![Namhyung Kim](/assets/img/avatar_default.png)
Current stack dump code scans entire stack and check each entry
contains a pointer to kernel code. If CONFIG_FRAME_POINTER=y it
could mark whether the pointer is valid or not based on value of
the frame pointer. Invalid entries could be preceded by '?' sign.
However this was not going to happen because scan start point
was always higher than the frame pointer so that they could not
meet.
Commit 9c0729dc80
("x86: Eliminate bp argument from the stack
tracing routines") delayed bp acquisition point, so the bp was
read in lower frame, thus all of the entries were marked
invalid.
This patch fixes this by reverting above commit while retaining
stack_frame() helper as suggested by Frederic Weisbecker.
End result looks like below:
before:
[ 3.508329] Call Trace:
[ 3.508551] [<ffffffff814f35c9>] ? panic+0x91/0x199
[ 3.508662] [<ffffffff814f3739>] ? printk+0x68/0x6a
[ 3.508770] [<ffffffff81a981b2>] ? mount_block_root+0x257/0x26e
[ 3.508876] [<ffffffff81a9821f>] ? mount_root+0x56/0x5a
[ 3.508975] [<ffffffff81a98393>] ? prepare_namespace+0x170/0x1a9
[ 3.509216] [<ffffffff81a9772b>] ? kernel_init+0x1d2/0x1e2
[ 3.509335] [<ffffffff81003894>] ? kernel_thread_helper+0x4/0x10
[ 3.509442] [<ffffffff814f6880>] ? restore_args+0x0/0x30
[ 3.509542] [<ffffffff81a97559>] ? kernel_init+0x0/0x1e2
[ 3.509641] [<ffffffff81003890>] ? kernel_thread_helper+0x0/0x10
after:
[ 3.522991] Call Trace:
[ 3.523351] [<ffffffff814f35b9>] panic+0x91/0x199
[ 3.523468] [<ffffffff814f3729>] ? printk+0x68/0x6a
[ 3.523576] [<ffffffff81a981b2>] mount_block_root+0x257/0x26e
[ 3.523681] [<ffffffff81a9821f>] mount_root+0x56/0x5a
[ 3.523780] [<ffffffff81a98393>] prepare_namespace+0x170/0x1a9
[ 3.523885] [<ffffffff81a9772b>] kernel_init+0x1d2/0x1e2
[ 3.523987] [<ffffffff81003894>] kernel_thread_helper+0x4/0x10
[ 3.524228] [<ffffffff814f6880>] ? restore_args+0x0/0x30
[ 3.524345] [<ffffffff81a97559>] ? kernel_init+0x0/0x1e2
[ 3.524445] [<ffffffff81003890>] ? kernel_thread_helper+0x0/0x10
-v5:
* fix build breakage with oprofile
-v4:
* use 0 instead of regs->bp
* separate out printk changes
-v3:
* apply comment from Frederic
* add a couple of printk fixes
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Soren Sandmann <ssp@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Robert Richter <robert.richter@amd.com>
LKML-Reference: <1300416006-3163-1-git-send-email-namhyung@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
42 lines
1 KiB
C
42 lines
1 KiB
C
#ifndef _ASM_X86_KDEBUG_H
|
|
#define _ASM_X86_KDEBUG_H
|
|
|
|
#include <linux/notifier.h>
|
|
|
|
struct pt_regs;
|
|
|
|
/* Grossly misnamed. */
|
|
enum die_val {
|
|
DIE_OOPS = 1,
|
|
DIE_INT3,
|
|
DIE_DEBUG,
|
|
DIE_PANIC,
|
|
DIE_NMI,
|
|
DIE_DIE,
|
|
DIE_KERNELDEBUG,
|
|
DIE_TRAP,
|
|
DIE_GPF,
|
|
DIE_CALL,
|
|
DIE_PAGE_FAULT,
|
|
DIE_NMIUNKNOWN,
|
|
};
|
|
|
|
extern void printk_address(unsigned long address, int reliable);
|
|
extern void die(const char *, struct pt_regs *,long);
|
|
extern int __must_check __die(const char *, struct pt_regs *, long);
|
|
extern void show_registers(struct pt_regs *regs);
|
|
extern void show_trace(struct task_struct *t, struct pt_regs *regs,
|
|
unsigned long *sp, unsigned long bp);
|
|
extern void __show_regs(struct pt_regs *regs, int all);
|
|
extern void show_regs(struct pt_regs *regs);
|
|
extern unsigned long oops_begin(void);
|
|
extern void oops_end(unsigned long, struct pt_regs *, int signr);
|
|
#ifdef CONFIG_KEXEC
|
|
extern int in_crash_kexec;
|
|
#else
|
|
/* no crash dump is ever in progress if no crash kernel can be kexec'd */
|
|
#define in_crash_kexec 0
|
|
#endif
|
|
|
|
#endif /* _ASM_X86_KDEBUG_H */
|