[sanitizer] Remove unneeded pointer check

[vitalybuka]

Summary

unpoison_passwd and unpoison_group support nullptrs

[eugenis]

LGTM

lib/sanitizer_common/sanitizer_common_interceptors.inc

 
 #if SANITIZER_INTERCEPT_GETPWNAM_AND_FRIENDS
 INTERCEPTOR(__sanitizer_passwd *, getpwnam, const char *name) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, getpwnam, name);
   if (name)
     COMMON_INTERCEPTOR_READ_RANGE(ctx, name, REAL(strlen)(name) + 1);
   __sanitizer_passwd *res = REAL(getpwnam)(name);
-  if (res) unpoison_passwd(ctx, res);
+  unpoison_passwd(ctx, res);
   return res;
 }
 INTERCEPTOR(__sanitizer_passwd *, getpwuid, u32 uid) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, getpwuid, uid);
   __sanitizer_passwd *res = REAL(getpwuid)(uid);
-  if (res) unpoison_passwd(ctx, res);
+  unpoison_passwd(ctx, res);
   return res;
 }
 INTERCEPTOR(__sanitizer_group *, getgrnam, const char *name) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, getgrnam, name);
   COMMON_INTERCEPTOR_READ_RANGE(ctx, name, REAL(strlen)(name) + 1);
   __sanitizer_group *res = REAL(getgrnam)(name);
-  if (res) unpoison_group(ctx, res);
+  unpoison_group(ctx, res);
   return res;
 }
 INTERCEPTOR(__sanitizer_group *, getgrgid, u32 gid) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, getgrgid, gid);
   __sanitizer_group *res = REAL(getgrgid)(gid);
-  if (res) unpoison_group(ctx, res);
+  unpoison_group(ctx, res);
   return res;
 }
 #define INIT_GETPWNAM_AND_FRIENDS      \
   COMMON_INTERCEPT_FUNCTION(getpwnam); \
   COMMON_INTERCEPT_FUNCTION(getpwuid); \
   COMMON_INTERCEPT_FUNCTION(getgrnam); \
   COMMON_INTERCEPT_FUNCTION(getgrgid);
 #else
 #define INIT_GETPWNAM_AND_FRIENDS
 #endif
 
 #if SANITIZER_INTERCEPT_GETPWNAM_R_AND_FRIENDS
 INTERCEPTOR(int, getpwnam_r, const char *name, __sanitizer_passwd *pwd,
             char *buf, SIZE_T buflen, __sanitizer_passwd **result) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, getpwnam_r, name, pwd, buf, buflen, result);
   COMMON_INTERCEPTOR_READ_RANGE(ctx, name, REAL(strlen)(name) + 1);
   // 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(getpwnam_r)(name, pwd, buf, buflen, result);
-  if (!res && result && *result)
+  if (!res && result)
     unpoison_passwd(ctx, *result);
   if (result) COMMON_INTERCEPTOR_WRITE_RANGE(ctx, result, sizeof(*result));
   return res;
 }
 INTERCEPTOR(int, getpwuid_r, u32 uid, __sanitizer_passwd *pwd, char *buf,
             SIZE_T buflen, __sanitizer_passwd **result) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, getpwuid_r, uid, pwd, buf, buflen, result);
   // 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(getpwuid_r)(uid, pwd, buf, buflen, result);
-  if (!res && result && *result)
+  if (!res && result)
     unpoison_passwd(ctx, *result);
   if (result) COMMON_INTERCEPTOR_WRITE_RANGE(ctx, result, sizeof(*result));
   return res;
 }
 INTERCEPTOR(int, getgrnam_r, const char *name, __sanitizer_group *grp,
             char *buf, SIZE_T buflen, __sanitizer_group **result) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, getgrnam_r, name, grp, buf, buflen, result);
   COMMON_INTERCEPTOR_READ_RANGE(ctx, name, REAL(strlen)(name) + 1);
   // 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(getgrnam_r)(name, grp, buf, buflen, result);
-  if (!res && result && *result)
+  if (!res && result)
     unpoison_group(ctx, *result);
   if (result) COMMON_INTERCEPTOR_WRITE_RANGE(ctx, result, sizeof(*result));
   return res;
 }
 INTERCEPTOR(int, getgrgid_r, u32 gid, __sanitizer_group *grp, char *buf,
             SIZE_T buflen, __sanitizer_group **result) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, getgrgid_r, gid, grp, buf, buflen, result);
   // 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(getgrgid_r)(gid, grp, buf, buflen, result);
-  if (!res && result && *result)
+  if (!res && result)
     unpoison_group(ctx, *result);
   if (result) COMMON_INTERCEPTOR_WRITE_RANGE(ctx, result, sizeof(*result));
   return res;
 }
 #define INIT_GETPWNAM_R_AND_FRIENDS      \
   COMMON_INTERCEPT_FUNCTION(getpwnam_r); \
   COMMON_INTERCEPT_FUNCTION(getpwuid_r); \
   COMMON_INTERCEPT_FUNCTION(getgrnam_r); \
   COMMON_INTERCEPT_FUNCTION(getgrgid_r);
 #else
 #define INIT_GETPWNAM_R_AND_FRIENDS
 #endif
 
