diff options
| author | hjl <hjl@138bc75d-0d04-0410-961f-82ee72b054a4> | 2018-04-19 17:05:39 +0000 |
|---|---|---|
| committer | hjl <hjl@138bc75d-0d04-0410-961f-82ee72b054a4> | 2018-04-19 17:05:39 +0000 |
| commit | 20d1a0756a0cf5072d0cdf3d2adab00063c224a7 (patch) | |
| tree | a43f6ec251c9c1de4fb01850c3b58f0720cb6b46 /libgcc | |
| parent | 47b6cf63fca600c911e7c0498bc740c74eb438a1 (diff) | |
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.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@259502 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'libgcc')
| -rw-r--r-- | libgcc/ChangeLog | 10 | ||||
| -rw-r--r-- | libgcc/config/i386/shadow-stack-unwind.h | 5 | ||||
| -rw-r--r-- | libgcc/unwind-generic.h | 3 | ||||
| -rw-r--r-- | libgcc/unwind.inc | 4 |
4 files changed, 20 insertions, 2 deletions
diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog index 674d2041bd7..8a645c80e3d 100644 --- a/libgcc/ChangeLog +++ b/libgcc/ChangeLog @@ -1,5 +1,15 @@ 2018-04-19 H.J. Lu <hongjiu.lu@intel.com> + 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. + +2018-04-19 H.J. Lu <hongjiu.lu@intel.com> + PR libgcc/85379 * config/i386/morestack.S (__stack_split_initialize): Add _CET_ENDBR. diff --git a/libgcc/config/i386/shadow-stack-unwind.h b/libgcc/config/i386/shadow-stack-unwind.h index 40f48df2aec..a32f3e74b52 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++ diff --git a/libgcc/unwind-generic.h b/libgcc/unwind-generic.h index b5e3568e1bc..639c96f438e 100644 --- a/libgcc/unwind-generic.h +++ b/libgcc/unwind-generic.h @@ -291,4 +291,7 @@ EXCEPTION_DISPOSITION _GCC_specific_handler (PEXCEPTION_RECORD, void *, /* Additional actions to unwind number of stack frames. */ #define _Unwind_Frames_Extra(frames) +/* Increment frame count. */ +#define _Unwind_Frames_Increment(context, frames) frames++ + #endif /* unwind.h */ diff --git a/libgcc/unwind.inc b/libgcc/unwind.inc index 68c08964d30..19a8e4f6c80 100644 --- a/libgcc/unwind.inc +++ b/libgcc/unwind.inc @@ -73,7 +73,7 @@ _Unwind_RaiseException_Phase2(struct _Unwind_Exception *exc, gcc_assert (!match_handler); uw_update_context (context, &fs); - frames++; + _Unwind_Frames_Increment (context, frames); } *frames_p = frames; @@ -190,7 +190,7 @@ _Unwind_ForcedUnwind_Phase2 (struct _Unwind_Exception *exc, /* Update cur_context to describe the same frame as fs, and discard the previous context if necessary. */ uw_advance_context (context, &fs); - frames++; + _Unwind_Frames_Increment (context, frames); } *frames_p = frames; |