// RUN: %clangxx_msan -fsanitize-memory-track-origins=2 -O1 %s -o %t && %run %t 2>&1 | FileCheck %s #include #include #include #include #include #include #include void handler(int sig, siginfo_t *info, void *uctx) { __msan_check_mem_is_initialized(uctx, sizeof(ucontext_t)); #if defined(__GLIBC__) && defined(__x86_64__) auto *mctx = &static_cast(uctx)->uc_mcontext; if (auto *fpregs = mctx->fpregs) { // The member names differ across header versions, but the actual layout // is always the same. So avoid using members, just use arithmetic. const uint32_t *after_xmm = reinterpret_cast(fpregs + 1) - 24; if (after_xmm[12] == FP_XSTATE_MAGIC1) { auto *xstate = reinterpret_cast<_xstate *>(mctx->fpregs); __msan_check_mem_is_initialized(xstate, sizeof(*xstate)); } } #endif } __attribute__((noinline)) void poison_stack() { char buf[64 << 10]; printf("buf: %p-%p\n", buf, buf + sizeof(buf)); } int main(int argc, char **argv) { struct sigaction act = {}; act.sa_sigaction = handler; act.sa_flags = SA_SIGINFO; sigaction(SIGPROF, &act, 0); poison_stack(); pthread_kill(pthread_self(), SIGPROF); return 0; } // CHECK-NOT: WARNING: MemorySanitizer: