Fix the handle locking in stdio
Fix the handle locking in stdio to use flockfile/funlockfile
internally when and where required. Macros in <stdio.h> are updated
to automatically call the underlying functions when the process is
threaded to obtain the necessary locking. A private mutex is added
to protect __sglue, the internal list of FILE handles, and another
to protect the one-time initialization. Some routines in libc that
use getc() change to use getc_unlocked() as they're either protected
by their own lock or aren't thread-safe routines anyway.
Based on OpenBSD change by guenther@openbsd.org
http://www.mail-archive.com/source-changes@cvs.openbsd.org/msg01015.html
Bug: 3446659
Change-Id: Ie82116e358c541718d6709ec45ca6796be5a007b
diff --git a/libc/stdio/vfscanf.c b/libc/stdio/vfscanf.c
index dbd0a8b..b16e3c7 100644
--- a/libc/stdio/vfscanf.c
+++ b/libc/stdio/vfscanf.c
@@ -117,6 +117,7 @@
static short basefix[17] =
{ 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
+ FLOCKFILE(fp);
_SET_ORIENTATION(fp, -1);
nassigned = 0;
@@ -124,8 +125,10 @@
base = 0; /* XXX just to keep gcc happy */
for (;;) {
c = *fmt++;
- if (c == 0)
+ if (c == 0) {
+ FUNLOCKFILE(fp);
return (nassigned);
+ }
if (isspace(c)) {
while ((fp->_r > 0 || __srefill(fp) == 0) &&
isspace(*fp->_p))
@@ -292,6 +295,7 @@
* Disgusting backwards compatibility hacks. XXX
*/
case '\0': /* compat */
+ FUNLOCKFILE(fp);
return (EOF);
default: /* compat */
@@ -689,8 +693,10 @@
}
}
input_failure:
- return (nassigned ? nassigned : -1);
+ if (nassigned == 0)
+ nassigned = -1;
match_failure:
+ FUNLOCKFILE(fp);
return (nassigned);
}