From c48c3e4bb3d1665f3e9fa2785daafa72dfe59399 Mon Sep 17 00:00:00 2001
From: Elliott Hughes <enh@google.com>
Date: Wed, 19 Nov 2014 15:16:51 -0800
Subject: [PATCH] Fix flockfile(3) and friends for stdin/stdout/stderr too.

stdin/stdout/stderr are special; their mutexes are initialized by
__sinit. There's no unit test for this, because __sinit has already
been called by the time the first unit test runs, but you could
reproduce this failure with a trivial main() that calls flockfile
or ftrylockfile on one of the standard streams before otherwise
using stdio.

Bug: 18208568
Change-Id: I28d232cf05a9f198a2bed61854d8047b23d2091d
---
 libc/bionic/flockfile.cpp | 12 ++++++++++++
 libc/stdio/fileext.h      |  4 ++++
 libc/stdio/glue.h         |  6 ++++++
 libc/stdio/local.h        |  4 ++++
 libc/stdio/wcio.h         |  6 ++++++
 5 files changed, 32 insertions(+)

diff --git a/libc/bionic/flockfile.cpp b/libc/bionic/flockfile.cpp
index 3381e8eb..b73907cb 100644
--- a/libc/bionic/flockfile.cpp
+++ b/libc/bionic/flockfile.cpp
@@ -36,12 +36,20 @@
 // struct __sfileext (see fileext.h).
 
 void flockfile(FILE* fp) {
+  if (!__sdidinit) {
+    __sinit();
+  }
+
   if (fp != NULL) {
     pthread_mutex_lock(&_FLOCK(fp));
   }
 }
 
 int ftrylockfile(FILE* fp) {
+  if (!__sdidinit) {
+    __sinit();
+  }
+
   // The specification for ftrylockfile() says it returns 0 on success,
   // or non-zero on error. So return an errno code directly on error.
   if (fp == NULL) {
@@ -52,6 +60,10 @@ int ftrylockfile(FILE* fp) {
 }
 
 void funlockfile(FILE* fp) {
+  if (!__sdidinit) {
+    __sinit();
+  }
+
   if (fp != NULL) {
     pthread_mutex_unlock(&_FLOCK(fp));
   }
diff --git a/libc/stdio/fileext.h b/libc/stdio/fileext.h
index dc89fff7..25b7bda2 100644
--- a/libc/stdio/fileext.h
+++ b/libc/stdio/fileext.h
@@ -34,6 +34,8 @@
 
 #include <pthread.h>
 
+__BEGIN_DECLS
+
 /*
  * file extension
  */
@@ -61,4 +63,6 @@ do { \
 	_FILEEXT_INIT(f); \
 } while (0)
 
+__END_DECLS
+
 #endif /* _FILEEXT_H_ */
diff --git a/libc/stdio/glue.h b/libc/stdio/glue.h
index 4ead20a8..a9e5d103 100644
--- a/libc/stdio/glue.h
+++ b/libc/stdio/glue.h
@@ -32,6 +32,10 @@
  * SUCH DAMAGE.
  */
 
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
 /*
  * The first few FILEs are statically allocated; others are dynamically
  * allocated and linked in via this glue structure.
@@ -44,3 +48,5 @@ struct glue {
 
 /* This was referenced by a couple of different pieces of middleware and the Crystax NDK. */
 __LIBC64_HIDDEN__ extern struct glue __sglue;
+
+__END_DECLS
diff --git a/libc/stdio/local.h b/libc/stdio/local.h
index 13188ee1..46b11f13 100644
--- a/libc/stdio/local.h
+++ b/libc/stdio/local.h
@@ -41,6 +41,8 @@
 #include "wcio.h"
 #include "fileext.h"
 
+__BEGIN_DECLS
+
 /*
  * Android <= KitKat had getc/putc macros in <stdio.h> that referred
  * to __srget/__swbuf, so those symbols need to be public for LP32
@@ -137,3 +139,5 @@ extern int __sfvwrite(FILE *, struct __suio *);
 wint_t __fputwc_unlock(wchar_t wc, FILE *fp);
 
 #pragma GCC visibility pop
+
+__END_DECLS
diff --git a/libc/stdio/wcio.h b/libc/stdio/wcio.h
index 584a3f20..2c1fa3c1 100644
--- a/libc/stdio/wcio.h
+++ b/libc/stdio/wcio.h
@@ -32,6 +32,10 @@
 #ifndef _WCIO_H_
 #define _WCIO_H_
 
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
 /* minimal requirement of SUSv2 */
 #define WCIO_UNGETWC_BUFSIZE 1
 
@@ -78,4 +82,6 @@ do {\
 #define WCIO_INIT(fp) \
 	memset(&(_EXT(fp)->_wcio), 0, sizeof(struct wchar_io_data))
 
+__END_DECLS
+
 #endif /*_WCIO_H_*/
-- 
2.39.2