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| author | trippels <trippels@138bc75d-0d04-0410-961f-82ee72b054a4> | 2016-11-16 11:28:57 +0000 |
|---|---|---|
| committer | trippels <trippels@138bc75d-0d04-0410-961f-82ee72b054a4> | 2016-11-16 11:28:57 +0000 |
| commit | 6f19e5f213ac8ac1c02b0221127b3968adf88f70 (patch) | |
| tree | 648ea31c0d09ba7d8d4c1f2d688c737b31f65aff | |
| parent | bf7dc25e40c18ef3930e916861295c70f7583a88 (diff) | |
| download | gcc-6f19e5f213ac8ac1c02b0221127b3968adf88f70.tar.gz | |
Fix PR78294 - thread sanitizer broken when using ld.gold
When one uses ld.gold to build gcc, the thread sanitizer doesn't work,
because gold is more conservative when applying TLS relaxations than
ld.bfd. In this case a missing initial-exec attribute on a declaration
causes gcc to assume the general dynamic model. With ld.bfd this gets
relaxed to initial exec when linking the shared library, so the missing
attribute doesn't matter. But ld.gold doesn't perform this optimization
and this leads to crashes on tsan instrumented binaries.
See: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78294
and: https://sourceware.org/bugzilla/show_bug.cgi?id=20805
The fix is easy, just add the missing attribute.
PR sanitizer/78294
* tsan/tsan_rtl.cc: Add missing attribute.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-6-branch@242482 138bc75d-0d04-0410-961f-82ee72b054a4
| -rw-r--r-- | libsanitizer/ChangeLog | 5 | ||||
| -rw-r--r-- | libsanitizer/tsan/tsan_rtl.cc | 1 |
2 files changed, 6 insertions, 0 deletions
diff --git a/libsanitizer/ChangeLog b/libsanitizer/ChangeLog index 1b1b7acec02..7b2f1d1e00e 100644 --- a/libsanitizer/ChangeLog +++ b/libsanitizer/ChangeLog @@ -1,3 +1,8 @@ +2016-11-16 Markus Trippelsdorf <markus@trippelsdorf.de> + + PR sanitizer/78294 + * tsan/tsan_rtl.cc: Add missing attribute. + 2016-09-16 Jakub Jelinek <jakub@redhat.com> Backported from mainline diff --git a/libsanitizer/tsan/tsan_rtl.cc b/libsanitizer/tsan/tsan_rtl.cc index 4fceca6f41f..94cf985150e 100644 --- a/libsanitizer/tsan/tsan_rtl.cc +++ b/libsanitizer/tsan/tsan_rtl.cc @@ -43,6 +43,7 @@ extern "C" void __tsan_resume() { namespace __tsan { #if !defined(SANITIZER_GO) && !SANITIZER_MAC +__attribute__((tls_model("initial-exec"))) THREADLOCAL char cur_thread_placeholder[sizeof(ThreadState)] ALIGNED(64); #endif static char ctx_placeholder[sizeof(Context)] ALIGNED(64); |