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Tracing changes for v4.21: 

- Rework of the kprobe/uprobe and synthetic events to consolidate all
    the dynamic event code. This will make changes in the future easier.
 
  - Partial rewrite of the function graph tracing infrastructure.
    This will allow for multiple users of hooking onto functions
    to get the callback (return) of the function. This is the ground
    work for having kprobes and function graph tracer using one code base.
 
  - Clean up of the histogram code that will facilitate adding more
    features to the histograms in the future.
 
  - Addition of str_has_prefix() and a few use cases. There currently
    is a similar function strstart() that is used in a few places, but
    only returns a bool and not a length. These instances will be
    removed in the future to use str_has_prefix() instead.
 
  - A few other various clean ups as well.
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Merge tag 'trace-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - Rework of the kprobe/uprobe and synthetic events to consolidate all
   the dynamic event code. This will make changes in the future easier.

 - Partial rewrite of the function graph tracing infrastructure. This
   will allow for multiple users of hooking onto functions to get the
   callback (return) of the function. This is the ground work for having
   kprobes and function graph tracer using one code base.

 - Clean up of the histogram code that will facilitate adding more
   features to the histograms in the future.

 - Addition of str_has_prefix() and a few use cases. There currently is
   a similar function strstart() that is used in a few places, but only
   returns a bool and not a length. These instances will be removed in
   the future to use str_has_prefix() instead.

 - A few other various clean ups as well.

* tag 'trace-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (57 commits)
  tracing: Use the return of str_has_prefix() to remove open coded numbers
  tracing: Have the historgram use the result of str_has_prefix() for len of prefix
  tracing: Use str_has_prefix() instead of using fixed sizes
  tracing: Use str_has_prefix() helper for histogram code
  string.h: Add str_has_prefix() helper function
  tracing: Make function ‘ftrace_exports’ static
  tracing: Simplify printf'ing in seq_print_sym
  tracing: Avoid -Wformat-nonliteral warning
  tracing: Merge seq_print_sym_short() and seq_print_sym_offset()
  tracing: Add hist trigger comments for variable-related fields
  tracing: Remove hist trigger synth_var_refs
  tracing: Use hist trigger's var_ref array to destroy var_refs
  tracing: Remove open-coding of hist trigger var_ref management
  tracing: Use var_refs[] for hist trigger reference checking
  tracing: Change strlen to sizeof for hist trigger static strings
  tracing: Remove unnecessary hist trigger struct field
  tracing: Fix ftrace_graph_get_ret_stack() to use task and not current
  seq_buf: Use size_t for len in seq_buf_puts()
  seq_buf: Make seq_buf_puts() null-terminate the buffer
  arm64: Use ftrace_graph_get_ret_stack() instead of curr_ret_stack
  ...
hifive-unleashed-5.1
Linus Torvalds 2018-12-31 11:46:59 -08:00
parent f12e840c81 3d739c1f61
commit 495d714ad1
49 changed files with 2519 additions and 1669 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
Documentation/trace/kprobetrace.rst
View File

@ -20,6 +20,9 @@ current_tracer. Instead of that, add probe points via
/sys/kernel/debug/tracing/kprobe_events, and enable it via
/sys/kernel/debug/tracing/events/kprobes/<EVENT>/enable.
You can also use /sys/kernel/debug/tracing/dynamic_events instead of
kprobe_events. That interface will provide unified access to other
dynamic events too.
Synopsis of kprobe_events
-------------------------

4
Documentation/trace/uprobetracer.rst
View File

@ -18,6 +18,10 @@ current_tracer. Instead of that, add probe points via
However unlike kprobe-event tracer, the uprobe event interface expects the
user to calculate the offset of the probepoint in the object.
You can also use /sys/kernel/debug/tracing/dynamic_events instead of
uprobe_events. That interface will provide unified access to other
dynamic events too.
Synopsis of uprobe_tracer
-------------------------
::

1
arch/arm64/kernel/ftrace.c
View File

@ -193,6 +193,7 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
void arch_ftrace_update_code(int command)
{
command |= FTRACE_MAY_SLEEP;
ftrace_modify_all_code(command);
}

2
arch/arm64/kernel/perf_callchain.c
View File

@ -168,7 +168,7 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
frame.fp = regs->regs[29];
frame.pc = regs->pc;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
frame.graph = current->curr_ret_stack;
frame.graph = 0;
#endif
walk_stackframe(current, &frame, callchain_trace, entry);

2
arch/arm64/kernel/process.c
View File

@ -461,7 +461,7 @@ unsigned long get_wchan(struct task_struct *p)
frame.fp = thread_saved_fp(p);
frame.pc = thread_saved_pc(p);
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
frame.graph = p->curr_ret_stack;
frame.graph = 0;
#endif
do {
if (unwind_frame(p, &frame))

2
arch/arm64/kernel/return_address.c
View File

@ -44,7 +44,7 @@ void *return_address(unsigned int level)
frame.fp = (unsigned long)__builtin_frame_address(0);
frame.pc = (unsigned long)return_address; /* dummy */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
frame.graph = current->curr_ret_stack;
frame.graph = 0;
#endif
walk_stackframe(current, &frame, save_return_addr, &data);

15
arch/arm64/kernel/stacktrace.c
View File

@ -59,18 +59,17 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
if (tsk->ret_stack &&
(frame->pc == (unsigned long)return_to_handler)) {
if (WARN_ON_ONCE(frame->graph == -1))
return -EINVAL;
if (frame->graph < -1)
frame->graph += FTRACE_NOTRACE_DEPTH;
struct ftrace_ret_stack *ret_stack;
/*
* This is a case where function graph tracer has
* modified a return address (LR) in a stack frame
* to hook a function return.
* So replace it to an original value.
*/
frame->pc = tsk->ret_stack[frame->graph--].ret;
ret_stack = ftrace_graph_get_ret_stack(tsk, frame->graph++);
if (WARN_ON_ONCE(!ret_stack))
return -EINVAL;
frame->pc = ret_stack->ret;
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
@ -137,7 +136,7 @@ void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
frame.fp = regs->regs[29];
frame.pc = regs->pc;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
frame.graph = current->curr_ret_stack;
frame.graph = 0;
#endif
walk_stackframe(current, &frame, save_trace, &data);
@ -168,7 +167,7 @@ static noinline void __save_stack_trace(struct task_struct *tsk,
frame.pc = (unsigned long)__save_stack_trace;
}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
frame.graph = tsk->curr_ret_stack;
frame.graph = 0;
#endif
walk_stackframe(tsk, &frame, save_trace, &data);

2
arch/arm64/kernel/time.c
View File

@ -52,7 +52,7 @@ unsigned long profile_pc(struct pt_regs *regs)
frame.fp = regs->regs[29];
frame.pc = regs->pc;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
frame.graph = current->curr_ret_stack;
frame.graph = 0;
#endif
do {
int ret = unwind_frame(NULL, &frame);

2
arch/arm64/kernel/traps.c
View File

@ -123,7 +123,7 @@ void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
frame.pc = thread_saved_pc(tsk);
}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
frame.graph = tsk->curr_ret_stack;
frame.graph = 0;
#endif
skip = !!regs;

13
arch/powerpc/kernel/process.c
View File

@ -2061,9 +2061,10 @@ void show_stack(struct task_struct *tsk, unsigned long *stack)
int count = 0;
int firstframe = 1;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
int curr_frame = current->curr_ret_stack;
struct ftrace_ret_stack *ret_stack;
extern void return_to_handler(void);
unsigned long rth = (unsigned long)return_to_handler;
int curr_frame = 0;
#endif
sp = (unsigned long) stack;
@ -2089,9 +2090,13 @@ void show_stack(struct task_struct *tsk, unsigned long *stack)
printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip);
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
if ((ip == rth) && curr_frame >= 0) {
pr_cont(" (%pS)",
(void *)current->ret_stack[curr_frame].ret);
curr_frame--;
ret_stack = ftrace_graph_get_ret_stack(current,
curr_frame++);
if (ret_stack)
pr_cont(" (%pS)",
(void *)ret_stack->ret);
else
curr_frame = -1;
}
#endif
if (firstframe)

11
arch/sh/kernel/dumpstack.c
View File

@ -56,17 +56,20 @@ print_ftrace_graph_addr(unsigned long addr, void *data,
struct thread_info *tinfo, int *graph)
{
struct task_struct *task = tinfo->task;
struct ftrace_ret_stack *ret_stack;
unsigned long ret_addr;
int index = task->curr_ret_stack;
if (addr != (unsigned long)return_to_handler)
return;
if (!task->ret_stack || index < *graph)
if (!task->ret_stack)
return;
index -= *graph;
ret_addr = task->ret_stack[index].ret;
ret_stack = ftrace_graph_get_ret_stack(task, *graph);
if (!ret_stack)
return;
ret_addr = ret_stack->ret;
ops->address(data, ret_addr, 1);

9
arch/sh/kernel/dwarf.c
View File

@ -605,17 +605,18 @@ struct dwarf_frame *dwarf_unwind_stack(unsigned long pc,
* expected to find the real return address.
*/
if (pc == (unsigned long)&return_to_handler) {
int index = current->curr_ret_stack;
struct ftrace_ret_stack *ret_stack;
ret_stack = ftrace_graph_get_ret_stack(current, 0);
if (ret_stack)
pc = ret_stack->ret;
/*
* We currently have no way of tracking how many
* return_to_handler()'s we've seen. If there is more
* than one patched return address on our stack,
* complain loudly.
*/
WARN_ON(index > 0);
pc = current->ret_stack[index].ret;
WARN_ON(ftrace_graph_get_ret_stack(current, 1);
}
#endif

8
arch/sparc/kernel/perf_event.c
View File

@ -1767,9 +1767,11 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
perf_callchain_store(entry, pc);
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
if ((pc + 8UL) == (unsigned long) &return_to_handler) {
int index = current->curr_ret_stack;
if (current->ret_stack && index >= graph) {
pc = current->ret_stack[index - graph].ret;
struct ftrace_ret_stack *ret_stack;
ret_stack = ftrace_graph_get_ret_stack(current,
graph);
if (ret_stack) {
pc = ret_stack->ret;
perf_callchain_store(entry, pc);
graph++;
}

8
arch/sparc/kernel/stacktrace.c
View File

@ -57,9 +57,11 @@ static void __save_stack_trace(struct thread_info *tp,
trace->entries[trace->nr_entries++] = pc;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
if ((pc + 8UL) == (unsigned long) &return_to_handler) {
int index = t->curr_ret_stack;
if (t->ret_stack && index >= graph) {
pc = t->ret_stack[index - graph].ret;
struct ftrace_ret_stack *ret_stack;
ret_stack = ftrace_graph_get_ret_stack(t,
graph);
if (ret_stack) {
pc = ret_stack->ret;
if (trace->nr_entries <
trace->max_entries)
trace->entries[trace->nr_entries++] = pc;

7
arch/sparc/kernel/traps_64.c
View File

@ -2502,9 +2502,10 @@ void show_stack(struct task_struct *tsk, unsigned long *_ksp)
printk(" [%016lx] %pS\n", pc, (void *) pc);
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
if ((pc + 8UL) == (unsigned long) &return_to_handler) {
int index = tsk->curr_ret_stack;
if (tsk->ret_stack && index >= graph) {
pc = tsk->ret_stack[index - graph].ret;
struct ftrace_ret_stack *ret_stack;
ret_stack = ftrace_graph_get_ret_stack(tsk, graph);
if (ret_stack) {
pc = ret_stack->ret;
printk(" [%016lx] %pS\n", pc, (void *) pc);
graph++;
}

41
arch/x86/kernel/ftrace.c
View File

@ -733,18 +733,20 @@ union ftrace_op_code_union {
} __attribute__((packed));
};
#define RET_SIZE 1
static unsigned long
create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
{
unsigned const char *jmp;
unsigned long start_offset;
unsigned long end_offset;
unsigned long op_offset;
unsigned long offset;
unsigned long size;
unsigned long ip;
unsigned long retq;
unsigned long *ptr;
void *trampoline;
void *ip;
/* 48 8b 15 <offset> is movq <offset>(%rip), %rdx */
unsigned const char op_ref[] = { 0x48, 0x8b, 0x15 };
union ftrace_op_code_union op_ptr;
@ -764,27 +766,27 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
/*
* Allocate enough size to store the ftrace_caller code,
* the jmp to ftrace_epilogue, as well as the address of
* the ftrace_ops this trampoline is used for.
* the iret , as well as the address of the ftrace_ops this
* trampoline is used for.
*/
trampoline = alloc_tramp(size + MCOUNT_INSN_SIZE + sizeof(void *));
trampoline = alloc_tramp(size + RET_SIZE + sizeof(void *));
if (!trampoline)
return 0;
*tramp_size = size + MCOUNT_INSN_SIZE + sizeof(void *);
*tramp_size = size + RET_SIZE + sizeof(void *);
/* Copy ftrace_caller onto the trampoline memory */
ret = probe_kernel_read(trampoline, (void *)start_offset, size);
if (WARN_ON(ret < 0)) {
tramp_free(trampoline, *tramp_size);
return 0;
}
if (WARN_ON(ret < 0))
goto fail;
ip = (unsigned long)trampoline + size;
ip = trampoline + size;
/* The trampoline ends with a jmp to ftrace_epilogue */
jmp = ftrace_jmp_replace(ip, (unsigned long)ftrace_epilogue);
memcpy(trampoline + size, jmp, MCOUNT_INSN_SIZE);
/* The trampoline ends with ret(q) */
retq = (unsigned long)ftrace_stub;
ret = probe_kernel_read(ip, (void *)retq, RET_SIZE);
if (WARN_ON(ret < 0))
goto fail;
/*
* The address of the ftrace_ops that is used for this trampoline
@ -794,17 +796,15 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
* the global function_trace_op variable.
*/
ptr = (unsigned long *)(trampoline + size + MCOUNT_INSN_SIZE);
ptr = (unsigned long *)(trampoline + size + RET_SIZE);
*ptr = (unsigned long)ops;
op_offset -= start_offset;
memcpy(&op_ptr, trampoline + op_offset, OP_REF_SIZE);
/* Are we pointing to the reference? */
if (WARN_ON(memcmp(op_ptr.op, op_ref, 3) != 0)) {
tramp_free(trampoline, *tramp_size);
return 0;
}
if (WARN_ON(memcmp(op_ptr.op, op_ref, 3) != 0))
goto fail;
/* Load the contents of ptr into the callback parameter */
offset = (unsigned long)ptr;
@ -819,6 +819,9 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
ops->flags |= FTRACE_OPS_FL_ALLOC_TRAMP;
return (unsigned long)trampoline;
fail:
tramp_free(trampoline, *tramp_size);
return 0;
}
static unsigned long calc_trampoline_call_offset(bool save_regs)

8
arch/x86/kernel/ftrace_64.S
View File

@ -171,9 +171,6 @@ GLOBAL(ftrace_call)
restore_mcount_regs
/*
* The copied trampoline must call ftrace_epilogue as it
* still may need to call the function graph tracer.
*
* The code up to this label is copied into trampolines so
* think twice before adding any new code or changing the
* layout here.
@ -185,7 +182,10 @@ GLOBAL(ftrace_graph_call)
jmp ftrace_stub
#endif
/* This is weak to keep gas from relaxing the jumps */
/*
* This is weak to keep gas from relaxing the jumps.
* It is also used to copy the retq for trampolines.
*/
WEAK(ftrace_stub)
retq
ENDPROC(ftrace_caller)

36
include/linux/ftrace.h
View File

@ -389,6 +389,7 @@ enum {
FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
FTRACE_START_FUNC_RET = (1 << 3),
FTRACE_STOP_FUNC_RET = (1 << 4),
FTRACE_MAY_SLEEP = (1 << 5),
};
/*
@ -752,6 +753,11 @@ typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
struct fgraph_ops {
trace_func_graph_ent_t entryfunc;
trace_func_graph_ret_t retfunc;
};
/*
* Stack of return addresses for functions
* of a thread.
@ -783,6 +789,9 @@ extern int
function_graph_enter(unsigned long ret, unsigned long func,
unsigned long frame_pointer, unsigned long *retp);
struct ftrace_ret_stack *
ftrace_graph_get_ret_stack(struct task_struct *task, int idx);
unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
unsigned long ret, unsigned long *retp);
@ -793,11 +802,11 @@ unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
*/
#define __notrace_funcgraph notrace
#define FTRACE_NOTRACE_DEPTH 65536
#define FTRACE_RETFUNC_DEPTH 50
#define FTRACE_RETSTACK_ALLOC_SIZE 32
extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
trace_func_graph_ent_t entryfunc);
extern int register_ftrace_graph(struct fgraph_ops *ops);
extern void unregister_ftrace_graph(struct fgraph_ops *ops);
extern bool ftrace_graph_is_dead(void);
extern void ftrace_graph_stop(void);
@ -806,17 +815,10 @@ extern void ftrace_graph_stop(void);
extern trace_func_graph_ret_t ftrace_graph_return;
extern trace_func_graph_ent_t ftrace_graph_entry;
extern void unregister_ftrace_graph(void);
extern void ftrace_graph_init_task(struct task_struct *t);
extern void ftrace_graph_exit_task(struct task_struct *t);
extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
static inline int task_curr_ret_stack(struct task_struct *t)
{
return t->curr_ret_stack;
}
static inline void pause_graph_tracing(void)
{
atomic_inc(&current->tracing_graph_pause);
@ -834,17 +836,9 @@ static inline void ftrace_graph_init_task(struct task_struct *t) { }
static inline void ftrace_graph_exit_task(struct task_struct *t) { }
static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
trace_func_graph_ent_t entryfunc)
{
return -1;
}
static inline void unregister_ftrace_graph(void) { }
static inline int task_curr_ret_stack(struct task_struct *tsk)
{
return -1;
}
/* Define as macros as fgraph_ops may not be defined */
#define register_ftrace_graph(ops) ({ -1; })
#define unregister_ftrace_graph(ops) do { } while (0)
static inline unsigned long
ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret,

4
include/linux/ring_buffer.h
View File

@ -97,7 +97,7 @@ __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *k
__ring_buffer_alloc((size), (flags), &__key); \
})
int ring_buffer_wait(struct ring_buffer *buffer, int cpu, bool full);
int ring_buffer_wait(struct ring_buffer *buffer, int cpu, int full);
__poll_t ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu,
struct file *filp, poll_table *poll_table);
@ -189,6 +189,8 @@ bool ring_buffer_time_stamp_abs(struct ring_buffer *buffer);
size_t ring_buffer_page_len(void *page);
size_t ring_buffer_nr_pages(struct ring_buffer *buffer, int cpu);
size_t ring_buffer_nr_dirty_pages(struct ring_buffer *buffer, int cpu);
void *ring_buffer_alloc_read_page(struct ring_buffer *buffer, int cpu);
void ring_buffer_free_read_page(struct ring_buffer *buffer, int cpu, void *data);

20
include/linux/string.h
View File

@ -456,4 +456,24 @@ static inline void memcpy_and_pad(void *dest, size_t dest_len,
memcpy(dest, src, dest_len);
}
/**
* str_has_prefix - Test if a string has a given prefix
* @str: The string to test
* @prefix: The string to see if @str starts with
*
* A common way to test a prefix of a string is to do:
* strncmp(str, prefix, sizeof(prefix) - 1)
*
* But this can lead to bugs due to typos, or if prefix is a pointer
* and not a constant. Instead use str_has_prefix().
*
* Returns: 0 if @str does not start with @prefix
strlen(@prefix) if @str does start with @prefix
*/
static __always_inline size_t str_has_prefix(const char *str, const char *prefix)
{
size_t len = strlen(prefix);
return strncmp(str, prefix, len) == 0 ? len : 0;
}
#endif /* _LINUX_STRING_H_ */

6
kernel/trace/Kconfig
View File

@ -461,6 +461,7 @@ config KPROBE_EVENTS
bool "Enable kprobes-based dynamic events"
select TRACING
select PROBE_EVENTS
select DYNAMIC_EVENTS
default y
help
This allows the user to add tracing events (similar to tracepoints)
@ -500,6 +501,7 @@ config UPROBE_EVENTS
depends on PERF_EVENTS
select UPROBES
select PROBE_EVENTS
select DYNAMIC_EVENTS
select TRACING
default y
help
@ -518,6 +520,9 @@ config BPF_EVENTS
help
This allows the user to attach BPF programs to kprobe events.
config DYNAMIC_EVENTS
def_bool n
config PROBE_EVENTS
def_bool n
@ -630,6 +635,7 @@ config HIST_TRIGGERS
depends on ARCH_HAVE_NMI_SAFE_CMPXCHG
select TRACING_MAP
select TRACING
select DYNAMIC_EVENTS
default n
help
Hist triggers allow one or more arbitrary trace event fields

2
kernel/trace/Makefile
View File

@ -57,6 +57,7 @@ obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o
obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o
obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o
obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += fgraph.o
ifeq ($(CONFIG_BLOCK),y)
obj-$(CONFIG_EVENT_TRACING) += blktrace.o
endif
@ -78,6 +79,7 @@ endif
ifeq ($(CONFIG_TRACING),y)
obj-$(CONFIG_KGDB_KDB) += trace_kdb.o
endif
obj-$(CONFIG_DYNAMIC_EVENTS) += trace_dynevent.o
obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o
obj-$(CONFIG_UPROBE_EVENTS) += trace_uprobe.o

626
kernel/trace/fgraph.c 100644
View File

@ -0,0 +1,626 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Infrastructure to took into function calls and returns.
* Copyright (c) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com>
* Mostly borrowed from function tracer which
* is Copyright (c) Steven Rostedt <srostedt@redhat.com>
*
* Highly modified by Steven Rostedt (VMware).
*/
#include <linux/suspend.h>
#include <linux/ftrace.h>
#include <linux/slab.h>
#include <trace/events/sched.h>
#include "ftrace_internal.h"
#ifdef CONFIG_DYNAMIC_FTRACE
#define ASSIGN_OPS_HASH(opsname, val) \
.func_hash = val, \
.local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
#else
#define ASSIGN_OPS_HASH(opsname, val)
#endif
static bool kill_ftrace_graph;
int ftrace_graph_active;
/* Both enabled by default (can be cleared by function_graph tracer flags */
static bool fgraph_sleep_time = true;
/**
* ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called
*
* ftrace_graph_stop() is called when a severe error is detected in
* the function graph tracing. This function is called by the critical
* paths of function graph to keep those paths from doing any more harm.
*/
bool ftrace_graph_is_dead(void)
{
return kill_ftrace_graph;
}
/**
* ftrace_graph_stop - set to permanently disable function graph tracincg
*
* In case of an error int function graph tracing, this is called
* to try to keep function graph tracing from causing any more harm.
* Usually this is pretty severe and this is called to try to at least
* get a warning out to the user.
*/
void ftrace_graph_stop(void)
{
kill_ftrace_graph = true;
}
/* Add a function return address to the trace stack on thread info.*/
static int
ftrace_push_return_trace(unsigned long ret, unsigned long func,
unsigned long frame_pointer, unsigned long *retp)
{
unsigned long long calltime;
int index;
if (unlikely(ftrace_graph_is_dead()))
return -EBUSY;
if (!current->ret_stack)
return -EBUSY;
/*
* We must make sure the ret_stack is tested before we read
* anything else.
*/
smp_rmb();
/* The return trace stack is full */
if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
atomic_inc(&current->trace_overrun);
return -EBUSY;
}
calltime = trace_clock_local();
index = ++current->curr_ret_stack;
barrier();
current->ret_stack[index].ret = ret;
current->ret_stack[index].func = func;
current->ret_stack[index].calltime = calltime;
#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
current->ret_stack[index].fp = frame_pointer;
#endif
#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
current->ret_stack[index].retp = retp;
#endif
return 0;
}
int function_graph_enter(unsigned long ret, unsigned long func,
unsigned long frame_pointer, unsigned long *retp)
{
struct ftrace_graph_ent trace;
trace.func = func;
trace.depth = ++current->curr_ret_depth;
if (ftrace_push_return_trace(ret, func, frame_pointer, retp))
goto out;
/* Only trace if the calling function expects to */
if (!ftrace_graph_entry(&trace))
goto out_ret;
return 0;
out_ret:
current->curr_ret_stack--;
out:
current->curr_ret_depth--;
return -EBUSY;
}
/* Retrieve a function return address to the trace stack on thread info.*/
static void
ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
unsigned long frame_pointer)
{
int index;
index = current->curr_ret_stack;
if (unlikely(index < 0 || index >= FTRACE_RETFUNC_DEPTH)) {
ftrace_graph_stop();
WARN_ON(1);
/* Might as well panic, otherwise we have no where to go */
*ret = (unsigned long)panic;
return;
}
#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
/*
* The arch may choose to record the frame pointer used
* and check it here to make sure that it is what we expect it
* to be. If gcc does not set the place holder of the return
* address in the frame pointer, and does a copy instead, then
* the function graph trace will fail. This test detects this
* case.
*
* Currently, x86_32 with optimize for size (-Os) makes the latest
* gcc do the above.
*
* Note, -mfentry does not use frame pointers, and this test
* is not needed if CC_USING_FENTRY is set.
*/
if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
ftrace_graph_stop();
WARN(1, "Bad frame pointer: expected %lx, received %lx\n"
" from func %ps return to %lx\n",
current->ret_stack[index].fp,
frame_pointer,
(void *)current->ret_stack[index].func,
current->ret_stack[index].ret);
*ret = (unsigned long)panic;
return;
}
#endif
*ret = current->ret_stack[index].ret;
trace->func = current->ret_stack[index].func;
trace->calltime = current->ret_stack[index].calltime;
trace->overrun = atomic_read(&current->trace_overrun);
trace->depth = current->curr_ret_depth--;
/*
* We still want to trace interrupts coming in if
* max_depth is set to 1. Make sure the decrement is
* seen before ftrace_graph_return.
*/
barrier();
}
/*
* 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;
}
static struct notifier_block ftrace_suspend_notifier = {
.notifier_call = ftrace_suspend_notifier_call,
};
/*
* Send the trace to the ring-buffer.
* @return the original return address.
*/
unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
{
struct ftrace_graph_ret trace;
unsigned long ret;
ftrace_pop_return_trace(&trace, &ret, frame_pointer);
trace.rettime = trace_clock_local();
ftrace_graph_return(&trace);
/*
* The ftrace_graph_return() may still access the current
* ret_stack structure, we need to make sure the update of
* curr_ret_stack is after that.
*/
barrier();
current->curr_ret_stack--;
if (unlikely(!ret)) {
ftrace_graph_stop();
WARN_ON(1);
/* Might as well panic. What else to do? */
ret = (unsigned long)panic;
}
return ret;
}
/**
* ftrace_graph_get_ret_stack - return the entry of the shadow stack
* @task: The task to read the shadow stack from
* @idx: Index down the shadow stack
*
* Return the ret_struct on the shadow stack of the @task at the
* call graph at @idx starting with zero. If @idx is zero, it
* will return the last saved ret_stack entry. If it is greater than
* zero, it will return the corresponding ret_stack for the depth
* of saved return addresses.
*/
struct ftrace_ret_stack *
ftrace_graph_get_ret_stack(struct task_struct *task, int idx)
{
idx = task->curr_ret_stack - idx;
if (idx >= 0 && idx <= task->curr_ret_stack)
return &task->ret_stack[idx];
return NULL;
}
/**
* ftrace_graph_ret_addr - convert a potentially modified stack return address
* to its original value
*
* This function can be called by stack unwinding code to convert a found stack
* return address ('ret') to its original value, in case the function graph
* tracer has modified it to be 'return_to_handler'. If the address hasn't
* been modified, the unchanged value of 'ret' is returned.
*
* 'idx' is a state variable which should be initialized by the caller to zero
* before the first call.
*
* 'retp' is a pointer to the return address on the stack. It's ignored if
* the arch doesn't have HAVE_FUNCTION_GRAPH_RET_ADDR_PTR defined.
*/
#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
unsigned long ret, unsigned long *retp)
{
int index = task->curr_ret_stack;
int i;
if (ret != (unsigned long)return_to_handler)
return ret;
if (index < 0)
return ret;
for (i = 0; i <= index; i++)
if (task->ret_stack[i].retp == retp)
return task->ret_stack[i].ret;
return ret;
}
#else /* !HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */
unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
unsigned long ret, unsigned long *retp)
{
int task_idx;
if (ret != (unsigned long)return_to_handler)
return ret;
task_idx = task->curr_ret_stack;
if (!task->ret_stack || task_idx < *idx)
return ret;
task_idx -= *idx;
(*idx)++;
return task->ret_stack[task_idx].ret;
}
#endif /* HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */
static struct ftrace_ops graph_ops = {
.func = ftrace_stub,
.flags = FTRACE_OPS_FL_RECURSION_SAFE |
FTRACE_OPS_FL_INITIALIZED |
FTRACE_OPS_FL_PID |
FTRACE_OPS_FL_STUB,
#ifdef FTRACE_GRAPH_TRAMP_ADDR
.trampoline = FTRACE_GRAPH_TRAMP_ADDR,
/* trampoline_size is only needed for dynamically allocated tramps */
#endif
ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash)
};
void ftrace_graph_sleep_time_control(bool enable)
{
fgraph_sleep_time = enable;
}
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;
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_array(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(&tasklist_lock);
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;
t->curr_ret_depth = -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(&tasklist_lock);
free:
for (i = start; i < end; i++)
kfree(ret_stack_list[i]);
return ret;
}
static void
ftrace_graph_probe_sched_switch(void *ignore, bool preempt,
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 (fgraph_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;
}
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.
*/
void update_function_graph_func(void)
{
struct ftrace_ops *op;
bool do_test = false;
/*
* The graph and global ops share the same set of functions
* to test. If any other ops is on the list, then
* the graph tracing needs to test if its the function
* it should call.
*/
do_for_each_ftrace_op(op, ftrace_ops_list) {
if (op != &global_ops && op != &graph_ops &&
op != &ftrace_list_end) {
do_test = true;
/* in double loop, break out with goto */
goto out;
}
} while_for_each_ftrace_op(op);
out:
if (do_test)
ftrace_graph_entry = ftrace_graph_entry_test;
else
ftrace_graph_entry = __ftrace_graph_entry;
}
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;
t->curr_ret_depth = -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_array(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;
t->curr_ret_depth = -1;
if (ftrace_graph_active) {
struct ftrace_ret_stack *ret_stack;
ret_stack = kmalloc_array(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);
}
/* 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_array(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;
}
int register_ftrace_graph(struct fgraph_ops *gops)
{
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;
}
register_pm_notifier(&ftrace_suspend_notifier);
ftrace_graph_active++;
ret = start_graph_tracing();
if (ret) {
ftrace_graph_active--;
goto out;
}
ftrace_graph_return = gops->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 = gops->entryfunc;
ftrace_graph_entry = ftrace_graph_entry_test;
update_function_graph_func();
ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET);
out:
mutex_unlock(&ftrace_lock);
return ret;
}
void unregister_ftrace_graph(struct fgraph_ops *gops)
{
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(&graph_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);
}

