![Linus Torvalds](/assets/img/avatar_default.png)
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: Fix text_poke_smp_batch() deadlock perf tools: Fix thread_map event synthesizing in top and record watchdog, nmi: Lower the severity of error messages ARM: oprofile: Fix backtraces in timer mode oprofile: Fix usage of CONFIG_HW_PERF_EVENTS for oprofile_perf_init and friends
123 lines
2.7 KiB
C
123 lines
2.7 KiB
C
/**
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* @file common.c
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*
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* @remark Copyright 2004 Oprofile Authors
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* @remark Copyright 2010 ARM Ltd.
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* @remark Read the file COPYING
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*
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* @author Zwane Mwaikambo
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* @author Will Deacon [move to perf]
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*/
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#include <linux/cpumask.h>
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#include <linux/init.h>
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#include <linux/mutex.h>
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#include <linux/oprofile.h>
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#include <linux/perf_event.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <asm/stacktrace.h>
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#include <linux/uaccess.h>
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#include <asm/perf_event.h>
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#include <asm/ptrace.h>
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#ifdef CONFIG_HW_PERF_EVENTS
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char *op_name_from_perf_id(void)
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{
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enum arm_perf_pmu_ids id = armpmu_get_pmu_id();
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switch (id) {
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case ARM_PERF_PMU_ID_XSCALE1:
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return "arm/xscale1";
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case ARM_PERF_PMU_ID_XSCALE2:
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return "arm/xscale2";
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case ARM_PERF_PMU_ID_V6:
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return "arm/armv6";
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case ARM_PERF_PMU_ID_V6MP:
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return "arm/mpcore";
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case ARM_PERF_PMU_ID_CA8:
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return "arm/armv7";
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case ARM_PERF_PMU_ID_CA9:
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return "arm/armv7-ca9";
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default:
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return NULL;
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}
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}
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#endif
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static int report_trace(struct stackframe *frame, void *d)
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{
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unsigned int *depth = d;
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if (*depth) {
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oprofile_add_trace(frame->pc);
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(*depth)--;
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}
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return *depth == 0;
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}
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/*
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* The registers we're interested in are at the end of the variable
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* length saved register structure. The fp points at the end of this
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* structure so the address of this struct is:
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* (struct frame_tail *)(xxx->fp)-1
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*/
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struct frame_tail {
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struct frame_tail *fp;
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unsigned long sp;
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unsigned long lr;
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} __attribute__((packed));
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static struct frame_tail* user_backtrace(struct frame_tail *tail)
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{
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struct frame_tail buftail[2];
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/* Also check accessibility of one struct frame_tail beyond */
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if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
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return NULL;
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if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail)))
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return NULL;
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oprofile_add_trace(buftail[0].lr);
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/* frame pointers should strictly progress back up the stack
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* (towards higher addresses) */
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if (tail + 1 >= buftail[0].fp)
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return NULL;
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return buftail[0].fp-1;
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}
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static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
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{
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struct frame_tail *tail = ((struct frame_tail *) regs->ARM_fp) - 1;
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if (!user_mode(regs)) {
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struct stackframe frame;
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frame.fp = regs->ARM_fp;
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frame.sp = regs->ARM_sp;
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frame.lr = regs->ARM_lr;
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frame.pc = regs->ARM_pc;
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walk_stackframe(&frame, report_trace, &depth);
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return;
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}
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while (depth-- && tail && !((unsigned long) tail & 3))
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tail = user_backtrace(tail);
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}
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int __init oprofile_arch_init(struct oprofile_operations *ops)
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{
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/* provide backtrace support also in timer mode: */
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ops->backtrace = arm_backtrace;
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return oprofile_perf_init(ops);
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}
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void __exit oprofile_arch_exit(void)
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{
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oprofile_perf_exit();
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}
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