From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: Peter Xu <peterx@redhat.com>, stable@vger.kernel.org
Subject: [PATCH] KVM: selftests: Always run vCPU thread with blocked SIG_IPI
Date: Tue, 20 Apr 2021 04:16:14 -0400 [thread overview]
Message-ID: <20210420081614.684787-1-pbonzini@redhat.com> (raw)
The main thread could start to send SIG_IPI at any time, even before signal
blocked on vcpu thread. Therefore, start the vcpu thread with the signal
blocked.
Without this patch, on very busy cores the dirty_log_test could fail directly
on receiving a SIGUSR1 without a handler (when vcpu runs far slower than main).
Reported-by: Peter Xu <peterx@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
tools/testing/selftests/kvm/dirty_log_test.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index ffa4e2791926..81edbd23d371 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -527,9 +527,8 @@ static void *vcpu_worker(void *data)
*/
sigmask->len = 8;
pthread_sigmask(0, NULL, sigset);
+ sigdelset(sigset, SIG_IPI);
vcpu_ioctl(vm, VCPU_ID, KVM_SET_SIGNAL_MASK, sigmask);
- sigaddset(sigset, SIG_IPI);
- pthread_sigmask(SIG_BLOCK, sigset, NULL);
sigemptyset(sigset);
sigaddset(sigset, SIG_IPI);
@@ -858,6 +857,7 @@ int main(int argc, char *argv[])
.interval = TEST_HOST_LOOP_INTERVAL,
};
int opt, i;
+ sigset_t sigset;
sem_init(&sem_vcpu_stop, 0, 0);
sem_init(&sem_vcpu_cont, 0, 0);
@@ -916,6 +916,11 @@ int main(int argc, char *argv[])
srandom(time(0));
+ /* Ensure that vCPU threads start with SIG_IPI blocked. */
+ sigemptyset(&sigset);
+ sigaddset(&sigset, SIG_IPI);
+ pthread_sigmask(SIG_BLOCK, &sigset, NULL);
+
if (host_log_mode_option == LOG_MODE_ALL) {
/* Run each log mode */
for (i = 0; i < LOG_MODE_NUM; i++) {
--
2.26.2
next reply other threads:[~2021-04-20 8:16 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-20 8:16 Paolo Bonzini [this message]
2021-04-20 14:37 ` [PATCH] KVM: selftests: Always run vCPU thread with blocked SIG_IPI Peter Xu
2021-04-20 15:32 ` Peter Xu
2021-04-20 16:24 ` Paolo Bonzini
2021-04-20 16:58 ` Peter Xu
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