490
kernel/trace/ftrace.c
View File

@ -19,7 +19,6 @@
#include <linux/sched/task.h>
#include <linux/kallsyms.h>
#include <linux/seq_file.h>
#include <linux/suspend.h>
#include <linux/tracefs.h>
#include <linux/hardirq.h>
#include <linux/kthread.h>
@ -40,6 +39,7 @@
#include <asm/sections.h>
#include <asm/setup.h>
#include "ftrace_internal.h"
#include "trace_output.h"
#include "trace_stat.h"
@ -77,7 +77,12 @@
#define ASSIGN_OPS_HASH(opsname, val)
#endif
static struct ftrace_ops ftrace_list_end __read_mostly = {
enum {
FTRACE_MODIFY_ENABLE_FL = (1 << 0),
FTRACE_MODIFY_MAY_SLEEP_FL = (1 << 1),
};
struct ftrace_ops ftrace_list_end __read_mostly = {
.func = ftrace_stub,
.flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB,
INIT_OPS_HASH(ftrace_list_end)
@ -112,11 +117,11 @@ static void ftrace_update_trampoline(struct ftrace_ops *ops);
*/
static int ftrace_disabled __read_mostly;
static DEFINE_MUTEX(ftrace_lock);
DEFINE_MUTEX(ftrace_lock);
static struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end;
struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end;
ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
static struct ftrace_ops global_ops;
struct ftrace_ops global_ops;
#if ARCH_SUPPORTS_FTRACE_OPS
static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
@ -127,26 +132,6 @@ static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
#define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
#endif
/*
* Traverse the ftrace_global_list, invoking all entries. The reason that we
* can use rcu_dereference_raw_notrace() is that elements removed from this list
* are simply leaked, so there is no need to interact with a grace-period
* mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
* concurrent insertions into the ftrace_global_list.
*
* Silly Alpha and silly pointer-speculation compiler optimizations!
*/
#define do_for_each_ftrace_op(op, list) \
op = rcu_dereference_raw_notrace(list); \
do
/*
* Optimized for just a single item in the list (as that is the normal case).
*/
#define while_for_each_ftrace_op(op) \
while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
unlikely((op) != &ftrace_list_end))
static inline void ftrace_ops_init(struct ftrace_ops *ops)
{
#ifdef CONFIG_DYNAMIC_FTRACE
@ -186,18 +171,6 @@ static void ftrace_sync_ipi(void *data)
smp_rmb();
}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static void update_function_graph_func(void);
/* Both enabled by default (can be cleared by function_graph tracer flags */
static bool fgraph_sleep_time = true;
static bool fgraph_graph_time = true;
#else
static inline void update_function_graph_func(void) { }
#endif
static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
{
/*
@ -334,7 +307,7 @@ static int remove_ftrace_ops(struct ftrace_ops __rcu **list,
static void ftrace_update_trampoline(struct ftrace_ops *ops);
static int __register_ftrace_function(struct ftrace_ops *ops)
int __register_ftrace_function(struct ftrace_ops *ops)
{
if (ops->flags & FTRACE_OPS_FL_DELETED)
return -EINVAL;
@ -375,7 +348,7 @@ static int __register_ftrace_function(struct ftrace_ops *ops)
return 0;
}
static int __unregister_ftrace_function(struct ftrace_ops *ops)
int __unregister_ftrace_function(struct ftrace_ops *ops)
{
int ret;
@ -815,9 +788,16 @@ function_profile_call(unsigned long ip, unsigned long parent_ip,
}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static bool fgraph_graph_time = true;
void ftrace_graph_graph_time_control(bool enable)
{
fgraph_graph_time = enable;
}
static int profile_graph_entry(struct ftrace_graph_ent *trace)
{
int index = current->curr_ret_stack;
struct ftrace_ret_stack *ret_stack;
function_profile_call(trace->func, 0, NULL, NULL);
@ -825,14 +805,16 @@ static int profile_graph_entry(struct ftrace_graph_ent *trace)
if (!current->ret_stack)
return 0;
if (index >= 0 && index < FTRACE_RETFUNC_DEPTH)
current->ret_stack[index].subtime = 0;
ret_stack = ftrace_graph_get_ret_stack(current, 0);
if (ret_stack)
ret_stack->subtime = 0;
return 1;
}
static void profile_graph_return(struct ftrace_graph_ret *trace)
{
struct ftrace_ret_stack *ret_stack;
struct ftrace_profile_stat *stat;
unsigned long long calltime;
struct ftrace_profile *rec;
@ -850,16 +832,15 @@ static void profile_graph_return(struct ftrace_graph_ret *trace)
calltime = trace->rettime - trace->calltime;
if (!fgraph_graph_time) {
int index;
index = current->curr_ret_stack;
/* Append this call time to the parent time to subtract */
if (index)
current->ret_stack[index - 1].subtime += calltime;
ret_stack = ftrace_graph_get_ret_stack(current, 1);
if (ret_stack)
ret_stack->subtime += calltime;
if (current->ret_stack[index].subtime < calltime)
calltime -= current->ret_stack[index].subtime;
ret_stack = ftrace_graph_get_ret_stack(current, 0);
if (ret_stack && ret_stack->subtime < calltime)
calltime -= ret_stack->subtime;
else
calltime = 0;
}
@ -874,15 +855,19 @@ static void profile_graph_return(struct ftrace_graph_ret *trace)
local_irq_restore(flags);
}
static struct fgraph_ops fprofiler_ops = {
.entryfunc = &profile_graph_entry,
.retfunc = &profile_graph_return,
};
static int register_ftrace_profiler(void)
{
return register_ftrace_graph(&profile_graph_return,
&profile_graph_entry);
return register_ftrace_graph(&fprofiler_ops);
}
static void unregister_ftrace_profiler(void)
{
unregister_ftrace_graph();
unregister_ftrace_graph(&fprofiler_ops);
}
#else
static struct ftrace_ops ftrace_profile_ops __read_mostly = {
@ -1021,12 +1006,6 @@ static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
}
#endif /* CONFIG_FUNCTION_PROFILER */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static int ftrace_graph_active;
#else
# define ftrace_graph_active 0
#endif
#ifdef CONFIG_DYNAMIC_FTRACE
static struct ftrace_ops *removed_ops;
@ -1067,7 +1046,7 @@ static const struct ftrace_hash empty_hash = {
};
#define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
static struct ftrace_ops global_ops = {
struct ftrace_ops global_ops = {
.func = ftrace_stub,
.local_hash.notrace_hash = EMPTY_HASH,
.local_hash.filter_hash = EMPTY_HASH,
@ -1503,7 +1482,7 @@ static bool hash_contains_ip(unsigned long ip,
* This needs to be called with preemption disabled as
* the hashes are freed with call_rcu().
*/
static int
int
ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
{
struct ftrace_ops_hash hash;
@ -2415,10 +2394,12 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
return -1; /* unknow ftrace bug */
}
void __weak ftrace_replace_code(int enable)
void __weak ftrace_replace_code(int mod_flags)
{
struct dyn_ftrace *rec;
struct ftrace_page *pg;
int enable = mod_flags & FTRACE_MODIFY_ENABLE_FL;
int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL;
int failed;
if (unlikely(ftrace_disabled))
@ -2435,6 +2416,8 @@ void __weak ftrace_replace_code(int enable)
/* Stop processing */
return;
}
if (schedulable)
cond_resched();
} while_for_each_ftrace_rec();
}
@ -2548,8 +2531,12 @@ int __weak ftrace_arch_code_modify_post_process(void)
void ftrace_modify_all_code(int command)
{
int update = command & FTRACE_UPDATE_TRACE_FUNC;
int mod_flags = 0;
int err = 0;
if (command & FTRACE_MAY_SLEEP)
mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL;
/*
* If the ftrace_caller calls a ftrace_ops func directly,
* we need to make sure that it only traces functions it
@ -2567,9 +2554,9 @@ void ftrace_modify_all_code(int command)
}
if (command & FTRACE_UPDATE_CALLS)
ftrace_replace_code(1);
ftrace_replace_code(mod_flags | FTRACE_MODIFY_ENABLE_FL);
else if (command & FTRACE_DISABLE_CALLS)
ftrace_replace_code(0);
ftrace_replace_code(mod_flags);
if (update && ftrace_trace_function != ftrace_ops_list_func) {
function_trace_op = set_function_trace_op;
@ -2682,7 +2669,7 @@ static void ftrace_startup_all(int command)
update_all_ops = false;
}
static int ftrace_startup(struct ftrace_ops *ops, int command)
int ftrace_startup(struct ftrace_ops *ops, int command)
{
int ret;
@ -2724,7 +2711,7 @@ static int ftrace_startup(struct ftrace_ops *ops, int command)
return 0;
}
static int ftrace_shutdown(struct ftrace_ops *ops, int command)
int ftrace_shutdown(struct ftrace_ops *ops, int command)
{
int ret;
@ -6178,7 +6165,7 @@ void ftrace_init_trace_array(struct trace_array *tr)
}
#else
static struct ftrace_ops global_ops = {
struct ftrace_ops global_ops = {
.func = ftrace_stub,
.flags = FTRACE_OPS_FL_RECURSION_SAFE |
FTRACE_OPS_FL_INITIALIZED |
@ -6195,31 +6182,10 @@ core_initcall(ftrace_nodyn_init);
static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
static inline void ftrace_startup_enable(int command) { }
static inline void ftrace_startup_all(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;
}
static void ftrace_update_trampoline(struct ftrace_ops *ops)
{
}
@ -6746,353 +6712,3 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
mutex_unlock(&ftrace_lock);
return ret;
}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static struct ftrace_ops graph_ops = {
.func = ftrace_stub,
.flags = FTRACE_OPS_FL_RECURSION_SAFE |
FTRACE_OPS_FL_INITIALIZED |
FTRACE_OPS_FL_PID |
FTRACE_OPS_FL_STUB,
#ifdef FTRACE_GRAPH_TRAMP_ADDR
.trampoline = FTRACE_GRAPH_TRAMP_ADDR,
/* trampoline_size is only needed for dynamically allocated tramps */
#endif
ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash)
};
void ftrace_graph_sleep_time_control(bool enable)
{
fgraph_sleep_time = enable;
}
void ftrace_graph_graph_time_control(bool enable)
{
fgraph_graph_time = enable;
}
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;
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_array(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(&tasklist_lock);
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;
t->curr_ret_depth = -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(&tasklist_lock);
free:
for (i = start; i < end; i++)
kfree(ret_stack_list[i]);
return ret;
}
static void
ftrace_graph_probe_sched_switch(void *ignore, bool preempt,
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 (fgraph_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_array(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;
}
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)
{
struct ftrace_ops *op;
bool do_test = false;
/*
* The graph and global ops share the same set of functions
* to test. If any other ops is on the list, then
* the graph tracing needs to test if its the function
* it should call.
*/
do_for_each_ftrace_op(op, ftrace_ops_list) {
if (op != &global_ops && op != &graph_ops &&
op != &ftrace_list_end) {
do_test = true;
/* in double loop, break out with goto */
goto out;
}
} while_for_each_ftrace_op(op);
out:
if (do_test)
ftrace_graph_entry = ftrace_graph_entry_test;
else
ftrace_graph_entry = __ftrace_graph_entry;
}
static struct notifier_block ftrace_suspend_notifier = {
.notifier_call = ftrace_suspend_notifier_call,
};
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;
}
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(&graph_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(&graph_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;
t->curr_ret_depth = -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_array(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;
t->curr_ret_depth = -1;
if (ftrace_graph_active) {
struct ftrace_ret_stack *ret_stack;
ret_stack = kmalloc_array(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);
}
#endif

75
kernel/trace/ftrace_internal.h 100644
View File

@ -0,0 +1,75 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_KERNEL_FTRACE_INTERNAL_H
#define _LINUX_KERNEL_FTRACE_INTERNAL_H
#ifdef CONFIG_FUNCTION_TRACER
/*
* Traverse the ftrace_global_list, invoking all entries. The reason that we
* can use rcu_dereference_raw_notrace() is that elements removed from this list
* are simply leaked, so there is no need to interact with a grace-period
* mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
* concurrent insertions into the ftrace_global_list.
*
* Silly Alpha and silly pointer-speculation compiler optimizations!
*/
#define do_for_each_ftrace_op(op, list) \
op = rcu_dereference_raw_notrace(list); \
do
/*
* Optimized for just a single item in the list (as that is the normal case).
*/
#define while_for_each_ftrace_op(op) \
while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
unlikely((op) != &ftrace_list_end))
extern struct ftrace_ops __rcu *ftrace_ops_list;
extern struct ftrace_ops ftrace_list_end;
extern struct mutex ftrace_lock;
extern struct ftrace_ops global_ops;
#ifdef CONFIG_DYNAMIC_FTRACE
int ftrace_startup(struct ftrace_ops *ops, int command);
int ftrace_shutdown(struct ftrace_ops *ops, int command);
int ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs);
#else /* !CONFIG_DYNAMIC_FTRACE */
int __register_ftrace_function(struct ftrace_ops *ops);
int __unregister_ftrace_function(struct ftrace_ops *ops);
/* 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; \
})
static inline int
ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
{
return 1;
}
#endif /* CONFIG_DYNAMIC_FTRACE */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
extern int ftrace_graph_active;
void update_function_graph_func(void);
#else /* !CONFIG_FUNCTION_GRAPH_TRACER */
# define ftrace_graph_active 0
static inline void update_function_graph_func(void) { }
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
#else /* !CONFIG_FUNCTION_TRACER */
#endif /* CONFIG_FUNCTION_TRACER */
#endif

94
kernel/trace/ring_buffer.c
View File

@ -487,6 +487,10 @@ struct ring_buffer_per_cpu {
local_t dropped_events;
local_t committing;
local_t commits;
local_t pages_touched;
local_t pages_read;
long last_pages_touch;
size_t shortest_full;
unsigned long read;
unsigned long read_bytes;
u64 write_stamp;
@ -529,6 +533,41 @@ struct ring_buffer_iter {
u64 read_stamp;
};
/**
* ring_buffer_nr_pages - get the number of buffer pages in the ring buffer
* @buffer: The ring_buffer to get the number of pages from
* @cpu: The cpu of the ring_buffer to get the number of pages from
*
* Returns the number of pages used by a per_cpu buffer of the ring buffer.
*/
size_t ring_buffer_nr_pages(struct ring_buffer *buffer, int cpu)
{
return buffer->buffers[cpu]->nr_pages;
}
/**
* ring_buffer_nr_pages_dirty - get the number of used pages in the ring buffer
* @buffer: The ring_buffer to get the number of pages from
* @cpu: The cpu of the ring_buffer to get the number of pages from
*
* Returns the number of pages that have content in the ring buffer.
*/
size_t ring_buffer_nr_dirty_pages(struct ring_buffer *buffer, int cpu)
{
size_t read;
size_t cnt;
read = local_read(&buffer->buffers[cpu]->pages_read);
cnt = local_read(&buffer->buffers[cpu]->pages_touched);
/* The reader can read an empty page, but not more than that */
if (cnt < read) {
WARN_ON_ONCE(read > cnt + 1);
return 0;
}
return cnt - read;
}
/*
* rb_wake_up_waiters - wake up tasks waiting for ring buffer input
*
@ -556,7 +595,7 @@ static void rb_wake_up_waiters(struct irq_work *work)
* as data is added to any of the @buffer's cpu buffers. Otherwise
* it will wait for data to be added to a specific cpu buffer.
*/
int ring_buffer_wait(struct ring_buffer *buffer, int cpu, bool full)
int ring_buffer_wait(struct ring_buffer *buffer, int cpu, int full)
{
struct ring_buffer_per_cpu *uninitialized_var(cpu_buffer);
DEFINE_WAIT(wait);
@ -571,7 +610,7 @@ int ring_buffer_wait(struct ring_buffer *buffer, int cpu, bool full)
if (cpu == RING_BUFFER_ALL_CPUS) {
work = &buffer->irq_work;
/* Full only makes sense on per cpu reads */
full = false;
full = 0;
} else {
if (!cpumask_test_cpu(cpu, buffer->cpumask))
return -ENODEV;
@ -623,15 +662,22 @@ int ring_buffer_wait(struct ring_buffer *buffer, int cpu, bool full)
!ring_buffer_empty_cpu(buffer, cpu)) {
unsigned long flags;
bool pagebusy;
size_t nr_pages;
size_t dirty;
if (!full)
break;
raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
pagebusy = cpu_buffer->reader_page == cpu_buffer->commit_page;
nr_pages = cpu_buffer->nr_pages;
dirty = ring_buffer_nr_dirty_pages(buffer, cpu);
if (!cpu_buffer->shortest_full ||
cpu_buffer->shortest_full < full)
cpu_buffer->shortest_full = full;
raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
if (!pagebusy)
if (!pagebusy &&
(!nr_pages || (dirty * 100) > full * nr_pages))
break;
}
@ -1054,6 +1100,7 @@ static void rb_tail_page_update(struct ring_buffer_per_cpu *cpu_buffer,
old_write = local_add_return(RB_WRITE_INTCNT, &next_page->write);
old_entries = local_add_return(RB_WRITE_INTCNT, &next_page->entries);
local_inc(&cpu_buffer->pages_touched);
/*
* Just make sure we have seen our old_write and synchronize
* with any interrupts that come in.
@ -2586,7 +2633,9 @@ static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer,
static __always_inline void
rb_wakeups(struct ring_buffer *buffer, struct ring_buffer_per_cpu *cpu_buffer)
{
bool pagebusy;
size_t nr_pages;
size_t dirty;
size_t full;
if (buffer->irq_work.waiters_pending) {
buffer->irq_work.waiters_pending = false;
@ -2600,14 +2649,27 @@ rb_wakeups(struct ring_buffer *buffer, struct ring_buffer_per_cpu *cpu_buffer)
irq_work_queue(&cpu_buffer->irq_work.work);
}
pagebusy = cpu_buffer->reader_page == cpu_buffer->commit_page;
if (cpu_buffer->last_pages_touch == local_read(&cpu_buffer->pages_touched))
return;
if (!pagebusy && cpu_buffer->irq_work.full_waiters_pending) {
cpu_buffer->irq_work.wakeup_full = true;
cpu_buffer->irq_work.full_waiters_pending = false;
/* irq_work_queue() supplies it's own memory barriers */
irq_work_queue(&cpu_buffer->irq_work.work);
}
if (cpu_buffer->reader_page == cpu_buffer->commit_page)
return;
if (!cpu_buffer->irq_work.full_waiters_pending)
return;
cpu_buffer->last_pages_touch = local_read(&cpu_buffer->pages_touched);
full = cpu_buffer->shortest_full;
nr_pages = cpu_buffer->nr_pages;
dirty = ring_buffer_nr_dirty_pages(buffer, cpu_buffer->cpu);
if (full && nr_pages && (dirty * 100) <= full * nr_pages)
return;
cpu_buffer->irq_work.wakeup_full = true;
cpu_buffer->irq_work.full_waiters_pending = false;
/* irq_work_queue() supplies it's own memory barriers */
irq_work_queue(&cpu_buffer->irq_work.work);
}
/*
@ -3732,13 +3794,15 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
goto spin;
/*
* Yeah! We succeeded in replacing the page.
* Yay! We succeeded in replacing the page.
*
* Now make the new head point back to the reader page.
*/
rb_list_head(reader->list.next)->prev = &cpu_buffer->reader_page->list;
rb_inc_page(cpu_buffer, &cpu_buffer->head_page);
local_inc(&cpu_buffer->pages_read);
/* Finally update the reader page to the new head */
cpu_buffer->reader_page = reader;
cpu_buffer->reader_page->read = 0;
@ -4334,6 +4398,10 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
local_set(&cpu_buffer->entries, 0);
local_set(&cpu_buffer->committing, 0);
local_set(&cpu_buffer->commits, 0);
local_set(&cpu_buffer->pages_touched, 0);
local_set(&cpu_buffer->pages_read, 0);
cpu_buffer->last_pages_touch = 0;
cpu_buffer->shortest_full = 0;
cpu_buffer->read = 0;
cpu_buffer->read_bytes = 0;