 #if SANITIZER_INTERCEPT_GETPWENT
 INTERCEPTOR(__sanitizer_passwd *, getpwent, int dummy) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, getpwent, dummy);
   __sanitizer_passwd *res = REAL(getpwent)(dummy);
-  if (res) unpoison_passwd(ctx, res);
+  unpoison_passwd(ctx, res);
   return res;
 }
 INTERCEPTOR(__sanitizer_group *, getgrent, int dummy) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, getgrent, dummy);
   __sanitizer_group *res = REAL(getgrent)(dummy);
-  if (res) unpoison_group(ctx, res);;
+  unpoison_group(ctx, res);
   return res;
 }
 #define INIT_GETPWENT                  \
   COMMON_INTERCEPT_FUNCTION(getpwent); \
   COMMON_INTERCEPT_FUNCTION(getgrent);
 #else
 #define INIT_GETPWENT
 #endif
 
 #if SANITIZER_INTERCEPT_FGETPWENT
 INTERCEPTOR(__sanitizer_passwd *, fgetpwent, void *fp) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, fgetpwent, fp);
   __sanitizer_passwd *res = REAL(fgetpwent)(fp);
-  if (res) unpoison_passwd(ctx, res);
+  unpoison_passwd(ctx, res);
   return res;
 }
 INTERCEPTOR(__sanitizer_group *, fgetgrent, void *fp) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, fgetgrent, fp);
   __sanitizer_group *res = REAL(fgetgrent)(fp);
-  if (res) unpoison_group(ctx, res);
+  unpoison_group(ctx, res);
   return res;
 }
 #define INIT_FGETPWENT                  \
   COMMON_INTERCEPT_FUNCTION(fgetpwent); \
   COMMON_INTERCEPT_FUNCTION(fgetgrent);
 #else
 #define INIT_FGETPWENT
 #endif
 
 #if SANITIZER_INTERCEPT_GETPWENT_R
 INTERCEPTOR(int, getpwent_r, __sanitizer_passwd *pwbuf, char *buf,
             SIZE_T buflen, __sanitizer_passwd **pwbufp) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, getpwent_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(getpwent_r)(pwbuf, buf, buflen, pwbufp);
-  if (!res && pwbufp && *pwbufp)
+  if (!res && pwbufp)
     unpoison_passwd(ctx, *pwbufp);
   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) {
   void *ctx;
   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(getgrent_r)(pwbuf, buf, buflen, pwbufp);
-  if (!res && pwbufp && *pwbufp)
+  if (!res && pwbufp)
     unpoison_group(ctx, *pwbufp);
   if (pwbufp) COMMON_INTERCEPTOR_WRITE_RANGE(ctx, pwbufp, sizeof(*pwbufp));
   return res;
 }
 #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, 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(fgetpwent_r)(fp, pwbuf, buf, buflen, pwbufp);
-  if (!res && pwbufp && *pwbufp)
+  if (!res && pwbufp)
     unpoison_passwd(ctx, *pwbufp);
   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 && pwbufp && *pwbufp)
+  if (!res && pwbufp)
     unpoison_group(ctx, *pwbufp);
   if (pwbufp) COMMON_INTERCEPTOR_WRITE_RANGE(ctx, pwbufp, sizeof(*pwbufp));
   return res;
 }
 #define INIT_FGETGRENT_R                  \
   COMMON_INTERCEPT_FUNCTION(fgetgrent_r);
 #else
 #define INIT_FGETGRENT_R