linux/arch/x86/oprofile/backtrace.c
Gabriel Krisman Bertazi 47cd4dac1f x86/oprofile: Avoid TIF_IA32 when checking 64bit mode
In preparation to remove TIF_IA32, stop using it in oprofile code. Use
user_64bit_mode() instead.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201004032536.1229030-4-krisman@collabora.com
2020-10-26 13:46:46 +01:00

128 lines
2.6 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>
#include <asm/unwind.h>
#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 || user_64bit_mode(regs))
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)) {
struct unwind_state state;
unsigned long addr;
if (!depth)
return;
oprofile_add_trace(regs->ip);
if (!--depth)
return;
for (unwind_start(&state, current, regs, NULL);
!unwind_done(&state); unwind_next_frame(&state)) {
addr = unwind_get_return_address(&state);
if (!addr)
break;
oprofile_add_trace(addr);
if (!--depth)
break;
}
return;
}
if (x86_backtrace_32(regs, depth))
return;
while (depth-- && head)
head = dump_user_backtrace(head);
}