+++ /dev/null
-/*
- * trace stack traces
- *
- * Copyright (C) 2004-2008, Soeren Sandmann
- * Copyright (C) 2007 Steven Rostedt <srostedt@redhat.com>
- * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
- */
-#include <linux/kallsyms.h>
-#include <linux/debugfs.h>
-#include <linux/hrtimer.h>
-#include <linux/uaccess.h>
-#include <linux/ftrace.h>
-#include <linux/module.h>
-#include <linux/irq.h>
-#include <linux/fs.h>
-
-#include <asm/stacktrace.h>
-
-#include "trace.h"
-
-static struct trace_array *sysprof_trace;
-static int __read_mostly tracer_enabled;
-
-/*
- * 1 msec sample interval by default:
- */
-static unsigned long sample_period = 1000000;
-static const unsigned int sample_max_depth = 512;
-
-static DEFINE_MUTEX(sample_timer_lock);
-/*
- * Per CPU hrtimers that do the profiling:
- */
-static DEFINE_PER_CPU(struct hrtimer, stack_trace_hrtimer);
-
-struct stack_frame_user {
- const void __user *next_fp;
- unsigned long return_address;
-};
-
-static int
-copy_stack_frame(const void __user *fp, struct stack_frame_user *frame)
-{
- int ret;
-
- if (!access_ok(VERIFY_READ, fp, sizeof(*frame)))
- return 0;
-
- ret = 1;
- pagefault_disable();
- if (__copy_from_user_inatomic(frame, fp, sizeof(*frame)))
- ret = 0;
- pagefault_enable();
-
- return ret;
-}
-
-struct backtrace_info {
- struct trace_array_cpu *data;
- struct trace_array *tr;
- int pos;
-};
-
-static void
-backtrace_warning_symbol(void *data, char *msg, unsigned long symbol)
-{
- /* Ignore warnings */
-}
-
-static void backtrace_warning(void *data, char *msg)
-{
- /* Ignore warnings */
-}
-
-static int backtrace_stack(void *data, char *name)
-{
- /* Don't bother with IRQ stacks for now */
- return -1;
-}
-
-static void backtrace_address(void *data, unsigned long addr, int reliable)
-{
- struct backtrace_info *info = data;
-
- if (info->pos < sample_max_depth && reliable) {
- __trace_special(info->tr, info->data, 1, addr, 0);
-
- info->pos++;
- }
-}
-
-static const struct stacktrace_ops backtrace_ops = {
- .warning = backtrace_warning,
- .warning_symbol = backtrace_warning_symbol,
- .stack = backtrace_stack,
- .address = backtrace_address,
- .walk_stack = print_context_stack,
-};
-
-static int
-trace_kernel(struct pt_regs *regs, struct trace_array *tr,
- struct trace_array_cpu *data)
-{
- struct backtrace_info info;
- unsigned long bp;
- char *stack;
-
- info.tr = tr;
- info.data = data;
- info.pos = 1;
-
- __trace_special(info.tr, info.data, 1, regs->ip, 0);
-
- stack = ((char *)regs + sizeof(struct pt_regs));
-#ifdef CONFIG_FRAME_POINTER
- bp = regs->bp;
-#else
- bp = 0;
-#endif
-
- dump_trace(NULL, regs, (void *)stack, bp, &backtrace_ops, &info);
-
- return info.pos;
-}
-
-static void timer_notify(struct pt_regs *regs, int cpu)
-{
- struct trace_array_cpu *data;
- struct stack_frame_user frame;
- struct trace_array *tr;
- const void __user *fp;
- int is_user;
- int i;
-
- if (!regs)
- return;
-
- tr = sysprof_trace;
- data = tr->data[cpu];
- is_user = user_mode(regs);
-
- if (!current || current->pid == 0)
- return;
-
- if (is_user && current->state != TASK_RUNNING)
- return;
-
- __trace_special(tr, data, 0, 0, current->pid);
-
- if (!is_user)
- i = trace_kernel(regs, tr, data);
- else
- i = 0;
-
- /*
- * Trace user stack if we are not a kernel thread
- */
- if (current->mm && i < sample_max_depth) {
- regs = (struct pt_regs *)current->thread.sp0 - 1;
-
- fp = (void __user *)regs->bp;
-
- __trace_special(tr, data, 2, regs->ip, 0);
-
- while (i < sample_max_depth) {
