commit 8460308d11ba6129bea6000cc4fc1a58795c82db
author Elliott Hughes <enh@google.com> Wed Feb 10 16:28:34 2021 +0000
committer Gerrit Code Review <noreply-gerritcodereview@google.com> Wed Feb 10 16:28:34 2021 +0000
tree 4e1242b598a8ecd1d714e8124e1e01e9c536a4f5
parent 8d1f9c2c3b57f725a78addcff05d9abeca38c46d
parent d3915c7b53b745c521046b0af2455b4db3251c54

Merge "Make fd overflow an abort."

libc/stdio/stdio.cpp

diff --git a/libc/stdio/stdio.cpp b/libc/stdio/stdio.cpp
index 2b0e2b2..c429ff2 100644
--- a/libc/stdio/stdio.cpp
+++ b/libc/stdio/stdio.cpp
@@ -226,9 +226,13 @@
   _fwalk(__sflush);
 }
 
-static FILE* __finit(FILE* fp, int fd, int flags) {
+static FILE* __FILE_init(FILE* fp, int fd, int flags) {
   if (fp == nullptr) return nullptr;
 
+#if !defined(__LP64__)
+  if (fd > SHRT_MAX) __fortify_fatal("stdio: fd %d > SHRT_MAX", fd);
+#endif
+
   fp->_file = fd;
   android_fdsan_exchange_owner_tag(fd, 0, __get_file_tag(fp));
   fp->_flags = flags;
@@ -237,15 +241,6 @@
   fp->_write = __swrite;
   fp->_close = __sclose;
   _EXT(fp)->_seek64 = __sseek64;
-
-#if !defined(__LP64__)
-  if (fd > SHRT_MAX) {
-    errno = EMFILE;
-    fclose(fp);
-    return nullptr;
-  }
-#endif
-
   return fp;
 }
 
@@ -259,7 +254,7 @@
     return nullptr;
   }
 
-  FILE* fp = __finit(__sfp(), fd, flags);
+  FILE* fp = __FILE_init(__sfp(), fd, flags);
   if (fp == nullptr) {
     ErrnoRestorer errno_restorer;
     close(fd);
@@ -298,7 +293,7 @@
     fcntl(fd, F_SETFD, tmp | FD_CLOEXEC);
   }
 
-  return __finit(__sfp(), fd, flags);
+  return __FILE_init(__sfp(), fd, flags);
 }
 
 FILE* freopen(const char* file, const char* mode, FILE* fp) {
@@ -398,11 +393,11 @@
     }
   }
 
-  fp = __finit(fp, fd, flags);
+  __FILE_init(fp, fd, flags);
 
   // For append mode, O_APPEND sets the write position for free, but we need to
   // set the read position manually.
-  if (fp && (mode_flags & O_APPEND) != 0) __sseek64(fp, 0, SEEK_END);
+  if ((mode_flags & O_APPEND) != 0) __sseek64(fp, 0, SEEK_END);
 
   return fp;
 }