From f0b6dfa6477590110bf9bd18d6c3cfa2e66420fe Mon Sep 17 00:00:00 2001 From: rth Date: Wed, 28 Nov 2012 21:01:26 +0000 Subject: [PATCH] PR libgcc/48076 * emutls.c (__emutls_get_address): Avoid race condition between obj->loc.offset read and emutls_key initialization. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@193907 138bc75d-0d04-0410-961f-82ee72b054a4 --- libgcc/ChangeLog | 6 ++++++ libgcc/emutls.c | 4 ++-- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog index c547dcb..6506e85 100644 --- a/libgcc/ChangeLog +++ b/libgcc/ChangeLog @@ -1,3 +1,9 @@ +2012-11-28 Richard Henderson + + PR libgcc/48076 + * emutls.c (__emutls_get_address): Avoid race condition between + obj->loc.offset read and emutls_key initialization. + 2012-11-22 Georg-Johann Lay Adjust decimal point of signed accum mode to GCC default. diff --git a/libgcc/emutls.c b/libgcc/emutls.c index 22ea440..f1b653b 100644 --- a/libgcc/emutls.c +++ b/libgcc/emutls.c @@ -136,7 +136,7 @@ __emutls_get_address (struct __emutls_object *obj) #ifndef __GTHREADS abort (); #else - pointer offset = obj->loc.offset; + pointer offset = __atomic_load_n (&obj->loc.offset, __ATOMIC_ACQUIRE); if (__builtin_expect (offset == 0, 0)) { @@ -147,7 +147,7 @@ __emutls_get_address (struct __emutls_object *obj) if (offset == 0) { offset = ++emutls_size; - obj->loc.offset = offset; + __atomic_store_n (&obj->loc.offset, offset, __ATOMIC_RELEASE); } __gthread_mutex_unlock (&emutls_mutex); } -- 2.7.4