From ecc7aee9a0eb4f9fbdf4dc2972e8c6361e531b6a Mon Sep 17 00:00:00 2001 From: Kenneth Soerensen Date: Wed, 10 Apr 2013 16:52:52 +0200 Subject: Make res_init() thread safe. res_init() was not atomic, which could give undesired behaviour. Now res_init() is completely locked under one lock and the locking is removed from __res_vinit(). Signed-off-by: Kenneth Soerensen Signed-off-by: Bernhard Reutner-Fischer --- libc/inet/resolv.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) (limited to 'libc') diff --git a/libc/inet/resolv.c b/libc/inet/resolv.c index ae0dce520..f334d0586 100644 --- a/libc/inet/resolv.c +++ b/libc/inet/resolv.c @@ -3426,6 +3426,7 @@ static void res_sync_func(void) */ } +/* has to be called under __resolv_lock */ static int __res_vinit(res_state rp, int preinit) { @@ -3434,7 +3435,6 @@ __res_vinit(res_state rp, int preinit) int m = 0; #endif - __UCLIBC_MUTEX_LOCK(__resolv_lock); __close_nameservers(); __open_nameservers(); @@ -3526,7 +3526,6 @@ __res_vinit(res_state rp, int preinit) rp->options |= RES_INIT; - __UCLIBC_MUTEX_UNLOCK(__resolv_lock); return 0; } @@ -3576,11 +3575,11 @@ res_init(void) if (!_res.id) _res.id = res_randomid(); - __UCLIBC_MUTEX_UNLOCK(__resolv_lock); - __res_vinit(&_res, 1); __res_sync = res_sync_func; + __UCLIBC_MUTEX_UNLOCK(__resolv_lock); + return 0; } libc_hidden_def(res_init) @@ -3679,7 +3678,11 @@ struct __res_state *__resp = &_res; int res_ninit(res_state statp) { - return __res_vinit(statp, 0); + int ret; + __UCLIBC_MUTEX_LOCK(__resolv_lock); + ret = __res_vinit(statp, 0); + __UCLIBC_MUTEX_UNLOCK(__resolv_lock); + return ret; } #endif /* L_res_init */ -- cgit v1.2.3