82
kernel/trace/trace.c
View File

@ -1431,7 +1431,7 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
}
#endif /* CONFIG_TRACER_MAX_TRACE */
static int wait_on_pipe(struct trace_iterator *iter, bool full)
static int wait_on_pipe(struct trace_iterator *iter, int full)
{
/* Iterators are static, they should be filled or empty */
if (trace_buffer_iter(iter, iter->cpu_file))
@ -2452,7 +2452,7 @@ static inline void ftrace_exports_disable(void)
static_branch_disable(&ftrace_exports_enabled);
}
void ftrace_exports(struct ring_buffer_event *event)
static void ftrace_exports(struct ring_buffer_event *event)
{
struct trace_export *export;
@ -4408,13 +4408,15 @@ static int trace_set_options(struct trace_array *tr, char *option)
int neg = 0;
int ret;
size_t orig_len = strlen(option);
int len;
cmp = strstrip(option);
if (strncmp(cmp, "no", 2) == 0) {
len = str_has_prefix(cmp, "no");
if (len)
neg = 1;
cmp += 2;
}
cmp += len;
mutex_lock(&trace_types_lock);
@ -4604,6 +4606,10 @@ static const char readme_msg[] =
"\t\t\t traces\n"
#endif
#endif /* CONFIG_STACK_TRACER */
#ifdef CONFIG_DYNAMIC_EVENTS
" dynamic_events\t\t- Add/remove/show the generic dynamic events\n"
"\t\t\t Write into this file to define/undefine new trace events.\n"
#endif
#ifdef CONFIG_KPROBE_EVENTS
" kprobe_events\t\t- Add/remove/show the kernel dynamic events\n"
"\t\t\t Write into this file to define/undefine new trace events.\n"
@ -4616,6 +4622,9 @@ static const char readme_msg[] =
"\t accepts: event-definitions (one definition per line)\n"
"\t Format: p[:[<group>/]<event>] <place> [<args>]\n"
"\t r[maxactive][:[<group>/]<event>] <place> [<args>]\n"
#ifdef CONFIG_HIST_TRIGGERS
"\t s:[synthetic/]<event> <field> [<field>]\n"
#endif
"\t -:[<group>/]<event>\n"
#ifdef CONFIG_KPROBE_EVENTS
"\t place: [<module>:]<symbol>[+<offset>]|<memaddr>\n"
@ -4634,6 +4643,11 @@ static const char readme_msg[] =
"\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n"
"\t b<bit-width>@<bit-offset>/<container-size>,\n"
"\t <type>\\[<array-size>\\]\n"
#ifdef CONFIG_HIST_TRIGGERS
"\t field: <stype> <name>;\n"
"\t stype: u8/u16/u32/u64, s8/s16/s32/s64, pid_t,\n"
"\t [unsigned] char/int/long\n"
#endif
#endif
" events/\t\t- Directory containing all trace event subsystems:\n"
" enable\t\t- Write 0/1 to enable/disable tracing of all events\n"
@ -5693,7 +5707,7 @@ static int tracing_wait_pipe(struct file *filp)
mutex_unlock(&iter->mutex);
ret = wait_on_pipe(iter, false);
ret = wait_on_pipe(iter, 0);
mutex_lock(&iter->mutex);
@ -6751,7 +6765,7 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
if ((filp->f_flags & O_NONBLOCK))
return -EAGAIN;
ret = wait_on_pipe(iter, false);
ret = wait_on_pipe(iter, 0);
if (ret)
return ret;
@ -6948,7 +6962,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK))
goto out;
ret = wait_on_pipe(iter, true);
ret = wait_on_pipe(iter, iter->tr->buffer_percent);
if (ret)
goto out;
@ -7662,6 +7676,53 @@ static const struct file_operations rb_simple_fops = {
.llseek = default_llseek,
};
static ssize_t
buffer_percent_read(struct file *filp, char __user *ubuf,
size_t cnt, loff_t *ppos)
{
struct trace_array *tr = filp->private_data;
char buf[64];
int r;
r = tr->buffer_percent;
r = sprintf(buf, "%d\n", r);
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}
static ssize_t
buffer_percent_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
struct trace_array *tr = filp->private_data;
unsigned long val;
int ret;
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
if (ret)
return ret;
if (val > 100)
return -EINVAL;
if (!val)
val = 1;
tr->buffer_percent = val;
(*ppos)++;
return cnt;
}
static const struct file_operations buffer_percent_fops = {
.open = tracing_open_generic_tr,
.read = buffer_percent_read,
.write = buffer_percent_write,
.release = tracing_release_generic_tr,
.llseek = default_llseek,
};
struct dentry *trace_instance_dir;
static void
@ -7970,6 +8031,11 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
trace_create_file("timestamp_mode", 0444, d_tracer, tr,
&trace_time_stamp_mode_fops);
tr->buffer_percent = 50;
trace_create_file("buffer_percent", 0444, d_tracer,
tr, &buffer_percent_fops);
create_trace_options_dir(tr);
#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)

13
kernel/trace/trace.h
View File

@ -247,6 +247,7 @@ struct trace_array {
int clock_id;
int nr_topts;
bool clear_trace;
int buffer_percent;
struct tracer *current_trace;
unsigned int trace_flags;
unsigned char trace_flags_index[TRACE_FLAGS_MAX_SIZE];
@ -534,6 +535,13 @@ enum {
TRACE_GRAPH_DEPTH_START_BIT,
TRACE_GRAPH_DEPTH_END_BIT,
/*
* To implement set_graph_notrace, if this bit is set, we ignore
* function graph tracing of called functions, until the return
* function is called to clear it.
*/
TRACE_GRAPH_NOTRACE_BIT,
};
#define trace_recursion_set(bit) do { (current)->trace_recursion |= (1<<(bit)); } while (0)
@ -855,7 +863,12 @@ static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
#define TRACE_GRAPH_PRINT_FILL_MASK (0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
extern void ftrace_graph_sleep_time_control(bool enable);
#ifdef CONFIG_FUNCTION_PROFILER
extern void ftrace_graph_graph_time_control(bool enable);
#else
static inline void ftrace_graph_graph_time_control(bool enable) { }
#endif
extern enum print_line_t
print_graph_function_flags(struct trace_iterator *iter, u32 flags);

217
kernel/trace/trace_dynevent.c 100644
View File

@ -0,0 +1,217 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Generic dynamic event control interface
*
* Copyright (C) 2018 Masami Hiramatsu <mhiramat@kernel.org>
*/
#include <linux/debugfs.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/mutex.h>
#include <linux/tracefs.h>
#include "trace.h"
#include "trace_dynevent.h"
static DEFINE_MUTEX(dyn_event_ops_mutex);
static LIST_HEAD(dyn_event_ops_list);
int dyn_event_register(struct dyn_event_operations *ops)
{
if (!ops || !ops->create || !ops->show || !ops->is_busy ||
!ops->free || !ops->match)
return -EINVAL;
INIT_LIST_HEAD(&ops->list);
mutex_lock(&dyn_event_ops_mutex);
list_add_tail(&ops->list, &dyn_event_ops_list);
mutex_unlock(&dyn_event_ops_mutex);
return 0;
}
int dyn_event_release(int argc, char **argv, struct dyn_event_operations *type)
{
struct dyn_event *pos, *n;
char *system = NULL, *event, *p;
int ret = -ENOENT;
if (argv[0][0] == '-') {
if (argv[0][1] != ':')
return -EINVAL;
event = &argv[0][2];
} else {
event = strchr(argv[0], ':');
if (!event)
return -EINVAL;
event++;
}
p = strchr(event, '/');
if (p) {
system = event;
event = p + 1;
*p = '\0';
}
if (event[0] == '\0')
return -EINVAL;
mutex_lock(&event_mutex);
for_each_dyn_event_safe(pos, n) {
if (type && type != pos->ops)
continue;
if (pos->ops->match(system, event, pos)) {
ret = pos->ops->free(pos);
break;
}
}
mutex_unlock(&event_mutex);
return ret;
}
static int create_dyn_event(int argc, char **argv)
{
struct dyn_event_operations *ops;
int ret;
if (argv[0][0] == '-' || argv[0][0] == '!')
return dyn_event_release(argc, argv, NULL);
mutex_lock(&dyn_event_ops_mutex);
list_for_each_entry(ops, &dyn_event_ops_list, list) {
ret = ops->create(argc, (const char **)argv);
if (!ret || ret != -ECANCELED)
break;
}
mutex_unlock(&dyn_event_ops_mutex);
if (ret == -ECANCELED)
ret = -EINVAL;
return ret;
}
/* Protected by event_mutex */
LIST_HEAD(dyn_event_list);
void *dyn_event_seq_start(struct seq_file *m, loff_t *pos)
{
mutex_lock(&event_mutex);
return seq_list_start(&dyn_event_list, *pos);
}
void *dyn_event_seq_next(struct seq_file *m, void *v, loff_t *pos)
{
return seq_list_next(v, &dyn_event_list, pos);
}
void dyn_event_seq_stop(struct seq_file *m, void *v)
{
mutex_unlock(&event_mutex);
}
static int dyn_event_seq_show(struct seq_file *m, void *v)
{
struct dyn_event *ev = v;
if (ev && ev->ops)
return ev->ops->show(m, ev);
return 0;
}
static const struct seq_operations dyn_event_seq_op = {
.start = dyn_event_seq_start,
.next = dyn_event_seq_next,
.stop = dyn_event_seq_stop,
.show = dyn_event_seq_show
};
/*
* dyn_events_release_all - Release all specific events
* @type: the dyn_event_operations * which filters releasing events
*
* This releases all events which ->ops matches @type. If @type is NULL,
* all events are released.
* Return -EBUSY if any of them are in use, and return other errors when
* it failed to free the given event. Except for -EBUSY, event releasing
* process will be aborted at that point and there may be some other
* releasable events on the list.
*/
int dyn_events_release_all(struct dyn_event_operations *type)
{
struct dyn_event *ev, *tmp;
int ret = 0;
mutex_lock(&event_mutex);
for_each_dyn_event(ev) {
if (type && ev->ops != type)
continue;
if (ev->ops->is_busy(ev)) {
ret = -EBUSY;
goto out;
}
}
for_each_dyn_event_safe(ev, tmp) {
if (type && ev->ops != type)
continue;
ret = ev->ops->free(ev);
if (ret)
break;
}
out:
mutex_unlock(&event_mutex);
return ret;
}
static int dyn_event_open(struct inode *inode, struct file *file)
{
int ret;
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
ret = dyn_events_release_all(NULL);
if (ret < 0)
return ret;
}
return seq_open(file, &dyn_event_seq_op);
}
static ssize_t dyn_event_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos)
{
return trace_parse_run_command(file, buffer, count, ppos,
create_dyn_event);
}
static const struct file_operations dynamic_events_ops = {
.owner = THIS_MODULE,
.open = dyn_event_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
.write = dyn_event_write,
};
/* Make a tracefs interface for controlling dynamic events */
static __init int init_dynamic_event(void)
{
struct dentry *d_tracer;
struct dentry *entry;
d_tracer = tracing_init_dentry();
if (IS_ERR(d_tracer))
return 0;
entry = tracefs_create_file("dynamic_events", 0644, d_tracer,
NULL, &dynamic_events_ops);
/* Event list interface */
if (!entry)
pr_warn("Could not create tracefs 'dynamic_events' entry\n");
return 0;
}
fs_initcall(init_dynamic_event);

119
kernel/trace/trace_dynevent.h 100644
View File

@ -0,0 +1,119 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Common header file for generic dynamic events.
*/
#ifndef _TRACE_DYNEVENT_H
#define _TRACE_DYNEVENT_H
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/seq_file.h>
#include "trace.h"
struct dyn_event;
/**
* struct dyn_event_operations - Methods for each type of dynamic events
*
* These methods must be set for each type, since there is no default method.
* Before using this for dyn_event_init(), it must be registered by
* dyn_event_register().
*
* @create: Parse and create event method. This is invoked when user passes
* a event definition to dynamic_events interface. This must not destruct
* the arguments and return -ECANCELED if given arguments doesn't match its
* command prefix.
* @show: Showing method. This is invoked when user reads the event definitions
* via dynamic_events interface.
* @is_busy: Check whether given event is busy so that it can not be deleted.
* Return true if it is busy, otherwides false.
* @free: Delete the given event. Return 0 if success, otherwides error.
* @match: Check whether given event and system name match this event.
* Return true if it matches, otherwides false.
*
* Except for @create, these methods are called under holding event_mutex.
*/
struct dyn_event_operations {
struct list_head list;
int (*create)(int argc, const char *argv[]);
int (*show)(struct seq_file *m, struct dyn_event *ev);
bool (*is_busy)(struct dyn_event *ev);
int (*free)(struct dyn_event *ev);
bool (*match)(const char *system, const char *event,
struct dyn_event *ev);
};
/* Register new dyn_event type -- must be called at first */
int dyn_event_register(struct dyn_event_operations *ops);
/**
* struct dyn_event - Dynamic event list header
*
* The dyn_event structure encapsulates a list and a pointer to the operators
* for making a global list of dynamic events.
* User must includes this in each event structure, so that those events can
* be added/removed via dynamic_events interface.
*/
struct dyn_event {
struct list_head list;
struct dyn_event_operations *ops;
};
extern struct list_head dyn_event_list;
static inline
int dyn_event_init(struct dyn_event *ev, struct dyn_event_operations *ops)
{
if (!ev || !ops)
return -EINVAL;
INIT_LIST_HEAD(&ev->list);
ev->ops = ops;
return 0;
}
static inline int dyn_event_add(struct dyn_event *ev)
{
lockdep_assert_held(&event_mutex);
if (!ev || !ev->ops)
return -EINVAL;
list_add_tail(&ev->list, &dyn_event_list);
return 0;
}
static inline void dyn_event_remove(struct dyn_event *ev)
{
lockdep_assert_held(&event_mutex);
list_del_init(&ev->list);
}
void *dyn_event_seq_start(struct seq_file *m, loff_t *pos);
void *dyn_event_seq_next(struct seq_file *m, void *v, loff_t *pos);
void dyn_event_seq_stop(struct seq_file *m, void *v);
int dyn_events_release_all(struct dyn_event_operations *type);
int dyn_event_release(int argc, char **argv, struct dyn_event_operations *type);
/*
* for_each_dyn_event - iterate over the dyn_event list
* @pos: the struct dyn_event * to use as a loop cursor
*
* This is just a basement of for_each macro. Wrap this for
* each actual event structure with ops filtering.
*/
#define for_each_dyn_event(pos) \
list_for_each_entry(pos, &dyn_event_list, list)
/*
* for_each_dyn_event - iterate over the dyn_event list safely
* @pos: the struct dyn_event * to use as a loop cursor
* @n: the struct dyn_event * to use as temporary storage
*/
#define for_each_dyn_event_safe(pos, n) \
list_for_each_entry_safe(pos, n, &dyn_event_list, list)
#endif

10
kernel/trace/trace_events.c
View File

@ -1251,7 +1251,7 @@ static int f_show(struct seq_file *m, void *v)
*/
array_descriptor = strchr(field->type, '[');
if (!strncmp(field->type, "__data_loc", 10))
if (str_has_prefix(field->type, "__data_loc"))
array_descriptor = NULL;
if (!array_descriptor)
@ -2309,7 +2309,8 @@ static void __add_event_to_tracers(struct trace_event_call *call);
int trace_add_event_call(struct trace_event_call *call)
{
int ret;
mutex_lock(&event_mutex);
lockdep_assert_held(&event_mutex);
mutex_lock(&trace_types_lock);
ret = __register_event(call, NULL);
@ -2317,7 +2318,6 @@ int trace_add_event_call(struct trace_event_call *call)
__add_event_to_tracers(call);
mutex_unlock(&trace_types_lock);
mutex_unlock(&event_mutex);
return ret;
}
@ -2371,13 +2371,13 @@ int trace_remove_event_call(struct trace_event_call *call)
{
int ret;
mutex_lock(&event_mutex);
lockdep_assert_held(&event_mutex);
mutex_lock(&trace_types_lock);
down_write(&trace_event_sem);
ret = probe_remove_event_call(call);
up_write(&trace_event_sem);
mutex_unlock(&trace_types_lock);
mutex_unlock(&event_mutex);
return ret;
}

