Fix prctl to handle PR_GET_PDEATHSIG. (#101749)

Author: kstoimenov

compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc

@@ -1255,6 +1255,7 @@ INTERCEPTOR(int, prctl, int option, unsigned long arg2, unsigned long arg3,
  static const int PR_SET_VMA = 0x53564d41;
  static const int PR_SCHED_CORE = 62;
  static const int PR_SCHED_CORE_GET = 0;
+ static const int PR_GET_PDEATHSIG = 2;
  if (option == PR_SET_VMA && arg2 == 0UL) {
  char *name = (char *)arg5;
  COMMON_INTERCEPTOR_READ_RANGE(ctx, name, internal_strlen(name) + 1);
@@ -1270,7 +1271,9 @@ INTERCEPTOR(int, prctl, int option, unsigned long arg2, unsigned long arg3,
  COMMON_INTERCEPTOR_WRITE_RANGE(ctx, name, internal_strlen(name) + 1);
  } else if (res != -1 && option == PR_SCHED_CORE &&
  arg2 == PR_SCHED_CORE_GET) {
- COMMON_INTERCEPTOR_WRITE_RANGE(ctx, (u64*)(arg5), sizeof(u64));
+ COMMON_INTERCEPTOR_WRITE_RANGE(ctx, (u64 *)(arg5), sizeof(u64));
+ } else if (res != -1 && option == PR_GET_PDEATHSIG) {
+ COMMON_INTERCEPTOR_WRITE_RANGE(ctx, (u64 *)(arg2), sizeof(u64));
  }
  return res;
 }
@@ -9980,7 +9983,7 @@ INTERCEPTOR(SSIZE_T, getrandom, void *buf, SIZE_T buflen, unsigned int flags) {
  void *ctx;
  COMMON_INTERCEPTOR_ENTER(ctx, getrandom, buf, buflen, flags);
  // If GRND_NONBLOCK is set in the flags, it is non blocking.
- static const int grnd_nonblock = 1; 
+ static const int grnd_nonblock = 1;
  SSIZE_T n;
  if ((flags & grnd_nonblock))
  n = REAL(getrandom)(buf, buflen, flags);

compiler-rt/test/sanitizer_common/TestCases/Linux/prctl.cpp

@@ -41,6 +41,14 @@ int main() {
  assert(cookie != 0);
  }
 
+ int signum;
+ res = prctl(PR_GET_PDEATHSIG, reinterpret_cast<unsigned long>(&signum));
+ if (res < 0) {
+ assert(errno == EINVAL);
+ } else {
+ assert(signum == 0);
+ }
+
  char invname[81], vlname[] = "prctl";
  for (auto i = 0; i < sizeof(invname); i++) {
  invname[i] = 0x1e;