.
|
|
*/
|
|
int ftrace_is_dead(void)
|
|
{
|
|
return ftrace_disabled;
|
|
}
|
|
|
|
/**
|
|
* register_ftrace_function - register a function for profiling
|
|
* @ops - ops structure that holds the function for profiling.
|
|
*
|
|
* Register a function to be called by all functions in the
|
|
* kernel.
|
|
*
|
|
* Note: @ops->func and all the functions it calls must be labeled
|
|
* with "notrace", otherwise it will go into a
|
|
* recursive loop.
|
|
*/
|
|
int register_ftrace_function(struct ftrace_ops *ops)
|
|
{
|
|
int ret = -1;
|
|
|
|
ftrace_ops_init(ops);
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
|
|
ret = ftrace_startup(ops, 0);
|
|
|
|
mutex_unlock(&ftrace_lock);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(register_ftrace_function);
|
|
|
|
/**
|
|
* unregister_ftrace_function - unregister a function for profiling.
|
|
* @ops - ops structure that holds the function to unregister
|
|
*
|
|
* Unregister a function that was added to be called by ftrace profiling.
|
|
*/
|
|
int unregister_ftrace_function(struct ftrace_ops *ops)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
ret = ftrace_shutdown(ops, 0);
|
|
mutex_unlock(&ftrace_lock);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(unregister_ftrace_function);
|
|
|
|
int
|
|
ftrace_enable_sysctl(struct ctl_table *table, int write,
|
|
void __user *buffer, size_t *lenp,
|
|
loff_t *ppos)
|
|
{
|
|
int ret = -ENODEV;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
goto out;
|
|
|
|
ret = proc_dointvec(table, write, buffer, lenp, ppos);
|
|
|
|
if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
|
|
goto out;
|
|
|
|
last_ftrace_enabled = !!ftrace_enabled;
|
|
|
|
if (ftrace_enabled) {
|
|
|
|
ftrace_startup_sysctl();
|
|
|
|
/* we are starting ftrace again */
|
|
if (ftrace_ops_list != &ftrace_list_end)
|
|
update_ftrace_function();
|
|
|
|
} else {
|
|
/* stopping ftrace calls (just send to ftrace_stub) */
|
|
ftrace_trace_function = ftrace_stub;
|
|
|
|
ftrace_shutdown_sysctl();
|
|
}
|
|
|
|
out:
|
|
mutex_unlock(&ftrace_lock);
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
|
|
static int ftrace_graph_active;
|
|
static struct notifier_block ftrace_suspend_notifier;
|
|
|
|
int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/* The callbacks that hook a function */
|
|
trace_func_graph_ret_t ftrace_graph_return =
|
|
(trace_func_graph_ret_t)ftrace_stub;
|
|
trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
|
|
static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub;
|
|
|
|
/* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
|
|
static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
|
|
{
|
|
int i;
|
|
int ret = 0;
|
|
unsigned long flags;
|
|
int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
|
|
struct task_struct *g, *t;
|
|
|
|
for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
|
|
ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
|
|
* sizeof(struct ftrace_ret_stack),
|
|
GFP_KERNEL);
|
|
if (!ret_stack_list[i]) {
|
|
start = 0;
|
|
end = i;
|
|
ret = -ENOMEM;
|
|
goto free;
|
|
}
|
|
}
|
|
|
|
read_lock_irqsave(&tasklist_lock, flags);
|
|
do_each_thread(g, t) {
|
|
if (start == end) {
|
|
ret = -EAGAIN;
|
|
goto unlock;
|
|
}
|
|
|
|
if (t->ret_stack == NULL) {
|
|
atomic_set(&t->tracing_graph_pause, 0);
|
|
atomic_set(&t->trace_overrun, 0);
|
|
t->curr_ret_stack = -1;
|
|
/* Make sure the tasks see the -1 first: */
|
|
smp_wmb();
|
|
t->ret_stack = ret_stack_list[start++];
|
|
}
|
|
} while_each_thread(g, t);
|
|
|
|
unlock:
|
|
read_unlock_irqrestore(&tasklist_lock, flags);
|
|
free:
|
|
for (i = start; i < end; i++)
|
|
kfree(ret_stack_list[i]);
|
|
return ret;
|
|
}
|
|
|
|
static void
|
|
ftrace_graph_probe_sched_switch(void *ignore,
|
|
struct task_struct *prev, struct task_struct *next)
|
|
{
|
|
unsigned long long timestamp;
|
|
int index;
|
|
|
|
/*
|
|
* Does the user want to count the time a function was asleep.
