From dd1f63493adbbb06fa16ed15f8fc16584f55ee81 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Fri, 30 Sep 2016 22:31:01 +0100 Subject: linux-user/syscall: extend lock around cpu-list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There is a potential race if several threads exit at once. To serialise the exits extend the lock above the initial checking of the CPU list. Signed-off-by: Alex Bennée Message-Id: <20160930213106.20186-11-alex.bennee@linaro.org> Signed-off-by: Paolo Bonzini --- linux-user/syscall.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 0815f30965..fa559be47f 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -7476,13 +7476,16 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, break; } + cpu_list_lock(); + if (CPU_NEXT(first_cpu)) { TaskState *ts; - cpu_list_lock(); /* Remove the CPU from the list. */ QTAILQ_REMOVE(&cpus, cpu, node); + cpu_list_unlock(); + ts = cpu->opaque; if (ts->child_tidptr) { put_user_u32(0, ts->child_tidptr); @@ -7495,6 +7498,8 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, rcu_unregister_thread(); pthread_exit(NULL); } + + cpu_list_unlock(); #ifdef TARGET_GPROF _mcleanup(); #endif -- cgit v1.2.3