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Groups > linux.kernel > #1465255
| From | Josh Poimboeuf <jpoimboe@redhat.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v4 54/57] x86/mm: convert arch_within_stack_frames() to use the new unwinder |
| Date | 2016-08-18 15:10 +0200 |
| Message-ID | <s7vf4-dJ-23@gated-at.bofh.it> (permalink) |
| References | <s7vf3-dJ-11@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Convert arch_within_stack_frames() to use the new unwinder.
This also changes some existing behavior:
- Skip checking of pt_regs frames.
- Warn if it can't reach the grandparent's stack frame.
- Warn if it doesn't unwind to the end of the stack.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
arch/x86/lib/usercopy.c | 44 ++++++++++++++++++++++++++++----------------
1 file changed, 28 insertions(+), 16 deletions(-)
diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c
index 2492fa7..8fe0a9c 100644
--- a/arch/x86/lib/usercopy.c
+++ b/arch/x86/lib/usercopy.c
@@ -50,30 +50,42 @@ int arch_within_stack_frames(const void * const stack,
const void * const stackend,
const void *obj, unsigned long len)
{
- const void *frame = NULL;
- const void *oldframe;
+ struct unwind_state state;
+ const void *frame, *frame_end;
+
+ /*
+ * Start at the end of our grandparent's frame (beginning of
+ * great-grandparent's frame).
+ */
+ unwind_start(&state, current, NULL, NULL);
+ if (WARN_ON_ONCE(!unwind_next_frame(&state) ||
+ !unwind_next_frame(&state)))
+ return 0;
+ frame = unwind_get_stack_ptr(&state);
- oldframe = __builtin_frame_address(2);
- if (oldframe)
- frame = __builtin_frame_address(3);
/*
* low ----------------------------------------------> high
* [saved bp][saved ip][args][local vars][saved bp][saved ip]
* ^----------------^
* allow copies only within here
*/
- while (stack <= frame && frame < stackend) {
- /*
- * If obj + len extends past the last frame, this
- * check won't pass and the next frame will be 0,
- * causing us to bail out and correctly report
- * the copy as invalid.
- */
- if (obj + len <= frame)
- return obj >= oldframe + 2 * sizeof(void *) ? 1 : -1;
- oldframe = frame;
- frame = *(const void * const *)frame;
+ frame += 2*sizeof(long);
+
+ while (unwind_next_frame(&state)) {
+ frame_end = unwind_get_stack_ptr(&state);
+
+ /* skip checking of pt_regs frames */
+ if (!unwind_get_entry_regs(&state) &&
+ obj >= frame && obj + len <= frame_end)
+ return 1;
+
+ frame = frame_end + 2*sizeof(long);
}
+
+ /* make sure the unwinder reached the end of the task stack */
+ if (WARN_ON_ONCE(frame != (void *)task_pt_regs(current)))
+ return 0;
+
return -1;
}
#endif /* CONFIG_HARDENED_USERCOPY && CONFIG_FRAME_POINTER */
--
2.7.4
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[PATCH v4 54/57] x86/mm: convert arch_within_stack_frames() to use the new unwinder Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 15:10 +0200
Re: [PATCH v4 54/57] x86/mm: convert arch_within_stack_frames() to use the new unwinder Kees Cook <keescook@chromium.org> - 2016-08-19 20:30 +0200
Re: [PATCH v4 54/57] x86/mm: convert arch_within_stack_frames() to use the new unwinder Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-20 00:00 +0200
Re: [PATCH v4 54/57] x86/mm: convert arch_within_stack_frames() to use the new unwinder Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-22 22:40 +0200
Re: [PATCH v4 54/57] x86/mm: convert arch_within_stack_frames() to use the new unwinder Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-23 01:40 +0200
Re: [PATCH v4 54/57] x86/mm: convert arch_within_stack_frames() to use the new unwinder Kees Cook <keescook@chromium.org> - 2016-08-23 03:00 +0200
Re: [PATCH v4 54/57] x86/mm: convert arch_within_stack_frames() to use the new unwinder Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-23 06:30 +0200
Re: [PATCH v4 54/57] x86/mm: convert arch_within_stack_frames() to use the new unwinder Linus Torvalds <torvalds@linux-foundation.org> - 2016-08-23 00:20 +0200
Re: [PATCH v4 54/57] x86/mm: convert arch_within_stack_frames() to use the new unwinder Kees Cook <keescook@chromium.org> - 2016-08-23 03:30 +0200
Re: [PATCH v4 54/57] x86/mm: convert arch_within_stack_frames() to use the new unwinder Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-23 18:40 +0200
Re: [PATCH v4 54/57] x86/mm: convert arch_within_stack_frames() to use the new unwinder Linus Torvalds <torvalds@linux-foundation.org> - 2016-08-24 01:20 +0200
Re: [PATCH v4 54/57] x86/mm: convert arch_within_stack_frames() to use the new unwinder Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-23 18:10 +0200
[PATCH 2/2] mm/usercopy: enable usercopy size checking for modern versions of gcc Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-23 21:30 +0200
Re: [PATCH 2/2] mm/usercopy: enable usercopy size checking for modern versions of gcc Kees Cook <keescook@chromium.org> - 2016-08-24 05:50 +0200
[PATCH 1/2] mm/usercopy: get rid of "provably correct" warnings Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-23 21:30 +0200
Re: [PATCH 1/2] mm/usercopy: get rid of "provably correct" warnings Kees Cook <keescook@chromium.org> - 2016-08-24 04:40 +0200
Re: [PATCH v4 54/57] x86/mm: convert arch_within_stack_frames() to use the new unwinder Andy Lutomirski <luto@kernel.org> - 2016-08-23 22:50 +0200
Re: [PATCH v4 54/57] x86/mm: convert arch_within_stack_frames() to use the new unwinder Linus Torvalds <torvalds@linux-foundation.org> - 2016-08-23 23:10 +0200
Re: [PATCH v4 54/57] x86/mm: convert arch_within_stack_frames() to use the new unwinder Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-23 23:20 +0200
Re: [PATCH v4 54/57] x86/mm: convert arch_within_stack_frames() to use the new unwinder Kees Cook <keescook@chromium.org> - 2016-08-24 03:50 +0200
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