Split getpwent and fgetgrent functions in interceptors

[krytarowski]

Summary

NetBSD does not ship with fgetpwent_r() and fgetgrent_r().
Split their interceptors from getpwent_r() and getgrent_r()
and disable for this OS.

Installation of supernumerary interceptors causes leaking of
errors to dlsym(3)-like operations.

No functional change for other OSes.

[vitalybuka]

lib/sanitizer_common/sanitizer_platform_interceptors.h

211

Now you intercept SANITIZER_INTERCEPT_FGETGRENT_R on SI_MAC
Title claims no changes for other oses

[krytarowski]

Remove unwanted SI_MAC.

[vitalybuka]

LGTM

lib/sanitizer_common/sanitizer_common_interceptors.inc

INTERCEPTOR(int, getpwent_r, __sanitizer_passwd *pwbuf, char *buf,
   int res = REAL(getpwent_r)(pwbuf, buf, buflen, pwbufp);
   if (!res) {
     if (pwbufp && *pwbufp) unpoison_passwd(ctx, *pwbufp);
     COMMON_INTERCEPTOR_WRITE_RANGE(ctx, buf, buflen);
   }
   if (pwbufp) COMMON_INTERCEPTOR_WRITE_RANGE(ctx, pwbufp, sizeof(*pwbufp));
   return res;
 }
-INTERCEPTOR(int, fgetpwent_r, void *fp, __sanitizer_passwd *pwbuf, char *buf,
-            SIZE_T buflen, __sanitizer_passwd **pwbufp) {
+INTERCEPTOR(int, getgrent_r, __sanitizer_group *pwbuf, char *buf, SIZE_T buflen,
+            __sanitizer_group **pwbufp) {
   void *ctx;
-  COMMON_INTERCEPTOR_ENTER(ctx, fgetpwent_r, fp, pwbuf, buf, buflen, pwbufp);
+  COMMON_INTERCEPTOR_ENTER(ctx, getgrent_r, pwbuf, buf, buflen, pwbufp);
   // FIXME: under ASan the call below may write to freed memory and corrupt
   // its metadata. See
   // https://github.com/google/sanitizers/issues/321.
-  int res = REAL(fgetpwent_r)(fp, pwbuf, buf, buflen, pwbufp);
+  int res = REAL(getgrent_r)(pwbuf, buf, buflen, pwbufp);
   if (!res) {
-    if (pwbufp && *pwbufp) unpoison_passwd(ctx, *pwbufp);
+    if (pwbufp && *pwbufp) unpoison_group(ctx, *pwbufp);
     COMMON_INTERCEPTOR_WRITE_RANGE(ctx, buf, buflen);
   }
   if (pwbufp) COMMON_INTERCEPTOR_WRITE_RANGE(ctx, pwbufp, sizeof(*pwbufp));
   return res;
 }
-INTERCEPTOR(int, getgrent_r, __sanitizer_group *pwbuf, char *buf, SIZE_T buflen,
-            __sanitizer_group **pwbufp) {
+#define INIT_GETPWENT_R                   \
+  COMMON_INTERCEPT_FUNCTION(getpwent_r);  \
+  COMMON_INTERCEPT_FUNCTION(getgrent_r);
+#else
+#define INIT_GETPWENT_R
+#endif
+
+#if SANITIZER_INTERCEPT_FGETPWENT_R
+INTERCEPTOR(int, fgetpwent_r, void *fp, __sanitizer_passwd *pwbuf, char *buf,
+            SIZE_T buflen, __sanitizer_passwd **pwbufp) {
   void *ctx;
-  COMMON_INTERCEPTOR_ENTER(ctx, getgrent_r, pwbuf, buf, buflen, pwbufp);
+  COMMON_INTERCEPTOR_ENTER(ctx, fgetpwent_r, fp, pwbuf, buf, buflen, pwbufp);
   // FIXME: under ASan the call below may write to freed memory and corrupt
   // its metadata. See
   // https://github.com/google/sanitizers/issues/321.
-  int res = REAL(getgrent_r)(pwbuf, buf, buflen, pwbufp);
+  int res = REAL(fgetpwent_r)(fp, pwbuf, buf, buflen, pwbufp);
   if (!res) {
-    if (pwbufp && *pwbufp) unpoison_group(ctx, *pwbufp);
+    if (pwbufp && *pwbufp) unpoison_passwd(ctx, *pwbufp);
     COMMON_INTERCEPTOR_WRITE_RANGE(ctx, buf, buflen);
   }
   if (pwbufp) COMMON_INTERCEPTOR_WRITE_RANGE(ctx, pwbufp, sizeof(*pwbufp));
   return res;
 }
+#define INIT_FGETPWENT_R                  \
+  COMMON_INTERCEPT_FUNCTION(fgetpwent_r);
+#else
+#define INIT_FGETPWENT_R
+#endif
+
+#if SANITIZER_INTERCEPT_FGETGRENT_R
 INTERCEPTOR(int, fgetgrent_r, void *fp, __sanitizer_group *pwbuf, char *buf,
             SIZE_T buflen, __sanitizer_group **pwbufp) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, fgetgrent_r, fp, pwbuf, buf, buflen, pwbufp);
   // FIXME: under ASan the call below may write to freed memory and corrupt
   // its metadata. See
   // https://github.com/google/sanitizers/issues/321.
   int res = REAL(fgetgrent_r)(fp, pwbuf, buf, buflen, pwbufp);
   if (!res) {
     if (pwbufp && *pwbufp) unpoison_group(ctx, *pwbufp);
     COMMON_INTERCEPTOR_WRITE_RANGE(ctx, buf, buflen);
   }
   if (pwbufp) COMMON_INTERCEPTOR_WRITE_RANGE(ctx, pwbufp, sizeof(*pwbufp));
   return res;
 }
-#define INIT_GETPWENT_R                   \
-  COMMON_INTERCEPT_FUNCTION(getpwent_r);  \
-  COMMON_INTERCEPT_FUNCTION(fgetpwent_r); \
-  COMMON_INTERCEPT_FUNCTION(getgrent_r);  \
+#define INIT_FGETGRENT_R                  \
   COMMON_INTERCEPT_FUNCTION(fgetgrent_r);
 #else
-#define INIT_GETPWENT_R
+#define INIT_FGETGRENT_R
 #endif
 
