diff options
| author | Josh Poimboeuf <[email protected]> | 2017-10-09 20:20:04 -0500 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2017-10-10 12:49:49 +0200 |
| commit | 99bd28a49b150e4b938313a63b5532d95ba77885 (patch) | |
| tree | c60a884f170b380829d741ddf1ffb46b4790c079 | |
| parent | 5c99b692cfd62f6915ed7ee7ed3c38d65ba3feab (diff) | |
x86/unwind: Align stack pointer in unwinder dump
When printing the unwinder dump, the stack pointer could be unaligned,
for one of two reasons:
- stack corruption; or
- GCC created an unaligned stack.
There's no way for the unwinder to tell the difference between the two,
so we have to assume one or the other. GCC unaligned stacks are very
rare, and have only been spotted before GCC 5. Presumably, if we're
doing an unwinder stack dump, stack corruption is more likely than a
GCC unaligned stack. So always align the stack before starting the
dump.
Reported-and-tested-by: Tetsuo Handa <[email protected]>
Reported-and-tested-by: Fengguang Wu <[email protected]>
Signed-off-by: Josh Poimboeuf <[email protected]>
Cc: Byungchul Park <[email protected]>
Cc: LKP <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/2f540c515946ab09ed267e1a1d6421202a0cce08.1507597785.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <[email protected]>
| -rw-r--r-- | arch/x86/kernel/unwind_frame.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c index 4949bbc95f75..81aca077fbb6 100644 --- a/arch/x86/kernel/unwind_frame.c +++ b/arch/x86/kernel/unwind_frame.c @@ -44,7 +44,8 @@ static void unwind_dump(struct unwind_state *state) state->stack_info.type, state->stack_info.next_sp, state->stack_mask, state->graph_idx); - for (sp = state->orig_sp; sp; sp = PTR_ALIGN(stack_info.next_sp, sizeof(long))) { + for (sp = PTR_ALIGN(state->orig_sp, sizeof(long)); sp; + sp = PTR_ALIGN(stack_info.next_sp, sizeof(long))) { if (get_stack_info(sp, state->task, &stack_info, &visit_mask)) break; |