- frame.next_fp = NULL;
- frame.return_address = 0;
- if (!copy_stack_frame(fp, &frame))
- break;
- if ((unsigned long)fp < regs->sp)
- break;
-
- __trace_special(tr, data, 2, frame.return_address,
- (unsigned long)fp);
- fp = frame.next_fp;
-
- i++;
- }
-
- }
-
- /*
- * Special trace entry if we overflow the max depth:
- */
- if (i == sample_max_depth)
- __trace_special(tr, data, -1, -1, -1);
-
- __trace_special(tr, data, 3, current->pid, i);
-}
-
-static enum hrtimer_restart stack_trace_timer_fn(struct hrtimer *hrtimer)
-{
- /* trace here */
- timer_notify(get_irq_regs(), smp_processor_id());
-
- hrtimer_forward_now(hrtimer, ns_to_ktime(sample_period));
-
- return HRTIMER_RESTART;
-}
-
-static void start_stack_timer(void *unused)
-{
- struct hrtimer *hrtimer = &__get_cpu_var(stack_trace_hrtimer);
-
- hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
- hrtimer->function = stack_trace_timer_fn;
-
- hrtimer_start(hrtimer, ns_to_ktime(sample_period),
- HRTIMER_MODE_REL_PINNED);
-}
-
-static void start_stack_timers(void)
-{
- on_each_cpu(start_stack_timer, NULL, 1);
-}
-
-static void stop_stack_timer(int cpu)
-{
- struct hrtimer *hrtimer = &per_cpu(stack_trace_hrtimer, cpu);
-
- hrtimer_cancel(hrtimer);
-}
-
-static void stop_stack_timers(void)
-{
- int cpu;
-
- for_each_online_cpu(cpu)
- stop_stack_timer(cpu);
-}
-
-static void stop_stack_trace(struct trace_array *tr)
-{
- mutex_lock(&sample_timer_lock);
- stop_stack_timers();
- tracer_enabled = 0;
- mutex_unlock(&sample_timer_lock);
-}
-
-static int stack_trace_init(struct trace_array *tr)
-{
- sysprof_trace = tr;
-
- tracing_start_cmdline_record();
-
- mutex_lock(&sample_timer_lock);
- start_stack_timers();
- tracer_enabled = 1;
- mutex_unlock(&sample_timer_lock);
- return 0;
-}
-
-static void stack_trace_reset(struct trace_array *tr)
-{
- tracing_stop_cmdline_record();
- stop_stack_trace(tr);
-}
-
-static struct tracer stack_trace __read_mostly =
-{
- .name = "sysprof",
- .init = stack_trace_init,
- .reset = stack_trace_reset,
-#ifdef CONFIG_FTRACE_SELFTEST
- .selftest = trace_selftest_startup_sysprof,
-#endif
-};
-
-__init static int init_stack_trace(void)
-{
- return register_tracer(&stack_trace);
-}
-device_initcall(init_stack_trace);
-
-#define MAX_LONG_DIGITS 22
-
-static ssize_t
-sysprof_sample_read(struct file *filp, char __user *ubuf,
- size_t cnt, loff_t *ppos)
-{
- char buf[MAX_LONG_DIGITS];
- int r;
-
- r = sprintf(buf, "%ld\n", nsecs_to_usecs(sample_period));
-
- return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
-}
-
-static ssize_t
-sysprof_sample_write(struct file *filp, const char __user *ubuf,
- size_t cnt, loff_t *ppos)
-{
- char buf[MAX_LONG_DIGITS];
- unsigned long val;
-
- if (cnt > MAX_LONG_DIGITS-1)
- cnt = MAX_LONG_DIGITS-1;
-
- if (copy_from_user(&buf, ubuf, cnt))
- return -EFAULT;
-
- buf[cnt] = 0;
-
- val = simple_strtoul(buf, NULL, 10);
- /*
- * Enforce a minimum sample period of 100 usecs:
- */
- if (val < 100)
- val = 100;
-
- mutex_lock(&sample_timer_lock);
- stop_stack_timers();
- sample_period = val * 1000;
- start_stack_timers();
- mutex_unlock(&sample_timer_lock);
-
- return cnt;
-}
-
-static const struct file_operations sysprof_sample_fops = {
- .read = sysprof_sample_read,
- .write = sysprof_sample_write,
-};
-
-void init_tracer_sysprof_debugfs(struct dentry *d_tracer)
-{
-
- trace_create_file("sysprof_sample_period", 0644,
- d_tracer, NULL, &sysprof_sample_fops);
-}
projects / mv-sheeva.git / commitdiff