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| author | Christopher Ferris <cferris@google.com> | 2016-03-07 15:55:09 -0800 |
|---|---|---|
| committer | Christopher Ferris <cferris@google.com> | 2016-03-08 11:07:43 -0800 |
| commit | 40e1c65f702a967458470ba5a8f35cf2683b37ae (patch) | |
| tree | b9c087360433557d34ba2fd1654da8f5e0b3575f | |
| parent | 6292bbbc3f678648fb5a1ec8222d33f6a5bb992a (diff) | |
| download | libunwind-40e1c65f702a967458470ba5a8f35cf2683b37ae.tar.gz | |
Do not try non-dwarf local unwinds for x86.
The frame-chain unwind code in libunwind never really works and it
has a high probability of trying to access unmapped memory. When
doing a remote unwind, this will simply result in the unwind stopping.
When doing a local unwind, this can lead to crashes. Disable this
method for local unwinds.
Bug: 26807329
(cherry picked from commit 936e80b1ede36884588abe481406d73344826d5b)
Change-Id: I0032ffd833b0b9e8931defef31e2277e41186abc
| -rw-r--r-- | src/x86/Gstep.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/src/x86/Gstep.c b/src/x86/Gstep.c index 308f220b..b037b71a 100644 --- a/src/x86/Gstep.c +++ b/src/x86/Gstep.c @@ -44,6 +44,12 @@ unw_step (unw_cursor_t *cursor) /* Try DWARF-based unwinding... */ ret = dwarf_step (&c->dwarf); +#if !defined(UNW_LOCAL_ONLY) + /* Do not use this method on a local unwind. There is a very high + * probability this method will try to access unmapped memory, which + * will crash the process. Since this almost never actually works, + * it should be okay to skip. + */ if (ret < 0) { /* DWARF failed, let's see if we can follow the frame-chain @@ -110,6 +116,7 @@ unw_step (unw_cursor_t *cursor) else c->dwarf.ip = 0; } +#endif /* ANDROID support update. */ if (ret >= 0) |