1 // RUN: %clangxx_msan -fsanitize-memory-track-origins=2 -O1 %s -o %t && not %run %t 2>&1 | FileCheck %s
2 
3 #include <pthread.h>
4 #include <signal.h>
5 #include <ucontext.h>
6 
7 void handler(int sig, siginfo_t *info, void *uctx) {
8   volatile int uninit;
9   auto *mctx = &static_cast<ucontext_t *>(uctx)->uc_mcontext;
10   auto *fpregs = mctx->fpregs;
11   if (fpregs && fpregs->__glibc_reserved1[12] == FP_XSTATE_MAGIC1)
12     reinterpret_cast<_xstate *>(mctx->fpregs)->ymmh.ymmh_space[0] = uninit;
13   else
14     mctx->gregs[REG_RAX] = uninit;
15 }
16 
17 int main(int argc, char **argv) {
18   struct sigaction act = {};
19   act.sa_sigaction = handler;
20   act.sa_flags = SA_SIGINFO;
21   sigfillset(&act.sa_mask);
22   sigaction(SIGPROF, &act, 0);
23   pthread_kill(pthread_self(), SIGPROF);
24   return 0;
25 }
26 
27 // CHECK: WARNING: MemorySanitizer:
28