[sanitizer] Add posix_spawn interceptor

To make pid initialized for Msan.

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D112784

compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc

@@ -2422,6 +2422,54 @@ INTERCEPTOR(int, glob64, const char *pattern, int flags,
 #define INIT_GLOB64
 #endif  // SANITIZER_INTERCEPT_GLOB64
 
+#if SANITIZER_INTERCEPT_POSIX_SPAWN
+
+template <class RealSpawnPtr>
+static int PosixSpawnImpl(void *ctx, RealSpawnPtr *real_posix_spawn, pid_t *pid,
+                          const char *file_or_path, const void *file_actions,
+                          const void *attrp, char *const argv[],
+                          char *const envp[]) {
+  COMMON_INTERCEPTOR_READ_RANGE(ctx, file_or_path,
+                                internal_strlen(file_or_path) + 1);
+  char *const *s = argv;
+  for (; *s; ++s)
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, *s, internal_strlen(*s) + 1);
+  COMMON_INTERCEPTOR_READ_RANGE(ctx, argv, (s - argv + 1) / sizeof(*s));
+  s = envp;
+  for (; *s; ++s)
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, *s, internal_strlen(*s) + 1);
+  COMMON_INTERCEPTOR_READ_RANGE(ctx, s, (s - envp + 1) / sizeof(*s));
+  int res =
+      real_posix_spawn(pid, file_or_path, file_actions, attrp, argv, envp);
+  if (res == 0)
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, pid, sizeof(*pid));
+  return res;
+}
+INTERCEPTOR(int, posix_spawn, pid_t *pid, const char *path,
+            const void *file_actions, const void *attrp, char *const argv[],
+            char *const envp[]) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, posix_spawn, pid, path, file_actions, attrp,
+                           argv, envp);
+  return PosixSpawnImpl(ctx, REAL(posix_spawn), pid, path, file_actions, attrp,
+                        argv, envp);
+}
+INTERCEPTOR(int, posix_spawnp, pid_t *pid, const char *file,
+            const void *file_actions, const void *attrp, char *const argv[],
+            char *const envp[]) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, posix_spawnp, pid, file, file_actions, attrp,
+                           argv, envp);
+  return PosixSpawnImpl(ctx, REAL(posix_spawnp), pid, file, file_actions, attrp,
+                        argv, envp);
+}
+#  define INIT_POSIX_SPAWN                  \
+    COMMON_INTERCEPT_FUNCTION(posix_spawn); \
+    COMMON_INTERCEPT_FUNCTION(posix_spawnp);
+#else  // SANITIZER_INTERCEPT_POSIX_SPAWN
+#  define INIT_POSIX_SPAWN
+#endif  // SANITIZER_INTERCEPT_POSIX_SPAWN
+
 #if SANITIZER_INTERCEPT_WAIT
 // According to sys/wait.h, wait(), waitid(), waitpid() may have symbol version
 // suffixes on Darwin. See the declaration of INTERCEPTOR_WITH_SUFFIX for
@@ -10229,6 +10277,7 @@ static void InitializeCommonInterceptors() {
   INIT_TIME;
   INIT_GLOB;
   INIT_GLOB64;
+  INIT_POSIX_SPAWN;
   INIT_WAIT;
   INIT_WAIT4;
   INIT_INET;

compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h

@@ -235,6 +235,7 @@
 #define SANITIZER_INTERCEPT_TIME SI_POSIX
 #define SANITIZER_INTERCEPT_GLOB (SI_GLIBC || SI_SOLARIS)
 #define SANITIZER_INTERCEPT_GLOB64 SI_GLIBC
+#define SANITIZER_INTERCEPT_POSIX_SPAWN SI_POSIX
 #define SANITIZER_INTERCEPT_WAIT SI_POSIX
 #define SANITIZER_INTERCEPT_INET SI_POSIX
 #define SANITIZER_INTERCEPT_PTHREAD_GETSCHEDPARAM SI_POSIX

compiler-rt/test/sanitizer_common/TestCases/Posix/posix_spawn.c

@@ -0,0 +1,40 @@
+// RUN: %clang %s -o %t && %run %t 2>&1 | FileCheck %s
+
+#include <assert.h>
+#include <spawn.h>
+#include <stdio.h>
+#include <wait.h>
+
+int main(int argc, char **argv) {
+  if (argc > 1) {
+    // CHECK: SPAWNED
+    // CHECK: SPAWNED
+    printf("SPAWNED\n");
+    return 0;
+  }
+
+  int s;
+
+  posix_spawnattr_t attr;
+  s = posix_spawnattr_init(&attr);
+  assert(!s);
+
+  posix_spawn_file_actions_t file_actions;
+  s = posix_spawn_file_actions_init(&file_actions);
+  assert(!s);
+
+  char *const args[] = {argv[0], "2", NULL};
+  char *const env[] = {"A=B", NULL};
+
+  pid_t pid;
+  s = posix_spawn(&pid, argv[0], &file_actions, &attr, args, env);
+  assert(!s);
+
+  waitpid(pid, &s, WUNTRACED | WCONTINUED);
+
+  s = posix_spawnp(&pid, argv[0], &file_actions, &attr, args, env);
+  assert(!s);
+
+  waitpid(pid, &s, WUNTRACED | WCONTINUED);
+  return 0;
+}