mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-19 18:24:14 +08:00
568b329a02
. avoid walking the stack when there is no room left in the buffer . generalize get_perf_callchain() to be called from bpf helper Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
129 lines
2.7 KiB
C
129 lines
2.7 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 <linux/compat.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
#include <asm/ptrace.h>
|
|
#include <asm/stacktrace.h>
|
|
|
|
static int backtrace_stack(void *data, char *name)
|
|
{
|
|
/* Yes, we want all stacks */
|
|
return 0;
|
|
}
|
|
|
|
static int backtrace_address(void *data, unsigned long addr, int reliable)
|
|
{
|
|
unsigned int *depth = data;
|
|
|
|
if ((*depth)--)
|
|
oprofile_add_trace(addr);
|
|
return 0;
|
|
}
|
|
|
|
static struct stacktrace_ops backtrace_ops = {
|
|
.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)
|
|
{
|
|
/* Also check accessibility of one struct frame_head beyond: */
|
|
struct stack_frame_ia32 bufhead[2];
|
|
struct stack_frame_ia32 *fp;
|
|
unsigned long bytes;
|
|
|
|
bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
|
|
if (bytes != 0)
|
|
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 IA32 */
|
|
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)
|
|
{
|
|
/* Also check accessibility of one struct frame_head beyond: */
|
|
struct stack_frame bufhead[2];
|
|
unsigned long bytes;
|
|
|
|
bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
|
|
if (bytes != 0)
|
|
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(regs)) {
|
|
unsigned long stack = kernel_stack_pointer(regs);
|
|
if (depth)
|
|
dump_trace(NULL, regs, (unsigned long *)stack, 0,
|
|
&backtrace_ops, &depth);
|
|
return;
|
|
}
|
|
|
|
if (x86_backtrace_32(regs, depth))
|
|
return;
|
|
|
|
while (depth-- && head)
|
|
head = dump_user_backtrace(head);
|
|
}
|