[msan] Intercept getutent and friends.

Differential Revision: https://reviews.llvm.org/D27791

llvm-svn: 289878

compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc

@@ -5890,6 +5890,72 @@ INTERCEPTOR(int, __lxstat64, int version, const char *path, void *buf) {
 
 // FIXME: add other *stat interceptor
 
+#if SANITIZER_INTERCEPT_UTMP
+INTERCEPTOR(void *, getutent, int dummy) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, getutent, dummy);
+  void *res = REAL(getutent)(dummy);
+  if (res)
+    COMMON_INTERCEPTOR_INITIALIZE_RANGE(res, __sanitizer::struct_utmp_sz);
+  return res;
+}
+INTERCEPTOR(void *, getutid, void *ut) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, getutid, ut);
+  void *res = REAL(getutid)(ut);
+  if (res)
+    COMMON_INTERCEPTOR_INITIALIZE_RANGE(res, __sanitizer::struct_utmp_sz);
+  return res;
+}
+INTERCEPTOR(void *, getutline, void *ut) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, getutline, ut);
+  void *res = REAL(getutline)(ut);
+  if (res)
+    COMMON_INTERCEPTOR_INITIALIZE_RANGE(res, __sanitizer::struct_utmp_sz);
+  return res;
+}
+#define INIT_UTMP                      \
+  COMMON_INTERCEPT_FUNCTION(getutent); \
+  COMMON_INTERCEPT_FUNCTION(getutid);  \
+  COMMON_INTERCEPT_FUNCTION(getutline);
+#else
+#define INIT_UTMP
+#endif
+
+#if SANITIZER_INTERCEPT_UTMPX
+INTERCEPTOR(void *, getutxent, int dummy) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, getutxent, dummy);
+  void *res = REAL(getutxent)(dummy);
+  if (res)
+    COMMON_INTERCEPTOR_INITIALIZE_RANGE(res, __sanitizer::struct_utmpx_sz);
+  return res;
+}
+INTERCEPTOR(void *, getutxid, void *ut) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, getutxid, ut);
+  void *res = REAL(getutxid)(ut);
+  if (res)
+    COMMON_INTERCEPTOR_INITIALIZE_RANGE(res, __sanitizer::struct_utmpx_sz);
+  return res;
+}
+INTERCEPTOR(void *, getutxline, void *ut) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, getutxline, ut);
+  void *res = REAL(getutxline)(ut);
+  if (res)
+    COMMON_INTERCEPTOR_INITIALIZE_RANGE(res, __sanitizer::struct_utmpx_sz);
+  return res;
+}
+#define INIT_UTMPX                      \
+  COMMON_INTERCEPT_FUNCTION(getutxent); \
+  COMMON_INTERCEPT_FUNCTION(getutxid);  \
+  COMMON_INTERCEPT_FUNCTION(getutxline);
+#else
+#define INIT_UTMPX
+#endif
+
 static void InitializeCommonInterceptors() {
   static u64 metadata_mem[sizeof(MetadataHashMap) / sizeof(u64) + 1];
   interceptor_metadata_map = new((void *)&metadata_mem) MetadataHashMap();
@@ -6086,4 +6152,6 @@ static void InitializeCommonInterceptors() {
   INIT___LXSTAT;
   INIT___LXSTAT64;
   // FIXME: add other *stat interceptors.
+  INIT_UTMP;
+  INIT_UTMPX;
 }

compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h

@@ -312,4 +312,8 @@
 #define SANITIZER_INTERCEPT___XSTAT64 SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT___LXSTAT SANITIZER_INTERCEPT___XSTAT
 #define SANITIZER_INTERCEPT___LXSTAT64 SI_LINUX_NOT_ANDROID
+
+#define SANITIZER_INTERCEPT_UTMP SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_UTMPX SI_LINUX_NOT_ANDROID || SI_MAC || SI_FREEBSD
+
 #endif  // #ifndef SANITIZER_PLATFORM_INTERCEPTORS_H

compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cc

@@ -51,6 +51,7 @@
 #include <termios.h>
 #include <time.h>
 #include <wchar.h>
+#include <utmp.h>
 
 #if !SANITIZER_IOS
 #include <net/route.h>
@@ -59,6 +60,7 @@
 #if !SANITIZER_ANDROID
 #include <sys/mount.h>
 #include <sys/timeb.h>
+#include <utmpx.h>
 #endif
 
 #if SANITIZER_LINUX
@@ -284,6 +286,11 @@ namespace __sanitizer {
   int shmctl_shm_stat = (int)SHM_STAT;
 #endif
 
+  unsigned struct_utmp_sz = sizeof(struct utmp);
+#if !SANITIZER_ANDROID
+  unsigned struct_utmpx_sz = sizeof(struct utmpx);
+#endif
+
   int map_fixed = MAP_FIXED;
 
   int af_inet = (int)AF_INET;

compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.h

@@ -862,6 +862,11 @@ namespace __sanitizer {
   extern int shmctl_shm_stat;
 #endif
 
+  extern unsigned struct_utmp_sz;
+#if !SANITIZER_ANDROID
+  extern unsigned struct_utmpx_sz;
+#endif
+
   extern int map_fixed;
 
   // ioctl arguments

compiler-rt/test/msan/getutent.cc

@@ -0,0 +1,17 @@
+// RUN: %clangxx_msan -O0 -g %s -o %t && %run %t
+
+#include <utmp.h>
+#include <utmpx.h>
+#include <sanitizer/msan_interface.h>
+
+int main(void) {
+  setutent();
+  while (struct utmp *ut = getutent())
+    __msan_check_mem_is_initialized(ut, sizeof(*ut));
+  endutent();
+
+  setutxent();
+  while (struct utmpx *utx = getutxent())
+    __msan_check_mem_is_initialized(utx, sizeof(*utx));
+  endutxent();
+}