https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85334
--- Comment #3 from hjl at gcc dot gnu.org <hjl at gcc dot gnu.org> --- Author: hjl Date: Thu Apr 19 17:05:39 2018 New Revision: 259502 URL: https://gcc.gnu.org/viewcvs?rev=259502&root=gcc&view=rev Log: 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. Added: trunk/gcc/testsuite/g++.dg/torture/pr85334.C Modified: trunk/gcc/testsuite/ChangeLog trunk/libgcc/ChangeLog trunk/libgcc/config/i386/shadow-stack-unwind.h trunk/libgcc/unwind-generic.h trunk/libgcc/unwind.inc