diff options
| -rw-r--r-- | kernel/trace/trace_sysprof.c | 80 |
1 files changed, 76 insertions, 4 deletions
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c index ba55b871b3d..b1137c11ef8 100644 --- a/kernel/trace/trace_sysprof.c +++ b/kernel/trace/trace_sysprof.c @@ -3,7 +3,7 @@ * * 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> @@ -11,13 +11,17 @@ #include <linux/uaccess.h> #include <linux/ftrace.h> #include <linux/module.h> +#include <linux/irq.h> #include <linux/fs.h> #include "trace.h" -static struct trace_array *ctx_trace; +static struct trace_array *sysprof_trace; static int __read_mostly tracer_enabled; +/* + * 10 msecs for now: + */ static const unsigned long sample_period = 1000000; /* @@ -25,10 +29,78 @@ static const unsigned long sample_period = 1000000; */ static DEFINE_PER_CPU(struct hrtimer, stack_trace_hrtimer); +struct stack_frame { + const void __user *next_fp; + unsigned long return_address; +}; + +static int copy_stack_frame(const void __user *fp, struct stack_frame *frame) +{ + if (!access_ok(VERIFY_READ, fp, sizeof(*frame))) + return 0; + + if (__copy_from_user_inatomic(frame, frame_pointer, sizeof(*frame))) + return 0; + + return 1; +} + +#define SYSPROF_MAX_ADDRESSES 512 + +static void timer_notify(struct pt_regs *regs, int cpu) +{ + const void __user *frame_pointer; + struct trace_array_cpu *data; + struct stack_frame frame; + struct trace_array *tr; + 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; + + if (!is_user) { + /* kernel */ + ftrace(tr, data, current->pid, 1, 0); + return; + + } + + trace_special(tr, data, 0, current->pid, regs->ip); + + frame_pointer = (void __user *)regs->bp; + + for (i = 0; i < SYSPROF_MAX_ADDRESSES; i++) { + if (!copy_stack_frame(frame_pointer, &frame)) + break; + if ((unsigned long)frame_pointer < regs->sp) + break; + + trace_special(tr, data, 1, frame.return_address, + (unsigned long)frame_pointer); + frame_pointer = frame.next_fp; + } + + trace_special(tr, data, 2, current->pid, i); + + if (i == SYSPROF_MAX_ADDRESSES) + trace_special(tr, data, -1, -1, -1); +} + static enum hrtimer_restart stack_trace_timer_fn(struct hrtimer *hrtimer) { /* trace here */ - panic_timeout++; + timer_notify(get_irq_regs(), smp_processor_id()); hrtimer_forward_now(hrtimer, ns_to_ktime(sample_period)); @@ -100,7 +172,7 @@ static notrace void stop_stack_trace(struct trace_array *tr) static notrace void stack_trace_init(struct trace_array *tr) { - ctx_trace = tr; + sysprof_trace = tr; if (tr->ctrl) start_stack_trace(tr); |