629
kernel/trace/trace_events_hist.c
View File

File diff suppressed because it is too large Load Diff

334
kernel/trace/trace_functions_graph.c
View File

@ -16,33 +16,6 @@
#include "trace.h"
#include "trace_output.h"
static bool kill_ftrace_graph;
/**
* ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called
*
* ftrace_graph_stop() is called when a severe error is detected in
* the function graph tracing. This function is called by the critical
* paths of function graph to keep those paths from doing any more harm.
*/
bool ftrace_graph_is_dead(void)
{
return kill_ftrace_graph;
}
/**
* ftrace_graph_stop - set to permanently disable function graph tracincg
*
* In case of an error int function graph tracing, this is called
* to try to keep function graph tracing from causing any more harm.
* Usually this is pretty severe and this is called to try to at least
* get a warning out to the user.
*/
void ftrace_graph_stop(void)
{
kill_ftrace_graph = true;
}
/* When set, irq functions will be ignored */
static int ftrace_graph_skip_irqs;
@ -87,8 +60,12 @@ static struct tracer_opt trace_opts[] = {
{ TRACER_OPT(funcgraph-tail, TRACE_GRAPH_PRINT_TAIL) },
/* Include sleep time (scheduled out) between entry and return */
{ TRACER_OPT(sleep-time, TRACE_GRAPH_SLEEP_TIME) },
#ifdef CONFIG_FUNCTION_PROFILER
/* Include time within nested functions */
{ TRACER_OPT(graph-time, TRACE_GRAPH_GRAPH_TIME) },
#endif
{ } /* Empty entry */
};
@ -117,258 +94,6 @@ static void
print_graph_duration(struct trace_array *tr, unsigned long long duration,
struct trace_seq *s, u32 flags);
/* Add a function return address to the trace stack on thread info.*/
static int
ftrace_push_return_trace(unsigned long ret, unsigned long func,
unsigned long frame_pointer, unsigned long *retp)
{
unsigned long long calltime;
int index;
if (unlikely(ftrace_graph_is_dead()))
return -EBUSY;
if (!current->ret_stack)
return -EBUSY;
/*
* We must make sure the ret_stack is tested before we read
* anything else.
*/
smp_rmb();
/* The return trace stack is full */
if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
atomic_inc(&current->trace_overrun);
return -EBUSY;
}
/*
* The curr_ret_stack is an index to ftrace return stack of
* current task. Its value should be in [0, FTRACE_RETFUNC_
* DEPTH) when the function graph tracer is used. To support
* filtering out specific functions, it makes the index
* negative by subtracting huge value (FTRACE_NOTRACE_DEPTH)
* so when it sees a negative index the ftrace will ignore
* the record. And the index gets recovered when returning
* from the filtered function by adding the FTRACE_NOTRACE_
* DEPTH and then it'll continue to record functions normally.
*
* The curr_ret_stack is initialized to -1 and get increased
* in this function. So it can be less than -1 only if it was
* filtered out via ftrace_graph_notrace_addr() which can be
* set from set_graph_notrace file in tracefs by user.
*/
if (current->curr_ret_stack < -1)
return -EBUSY;
calltime = trace_clock_local();
index = ++current->curr_ret_stack;
if (ftrace_graph_notrace_addr(func))
current->curr_ret_stack -= FTRACE_NOTRACE_DEPTH;
barrier();
current->ret_stack[index].ret = ret;
current->ret_stack[index].func = func;
current->ret_stack[index].calltime = calltime;
#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
current->ret_stack[index].fp = frame_pointer;
#endif
#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
current->ret_stack[index].retp = retp;
#endif
return 0;
}
int function_graph_enter(unsigned long ret, unsigned long func,
unsigned long frame_pointer, unsigned long *retp)
{
struct ftrace_graph_ent trace;
trace.func = func;
trace.depth = ++current->curr_ret_depth;
if (ftrace_push_return_trace(ret, func,
frame_pointer, retp))
goto out;
/* Only trace if the calling function expects to */
if (!ftrace_graph_entry(&trace))
goto out_ret;
return 0;
out_ret:
current->curr_ret_stack--;
out:
current->curr_ret_depth--;
return -EBUSY;
}
/* Retrieve a function return address to the trace stack on thread info.*/
static void
ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
unsigned long frame_pointer)
{
int index;
index = current->curr_ret_stack;
/*
* A negative index here means that it's just returned from a
* notrace'd function. Recover index to get an original
* return address. See ftrace_push_return_trace().
*
* TODO: Need to check whether the stack gets corrupted.
*/
if (index < 0)
index += FTRACE_NOTRACE_DEPTH;
if (unlikely(index < 0 || index >= FTRACE_RETFUNC_DEPTH)) {
ftrace_graph_stop();
WARN_ON(1);
/* Might as well panic, otherwise we have no where to go */
*ret = (unsigned long)panic;
return;
}
#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
/*
* The arch may choose to record the frame pointer used
* and check it here to make sure that it is what we expect it
* to be. If gcc does not set the place holder of the return
* address in the frame pointer, and does a copy instead, then
* the function graph trace will fail. This test detects this
* case.
*
* Currently, x86_32 with optimize for size (-Os) makes the latest
* gcc do the above.
*
* Note, -mfentry does not use frame pointers, and this test
* is not needed if CC_USING_FENTRY is set.
*/
if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
ftrace_graph_stop();
WARN(1, "Bad frame pointer: expected %lx, received %lx\n"
" from func %ps return to %lx\n",
current->ret_stack[index].fp,
frame_pointer,
(void *)current->ret_stack[index].func,
current->ret_stack[index].ret);
*ret = (unsigned long)panic;
return;
}
#endif
*ret = current->ret_stack[index].ret;
trace->func = current->ret_stack[index].func;
trace->calltime = current->ret_stack[index].calltime;
trace->overrun = atomic_read(&current->trace_overrun);
trace->depth = current->curr_ret_depth--;
/*
* We still want to trace interrupts coming in if
* max_depth is set to 1. Make sure the decrement is
* seen before ftrace_graph_return.
*/
barrier();
}
/*
* Send the trace to the ring-buffer.
* @return the original return address.
*/
unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
{
struct ftrace_graph_ret trace;
unsigned long ret;
ftrace_pop_return_trace(&trace, &ret, frame_pointer);
trace.rettime = trace_clock_local();
ftrace_graph_return(&trace);
/*
* The ftrace_graph_return() may still access the current
* ret_stack structure, we need to make sure the update of
* curr_ret_stack is after that.
*/
barrier();
current->curr_ret_stack--;
/*
* The curr_ret_stack can be less than -1 only if it was
* filtered out and it's about to return from the function.
* Recover the index and continue to trace normal functions.
*/
if (current->curr_ret_stack < -1) {
current->curr_ret_stack += FTRACE_NOTRACE_DEPTH;
return ret;
}
if (unlikely(!ret)) {
ftrace_graph_stop();
WARN_ON(1);
/* Might as well panic. What else to do? */
ret = (unsigned long)panic;
}
return ret;
}
/**
* ftrace_graph_ret_addr - convert a potentially modified stack return address
* to its original value
*
* This function can be called by stack unwinding code to convert a found stack
* return address ('ret') to its original value, in case the function graph
* tracer has modified it to be 'return_to_handler'. If the address hasn't
* been modified, the unchanged value of 'ret' is returned.
*
* 'idx' is a state variable which should be initialized by the caller to zero
* before the first call.
*
* 'retp' is a pointer to the return address on the stack. It's ignored if
* the arch doesn't have HAVE_FUNCTION_GRAPH_RET_ADDR_PTR defined.
*/
#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
unsigned long ret, unsigned long *retp)
{
int index = task->curr_ret_stack;
int i;
if (ret != (unsigned long)return_to_handler)
return ret;
if (index < -1)
index += FTRACE_NOTRACE_DEPTH;
if (index < 0)
return ret;
for (i = 0; i <= index; i++)
if (task->ret_stack[i].retp == retp)
return task->ret_stack[i].ret;
return ret;
}
#else /* !HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */
unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
unsigned long ret, unsigned long *retp)
{
int task_idx;
if (ret != (unsigned long)return_to_handler)
return ret;
task_idx = task->curr_ret_stack;
if (!task->ret_stack || task_idx < *idx)
return ret;
task_idx -= *idx;
(*idx)++;
return task->ret_stack[task_idx].ret;
}
#endif /* HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */
int __trace_graph_entry(struct trace_array *tr,
struct ftrace_graph_ent *trace,
unsigned long flags,
@ -409,6 +134,18 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
int cpu;
int pc;
if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT))
return 0;
if (ftrace_graph_notrace_addr(trace->func)) {
trace_recursion_set(TRACE_GRAPH_NOTRACE_BIT);
/*
* Need to return 1 to have the return called
* that will clear the NOTRACE bit.
*/
return 1;
}
if (!ftrace_trace_task(tr))
return 0;
@ -511,6 +248,11 @@ void trace_graph_return(struct ftrace_graph_ret *trace)
ftrace_graph_addr_finish(trace);
if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT)) {
trace_recursion_clear(TRACE_GRAPH_NOTRACE_BIT);
return;
}
local_irq_save(flags);
cpu = raw_smp_processor_id();
data = per_cpu_ptr(tr->trace_buffer.data, cpu);
@ -536,6 +278,11 @@ static void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
{
ftrace_graph_addr_finish(trace);
if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT)) {
trace_recursion_clear(TRACE_GRAPH_NOTRACE_BIT);
return;
}
if (tracing_thresh &&
(trace->rettime - trace->calltime < tracing_thresh))
return;
@ -543,17 +290,25 @@ static void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
trace_graph_return(trace);
}
static struct fgraph_ops funcgraph_thresh_ops = {
.entryfunc = &trace_graph_entry,
.retfunc = &trace_graph_thresh_return,
};
static struct fgraph_ops funcgraph_ops = {
.entryfunc = &trace_graph_entry,
.retfunc = &trace_graph_return,
};
static int graph_trace_init(struct trace_array *tr)
{
int ret;
set_graph_array(tr);
if (tracing_thresh)
ret = register_ftrace_graph(&trace_graph_thresh_return,
&trace_graph_entry);
ret = register_ftrace_graph(&funcgraph_thresh_ops);
else
ret = register_ftrace_graph(&trace_graph_return,
&trace_graph_entry);
ret = register_ftrace_graph(&funcgraph_ops);
if (ret)
return ret;
tracing_start_cmdline_record();
@ -564,7 +319,10 @@ static int graph_trace_init(struct trace_array *tr)
static void graph_trace_reset(struct trace_array *tr)
{
tracing_stop_cmdline_record();
unregister_ftrace_graph();
if (tracing_thresh)
unregister_ftrace_graph(&funcgraph_thresh_ops);
else
unregister_ftrace_graph(&funcgraph_ops);
}
static int graph_trace_update_thresh(struct trace_array *tr)
@ -874,10 +632,6 @@ print_graph_entry_leaf(struct trace_iterator *iter,
cpu_data = per_cpu_ptr(data->cpu_data, cpu);
/* If a graph tracer ignored set_graph_notrace */
if (call->depth < -1)
call->depth += FTRACE_NOTRACE_DEPTH;
/*
* Comments display at + 1 to depth. Since
* this is a leaf function, keep the comments
@ -920,10 +674,6 @@ print_graph_entry_nested(struct trace_iterator *iter,
struct fgraph_cpu_data *cpu_data;
int cpu = iter->cpu;
/* If a graph tracer ignored set_graph_notrace */
if (call->depth < -1)
call->depth += FTRACE_NOTRACE_DEPTH;
cpu_data = per_cpu_ptr(data->cpu_data, cpu);
cpu_data->depth = call->depth;

18
kernel/trace/trace_irqsoff.c
View File

@ -218,6 +218,11 @@ static void irqsoff_graph_return(struct ftrace_graph_ret *trace)
atomic_dec(&data->disabled);
}
static struct fgraph_ops fgraph_ops = {
.entryfunc = &irqsoff_graph_entry,
.retfunc = &irqsoff_graph_return,
};
static void irqsoff_trace_open(struct trace_iterator *iter)
{
if (is_graph(iter->tr))
@ -272,13 +277,6 @@ __trace_function(struct trace_array *tr,
#else
#define __trace_function trace_function
#ifdef CONFIG_FUNCTION_TRACER
static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
{
return -1;
}
#endif
static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
{
return TRACE_TYPE_UNHANDLED;
@ -288,7 +286,6 @@ static void irqsoff_trace_open(struct trace_iterator *iter) { }
static void irqsoff_trace_close(struct trace_iterator *iter) { }
#ifdef CONFIG_FUNCTION_TRACER
static void irqsoff_graph_return(struct ftrace_graph_ret *trace) { }
static void irqsoff_print_header(struct seq_file *s)
{
trace_default_header(s);
@ -468,8 +465,7 @@ static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
return 0;
if (graph)
ret = register_ftrace_graph(&irqsoff_graph_return,
&irqsoff_graph_entry);
ret = register_ftrace_graph(&fgraph_ops);
else
ret = register_ftrace_function(tr->ops);
@ -485,7 +481,7 @@ static void unregister_irqsoff_function(struct trace_array *tr, int graph)
return;
if (graph)
unregister_ftrace_graph();
unregister_ftrace_graph(&fgraph_ops);
else
unregister_ftrace_function(tr->ops);