|
|
* If so, do not update the time stamps.
|
|
*/
|
|
if (trace_flags & TRACE_ITER_SLEEP_TIME)
|
|
return;
|
|
|
|
timestamp = trace_clock_local();
|
|
|
|
prev->ftrace_timestamp = timestamp;
|
|
|
|
/* only process tasks that we timestamped */
|
|
if (!next->ftrace_timestamp)
|
|
return;
|
|
|
|
/*
|
|
* Update all the counters in next to make up for the
|
|
* time next was sleeping.
|
|
*/
|
|
timestamp -= next->ftrace_timestamp;
|
|
|
|
for (index = next->curr_ret_stack; index >= 0; index--)
|
|
next->ret_stack[index].calltime += timestamp;
|
|
}
|
|
|
|
/* Allocate a return stack for each task */
|
|
static int start_graph_tracing(void)
|
|
{
|
|
struct ftrace_ret_stack **ret_stack_list;
|
|
int ret, cpu;
|
|
|
|
ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
|
|
sizeof(struct ftrace_ret_stack *),
|
|
GFP_KERNEL);
|
|
|
|
if (!ret_stack_list)
|
|
return -ENOMEM;
|
|
|
|
/* The cpu_boot init_task->ret_stack will never be freed */
|
|
for_each_online_cpu(cpu) {
|
|
if (!idle_task(cpu)->ret_stack)
|
|
ftrace_graph_init_idle_task(idle_task(cpu), cpu);
|
|
}
|
|
|
|
do {
|
|
ret = alloc_retstack_tasklist(ret_stack_list);
|
|
} while (ret == -EAGAIN);
|
|
|
|
if (!ret) {
|
|
ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
|
|
if (ret)
|
|
pr_info("ftrace_graph: Couldn't activate tracepoint"
|
|
" probe to kernel_sched_switch\n");
|
|
}
|
|
|
|
kfree(ret_stack_list);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Hibernation protection.
|
|
* The state of the current task is too much unstable during
|
|
* suspend/restore to disk. We want to protect against that.
|
|
*/
|
|
static int
|
|
ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
|
|
void *unused)
|
|
{
|
|
switch (state) {
|
|
case PM_HIBERNATION_PREPARE:
|
|
pause_graph_tracing();
|
|
break;
|
|
|
|
case PM_POST_HIBERNATION:
|
|
unpause_graph_tracing();
|
|
break;
|
|
}
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
/* Just a place holder for function graph */
|
|
static struct ftrace_ops fgraph_ops __read_mostly = {
|
|
.func = ftrace_stub,
|
|
.flags = FTRACE_OPS_FL_STUB | FTRACE_OPS_FL_GLOBAL |
|
|
FTRACE_OPS_FL_RECURSION_SAFE,
|
|
};
|
|
|
|
static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace)
|
|
{
|
|
if (!ftrace_ops_test(&global_ops, trace->func, NULL))
|
|
return 0;
|
|
return __ftrace_graph_entry(trace);
|
|
}
|
|
|
|
/*
|
|
* The function graph tracer should only trace the functions defined
|
|
* by set_ftrace_filter and set_ftrace_notrace. If another function
|
|
* tracer ops is registered, the graph tracer requires testing the
|
|
* function against the global ops, and not just trace any function
|
|
* that any ftrace_ops registered.
|
|
*/
|
|
static void update_function_graph_func(void)
|
|
{
|
|
if (ftrace_ops_list == &ftrace_list_end ||
|
|
(ftrace_ops_list == &global_ops &&
|
|
global_ops.next == &ftrace_list_end))
|
|
ftrace_graph_entry = __ftrace_graph_entry;
|
|
else
|
|
ftrace_graph_entry = ftrace_graph_entry_test;
|
|
}
|
|
|
|
int register_ftrace_graph(trace_func_graph_ret_t retfunc,
|
|
trace_func_graph_ent_t entryfunc)
|
|
{
|
|
int ret = 0;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
|
|
/* we currently allow only one tracer registered at a time */
|
|
if (ftrace_graph_active) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
|
|
register_pm_notifier(&ftrace_suspend_notifier);
|
|
|
|
ftrace_graph_active++;
|
|
ret = start_graph_tracing();
|
|
if (ret) {
|
|
ftrace_graph_active--;
|
|
goto out;
|
|
}
|
|
|
|
ftrace_graph_return = retfunc;
|
|
|
|
/*
|
|
* Update the indirect function to the entryfunc, and the
|
|
* function that gets called to the entry_test first. Then
|
|
* call the update fgraph entry function to determine if
|
|
* the entryfunc should be called directly or not.
