From 5444973bd08ff8e9a103fb3436adbdcbb2f666b8 Mon Sep 17 00:00:00 2001 From: Guillaume Solignac Date: Wed, 22 May 2024 10:47:33 +0200 Subject: [PATCH] vlib: prevent some signals from being executed on workers Before this commit, SIGINT, SIGHUP and SIGTERM could be executed on the workers. Since those signals don't stop execution, it meant that atexit handlers (like the `vl_unmap_shmem`) could run while the main thread was still running, which can cause race conditions. To avoid that, we prevent workers from handling those signals. Type: fix Signed-off-by: Guillaume Solignac Change-Id: I27a87d96a027d7423ced881a614427af4ab0f969 --- src/vlib/threads.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/src/vlib/threads.c b/src/vlib/threads.c index 87b71adc2bc..854d69448ac 100644 --- a/src/vlib/threads.c +++ b/src/vlib/threads.c @@ -370,6 +370,8 @@ void vlib_worker_thread_init (vlib_worker_thread_t * w) { vlib_thread_main_t *tm = vlib_get_thread_main (); + sigset_t signals; + int rv; /* * Note: disabling signals in worker threads as follows @@ -379,7 +381,17 @@ vlib_worker_thread_init (vlib_worker_thread_t * w) * sigfillset (&s); * pthread_sigmask (SIG_SETMASK, &s, 0); * } + * We can still disable signals for SIGINT,SIGHUP and SIGTERM as they don't + * trigger post-dump handlers anyway. */ + sigemptyset (&signals); + sigaddset (&signals, SIGINT); + sigaddset (&signals, SIGHUP); + sigaddset (&signals, SIGTERM); + rv = pthread_sigmask (SIG_BLOCK, &signals, NULL); + + if (rv) + clib_warning ("Failed to set the worker signal mask"); clib_mem_set_heap (w->thread_mheap); -- 2.16.6