From:   Mike Christie <michael.christie@oracle.com>
To:     hch@infradead.org, stefanha@redhat.com, jasowang@redhat.com,
        mst@redhat.com, sgarzare@redhat.com,
        virtualization@lists.linux-foundation.org, brauner@kernel.org,
        ebiederm@xmission.com, torvalds@linux-foundation.org,
        konrad.wilk@oracle.com, linux-kernel@vger.kernel.org
Cc:     Mike Christie <michael.christie@oracle.com>,
        Christoph Hellwig <hch@lst.de>
Subject: [PATCH 07/11] fork: Add kernel_clone_args flag to ignore signals
Date:   Fri, 10 Mar 2023 16:03:28 -0600
Message-Id: <20230310220332.5309-8-michael.christie@oracle.com>
In-Reply-To: <20230310220332.5309-1-michael.christie@oracle.com>
References: <20230310220332.5309-1-michael.christie@oracle.com>
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Since:

commit 10ab825bdef8 ("change kernel threads to ignore signals instead of
blocking them")

kthreads have been ignoring signals by default, and the vhost layer has
never had a need to change that. This patch adds an option flag,
USER_WORKER_SIG_IGN, handled in copy_process() after copy_sighand()
and copy_signals() so vhost_tasks added in the next patches can continue
to ignore singals.

Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
---
 include/linux/sched/task.h | 1 +
 kernel/fork.c              | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index 4f816048794f..00c54bfac0b5 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -29,6 +29,7 @@ struct kernel_clone_args {
 	u32 io_thread:1;
 	u32 user_worker:1;
 	u32 no_files:1;
+	u32 ignore_signals:1;
 	unsigned long stack;
 	unsigned long stack_size;
 	unsigned long tls;
diff --git a/kernel/fork.c b/kernel/fork.c
index 258163ea5cd2..244aae6c2395 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2287,6 +2287,9 @@ static __latent_entropy struct task_struct *copy_process(
 	if (retval)
 		goto bad_fork_cleanup_io;
 
+	if (args->ignore_signals)
+		ignore_signals(p);
+
 	stackleak_task_init(p);
 
 	if (pid != &init_struct_pid) {
-- 
2.25.1