mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-23 20:53:53 +08:00
35de3b1aa1
It has come to my attention that kprobe event stack tracing does not work on powerpc. You can see with the following: # cd /sys/kernel/debug/tracing # echo stacktrace > trace_options # echo 'p kfree' > kprobe_events # echo 1 > events/kprobes/enable Will print the following warning: save_stack_trace_regs() not implemented yet. Although save_stack_trace() (which normal event stack traces use) is implemented, save_stack_trace_regs() which kprobe events use is not. This is a cheap attempt to implement that function. Note, This may have issues if a task tries to get a stack trace from another task with its regs, because it just passes in "current" to save_context_stack(). But this does solve the issue with stack tracing kprobe events. Reported-by: Chunyu Hu <chuhu@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
71 lines
1.6 KiB
C
71 lines
1.6 KiB
C
/*
|
|
* Stack trace utility
|
|
*
|
|
* Copyright 2008 Christoph Hellwig, IBM Corp.
|
|
*
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/export.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/stacktrace.h>
|
|
#include <asm/ptrace.h>
|
|
#include <asm/processor.h>
|
|
|
|
/*
|
|
* Save stack-backtrace addresses into a stack_trace buffer.
|
|
*/
|
|
static void save_context_stack(struct stack_trace *trace, unsigned long sp,
|
|
struct task_struct *tsk, int savesched)
|
|
{
|
|
for (;;) {
|
|
unsigned long *stack = (unsigned long *) sp;
|
|
unsigned long newsp, ip;
|
|
|
|
if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
|
|
return;
|
|
|
|
newsp = stack[0];
|
|
ip = stack[STACK_FRAME_LR_SAVE];
|
|
|
|
if (savesched || !in_sched_functions(ip)) {
|
|
if (!trace->skip)
|
|
trace->entries[trace->nr_entries++] = ip;
|
|
else
|
|
trace->skip--;
|
|
}
|
|
|
|
if (trace->nr_entries >= trace->max_entries)
|
|
return;
|
|
|
|
sp = newsp;
|
|
}
|
|
}
|
|
|
|
void save_stack_trace(struct stack_trace *trace)
|
|
{
|
|
unsigned long sp;
|
|
|
|
sp = current_stack_pointer();
|
|
|
|
save_context_stack(trace, sp, current, 1);
|
|
}
|
|
EXPORT_SYMBOL_GPL(save_stack_trace);
|
|
|
|
void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
|
|
{
|
|
save_context_stack(trace, tsk->thread.ksp, tsk, 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
|
|
|
|
void
|
|
save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
|
|
{
|
|
save_context_stack(trace, regs->gpr[1], current, 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(save_stack_trace_regs);
|