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| author | H.J. Lu <hongjiu.lu@intel.com> | 2018-04-19 17:05:39 +0000 |
|---|---|---|
| committer | H.J. Lu <hjl@gcc.gnu.org> | 2018-04-19 10:05:39 -0700 |
| commit | 5707be3c7da6196efcef2d86e623771153eb6c7f (patch) | |
| tree | a43f6ec251c9c1de4fb01850c3b58f0720cb6b46 /libgcc/config | |
| parent | f22723f93dd662c419e810e04390cf2319d4b29f (diff) | |
| download | gcc-5707be3c7da6196efcef2d86e623771153eb6c7f.zip gcc-5707be3c7da6196efcef2d86e623771153eb6c7f.tar.gz gcc-5707be3c7da6196efcef2d86e623771153eb6c7f.tar.bz2 | |
libgcc/CET: Skip signal frames when unwinding shadow stack
When -fcf-protection -mcet is used, I got
FAIL: g++.dg/eh/sighandle.C
(gdb) bt
#0 _Unwind_RaiseException (exc=exc@entry=0x416ed0)
at /export/gnu/import/git/sources/gcc/libgcc/unwind.inc:140
#1 0x00007ffff7d9936b in __cxxabiv1::__cxa_throw (obj=<optimized out>,
tinfo=0x403dd0 <typeinfo for int@@CXXABI_1.3>, dest=0x0)
at /export/gnu/import/git/sources/gcc/libstdc++-v3/libsupc++/eh_throw.cc:90
#2 0x0000000000401255 in sighandler (signo=11, si=0x7fffffffd6f8,
uc=0x7fffffffd5c0)
at /export/gnu/import/git/sources/gcc/gcc/testsuite/g++.dg/eh/sighandle.C:9
#3 <signal handler called> <<<< Signal frame which isn't on shadow stack
#4 dosegv ()
at /export/gnu/import/git/sources/gcc/gcc/testsuite/g++.dg/eh/sighandle.C:14
#5 0x00000000004012e3 in main ()
at /export/gnu/import/git/sources/gcc/gcc/testsuite/g++.dg/eh/sighandle.C:30
(gdb) p frames
$6 = 5
(gdb)
frame count should be 4, not 5. This patch skips signal frames when
unwinding shadow stack.
gcc/testsuite/
PR libgcc/85334
* g++.dg/torture/pr85334.C: New test.
libgcc/
PR libgcc/85334
* unwind-generic.h (_Unwind_Frames_Increment): New.
* config/i386/shadow-stack-unwind.h (_Unwind_Frames_Increment):
Likewise.
* unwind.inc (_Unwind_RaiseException_Phase2): Increment frame
count with _Unwind_Frames_Increment.
(_Unwind_ForcedUnwind_Phase2): Likewise.
From-SVN: r259502
Diffstat (limited to 'libgcc/config')
| -rw-r--r-- | libgcc/config/i386/shadow-stack-unwind.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/libgcc/config/i386/shadow-stack-unwind.h b/libgcc/config/i386/shadow-stack-unwind.h index 40f48df..a32f3e7 100644 --- a/libgcc/config/i386/shadow-stack-unwind.h +++ b/libgcc/config/i386/shadow-stack-unwind.h @@ -49,3 +49,8 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see } \ } \ while (0) + +/* Increment frame count. Skip signal frames. */ +#undef _Unwind_Frames_Increment +#define _Unwind_Frames_Increment(context, frames) \ + if (!_Unwind_IsSignalFrame (context)) frames++ |