perf_event: Provide vmalloc() based mmap() backing
[safe/jmp/linux-2.6] / kernel / trace / trace_sysprof.c
index ebcb66d..f669396 100644 (file)
@@ -1,9 +1,9 @@
 /*
  * 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>
- * Copyright (C) 2004, 2005, Soeren Sandmann
  */
 #include <linux/kallsyms.h>
 #include <linux/debugfs.h>
@@ -88,20 +88,19 @@ static void backtrace_address(void *data, unsigned long addr, int reliable)
        }
 }
 
-const static struct stacktrace_ops backtrace_ops = {
+static const struct stacktrace_ops backtrace_ops = {
        .warning                = backtrace_warning,
        .warning_symbol         = backtrace_warning_symbol,
        .stack                  = backtrace_stack,
        .address                = backtrace_address,
 };
 
-static struct pt_regs *
+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 *user_stack;
        char *stack;
 
        info.tr = tr;
@@ -119,10 +118,7 @@ trace_kernel(struct pt_regs *regs, struct trace_array *tr,
 
        dump_trace(NULL, regs, (void *)stack, bp, &backtrace_ops, &info);
 
-       /* Now trace the user stack */
-       user_stack = ((char *)current->thread.sp0 - sizeof(struct pt_regs));
-
-       return (struct pt_regs *)user_stack;
+       return info.pos;
 }
 
 static void timer_notify(struct pt_regs *regs, int cpu)
@@ -150,32 +146,44 @@ static void timer_notify(struct pt_regs *regs, int cpu)
        __trace_special(tr, data, 0, 0, current->pid);
 
        if (!is_user)
-               regs = trace_kernel(regs, tr, data);
+               i = trace_kernel(regs, tr, data);
+       else
+               i = 0;
 
-       fp = (void __user *)regs->bp;
+       /*
+        * 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;
 
-       __trace_special(tr, data, 2, regs->ip, 0);
+               fp = (void __user *)regs->bp;
 
-       for (i = 0; i < sample_max_depth; i++) {
-               frame.next_fp = 0;
-               frame.return_address = 0;
-               if (!copy_stack_frame(fp, &frame))
-                       break;
-               if ((unsigned long)fp < regs->sp)
-                       break;
+               __trace_special(tr, data, 2, regs->ip, 0);
 
-               __trace_special(tr, data, 2, frame.return_address,
-                             (unsigned long)fp);
-               fp = frame.next_fp;
-       }
+               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, 3, current->pid, i);
+                       __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)
@@ -188,27 +196,20 @@ static enum hrtimer_restart stack_trace_timer_fn(struct hrtimer *hrtimer)
        return HRTIMER_RESTART;
 }
 
-static void start_stack_timer(int cpu)
+static void start_stack_timer(void *unused)
 {
-       struct hrtimer *hrtimer = &per_cpu(stack_trace_hrtimer, cpu);
+       struct hrtimer *hrtimer = &__get_cpu_var(stack_trace_hrtimer);
 
        hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
        hrtimer->function = stack_trace_timer_fn;
-       hrtimer->cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;
 
-       hrtimer_start(hrtimer, ns_to_ktime(sample_period), HRTIMER_MODE_REL);
+       hrtimer_start(hrtimer, ns_to_ktime(sample_period),
+                     HRTIMER_MODE_REL_PINNED);
 }
 
 static void start_stack_timers(void)
 {
-       cpumask_t saved_mask = current->cpus_allowed;
-       int cpu;
-
-       for_each_online_cpu(cpu) {
-               set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
-               start_stack_timer(cpu);
-       }
-       set_cpus_allowed_ptr(current, &saved_mask);
+       on_each_cpu(start_stack_timer, NULL, 1);
 }
 
 static void stop_stack_timer(int cpu)
@@ -226,25 +227,6 @@ static void stop_stack_timers(void)
                stop_stack_timer(cpu);
 }
 
-static void stack_reset(struct trace_array *tr)
-{
-       int cpu;
-
-       tr->time_start = ftrace_now(tr->cpu);
-
-       for_each_online_cpu(cpu)
-               tracing_reset(tr->data[cpu]);
-}
-
-static void start_stack_trace(struct trace_array *tr)
-{
-       mutex_lock(&sample_timer_lock);
-       stack_reset(tr);
-       start_stack_timers();
-       tracer_enabled = 1;
-       mutex_unlock(&sample_timer_lock);
-}
-
 static void stop_stack_trace(struct trace_array *tr)
 {
        mutex_lock(&sample_timer_lock);
@@ -253,27 +235,23 @@ static void stop_stack_trace(struct trace_array *tr)
        mutex_unlock(&sample_timer_lock);
 }
 
-static void stack_trace_init(struct trace_array *tr)
+static int stack_trace_init(struct trace_array *tr)
 {
        sysprof_trace = tr;
 
-       if (tr->ctrl)
-               start_stack_trace(tr);
-}
+       tracing_start_cmdline_record();
 
-static void stack_trace_reset(struct trace_array *tr)
-{
-       if (tr->ctrl)
-               stop_stack_trace(tr);
+       mutex_lock(&sample_timer_lock);
+       start_stack_timers();
+       tracer_enabled = 1;
+       mutex_unlock(&sample_timer_lock);
+       return 0;
 }
 
-static void stack_trace_ctrl_update(struct trace_array *tr)
+static void stack_trace_reset(struct trace_array *tr)
 {
-       /* When starting a new trace, reset the buffers */
-       if (tr->ctrl)
-               start_stack_trace(tr);
-       else
-               stop_stack_trace(tr);
+       tracing_stop_cmdline_record();
+       stop_stack_trace(tr);
 }
 
 static struct tracer stack_trace __read_mostly =
@@ -281,7 +259,6 @@ static struct tracer stack_trace __read_mostly =
        .name           = "sysprof",
        .init           = stack_trace_init,
        .reset          = stack_trace_reset,
-       .ctrl_update    = stack_trace_ctrl_update,
 #ifdef CONFIG_FTRACE_SELFTEST
        .selftest    = trace_selftest_startup_sysprof,
 #endif
@@ -338,18 +315,14 @@ sysprof_sample_write(struct file *filp, const char __user *ubuf,
        return cnt;
 }
 
-static struct file_operations sysprof_sample_fops = {
+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)
 {
-       struct dentry *entry;
 
-       entry = debugfs_create_file("sysprof_sample_period", 0644,
+       trace_create_file("sysprof_sample_period", 0644,
                        d_tracer, NULL, &sysprof_sample_fops);
-       if (entry)
-               return;
-       pr_warning("Could not create debugfs 'dyn_ftrace_total_info' entry\n");
 }