 #if SANITIZER_INTERCEPT_SETPWENT
 // The only thing these interceptors do is disable any nested interceptors.
 // These functions may open nss modules and call uninstrumented functions from
 // them, and we don't want things like strlen() to trigger.
 INTERCEPTOR(void, setpwent, int dummy) {
   void *ctx;
static void InitializeCommonInterceptors() {
   INIT_ISOC99_PRINTF;
   INIT_FREXP;
   INIT_FREXPF_FREXPL;
   INIT_GETPWNAM_AND_FRIENDS;
   INIT_GETPWNAM_R_AND_FRIENDS;
   INIT_GETPWENT;
   INIT_FGETPWENT;
   INIT_GETPWENT_R;
+  INIT_FGETPWENT_R;
+  INIT_FGETGRENT_R;
   INIT_SETPWENT;
   INIT_CLOCK_GETTIME;
   INIT_GETITIMER;
   INIT_TIME;
   INIT_GLOB;
   INIT_GLOB64;
   INIT_WAIT;
   INIT_WAIT4;

lib/sanitizer_common/sanitizer_platform_interceptors.h

 
 #define SANITIZER_INTERCEPT_GETPWNAM_AND_FRIENDS SI_POSIX
 #define SANITIZER_INTERCEPT_GETPWNAM_R_AND_FRIENDS                            \
   (SI_FREEBSD || SI_NETBSD || SI_OPENBSD || SI_MAC || SI_LINUX_NOT_ANDROID || \
   SI_SOLARIS)
 #define SANITIZER_INTERCEPT_GETPWENT                                          \
   (SI_FREEBSD || SI_NETBSD || SI_OPENBSD || SI_MAC || SI_LINUX_NOT_ANDROID || \
   SI_SOLARIS)
+#define SANITIZER_INTERCEPT_FGETGRENT_R                                       \
+  (SI_FREEBSD || SI_OPENBSD || SI_LINUX_NOT_ANDROID || SI_SOLARIS)
 #define SANITIZER_INTERCEPT_FGETPWENT SI_LINUX_NOT_ANDROID || SI_SOLARIS
 #define SANITIZER_INTERCEPT_GETPWENT_R \
   (SI_FREEBSD || SI_NETBSD || SI_OPENBSD || SI_LINUX_NOT_ANDROID || SI_SOLARIS)
+#define SANITIZER_INTERCEPT_FGETPWENT_R \
+  (SI_FREEBSD || SI_OPENBSD || SI_LINUX_NOT_ANDROID || SI_SOLARIS)
 #define SANITIZER_INTERCEPT_SETPWENT \
   (SI_MAC || SI_LINUX_NOT_ANDROID || SI_SOLARIS)
 #define SANITIZER_INTERCEPT_CLOCK_GETTIME \
   (SI_FREEBSD || SI_NETBSD || SI_OPENBSD || SI_LINUX || SI_SOLARIS)
 #define SANITIZER_INTERCEPT_GETITIMER SI_POSIX
 #define SANITIZER_INTERCEPT_TIME SI_POSIX
 #define SANITIZER_INTERCEPT_GLOB SI_LINUX_NOT_ANDROID || SI_SOLARIS
 #define SANITIZER_INTERCEPT_GLOB64 SI_LINUX_NOT_ANDROID