359
kernel/trace/trace_kprobe.c
View File

@ -12,6 +12,7 @@
#include <linux/rculist.h>
#include <linux/error-injection.h>
#include "trace_dynevent.h"
#include "trace_kprobe_selftest.h"
#include "trace_probe.h"
#include "trace_probe_tmpl.h"
@ -19,17 +20,51 @@
#define KPROBE_EVENT_SYSTEM "kprobes"
#define KRETPROBE_MAXACTIVE_MAX 4096
static int trace_kprobe_create(int argc, const char **argv);
static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev);
static int trace_kprobe_release(struct dyn_event *ev);
static bool trace_kprobe_is_busy(struct dyn_event *ev);
static bool trace_kprobe_match(const char *system, const char *event,
struct dyn_event *ev);
static struct dyn_event_operations trace_kprobe_ops = {
.create = trace_kprobe_create,
.show = trace_kprobe_show,
.is_busy = trace_kprobe_is_busy,
.free = trace_kprobe_release,
.match = trace_kprobe_match,
};
/**
* Kprobe event core functions
*/
struct trace_kprobe {
struct list_head list;
struct dyn_event devent;
struct kretprobe rp; /* Use rp.kp for kprobe use */
unsigned long __percpu *nhit;
const char *symbol; /* symbol name */
struct trace_probe tp;
};
static bool is_trace_kprobe(struct dyn_event *ev)
{
return ev->ops == &trace_kprobe_ops;
}
static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev)
{
return container_of(ev, struct trace_kprobe, devent);
}
/**
* for_each_trace_kprobe - iterate over the trace_kprobe list
* @pos: the struct trace_kprobe * for each entry
* @dpos: the struct dyn_event * to use as a loop cursor
*/
#define for_each_trace_kprobe(pos, dpos) \
for_each_dyn_event(dpos) \
if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos)))
#define SIZEOF_TRACE_KPROBE(n) \
(offsetof(struct trace_kprobe, tp.args) + \
(sizeof(struct probe_arg) * (n)))
@ -81,6 +116,22 @@ static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
return ret;
}
static bool trace_kprobe_is_busy(struct dyn_event *ev)
{
struct trace_kprobe *tk = to_trace_kprobe(ev);
return trace_probe_is_enabled(&tk->tp);
}
static bool trace_kprobe_match(const char *system, const char *event,
struct dyn_event *ev)
{
struct trace_kprobe *tk = to_trace_kprobe(ev);
return strcmp(trace_event_name(&tk->tp.call), event) == 0 &&
(!system || strcmp(tk->tp.call.class->system, system) == 0);
}
static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
{
unsigned long nhit = 0;
@ -128,9 +179,6 @@ bool trace_kprobe_error_injectable(struct trace_event_call *call)
static int register_kprobe_event(struct trace_kprobe *tk);
static int unregister_kprobe_event(struct trace_kprobe *tk);
static DEFINE_MUTEX(probe_lock);
static LIST_HEAD(probe_list);
static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
static int kretprobe_dispatcher(struct kretprobe_instance *ri,
struct pt_regs *regs);
@ -192,7 +240,7 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group,
if (!tk->tp.class.system)
goto error;
INIT_LIST_HEAD(&tk->list);
dyn_event_init(&tk->devent, &trace_kprobe_ops);
INIT_LIST_HEAD(&tk->tp.files);
return tk;
error:
@ -207,6 +255,9 @@ static void free_trace_kprobe(struct trace_kprobe *tk)
{
int i;
if (!tk)
return;
for (i = 0; i < tk->tp.nr_args; i++)
traceprobe_free_probe_arg(&tk->tp.args[i]);
@ -220,9 +271,10 @@ static void free_trace_kprobe(struct trace_kprobe *tk)
static struct trace_kprobe *find_trace_kprobe(const char *event,
const char *group)
{
struct dyn_event *pos;
struct trace_kprobe *tk;
list_for_each_entry(tk, &probe_list, list)
for_each_trace_kprobe(tk, pos)
if (strcmp(trace_event_name(&tk->tp.call), event) == 0 &&
strcmp(tk->tp.call.class->system, group) == 0)
return tk;
@ -321,7 +373,7 @@ disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
* created with perf_event_open. We don't need to wait for these
* trace_kprobes
*/
if (list_empty(&tk->list))
if (list_empty(&tk->devent.list))
wait = 0;
out:
if (wait) {
@ -419,7 +471,7 @@ static void __unregister_trace_kprobe(struct trace_kprobe *tk)
}
}
/* Unregister a trace_probe and probe_event: call with locking probe_lock */
/* Unregister a trace_probe and probe_event */
static int unregister_trace_kprobe(struct trace_kprobe *tk)
{
/* Enabled event can not be unregistered */
@ -431,7 +483,7 @@ static int unregister_trace_kprobe(struct trace_kprobe *tk)
return -EBUSY;
__unregister_trace_kprobe(tk);
list_del(&tk->list);
dyn_event_remove(&tk->devent);
return 0;
}
@ -442,7 +494,7 @@ static int register_trace_kprobe(struct trace_kprobe *tk)
struct trace_kprobe *old_tk;
int ret;
mutex_lock(&probe_lock);
mutex_lock(&event_mutex);
/* Delete old (same name) event if exist */
old_tk = find_trace_kprobe(trace_event_name(&tk->tp.call),
@ -471,10 +523,10 @@ static int register_trace_kprobe(struct trace_kprobe *tk)
if (ret < 0)
unregister_kprobe_event(tk);
else
list_add_tail(&tk->list, &probe_list);
dyn_event_add(&tk->devent);
end:
mutex_unlock(&probe_lock);
mutex_unlock(&event_mutex);
return ret;
}
@ -483,6 +535,7 @@ static int trace_kprobe_module_callback(struct notifier_block *nb,
unsigned long val, void *data)
{
struct module *mod = data;
struct dyn_event *pos;
struct trace_kprobe *tk;
int ret;
@ -490,8 +543,8 @@ static int trace_kprobe_module_callback(struct notifier_block *nb,
return NOTIFY_DONE;
/* Update probes on coming module */
mutex_lock(&probe_lock);
list_for_each_entry(tk, &probe_list, list) {
mutex_lock(&event_mutex);
for_each_trace_kprobe(tk, pos) {
if (trace_kprobe_within_module(tk, mod)) {
/* Don't need to check busy - this should have gone. */
__unregister_trace_kprobe(tk);
@ -502,7 +555,7 @@ static int trace_kprobe_module_callback(struct notifier_block *nb,
mod->name, ret);
}
}
mutex_unlock(&probe_lock);
mutex_unlock(&event_mutex);
return NOTIFY_DONE;
}
@ -520,7 +573,7 @@ static inline void sanitize_event_name(char *name)
*name = '_';
}
static int create_trace_kprobe(int argc, char **argv)
static int trace_kprobe_create(int argc, const char *argv[])
{
/*
* Argument syntax:
@ -544,37 +597,37 @@ static int create_trace_kprobe(int argc, char **argv)
* FETCHARG:TYPE : use TYPE instead of unsigned long.
*/
struct trace_kprobe *tk;
int i, ret = 0;
bool is_return = false, is_delete = false;
char *symbol = NULL, *event = NULL, *group = NULL;
int i, len, ret = 0;
bool is_return = false;
char *symbol = NULL, *tmp = NULL;
const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;
int maxactive = 0;
char *arg;
long offset = 0;
void *addr = NULL;
char buf[MAX_EVENT_NAME_LEN];
unsigned int flags = TPARG_FL_KERNEL;
/* argc must be >= 1 */
if (argv[0][0] == 'p')
is_return = false;
else if (argv[0][0] == 'r') {
if (argv[0][0] == 'r') {
is_return = true;
flags |= TPARG_FL_RETURN;
} else if (argv[0][0] == '-')
is_delete = true;
else {
pr_info("Probe definition must be started with 'p', 'r' or"
" '-'.\n");
return -EINVAL;
}
} else if (argv[0][0] != 'p' || argc < 2)
return -ECANCELED;
event = strchr(&argv[0][1], ':');
if (event) {
event[0] = '\0';
if (event)
event++;
}
if (is_return && isdigit(argv[0][1])) {
ret = kstrtouint(&argv[0][1], 0, &maxactive);
if (event)
len = event - &argv[0][1] - 1;
else
len = strlen(&argv[0][1]);
if (len > MAX_EVENT_NAME_LEN - 1)
return -E2BIG;
memcpy(buf, &argv[0][1], len);
buf[len] = '\0';
ret = kstrtouint(buf, 0, &maxactive);
if (ret) {
pr_info("Failed to parse maxactive.\n");
return ret;
@ -589,74 +642,37 @@ static int create_trace_kprobe(int argc, char **argv)
}
}
if (event) {
char *slash;
slash = strchr(event, '/');
if (slash) {
group = event;
event = slash + 1;
slash[0] = '\0';
if (strlen(group) == 0) {
pr_info("Group name is not specified\n");
return -EINVAL;
}
}
if (strlen(event) == 0) {
pr_info("Event name is not specified\n");
return -EINVAL;
}
}
if (!group)
group = KPROBE_EVENT_SYSTEM;
if (is_delete) {
if (!event) {
pr_info("Delete command needs an event name.\n");
return -EINVAL;
}
mutex_lock(&probe_lock);
tk = find_trace_kprobe(event, group);
if (!tk) {
mutex_unlock(&probe_lock);
pr_info("Event %s/%s doesn't exist.\n", group, event);
return -ENOENT;
}
/* delete an event */
ret = unregister_trace_kprobe(tk);
if (ret == 0)
free_trace_kprobe(tk);
mutex_unlock(&probe_lock);
return ret;
}
if (argc < 2) {
pr_info("Probe point is not specified.\n");
return -EINVAL;
}
/* try to parse an address. if that fails, try to read the
* input as a symbol. */
if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) {
/* Check whether uprobe event specified */
if (strchr(argv[1], '/') && strchr(argv[1], ':'))
return -ECANCELED;
/* a symbol specified */
symbol = argv[1];
symbol = kstrdup(argv[1], GFP_KERNEL);
if (!symbol)
return -ENOMEM;
/* TODO: support .init module functions */
ret = traceprobe_split_symbol_offset(symbol, &offset);
if (ret || offset < 0 || offset > UINT_MAX) {
pr_info("Failed to parse either an address or a symbol.\n");
return ret;
goto out;
}
if (kprobe_on_func_entry(NULL, symbol, offset))
flags |= TPARG_FL_FENTRY;
if (offset && is_return && !(flags & TPARG_FL_FENTRY)) {
pr_info("Given offset is not valid for return probe.\n");
return -EINVAL;
ret = -EINVAL;
goto out;
}
}
argc -= 2; argv += 2;
/* setup a probe */
if (!event) {
if (event) {
ret = traceprobe_parse_event_name(&event, &group, buf);
if (ret)
goto out;
} else {
/* Make a new event name */
if (symbol)
snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
@ -667,121 +683,67 @@ static int create_trace_kprobe(int argc, char **argv)
sanitize_event_name(buf);
event = buf;
}
/* setup a probe */
tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
argc, is_return);
if (IS_ERR(tk)) {
pr_info("Failed to allocate trace_probe.(%d)\n",
(int)PTR_ERR(tk));
return PTR_ERR(tk);
ret = PTR_ERR(tk);
goto out;
}
/* parse arguments */
ret = 0;
for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
struct probe_arg *parg = &tk->tp.args[i];
/* Increment count for freeing args in error case */
tk->tp.nr_args++;
/* Parse argument name */
arg = strchr(argv[i], '=');
if (arg) {
*arg++ = '\0';
parg->name = kstrdup(argv[i], GFP_KERNEL);
} else {
arg = argv[i];
/* If argument name is omitted, set "argN" */
snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
parg->name = kstrdup(buf, GFP_KERNEL);
}
if (!parg->name) {
pr_info("Failed to allocate argument[%d] name.\n", i);
tmp = kstrdup(argv[i], GFP_KERNEL);
if (!tmp) {
ret = -ENOMEM;
goto error;
}
if (!is_good_name(parg->name)) {
pr_info("Invalid argument[%d] name: %s\n",
i, parg->name);
ret = -EINVAL;
ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags);
kfree(tmp);
if (ret)
goto error;
}
if (traceprobe_conflict_field_name(parg->name,
tk->tp.args, i)) {
pr_info("Argument[%d] name '%s' conflicts with "
"another field.\n", i, argv[i]);
ret = -EINVAL;
goto error;
}
/* Parse fetch argument */
ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg,
flags);
if (ret) {
pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
goto error;
}
}
ret = register_trace_kprobe(tk);
if (ret)
goto error;
return 0;
out:
kfree(symbol);
return ret;
error:
free_trace_kprobe(tk);
return ret;
goto out;
}
static int release_all_trace_kprobes(void)
static int create_or_delete_trace_kprobe(int argc, char **argv)
{
struct trace_kprobe *tk;
int ret = 0;
int ret;
mutex_lock(&probe_lock);
/* Ensure no probe is in use. */
list_for_each_entry(tk, &probe_list, list)
if (trace_probe_is_enabled(&tk->tp)) {
ret = -EBUSY;
goto end;
}
/* TODO: Use batch unregistration */
while (!list_empty(&probe_list)) {
tk = list_entry(probe_list.next, struct trace_kprobe, list);
ret = unregister_trace_kprobe(tk);
if (ret)
goto end;
if (argv[0][0] == '-')
return dyn_event_release(argc, argv, &trace_kprobe_ops);
ret = trace_kprobe_create(argc, (const char **)argv);
return ret == -ECANCELED ? -EINVAL : ret;
}
static int trace_kprobe_release(struct dyn_event *ev)
{
struct trace_kprobe *tk = to_trace_kprobe(ev);
int ret = unregister_trace_kprobe(tk);
if (!ret)
free_trace_kprobe(tk);
}
end:
mutex_unlock(&probe_lock);
return ret;
}
/* Probes listing interfaces */
static void *probes_seq_start(struct seq_file *m, loff_t *pos)
static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
{
mutex_lock(&probe_lock);
return seq_list_start(&probe_list, *pos);
}
static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
{
return seq_list_next(v, &probe_list, pos);
}
static void probes_seq_stop(struct seq_file *m, void *v)
{
mutex_unlock(&probe_lock);
}
static int probes_seq_show(struct seq_file *m, void *v)
{
struct trace_kprobe *tk = v;
struct trace_kprobe *tk = to_trace_kprobe(ev);
int i;
seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
@ -803,10 +765,20 @@ static int probes_seq_show(struct seq_file *m, void *v)
return 0;
}
static int probes_seq_show(struct seq_file *m, void *v)
{
struct dyn_event *ev = v;
if (!is_trace_kprobe(ev))
return 0;
return trace_kprobe_show(m, ev);
}
static const struct seq_operations probes_seq_op = {
.start = probes_seq_start,
.next = probes_seq_next,
.stop = probes_seq_stop,
.start = dyn_event_seq_start,
.next = dyn_event_seq_next,
.stop = dyn_event_seq_stop,
.show = probes_seq_show
};
@ -815,7 +787,7 @@ static int probes_open(struct inode *inode, struct file *file)
int ret;
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
ret = release_all_trace_kprobes();
ret = dyn_events_release_all(&trace_kprobe_ops);
if (ret < 0)
return ret;
}
@ -827,7 +799,7 @@ static ssize_t probes_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos)
{
return trace_parse_run_command(file, buffer, count, ppos,
create_trace_kprobe);
create_or_delete_trace_kprobe);
}
static const struct file_operations kprobe_events_ops = {
@ -842,8 +814,13 @@ static const struct file_operations kprobe_events_ops = {
/* Probes profiling interfaces */
static int probes_profile_seq_show(struct seq_file *m, void *v)
{
struct trace_kprobe *tk = v;
struct dyn_event *ev = v;
struct trace_kprobe *tk;
if (!is_trace_kprobe(ev))
return 0;
tk = to_trace_kprobe(ev);
seq_printf(m, " %-44s %15lu %15lu\n",
trace_event_name(&tk->tp.call),
trace_kprobe_nhit(tk),
@ -853,9 +830,9 @@ static int probes_profile_seq_show(struct seq_file *m, void *v)
}
static const struct seq_operations profile_seq_op = {
.start = probes_seq_start,
.next = probes_seq_next,
.stop = probes_seq_stop,
.start = dyn_event_seq_start,
.next = dyn_event_seq_next,
.stop = dyn_event_seq_stop,
.show = probes_profile_seq_show
};
@ -1408,7 +1385,7 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
char *event;
/*
* local trace_kprobes are not added to probe_list, so they are never
* local trace_kprobes are not added to dyn_event, so they are never
* searched in find_trace_kprobe(). Therefore, there is no concern of
* duplicated name here.
*/
@ -1466,6 +1443,11 @@ static __init int init_kprobe_trace(void)
{
struct dentry *d_tracer;
struct dentry *entry;
int ret;
ret = dyn_event_register(&trace_kprobe_ops);
if (ret)
return ret;
if (register_module_notifier(&trace_kprobe_module_nb))
return -EINVAL;
@ -1523,9 +1505,8 @@ static __init int kprobe_trace_self_tests_init(void)
pr_info("Testing kprobe tracing: ");
ret = trace_run_command("p:testprobe kprobe_trace_selftest_target "
"$stack $stack0 +0($stack)",
create_trace_kprobe);
ret = trace_run_command("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)",
create_or_delete_trace_kprobe);
if (WARN_ON_ONCE(ret)) {
pr_warn("error on probing function entry.\n");
warn++;
@ -1545,8 +1526,8 @@ static __init int kprobe_trace_self_tests_init(void)
}
}
ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target "
"$retval", create_trace_kprobe);
ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target $retval",
create_or_delete_trace_kprobe);
if (WARN_ON_ONCE(ret)) {
pr_warn("error on probing function return.\n");
warn++;
@ -1616,20 +1597,24 @@ static __init int kprobe_trace_self_tests_init(void)
disable_trace_kprobe(tk, file);
}
ret = trace_run_command("-:testprobe", create_trace_kprobe);
ret = trace_run_command("-:testprobe", create_or_delete_trace_kprobe);
if (WARN_ON_ONCE(ret)) {
pr_warn("error on deleting a probe.\n");
warn++;
}
ret = trace_run_command("-:testprobe2", create_trace_kprobe);
ret = trace_run_command("-:testprobe2", create_or_delete_trace_kprobe);
if (WARN_ON_ONCE(ret)) {
pr_warn("error on deleting a probe.\n");
warn++;
}
end:
release_all_trace_kprobes();
ret = dyn_events_release_all(&trace_kprobe_ops);
if (WARN_ON_ONCE(ret)) {
pr_warn("error on cleaning up probes.\n");
warn++;
}
/*
* Wait for the optimizer work to finish. Otherwise it might fiddle
* with probes in already freed __init text.

40
kernel/trace/trace_output.c
View File

@ -339,43 +339,24 @@ static inline const char *kretprobed(const char *name)
#endif /* CONFIG_KRETPROBES */
static void
seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
seq_print_sym(struct trace_seq *s, unsigned long address, bool offset)
{
char str[KSYM_SYMBOL_LEN];
#ifdef CONFIG_KALLSYMS
char str[KSYM_SYMBOL_LEN];
const char *name;
kallsyms_lookup(address, NULL, NULL, NULL, str);
if (offset)
sprint_symbol(str, address);
else
kallsyms_lookup(address, NULL, NULL, NULL, str);
name = kretprobed(str);
if (name && strlen(name)) {
trace_seq_printf(s, fmt, name);
trace_seq_puts(s, name);
return;
}
#endif
snprintf(str, KSYM_SYMBOL_LEN, "0x%08lx", address);
trace_seq_printf(s, fmt, str);
}
static void
seq_print_sym_offset(struct trace_seq *s, const char *fmt,
unsigned long address)
{
char str[KSYM_SYMBOL_LEN];
#ifdef CONFIG_KALLSYMS
const char *name;
sprint_symbol(str, address);
name = kretprobed(str);
if (name && strlen(name)) {
trace_seq_printf(s, fmt, name);
return;
}
#endif
snprintf(str, KSYM_SYMBOL_LEN, "0x%08lx", address);
trace_seq_printf(s, fmt, str);
trace_seq_printf(s, "0x%08lx", address);
}
#ifndef CONFIG_64BIT
@ -424,10 +405,7 @@ seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
goto out;
}
if (sym_flags & TRACE_ITER_SYM_OFFSET)
seq_print_sym_offset(s, "%s", ip);
else
seq_print_sym_short(s, "%s", ip);
seq_print_sym(s, ip, sym_flags & TRACE_ITER_SYM_OFFSET);
if (sym_flags & TRACE_ITER_SYM_ADDR)
trace_seq_printf(s, " <" IP_FMT ">", ip);

91
kernel/trace/trace_probe.c
View File

@ -154,24 +154,52 @@ int traceprobe_split_symbol_offset(char *symbol, long *offset)
return 0;
}
/* @buf must has MAX_EVENT_NAME_LEN size */
int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
char *buf)
{
const char *slash, *event = *pevent;
slash = strchr(event, '/');
if (slash) {
if (slash == event) {
pr_info("Group name is not specified\n");
return -EINVAL;
}
if (slash - event + 1 > MAX_EVENT_NAME_LEN) {
pr_info("Group name is too long\n");
return -E2BIG;
}
strlcpy(buf, event, slash - event + 1);
*pgroup = buf;
*pevent = slash + 1;
}
if (strlen(event) == 0) {
pr_info("Event name is not specified\n");
return -EINVAL;
}
return 0;
}
#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
static int parse_probe_vars(char *arg, const struct fetch_type *t,
struct fetch_insn *code, unsigned int flags)
{
int ret = 0;
unsigned long param;
int ret = 0;
int len;
if (strcmp(arg, "retval") == 0) {
if (flags & TPARG_FL_RETURN)
code->op = FETCH_OP_RETVAL;
else
ret = -EINVAL;
} else if (strncmp(arg, "stack", 5) == 0) {
if (arg[5] == '\0') {
} else if ((len = str_has_prefix(arg, "stack"))) {
if (arg[len] == '\0') {
code->op = FETCH_OP_STACKP;
} else if (isdigit(arg[5])) {
ret = kstrtoul(arg + 5, 10, &param);
} else if (isdigit(arg[len])) {
ret = kstrtoul(arg + len, 10, &param);
if (ret || ((flags & TPARG_FL_KERNEL) &&
param > PARAM_MAX_STACK))
ret = -EINVAL;
@ -186,10 +214,10 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
} else if (((flags & TPARG_FL_MASK) ==
(TPARG_FL_KERNEL | TPARG_FL_FENTRY)) &&
strncmp(arg, "arg", 3) == 0) {
if (!isdigit(arg[3]))
(len = str_has_prefix(arg, "arg"))) {
if (!isdigit(arg[len]))
return -EINVAL;
ret = kstrtoul(arg + 3, 10, &param);
ret = kstrtoul(arg + len, 10, &param);
if (ret || !param || param > PARAM_MAX_STACK)
return -EINVAL;
code->op = FETCH_OP_ARG;
@ -348,7 +376,7 @@ static int __parse_bitfield_probe_arg(const char *bf,
}
/* String length checking wrapper */
int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
struct probe_arg *parg, unsigned int flags)
{
struct fetch_insn *code, *scode, *tmp = NULL;
@ -491,8 +519,8 @@ fail:
}
/* Return 1 if name is reserved or already used by another argument */
int traceprobe_conflict_field_name(const char *name,
struct probe_arg *args, int narg)
static int traceprobe_conflict_field_name(const char *name,
struct probe_arg *args, int narg)
{
int i;
@ -507,6 +535,47 @@ int traceprobe_conflict_field_name(const char *name,
return 0;
}
int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, char *arg,
unsigned int flags)
{
struct probe_arg *parg = &tp->args[i];
char *body;
int ret;
/* Increment count for freeing args in error case */
tp->nr_args++;
body = strchr(arg, '=');
if (body) {
parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL);
body++;
} else {
/* If argument name is omitted, set "argN" */
parg->name = kasprintf(GFP_KERNEL, "arg%d", i + 1);
body = arg;
}
if (!parg->name)
return -ENOMEM;
if (!is_good_name(parg->name)) {
pr_info("Invalid argument[%d] name: %s\n",
i, parg->name);
return -EINVAL;
}
if (traceprobe_conflict_field_name(parg->name, tp->args, i)) {
pr_info("Argument[%d]: '%s' conflicts with another field.\n",
i, parg->name);
return -EINVAL;
}
/* Parse fetch argument */
ret = traceprobe_parse_probe_arg_body(body, &tp->size, parg, flags);
if (ret)
pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
return ret;
}
void traceprobe_free_probe_arg(struct probe_arg *arg)
{
struct fetch_insn *code = arg->code;

