musl - musl - an implementation of the standard library for Linux-based systems

musl - an implementation of the standard library for Linux-based systems

diff options

author	Rich Felker <dalias@aerifal.cx>	2014年09月04日 22:21:17 -0400
committer	Rich Felker <dalias@aerifal.cx>	2014年09月04日 22:21:17 -0400
commit	6e2bb7acf42589fb7130b039d0623e2ca42503dd (patch)
tree	7af4719cfa84bc8cf0c6fa73fdca42035eaf03e9 /src/stdio/fwrite.c
parent	402611c3ba3be5b3b0486835d98e22ac7ced2722 (diff)
download	musl-6e2bb7acf42589fb7130b039d0623e2ca42503dd.tar.gz

fix multiple stdio functions' behavior on zero-length operations

previously, fgets, fputs, fread, and fwrite completely omitted locking and access to the FILE object when their arguments yielded a zero length read or write operation independent of the FILE state. this optimization was invalid; it wrongly skipped marking the stream as byte-oriented (a C conformance bug) and exposed observably missing synchronization (a POSIX conformance bug) where one of these functions could wrongly complete despite another thread provably holding the lock.

Diffstat (limited to 'src/stdio/fwrite.c')

-rw-r--r--

src/stdio/fwrite.c

1 files changed, 0 insertions, 1 deletions

diff --git a/src/stdio/fwrite.c b/src/stdio/fwrite.c
index d5f6542d..81ec271e 100644
--- a/src/stdio/fwrite.c
+++ b/src/stdio/fwrite.c

@@ -28,7 +28,6 @@ size_t __fwritex(const unsigned char *restrict s, size_t l, FILE *restrict f)

size_t fwrite(const void *restrict src, size_t size, size_t nmemb, FILE *restrict f)

{

size_t k, l = size*nmemb;

- if (!l) return l;

FLOCK(f);

k = __fwritex(src, l, f);

FUNLOCK(f);

generated by cgit v1.2.1 (git 2.18.0) at 2025年09月10日 20:37:38 +0000