|
|
*/
|
|
__ftrace_graph_entry = entryfunc;
|
|
ftrace_graph_entry = ftrace_graph_entry_test;
|
|
update_function_graph_func();
|
|
|
|
ret = ftrace_startup(&fgraph_ops, FTRACE_START_FUNC_RET);
|
|
|
|
out:
|
|
mutex_unlock(&ftrace_lock);
|
|
return ret;
|
|
}
|
|
|
|
void unregister_ftrace_graph(void)
|
|
{
|
|
mutex_lock(&ftrace_lock);
|
|
|
|
if (unlikely(!ftrace_graph_active))
|
|
goto out;
|
|
|
|
ftrace_graph_active--;
|
|
ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
|
|
ftrace_graph_entry = ftrace_graph_entry_stub;
|
|
__ftrace_graph_entry = ftrace_graph_entry_stub;
|
|
ftrace_shutdown(&fgraph_ops, FTRACE_STOP_FUNC_RET);
|
|
unregister_pm_notifier(&ftrace_suspend_notifier);
|
|
unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
|
|
|
|
out:
|
|
mutex_unlock(&ftrace_lock);
|
|
}
|
|
|
|
static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
|
|
|
|
static void
|
|
graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
|
|
{
|
|
atomic_set(&t->tracing_graph_pause, 0);
|
|
atomic_set(&t->trace_overrun, 0);
|
|
t->ftrace_timestamp = 0;
|
|
/* make curr_ret_stack visible before we add the ret_stack */
|
|
smp_wmb();
|
|
t->ret_stack = ret_stack;
|
|
}
|
|
|
|
/*
|
|
* Allocate a return stack for the idle task. May be the first
|
|
* time through, or it may be done by CPU hotplug online.
|
|
*/
|
|
void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
|
|
{
|
|
t->curr_ret_stack = -1;
|
|
/*
|
|
* The idle task has no parent, it either has its own
|
|
* stack or no stack at all.
|
|
*/
|
|
if (t->ret_stack)
|
|
WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
|
|
|
|
if (ftrace_graph_active) {
|
|
struct ftrace_ret_stack *ret_stack;
|
|
|
|
ret_stack = per_cpu(idle_ret_stack, cpu);
|
|
if (!ret_stack) {
|
|
ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
|
|
* sizeof(struct ftrace_ret_stack),
|
|
GFP_KERNEL);
|
|
if (!ret_stack)
|
|
return;
|
|
per_cpu(idle_ret_stack, cpu) = ret_stack;
|
|
}
|
|
graph_init_task(t, ret_stack);
|
|
}
|
|
}
|
|
|
|
/* Allocate a return stack for newly created task */
|
|
void ftrace_graph_init_task(struct task_struct *t)
|
|
{
|
|
/* Make sure we do not use the parent ret_stack */
|
|
t->ret_stack = NULL;
|
|
t->curr_ret_stack = -1;
|
|
|
|
if (ftrace_graph_active) {
|
|
struct ftrace_ret_stack *ret_stack;
|
|
|
|
ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
|
|
* sizeof(struct ftrace_ret_stack),
|
|
GFP_KERNEL);
|
|
if (!ret_stack)
|
|
return;
|
|
graph_init_task(t, ret_stack);
|
|
}
|
|
}
|
|
|
|
void ftrace_graph_exit_task(struct task_struct *t)
|
|
{
|
|
struct ftrace_ret_stack *ret_stack = t->ret_stack;
|
|
|
|
t->ret_stack = NULL;
|
|
/* NULL must become visible to IRQs before we free it: */
|
|
barrier();
|
|
|
|
kfree(ret_stack);
|
|
}
|
|
|
|
void ftrace_graph_stop(void)
|
|
{
|
|
ftrace_stop();
|
|
}
|
|
#endif
|