9
kernel/trace/trace_probe.h
View File

@ -272,16 +272,15 @@ find_event_file_link(struct trace_probe *tp, struct trace_event_file *file)
#define TPARG_FL_FENTRY BIT(2)
#define TPARG_FL_MASK GENMASK(2, 0)
extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
struct probe_arg *parg, unsigned int flags);
extern int traceprobe_conflict_field_name(const char *name,
struct probe_arg *args, int narg);
extern int traceprobe_parse_probe_arg(struct trace_probe *tp, int i,
char *arg, unsigned int flags);
extern int traceprobe_update_arg(struct probe_arg *arg);
extern void traceprobe_free_probe_arg(struct probe_arg *arg);
extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
extern int traceprobe_parse_event_name(const char **pevent,
const char **pgroup, char *buf);
extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return);

272
kernel/trace/trace_sched_wakeup.c
View File

@ -35,26 +35,19 @@ static arch_spinlock_t wakeup_lock =
static void wakeup_reset(struct trace_array *tr);
static void __wakeup_reset(struct trace_array *tr);
static int start_func_tracer(struct trace_array *tr, int graph);
static void stop_func_tracer(struct trace_array *tr, int graph);
static int save_flags;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static int wakeup_display_graph(struct trace_array *tr, int set);
# define is_graph(tr) ((tr)->trace_flags & TRACE_ITER_DISPLAY_GRAPH)
#else
static inline int wakeup_display_graph(struct trace_array *tr, int set)
{
return 0;
}
# define is_graph(tr) false
#endif
#ifdef CONFIG_FUNCTION_TRACER
static int wakeup_graph_entry(struct ftrace_graph_ent *trace);
static void wakeup_graph_return(struct ftrace_graph_ret *trace);
static bool function_enabled;
/*
@ -104,122 +97,8 @@ out_enable:
return 0;
}
/*
* wakeup uses its own tracer function to keep the overhead down:
*/
static void
wakeup_tracer_call(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *pt_regs)
{
struct trace_array *tr = wakeup_trace;
struct trace_array_cpu *data;
unsigned long flags;
int pc;
if (!func_prolog_preempt_disable(tr, &data, &pc))
return;
local_irq_save(flags);
trace_function(tr, ip, parent_ip, flags, pc);
local_irq_restore(flags);
atomic_dec(&data->disabled);
preempt_enable_notrace();
}
static int register_wakeup_function(struct trace_array *tr, int graph, int set)
{
int ret;
/* 'set' is set if TRACE_ITER_FUNCTION is about to be set */
if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION)))
return 0;
if (graph)
ret = register_ftrace_graph(&wakeup_graph_return,
&wakeup_graph_entry);
else
ret = register_ftrace_function(tr->ops);
if (!ret)
function_enabled = true;
return ret;
}
static void unregister_wakeup_function(struct trace_array *tr, int graph)
{
if (!function_enabled)
return;
if (graph)
unregister_ftrace_graph();
else
unregister_ftrace_function(tr->ops);
function_enabled = false;
}
static int wakeup_function_set(struct trace_array *tr, u32 mask, int set)
{
if (!(mask & TRACE_ITER_FUNCTION))
return 0;
if (set)
register_wakeup_function(tr, is_graph(tr), 1);
else
unregister_wakeup_function(tr, is_graph(tr));
return 1;
}
#else
static int register_wakeup_function(struct trace_array *tr, int graph, int set)
{
return 0;
}
static void unregister_wakeup_function(struct trace_array *tr, int graph) { }
static int wakeup_function_set(struct trace_array *tr, u32 mask, int set)
{
return 0;
}
#endif /* CONFIG_FUNCTION_TRACER */
static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set)
{
struct tracer *tracer = tr->current_trace;
if (wakeup_function_set(tr, mask, set))
return 0;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
if (mask & TRACE_ITER_DISPLAY_GRAPH)
return wakeup_display_graph(tr, set);
#endif
return trace_keep_overwrite(tracer, mask, set);
}
static int start_func_tracer(struct trace_array *tr, int graph)
{
int ret;
ret = register_wakeup_function(tr, graph, 0);
if (!ret && tracing_is_enabled())
tracer_enabled = 1;
else
tracer_enabled = 0;
return ret;
}
static void stop_func_tracer(struct trace_array *tr, int graph)
{
tracer_enabled = 0;
unregister_wakeup_function(tr, graph);
}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static int wakeup_display_graph(struct trace_array *tr, int set)
{
if (!(is_graph(tr) ^ set))
@ -283,6 +162,11 @@ static void wakeup_graph_return(struct ftrace_graph_ret *trace)
return;
}
static struct fgraph_ops fgraph_wakeup_ops = {
.entryfunc = &wakeup_graph_entry,
.retfunc = &wakeup_graph_return,
};
static void wakeup_trace_open(struct trace_iterator *iter)
{
if (is_graph(iter->tr))
@ -318,6 +202,100 @@ static void wakeup_print_header(struct seq_file *s)
else
trace_default_header(s);
}
#endif /* else CONFIG_FUNCTION_GRAPH_TRACER */
/*
* wakeup uses its own tracer function to keep the overhead down:
*/
static void
wakeup_tracer_call(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *pt_regs)
{
struct trace_array *tr = wakeup_trace;
struct trace_array_cpu *data;
unsigned long flags;
int pc;
if (!func_prolog_preempt_disable(tr, &data, &pc))
return;
local_irq_save(flags);
trace_function(tr, ip, parent_ip, flags, pc);
local_irq_restore(flags);
atomic_dec(&data->disabled);
preempt_enable_notrace();
}
static int register_wakeup_function(struct trace_array *tr, int graph, int set)
{
int ret;
/* 'set' is set if TRACE_ITER_FUNCTION is about to be set */
if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION)))
return 0;
if (graph)
ret = register_ftrace_graph(&fgraph_wakeup_ops);
else
ret = register_ftrace_function(tr->ops);
if (!ret)
function_enabled = true;
return ret;
}
static void unregister_wakeup_function(struct trace_array *tr, int graph)
{
if (!function_enabled)
return;
if (graph)
unregister_ftrace_graph(&fgraph_wakeup_ops);
else
unregister_ftrace_function(tr->ops);
function_enabled = false;
}
static int wakeup_function_set(struct trace_array *tr, u32 mask, int set)
{
if (!(mask & TRACE_ITER_FUNCTION))
return 0;
if (set)
register_wakeup_function(tr, is_graph(tr), 1);
else
unregister_wakeup_function(tr, is_graph(tr));
return 1;
}
#else /* CONFIG_FUNCTION_TRACER */
static int register_wakeup_function(struct trace_array *tr, int graph, int set)
{
return 0;
}
static void unregister_wakeup_function(struct trace_array *tr, int graph) { }
static int wakeup_function_set(struct trace_array *tr, u32 mask, int set)
{
return 0;
}
#endif /* else CONFIG_FUNCTION_TRACER */
#ifndef CONFIG_FUNCTION_GRAPH_TRACER
static enum print_line_t wakeup_print_line(struct trace_iterator *iter)
{
return TRACE_TYPE_UNHANDLED;
}
static void wakeup_trace_open(struct trace_iterator *iter) { }
static void wakeup_trace_close(struct trace_iterator *iter) { }
static void wakeup_print_header(struct seq_file *s)
{
trace_default_header(s);
}
#endif /* !CONFIG_FUNCTION_GRAPH_TRACER */
static void
__trace_function(struct trace_array *tr,
@ -329,34 +307,42 @@ __trace_function(struct trace_array *tr,
else
trace_function(tr, ip, parent_ip, flags, pc);
}
#else
#define __trace_function trace_function
static enum print_line_t wakeup_print_line(struct trace_iterator *iter)
static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set)
{
return TRACE_TYPE_UNHANDLED;
struct tracer *tracer = tr->current_trace;
if (wakeup_function_set(tr, mask, set))
return 0;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
if (mask & TRACE_ITER_DISPLAY_GRAPH)
return wakeup_display_graph(tr, set);
#endif
return trace_keep_overwrite(tracer, mask, set);
}
static void wakeup_trace_open(struct trace_iterator *iter) { }
static void wakeup_trace_close(struct trace_iterator *iter) { }
static int start_func_tracer(struct trace_array *tr, int graph)
{
int ret;
#ifdef CONFIG_FUNCTION_TRACER
static int wakeup_graph_entry(struct ftrace_graph_ent *trace)
{
return -1;
ret = register_wakeup_function(tr, graph, 0);
if (!ret && tracing_is_enabled())
tracer_enabled = 1;
else
tracer_enabled = 0;
return ret;
}
static void wakeup_graph_return(struct ftrace_graph_ret *trace) { }
static void wakeup_print_header(struct seq_file *s)
static void stop_func_tracer(struct trace_array *tr, int graph)
{
trace_default_header(s);
tracer_enabled = 0;
unregister_wakeup_function(tr, graph);
}
#else
static void wakeup_print_header(struct seq_file *s)
{
trace_latency_header(s);
}
#endif /* CONFIG_FUNCTION_TRACER */
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
/*
* Should this new latency be reported/recorded?

8
kernel/trace/trace_selftest.c
View File

@ -741,6 +741,11 @@ static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace)
return trace_graph_entry(trace);
}
static struct fgraph_ops fgraph_ops __initdata = {
.entryfunc = &trace_graph_entry_watchdog,
.retfunc = &trace_graph_return,
};
/*
* Pretty much the same than for the function tracer from which the selftest
* has been borrowed.
@ -765,8 +770,7 @@ trace_selftest_startup_function_graph(struct tracer *trace,
*/
tracing_reset_online_cpus(&tr->trace_buffer);
set_graph_array(tr);
ret = register_ftrace_graph(&trace_graph_return,
&trace_graph_entry_watchdog);
ret = register_ftrace_graph(&fgraph_ops);
if (ret) {
warn_failed_init_tracer(trace, ret);
goto out;

8
kernel/trace/trace_stack.c
View File

@ -286,7 +286,7 @@ __next(struct seq_file *m, loff_t *pos)
{
long n = *pos - 1;
if (n > stack_trace_max.nr_entries || stack_dump_trace[n] == ULONG_MAX)
if (n >= stack_trace_max.nr_entries || stack_dump_trace[n] == ULONG_MAX)
return NULL;
m->private = (void *)n;
@ -448,8 +448,10 @@ static char stack_trace_filter_buf[COMMAND_LINE_SIZE+1] __initdata;
static __init int enable_stacktrace(char *str)
{
if (strncmp(str, "_filter=", 8) == 0)
strncpy(stack_trace_filter_buf, str+8, COMMAND_LINE_SIZE);
int len;
if ((len = str_has_prefix(str, "_filter=")))
strncpy(stack_trace_filter_buf, str + len, COMMAND_LINE_SIZE);
stack_tracer_enabled = 1;
last_stack_tracer_enabled = 1;

