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| author |   Torvald Riegel <triegel@redhat.com> | 2016-08-17 13:56:11 +0200 |
|---|---|---|
| committer | Torvald Riegel <triegel@redhat.com> | 2016-08-18 20:53:37 +0200 |
| commit | 6f9d4f595e4073807ad0e844cbb3b3d7158b76d5 (patch) | |
| tree | d0064a3e11f1326fcdfcad1b239076044da9a762 /nscd | |
| parent | Get rid of array-bounds warning in __kernel_rem_pio2[f] with gcc 6.1 -O3. (diff) | |
| download | glibc-6f9d4f595e4073807ad0e844cbb3b3d7158b76d5.tar.gz glibc-6f9d4f595e4073807ad0e844cbb3b3d7158b76d5.tar.bz2 glibc-6f9d4f595e4073807ad0e844cbb3b3d7158b76d5.zip | |
Fix incorrect double-checked locking related to _res_hconf.initialized.
_res_hconf.initialized was not suitable for use in a multi-threaded
environment due to the lack of atomics and memory barriers. Use of it was
also unnecessary because _res_hconf_init did the right thing by using
__libc_once. This patch fixes the glibc-internal uses by just calling
_res_hconf_init unconditionally, and switches to a release MO atomic store
for _res_hconf.initialized to fix the glibc side of the synchronization
problem (which will maintain backward compatibility, but cannot fix the
lack of acquire MO on any glibc-external loads).
[BZ #20477]
* resolv/res_hconf.c (do_init): Use atomic access.
* resolv/res_hconf.h: Add comments.
* nscd/aicache.c (addhstaiX): Call _res_hconf_init unconditionally.
* nss/getXXbyYY_r.c (REENTRANT_NAME): Likewise.
* sysdeps/posix/getaddrinfo.c (gaih_inet): Likewise.
Diffstat (limited to 'nscd')
| -rw-r--r-- | nscd/aicache.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/nscd/aicache.c b/nscd/aicache.c index a2e6cf8475..32c8f57b41 100644 --- a/nscd/aicache.c +++ b/nscd/aicache.c @@ -101,8 +101,7 @@ addhstaiX (struct database_dyn *db, int fd, request_header *req, nip = hosts_database; /* Initialize configurations. */ - if (__glibc_unlikely (!_res_hconf.initialized)) - _res_hconf_init (); + _res_hconf_init (); if (__res_maybe_init (&_res, 0) == -1) no_more = 1; |