From c557191ca02f326bd314963f88118301d891aa89 Mon Sep 17 00:00:00 2001
From: Libor Peltan <libor.peltan@nic.cz>
Date: Fri, 30 Aug 2024 10:29:49 +0200
Subject: [PATCH] concurrent CTL: disable signals temporarily when launching
subthreads to avoid losing them
---
src/utils/knotd/main.c | 24 ++++++++++++++++++++++--
1 file changed, 22 insertions(+), 2 deletions(-)
diff --git a/src/utils/knotd/main.c b/src/utils/knotd/main.c
index 203d31324d..d141f74fce 100644
--- a/src/utils/knotd/main.c
+++ b/src/utils/knotd/main.c
@@ -66,6 +66,7 @@ typedef struct {
knot_ctl_t *ctl;
server_t *server;
pthread_t thread;
+ sigset_t sigmask;
int ret;
bool exclusive;
} concurrent_ctl_ctx_t;
@@ -184,13 +185,14 @@ static void setup_signals(void)
sigdelset(&all, SIGBUS);
sigdelset(&all, SIGFPE);
sigdelset(&all, SIGSEGV);
- pthread_sigmask(SIG_SETMASK, &all, NULL);
/* Setup handlers. */
struct sigaction action = { .sa_handler = handle_signal };
for (const struct signal *s = SIGNALS; s->signum > 0; s++) {
sigaction(s->signum, &action, NULL);
}
+
+ pthread_sigmask(SIG_SETMASK, &all, NULL);
}
/*! \brief Unblock server control signals. */
@@ -208,6 +210,24 @@ static void enable_signals(void)
pthread_sigmask(SIG_UNBLOCK, &mask, NULL);
}
+/*! \brief Create a control thread with correct signals setting. */
+static void create_thread_sigmask(pthread_t *thr, void *(*fcn)(void*), void *ctx,
+ sigset_t *out_mask)
+{
+ /* Block all blockable signals. */
+ sigset_t mask;
+ sigfillset(&mask);
+ sigdelset(&mask, SIGBUS);
+ sigdelset(&mask, SIGFPE);
+ sigdelset(&mask, SIGILL);
+ sigdelset(&mask, SIGSEGV);
+ pthread_sigmask(SIG_SETMASK, &mask, out_mask);
+
+ pthread_create(thr, NULL, fcn, ctx);
+
+ pthread_sigmask(SIG_SETMASK, out_mask, NULL);
+}
+
/*! \brief Drop POSIX 1003.1e capabilities. */
static void drop_capabilities(void)
{
@@ -306,7 +326,7 @@ static concurrent_ctl_ctx_t *find_free_ctx(concurrent_ctl_ctx_t *concurrent_ctxs
pthread_mutex_lock(&cctx->mutex);
switch (cctx->state) {
case CONCURRENT_EMPTY:
- pthread_create(&cctx->thread, NULL, ctl_process_thread, cctx);
+ create_thread_sigmask(&cctx->thread, ctl_process_thread, cctx, &cctx->sigmask);
break;
case CONCURRENT_IDLE:
knot_ctl_free(cctx->ctl);
--
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