309
kernel/trace/trace_uprobe.c
View File

@ -7,6 +7,7 @@
*/
#define pr_fmt(fmt) "trace_kprobe: " fmt
#include <linux/ctype.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/uprobes.h>
@ -14,6 +15,7 @@
#include <linux/string.h>
#include <linux/rculist.h>
#include "trace_dynevent.h"
#include "trace_probe.h"
#include "trace_probe_tmpl.h"
@ -37,11 +39,26 @@ struct trace_uprobe_filter {
struct list_head perf_events;
};
static int trace_uprobe_create(int argc, const char **argv);
static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
static int trace_uprobe_release(struct dyn_event *ev);
static bool trace_uprobe_is_busy(struct dyn_event *ev);
static bool trace_uprobe_match(const char *system, const char *event,
struct dyn_event *ev);
static struct dyn_event_operations trace_uprobe_ops = {
.create = trace_uprobe_create,
.show = trace_uprobe_show,
.is_busy = trace_uprobe_is_busy,
.free = trace_uprobe_release,
.match = trace_uprobe_match,
};
/*
* uprobe event core functions
*/
struct trace_uprobe {
struct list_head list;
struct dyn_event devent;
struct trace_uprobe_filter filter;
struct uprobe_consumer consumer;
struct path path;
@ -53,6 +70,25 @@ struct trace_uprobe {
struct trace_probe tp;
};
static bool is_trace_uprobe(struct dyn_event *ev)
{
return ev->ops == &trace_uprobe_ops;
}
static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev)
{
return container_of(ev, struct trace_uprobe, devent);
}
/**
* for_each_trace_uprobe - iterate over the trace_uprobe list
* @pos: the struct trace_uprobe * for each entry
* @dpos: the struct dyn_event * to use as a loop cursor
*/
#define for_each_trace_uprobe(pos, dpos) \
for_each_dyn_event(dpos) \
if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos)))
#define SIZEOF_TRACE_UPROBE(n) \
(offsetof(struct trace_uprobe, tp.args) + \
(sizeof(struct probe_arg) * (n)))
@ -60,9 +96,6 @@ struct trace_uprobe {
static int register_uprobe_event(struct trace_uprobe *tu);
static int unregister_uprobe_event(struct trace_uprobe *tu);
static DEFINE_MUTEX(uprobe_lock);
static LIST_HEAD(uprobe_list);
struct uprobe_dispatch_data {
struct trace_uprobe *tu;
unsigned long bp_addr;
@ -209,6 +242,22 @@ static inline bool is_ret_probe(struct trace_uprobe *tu)
return tu->consumer.ret_handler != NULL;
}
static bool trace_uprobe_is_busy(struct dyn_event *ev)
{
struct trace_uprobe *tu = to_trace_uprobe(ev);
return trace_probe_is_enabled(&tu->tp);
}
static bool trace_uprobe_match(const char *system, const char *event,
struct dyn_event *ev)
{
struct trace_uprobe *tu = to_trace_uprobe(ev);
return strcmp(trace_event_name(&tu->tp.call), event) == 0 &&
(!system || strcmp(tu->tp.call.class->system, system) == 0);
}
/*
* Allocate new trace_uprobe and initialize it (including uprobes).
*/
@ -236,7 +285,7 @@ alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
if (!tu->tp.class.system)
goto error;
INIT_LIST_HEAD(&tu->list);
dyn_event_init(&tu->devent, &trace_uprobe_ops);
INIT_LIST_HEAD(&tu->tp.files);
tu->consumer.handler = uprobe_dispatcher;
if (is_ret)
@ -255,6 +304,9 @@ static void free_trace_uprobe(struct trace_uprobe *tu)
{
int i;
if (!tu)
return;
for (i = 0; i < tu->tp.nr_args; i++)
traceprobe_free_probe_arg(&tu->tp.args[i]);
@ -267,9 +319,10 @@ static void free_trace_uprobe(struct trace_uprobe *tu)
static struct trace_uprobe *find_probe_event(const char *event, const char *group)
{
struct dyn_event *pos;
struct trace_uprobe *tu;
list_for_each_entry(tu, &uprobe_list, list)
for_each_trace_uprobe(tu, pos)
if (strcmp(trace_event_name(&tu->tp.call), event) == 0 &&
strcmp(tu->tp.call.class->system, group) == 0)
return tu;
@ -277,7 +330,7 @@ static struct trace_uprobe *find_probe_event(const char *event, const char *grou
return NULL;
}
/* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */
/* Unregister a trace_uprobe and probe_event */
static int unregister_trace_uprobe(struct trace_uprobe *tu)
{
int ret;
@ -286,7 +339,7 @@ static int unregister_trace_uprobe(struct trace_uprobe *tu)
if (ret)
return ret;
list_del(&tu->list);
dyn_event_remove(&tu->devent);
free_trace_uprobe(tu);
return 0;
}
@ -302,13 +355,14 @@ static int unregister_trace_uprobe(struct trace_uprobe *tu)
*/
static struct trace_uprobe *find_old_trace_uprobe(struct trace_uprobe *new)
{
struct dyn_event *pos;
struct trace_uprobe *tmp, *old = NULL;
struct inode *new_inode = d_real_inode(new->path.dentry);
old = find_probe_event(trace_event_name(&new->tp.call),
new->tp.call.class->system);
list_for_each_entry(tmp, &uprobe_list, list) {
for_each_trace_uprobe(tmp, pos) {
if ((old ? old != tmp : true) &&
new_inode == d_real_inode(tmp->path.dentry) &&
new->offset == tmp->offset &&
@ -326,7 +380,7 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
struct trace_uprobe *old_tu;
int ret;
mutex_lock(&uprobe_lock);
mutex_lock(&event_mutex);
/* register as an event */
old_tu = find_old_trace_uprobe(tu);
@ -348,10 +402,10 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
goto end;
}
list_add_tail(&tu->list, &uprobe_list);
dyn_event_add(&tu->devent);
end:
mutex_unlock(&uprobe_lock);
mutex_unlock(&event_mutex);
return ret;
}
@ -362,91 +416,49 @@ end:
*
* - Remove uprobe: -:[GRP/]EVENT
*/
static int create_trace_uprobe(int argc, char **argv)
static int trace_uprobe_create(int argc, const char **argv)
{
struct trace_uprobe *tu;
char *arg, *event, *group, *filename, *rctr, *rctr_end;
const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
char *arg, *filename, *rctr, *rctr_end, *tmp;
char buf[MAX_EVENT_NAME_LEN];
struct path path;
unsigned long offset, ref_ctr_offset;
bool is_delete, is_return;
bool is_return = false;
int i, ret;
ret = 0;
is_delete = false;
is_return = false;
event = NULL;
group = NULL;
ref_ctr_offset = 0;
/* argc must be >= 1 */
if (argv[0][0] == '-')
is_delete = true;
else if (argv[0][0] == 'r')
if (argv[0][0] == 'r')
is_return = true;
else if (argv[0][0] != 'p') {
pr_info("Probe definition must be started with 'p', 'r' or '-'.\n");
return -EINVAL;
}
else if (argv[0][0] != 'p' || argc < 2)
return -ECANCELED;
if (argv[0][1] == ':') {
if (argv[0][1] == ':')
event = &argv[0][2];
arg = strchr(event, '/');
if (arg) {
group = event;
event = arg + 1;
event[-1] = '\0';
if (!strchr(argv[1], '/'))
return -ECANCELED;
if (strlen(group) == 0) {
pr_info("Group name is not specified\n");
return -EINVAL;
}
}
if (strlen(event) == 0) {
pr_info("Event name is not specified\n");
return -EINVAL;
}
}
if (!group)
group = UPROBE_EVENT_SYSTEM;
filename = kstrdup(argv[1], GFP_KERNEL);
if (!filename)
return -ENOMEM;
if (is_delete) {
int ret;
if (!event) {
pr_info("Delete command needs an event name.\n");
return -EINVAL;
}
mutex_lock(&uprobe_lock);
tu = find_probe_event(event, group);
if (!tu) {
mutex_unlock(&uprobe_lock);
pr_info("Event %s/%s doesn't exist.\n", group, event);
return -ENOENT;
}
/* delete an event */
ret = unregister_trace_uprobe(tu);
mutex_unlock(&uprobe_lock);
return ret;
}
if (argc < 2) {
pr_info("Probe point is not specified.\n");
return -EINVAL;
}
/* Find the last occurrence, in case the path contains ':' too. */
arg = strrchr(argv[1], ':');
if (!arg)
return -EINVAL;
arg = strrchr(filename, ':');
if (!arg || !isdigit(arg[1])) {
kfree(filename);
return -ECANCELED;
}
*arg++ = '\0';
filename = argv[1];
ret = kern_path(filename, LOOKUP_FOLLOW, &path);
if (ret)
if (ret) {
kfree(filename);
return ret;
}
if (!d_is_reg(path.dentry)) {
ret = -EINVAL;
goto fail_address_parse;
@ -480,7 +492,11 @@ static int create_trace_uprobe(int argc, char **argv)
argv += 2;
/* setup a probe */
if (!event) {
if (event) {
ret = traceprobe_parse_event_name(&event, &group, buf);
if (ret)
goto fail_address_parse;
} else {
char *tail;
char *ptr;
@ -508,60 +524,21 @@ static int create_trace_uprobe(int argc, char **argv)
tu->offset = offset;
tu->ref_ctr_offset = ref_ctr_offset;
tu->path = path;
tu->filename = kstrdup(filename, GFP_KERNEL);
if (!tu->filename) {
pr_info("Failed to allocate filename.\n");
ret = -ENOMEM;
goto error;
}
tu->filename = filename;
/* parse arguments */
ret = 0;
for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
struct probe_arg *parg = &tu->tp.args[i];
/* Increment count for freeing args in error case */
tu->tp.nr_args++;
/* Parse argument name */
arg = strchr(argv[i], '=');
if (arg) {
*arg++ = '\0';
parg->name = kstrdup(argv[i], GFP_KERNEL);
} else {
arg = argv[i];
/* If argument name is omitted, set "argN" */
snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
parg->name = kstrdup(buf, GFP_KERNEL);
}
if (!parg->name) {
pr_info("Failed to allocate argument[%d] name.\n", i);
tmp = kstrdup(argv[i], GFP_KERNEL);
if (!tmp) {
ret = -ENOMEM;
goto error;
}
if (!is_good_name(parg->name)) {
pr_info("Invalid argument[%d] name: %s\n", i, parg->name);
ret = -EINVAL;
goto error;
}
if (traceprobe_conflict_field_name(parg->name, tu->tp.args, i)) {
pr_info("Argument[%d] name '%s' conflicts with "
"another field.\n", i, argv[i]);
ret = -EINVAL;
goto error;
}
/* Parse fetch argument */
ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg,
ret = traceprobe_parse_probe_arg(&tu->tp, i, tmp,
is_return ? TPARG_FL_RETURN : 0);
if (ret) {
pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
kfree(tmp);
if (ret)
goto error;
}
}
ret = register_trace_uprobe(tu);
@ -575,48 +552,35 @@ error:
fail_address_parse:
path_put(&path);
kfree(filename);
pr_info("Failed to parse address or file.\n");
return ret;
}
static int cleanup_all_probes(void)
static int create_or_delete_trace_uprobe(int argc, char **argv)
{
struct trace_uprobe *tu;
int ret = 0;
int ret;
mutex_lock(&uprobe_lock);
while (!list_empty(&uprobe_list)) {
tu = list_entry(uprobe_list.next, struct trace_uprobe, list);
ret = unregister_trace_uprobe(tu);
if (ret)
break;
}
mutex_unlock(&uprobe_lock);
return ret;
if (argv[0][0] == '-')
return dyn_event_release(argc, argv, &trace_uprobe_ops);
ret = trace_uprobe_create(argc, (const char **)argv);
return ret == -ECANCELED ? -EINVAL : ret;
}
static int trace_uprobe_release(struct dyn_event *ev)
{
struct trace_uprobe *tu = to_trace_uprobe(ev);
return unregister_trace_uprobe(tu);
}
/* Probes listing interfaces */
static void *probes_seq_start(struct seq_file *m, loff_t *pos)
static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev)
{
mutex_lock(&uprobe_lock);
return seq_list_start(&uprobe_list, *pos);
}
static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
{
return seq_list_next(v, &uprobe_list, pos);
}
static void probes_seq_stop(struct seq_file *m, void *v)
{
mutex_unlock(&uprobe_lock);
}
static int probes_seq_show(struct seq_file *m, void *v)
{
struct trace_uprobe *tu = v;
struct trace_uprobe *tu = to_trace_uprobe(ev);
char c = is_ret_probe(tu) ? 'r' : 'p';
int i;
@ -634,11 +598,21 @@ static int probes_seq_show(struct seq_file *m, void *v)
return 0;
}
static int probes_seq_show(struct seq_file *m, void *v)
{
struct dyn_event *ev = v;
if (!is_trace_uprobe(ev))
return 0;
return trace_uprobe_show(m, ev);
}
static const struct seq_operations probes_seq_op = {
.start = probes_seq_start,
.next = probes_seq_next,
.stop = probes_seq_stop,
.show = probes_seq_show
.start = dyn_event_seq_start,
.next = dyn_event_seq_next,
.stop = dyn_event_seq_stop,
.show = probes_seq_show
};
static int probes_open(struct inode *inode, struct file *file)
@ -646,7 +620,7 @@ static int probes_open(struct inode *inode, struct file *file)
int ret;
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
ret = cleanup_all_probes();
ret = dyn_events_release_all(&trace_uprobe_ops);
if (ret)
return ret;
}
@ -657,7 +631,8 @@ static int probes_open(struct inode *inode, struct file *file)
static ssize_t probes_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos)
{
return trace_parse_run_command(file, buffer, count, ppos, create_trace_uprobe);
return trace_parse_run_command(file, buffer, count, ppos,
create_or_delete_trace_uprobe);
}
static const struct file_operations uprobe_events_ops = {
@ -672,17 +647,22 @@ static const struct file_operations uprobe_events_ops = {
/* Probes profiling interfaces */
static int probes_profile_seq_show(struct seq_file *m, void *v)
{
struct trace_uprobe *tu = v;
struct dyn_event *ev = v;
struct trace_uprobe *tu;
if (!is_trace_uprobe(ev))
return 0;
tu = to_trace_uprobe(ev);
seq_printf(m, " %s %-44s %15lu\n", tu->filename,
trace_event_name(&tu->tp.call), tu->nhit);
return 0;
}
static const struct seq_operations profile_seq_op = {
.start = probes_seq_start,
.next = probes_seq_next,
.stop = probes_seq_stop,
.start = dyn_event_seq_start,
.next = dyn_event_seq_next,
.stop = dyn_event_seq_stop,
.show = probes_profile_seq_show
};
@ -1384,7 +1364,7 @@ create_local_trace_uprobe(char *name, unsigned long offs,
}
/*
* local trace_kprobes are not added to probe_list, so they are never
* local trace_kprobes are not added to dyn_event, so they are never
* searched in find_trace_kprobe(). Therefore, there is no concern of
* duplicated name "DUMMY_EVENT" here.
*/
@ -1432,6 +1412,11 @@ void destroy_local_trace_uprobe(struct trace_event_call *event_call)
static __init int init_uprobe_trace(void)
{
struct dentry *d_tracer;
int ret;
ret = dyn_event_register(&trace_uprobe_ops);
if (ret)
return ret;
d_tracer = tracing_init_dentry();
if (IS_ERR(d_tracer))

8
lib/seq_buf.c
View File

@ -140,13 +140,17 @@ int seq_buf_bprintf(struct seq_buf *s, const char *fmt, const u32 *binary)
*/
int seq_buf_puts(struct seq_buf *s, const char *str)
{
unsigned int len = strlen(str);
size_t len = strlen(str);
WARN_ON(s->size == 0);
/* Add 1 to len for the trailing null byte which must be there */
len += 1;
if (seq_buf_can_fit(s, len)) {
memcpy(s->buffer + s->len, str, len);
s->len += len;
/* Don't count the trailing null byte against the capacity */
s->len += len - 1;
return 0;
}
seq_buf_set_overflow(s);

2
scripts/recordmcount.c
View File

@ -397,7 +397,7 @@ static uint32_t (*w2)(uint16_t);
static int
is_mcounted_section_name(char const *const txtname)
{
return strcmp(".text", txtname) == 0 ||
return strncmp(".text", txtname, 5) == 0 ||
strcmp(".init.text", txtname) == 0 ||
strcmp(".ref.text", txtname) == 0 ||
strcmp(".sched.text", txtname) == 0 ||

13
scripts/recordmcount.pl
View File

@ -142,6 +142,11 @@ my %text_sections = (
".text.unlikely" => 1,
);
# Acceptable section-prefixes to record.
my %text_section_prefixes = (
".text." => 1,
);
# Note: we are nice to C-programmers here, thus we skip the '||='-idiom.
$objdump = 'objdump' if (!$objdump);
$objcopy = 'objcopy' if (!$objcopy);
@ -519,6 +524,14 @@ while (<IN>) {
# Only record text sections that we know are safe
$read_function = defined($text_sections{$1});
if (!$read_function) {
foreach my $prefix (keys %text_section_prefixes) {
if (substr($1, 0, length $prefix) eq $prefix) {
$read_function = 1;
last;
}
}
}
# print out any recorded offsets
update_funcs();

30
tools/testing/selftests/ftrace/test.d/dynevent/add_remove_kprobe.tc 100644
View File

@ -0,0 +1,30 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
# description: Generic dynamic event - add/remove kprobe events
[ -f dynamic_events ] || exit_unsupported
grep -q "place: \[<module>:\]<symbol>" README || exit_unsupported
grep -q "place (kretprobe): \[<module>:\]<symbol>" README || exit_unsupported
echo 0 > events/enable
echo > dynamic_events
PLACE=_do_fork
echo "p:myevent1 $PLACE" >> dynamic_events
echo "r:myevent2 $PLACE" >> dynamic_events
grep -q myevent1 dynamic_events
grep -q myevent2 dynamic_events
test -d events/kprobes/myevent1
test -d events/kprobes/myevent2
echo "-:myevent2" >> dynamic_events
grep -q myevent1 dynamic_events
! grep -q myevent2 dynamic_events
echo > dynamic_events
clear_trace

27
tools/testing/selftests/ftrace/test.d/dynevent/add_remove_synth.tc 100644
View File

@ -0,0 +1,27 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
# description: Generic dynamic event - add/remove synthetic events
[ -f dynamic_events ] || exit_unsupported
grep -q "s:\[synthetic/\]" README || exit_unsupported
echo 0 > events/enable
echo > dynamic_events
echo "s:latency1 u64 lat; pid_t pid;" >> dynamic_events
echo "s:latency2 u64 lat; pid_t pid;" >> dynamic_events
grep -q latency1 dynamic_events
grep -q latency2 dynamic_events
test -d events/synthetic/latency1
test -d events/synthetic/latency2
echo "-:synthetic/latency2" >> dynamic_events
grep -q latency1 dynamic_events
! grep -q latency2 dynamic_events
echo > dynamic_events
clear_trace

50
tools/testing/selftests/ftrace/test.d/dynevent/clear_select_events.tc 100644
View File

@ -0,0 +1,50 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
# description: Generic dynamic event - selective clear (compatibility)
[ -f dynamic_events ] || exit_unsupported
grep -q "place: \[<module>:\]<symbol>" README || exit_unsupported
grep -q "place (kretprobe): \[<module>:\]<symbol>" README || exit_unsupported
grep -q "s:\[synthetic/\]" README || exit_unsupported
[ -f synthetic_events ] || exit_unsupported
[ -f kprobe_events ] || exit_unsupported
echo 0 > events/enable
echo > dynamic_events
PLACE=_do_fork
setup_events() {
echo "p:myevent1 $PLACE" >> dynamic_events
echo "s:latency1 u64 lat; pid_t pid;" >> dynamic_events
echo "r:myevent2 $PLACE" >> dynamic_events
echo "s:latency2 u64 lat; pid_t pid;" >> dynamic_events
grep -q myevent1 dynamic_events
grep -q myevent2 dynamic_events
grep -q latency1 dynamic_events
grep -q latency2 dynamic_events
}
setup_events
echo > synthetic_events
grep -q myevent1 dynamic_events
grep -q myevent2 dynamic_events
! grep -q latency1 dynamic_events
! grep -q latency2 dynamic_events
echo > dynamic_events
setup_events
echo > kprobe_events
! grep -q myevent1 dynamic_events
! grep -q myevent2 dynamic_events
grep -q latency1 dynamic_events
grep -q latency2 dynamic_events
echo > dynamic_events

49
tools/testing/selftests/ftrace/test.d/dynevent/generic_clear_event.tc 100644
View File

@ -0,0 +1,49 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
# description: Generic dynamic event - generic clear event
[ -f dynamic_events ] || exit_unsupported
grep -q "place: \[<module>:\]<symbol>" README || exit_unsupported
grep -q "place (kretprobe): \[<module>:\]<symbol>" README || exit_unsupported
grep -q "s:\[synthetic/\]" README || exit_unsupported
echo 0 > events/enable
echo > dynamic_events
PLACE=_do_fork
setup_events() {
echo "p:myevent1 $PLACE" >> dynamic_events
echo "s:latency1 u64 lat; pid_t pid;" >> dynamic_events
echo "r:myevent2 $PLACE" >> dynamic_events
echo "s:latency2 u64 lat; pid_t pid;" >> dynamic_events
grep -q myevent1 dynamic_events
grep -q myevent2 dynamic_events
grep -q latency1 dynamic_events
grep -q latency2 dynamic_events
}
setup_events
echo "!p:myevent1 $PLACE" >> dynamic_events
! grep -q myevent1 dynamic_events
grep -q myevent2 dynamic_events
grep -q latency1 dynamic_events
grep -q latency2 dynamic_events
echo "!s:latency1 u64 lat; pid_t pid;" >> dynamic_events
grep -q myevent2 dynamic_events
! grep -q latency1 dynamic_events
grep -q latency2 dynamic_events
echo "!r:myevent2 $PLACE" >> dynamic_events
! grep -q myevent2 dynamic_events
grep -q latency2 dynamic_events
echo "!s:latency2 u64 lat; pid_t pid;" >> dynamic_events
! grep -q latency2 dynamic_events
echo > dynamic_events