mirror of
https://github.com/torvalds/linux.git
synced 2024-11-08 05:01:48 +00:00
9c0729dc80
The various stack tracing routines take a 'bp' argument in which the caller is supposed to provide the base pointer to use, or 0 if doesn't have one. Since bp is garbage whenever CONFIG_FRAME_POINTER is not defined, this means all callers in principle should either always pass 0, or be conditional on CONFIG_FRAME_POINTER. However, there are only really three use cases for stack tracing: (a) Trace the current task, including IRQ stack if any (b) Trace the current task, but skip IRQ stack (c) Trace some other task In all cases, if CONFIG_FRAME_POINTER is not defined, bp should just be 0. If it _is_ defined, then - in case (a) bp should be gotten directly from the CPU's register, so the caller should pass NULL for regs, - in case (b) the caller should should pass the IRQ registers to dump_trace(), - in case (c) bp should be gotten from the top of the task's stack, so the caller should pass NULL for regs. Hence, the bp argument is not necessary because the combination of task and regs is sufficient to determine an appropriate value for bp. This patch introduces a new inline function stack_frame(task, regs) that computes the desired bp. This function is then called from the two versions of dump_stack(). Signed-off-by: Soren Sandmann <ssp@redhat.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arjan van de Ven <arjan@infradead.org>, Cc: Frederic Weisbecker <fweisbec@gmail.com>, Cc: Arnaldo Carvalho de Melo <acme@redhat.com>, LKML-Reference: <m3oc9rop28.fsf@dhcp-100-3-82.bos.redhat.com>> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
140 lines
3.0 KiB
C
140 lines
3.0 KiB
C
/**
|
|
* @file backtrace.c
|
|
*
|
|
* @remark Copyright 2002 OProfile authors
|
|
* @remark Read the file COPYING
|
|
*
|
|
* @author John Levon
|
|
* @author David Smith
|
|
*/
|
|
|
|
#include <linux/oprofile.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/mm.h>
|
|
#include <asm/ptrace.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/stacktrace.h>
|
|
#include <linux/compat.h>
|
|
|
|
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)
|
|
{
|
|
/* Yes, we want all stacks */
|
|
return 0;
|
|
}
|
|
|
|
static void backtrace_address(void *data, unsigned long addr, int reliable)
|
|
{
|
|
unsigned int *depth = data;
|
|
|
|
if ((*depth)--)
|
|
oprofile_add_trace(addr);
|
|
}
|
|
|
|
static struct stacktrace_ops backtrace_ops = {
|
|
.warning = backtrace_warning,
|
|
.warning_symbol = backtrace_warning_symbol,
|
|
.stack = backtrace_stack,
|
|
.address = backtrace_address,
|
|
.walk_stack = print_context_stack,
|
|
};
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static struct stack_frame_ia32 *
|
|
dump_user_backtrace_32(struct stack_frame_ia32 *head)
|
|
{
|
|
struct stack_frame_ia32 bufhead[2];
|
|
struct stack_frame_ia32 *fp;
|
|
|
|
/* Also check accessibility of one struct frame_head beyond */
|
|
if (!access_ok(VERIFY_READ, head, sizeof(bufhead)))
|
|
return NULL;
|
|
if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead)))
|
|
return NULL;
|
|
|
|
fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame);
|
|
|
|
oprofile_add_trace(bufhead[0].return_address);
|
|
|
|
/* frame pointers should strictly progress back up the stack
|
|
* (towards higher addresses) */
|
|
if (head >= fp)
|
|
return NULL;
|
|
|
|
return fp;
|
|
}
|
|
|
|
static inline int
|
|
x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)
|
|
{
|
|
struct stack_frame_ia32 *head;
|
|
|
|
/* User process is 32-bit */
|
|
if (!current || !test_thread_flag(TIF_IA32))
|
|
return 0;
|
|
|
|
head = (struct stack_frame_ia32 *) regs->bp;
|
|
while (depth-- && head)
|
|
head = dump_user_backtrace_32(head);
|
|
|
|
return 1;
|
|
}
|
|
|
|
#else
|
|
static inline int
|
|
x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_COMPAT */
|
|
|
|
static struct stack_frame *dump_user_backtrace(struct stack_frame *head)
|
|
{
|
|
struct stack_frame bufhead[2];
|
|
|
|
/* Also check accessibility of one struct stack_frame beyond */
|
|
if (!access_ok(VERIFY_READ, head, sizeof(bufhead)))
|
|
return NULL;
|
|
if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead)))
|
|
return NULL;
|
|
|
|
oprofile_add_trace(bufhead[0].return_address);
|
|
|
|
/* frame pointers should strictly progress back up the stack
|
|
* (towards higher addresses) */
|
|
if (head >= bufhead[0].next_frame)
|
|
return NULL;
|
|
|
|
return bufhead[0].next_frame;
|
|
}
|
|
|
|
void
|
|
x86_backtrace(struct pt_regs * const regs, unsigned int depth)
|
|
{
|
|
struct stack_frame *head = (struct stack_frame *)frame_pointer(regs);
|
|
|
|
if (!user_mode_vm(regs)) {
|
|
unsigned long stack = kernel_stack_pointer(regs);
|
|
if (depth)
|
|
dump_trace(NULL, regs, (unsigned long *)stack,
|
|
&backtrace_ops, &depth);
|
|
return;
|
|
}
|
|
|
|
if (x86_backtrace_32(regs, depth))
|
|
return;
|
|
|
|
while (depth-- && head)
|
|
head = dump_user_backtrace(head);
|
|
}
|