diff options
| author | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2017-07-12 10:53:13 +0100 |
|---|---|---|
| committer | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2017-07-14 16:09:56 +0100 |
| commit | de895ddcd7fc45caeeeb0ae312311b8bd31d82c5 (patch) | |
| tree | 7c4d633905c2e5b2fb466ff6ccf32afe735893b2 /libio | |
| parent | 8bd8c052e765d626fae1424e2739d009a185a6ba (diff) | |
Disable single thread optimization for open_memstream
Single thread optimization is valid if at thread creation time the
optimization can be disabled. This is in principle true for all
stream objects that user code can access (and thus needs locking),
using the same internal list as fflush(0) uses. However in glibc
open_memstream is not on that list (BZ 21735) so the optimization
has to be disabled.
* libio/memstream.c (__open_memstream): Set _IO_FLAGS2_NEED_LOCK.
* libio/wmemstream.c (open_wmemstream): Likewise.
* nptl/tst-memstream.c: New.
Diffstat (limited to 'libio')
| -rw-r--r-- | libio/memstream.c | 3 | ||||
| -rw-r--r-- | libio/wmemstream.c | 3 |
2 files changed, 6 insertions, 0 deletions
diff --git a/libio/memstream.c b/libio/memstream.c index f83d4a5213..e391efd48a 100644 --- a/libio/memstream.c +++ b/libio/memstream.c @@ -96,6 +96,9 @@ __open_memstream (char **bufloc, _IO_size_t *sizeloc) new_f->fp.bufloc = bufloc; new_f->fp.sizeloc = sizeloc; + /* Disable single thread optimization. BZ 21735. */ + new_f->fp._sf._sbf._f._flags2 |= _IO_FLAGS2_NEED_LOCK; + return (_IO_FILE *) &new_f->fp._sf._sbf; } libc_hidden_def (__open_memstream) diff --git a/libio/wmemstream.c b/libio/wmemstream.c index 5bc77f52ee..103a760bf5 100644 --- a/libio/wmemstream.c +++ b/libio/wmemstream.c @@ -98,6 +98,9 @@ open_wmemstream (wchar_t **bufloc, _IO_size_t *sizeloc) new_f->fp.bufloc = bufloc; new_f->fp.sizeloc = sizeloc; + /* Disable single thread optimization. BZ 21735. */ + new_f->fp._sf._sbf._f._flags2 |= _IO_FLAGS2_NEED_LOCK; + return (_IO_FILE *) &new_f->fp._sf._sbf; } |