compiler-rt/test/msan/Linux/signal_mcontext.cpp

   1 // RUN: %clangxx_msan -fsanitize-memory-track-origins=2 -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
   2
   3 #include <pthread.h>
   4 #include <sanitizer/msan_interface.h>
   5 #include <signal.h>
   6 #include <stdint.h>
   7 #include <stdio.h>
   8 #include <ucontext.h>
   9 #include <unistd.h>
  10
  11 void handler(int sig, siginfo_t *info, void *uctx) {
  12   __msan_check_mem_is_initialized(uctx, sizeof(ucontext_t));
  13 #if defined(__GLIBC__) && defined(__x86_64__)
  14   auto *mctx = &static_cast<ucontext_t *>(uctx)->uc_mcontext;
  15   if (auto *fpregs = mctx->fpregs) {
  16     // The member names differ across header versions, but the actual layout
  17     // is always the same.  So avoid using members, just use arithmetic.
  18     const uint32_t *after_xmm =
  19         reinterpret_cast<const uint32_t *>(fpregs + 1) - 24;
  20     if (after_xmm[12] == FP_XSTATE_MAGIC1) {
  21       auto *xstate = reinterpret_cast<_xstate *>(mctx->fpregs);
  22       __msan_check_mem_is_initialized(xstate, sizeof(*xstate));
  23     }
  24   }
  25 #endif
  26 }
  27
  28 __attribute__((noinline)) void poison_stack() {
  29   char buf[64 << 10];
  30   printf("buf: %p-%p\n", buf, buf + sizeof(buf));
  31 }
  32
  33 int main(int argc, char **argv) {
  34   struct sigaction act = {};
  35   act.sa_sigaction = handler;
  36   act.sa_flags = SA_SIGINFO;
  37   sigaction(SIGPROF, &act, 0);
  38   poison_stack();
  39   pthread_kill(pthread_self(), SIGPROF);
  40   return 0;
  41 }
  42
  43 // CHECK-NOT: WARNING: MemorySanitizer: