git: 82512c17ea39 - main - clnt_vc.c: Replace msleep() with pause() to avoid assert panic
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Date: Fri, 14 Oct 2022 22:48:19 UTC
The branch main has been updated by rmacklem: URL: https://cgit.FreeBSD.org/src/commit/?id=82512c17ea39fcc272483024cb55d567dfd55366 commit 82512c17ea39fcc272483024cb55d567dfd55366 Author: Rick Macklem <rmacklem@FreeBSD.org> AuthorDate: 2022-10-14 22:46:55 +0000 Commit: Rick Macklem <rmacklem@FreeBSD.org> CommitDate: 2022-10-14 22:46:55 +0000 clnt_vc.c: Replace msleep() with pause() to avoid assert panic An msleep() in clnt_vc.c used a global "fake_wchan" wchan argument along with the mutex in a CLIENT structure. As such, it was possible to use different mutexes for the same wchan and cause a panic assert. Since this is in a rarely executed code path, the assert panic was only recently observed. Since "fake_wchan" never gets a wakeup, this msleep() can be replaced with a pause() to avoid the panic assert, which is what this patch does. Reviewed by: kib, markj MFC after: 3 days Differential Revision: https://reviews.freebsd.org/D36977 --- sys/rpc/clnt_vc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/sys/rpc/clnt_vc.c b/sys/rpc/clnt_vc.c index 0c415d048141..38aead381619 100644 --- a/sys/rpc/clnt_vc.c +++ b/sys/rpc/clnt_vc.c @@ -116,8 +116,6 @@ static const struct clnt_ops clnt_vc_ops = { static void clnt_vc_upcallsdone(struct ct_data *); -static int fake_wchan; - /* * Create a client handle for a connection. * Default options are set, which the user can change using clnt_control()'s. @@ -453,7 +451,9 @@ call_again: mtx_lock(&ct->ct_lock); TAILQ_REMOVE(&ct->ct_pending, cr, cr_link); /* Sleep for 1 clock tick before trying the sosend() again. */ - msleep(&fake_wchan, &ct->ct_lock, 0, "rpclpsnd", 1); + mtx_unlock(&ct->ct_lock); + pause("rpclpsnd", 1); + mtx_lock(&ct->ct_lock); goto call_again; }