Add new interceptors: access(2), faccessat(2)

[krytarowski]

Summary

access, faccessat - check access permissions of a file or pathname

Sponsored by <The NetBSD Foundation>

[krytarowski]

• add tests
• improve interceptors

[vitalybuka]

Please move tests into sanitizer_common

[krytarowski]

Move tests to common_sanitizer

lib/sanitizer_common/sanitizer_common_interceptors.inc

if (file)
     COMMON_INTERCEPTOR_READ_RANGE(ctx, file, REAL(strlen)(file) + 1);
   return REAL(acct)(file);
 }
 #define INIT_ACCT COMMON_INTERCEPT_FUNCTION(acct)
 #else
 #define INIT_ACCT
 #endif
 
+#if SANITIZER_INTERCEPT_ACCESS
+INTERCEPTOR(int, access, const char *path, int mode) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, access, path, mode);
+  if (path)
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, path, REAL(strlen)(path) + 1);
+  return REAL(access)(path, mode);
+}
+#define INIT_ACCESS COMMON_INTERCEPT_FUNCTION(access)
+#else
+#define INIT_ACCESS
+#endif
+
+#if SANITIZER_INTERCEPT_FACCESSAT
+INTERCEPTOR(int, faccessat, int fd, const char *path, int mode, int flags) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, faccessat, fd, path, mode, flags);
+  if (path)
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, path, REAL(strlen)(path) + 1);
+  return REAL(faccessat)(fd, path, mode, flags);
+}
+#define INIT_FACCESSAT COMMON_INTERCEPT_FUNCTION(faccessat)
+#else
+#define INIT_FACCESSAT
+#endif
+
 static void InitializeCommonInterceptors() {
   static u64 metadata_mem[sizeof(MetadataHashMap) / sizeof(u64) + 1];
   interceptor_metadata_map = new((void *)&metadata_mem) MetadataHashMap();
 
   INIT_TEXTDOMAIN;
   INIT_STRLEN;
   INIT_STRNLEN;
   INIT_STRNDUP;
static void InitializeCommonInterceptors() {
   INIT___LXSTAT64;
   // FIXME: add other *stat interceptors.
   INIT_UTMP;
   INIT_UTMPX;
   INIT_GETLOADAVG;
   INIT_WCSLEN;
   INIT_WCSCAT;
   INIT_ACCT;
+  INIT_ACCESS;
+  INIT_FACCESSAT;
 
 #if SANITIZER_NETBSD
   COMMON_INTERCEPT_FUNCTION(__libc_mutex_lock);
   COMMON_INTERCEPT_FUNCTION(__libc_mutex_unlock);
   COMMON_INTERCEPT_FUNCTION(__libc_thr_setcancelstate);
 #endif
 
   INIT___PRINTF_CHK;
 }

lib/sanitizer_common/sanitizer_platform_interceptors.h

 #define SANITIZER_INTERCEPT_MALLOC_USABLE_SIZE (!SI_MAC)
 #define SANITIZER_INTERCEPT_MCHECK_MPROBE SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_WCSCAT SI_POSIX
 #define SANITIZER_INTERCEPT_SIGNAL_AND_SIGACTION (!SI_WINDOWS && SI_NOT_FUCHSIA)
 #define SANITIZER_INTERCEPT_BSD_SIGNAL SI_ANDROID
 
 #define SANITIZER_INTERCEPT_ACCT SI_NETBSD
 
+#define SANITIZER_INTERCEPT_ACCESS SI_NETBSD
+#define SANITIZER_INTERCEPT_FACCESSAT SI_NETBSD
+
 #endif  // #ifndef SANITIZER_PLATFORM_INTERCEPTORS_H

test/msan/access.cc

+// RUN: %clangxx_msan -O0 %s -o %t && %run %t
+// UNSUPPORTED: linux
+
+#include <unistd.h>
+
+int main(void) { return access("/root", F_OK); }

test/msan/faccessat.cc

+// RUN: %clangxx_msan -O0 %s -o %t && %run %t
+// UNSUPPORTED: linux
+
+#include <fcntl.h>
+#include <unistd.h>
+
+int main(void) { return faccessat(AT_FDCWD, "/root", F_OK, 0); }