From 6f8f25440d791855e8b6a26cd2bff9d738468416 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Tue, 15 Dec 2020 20:45:50 -0800 Subject: [PATCH] relay: require non-NULL callbacks in relay_open() There are no clients passing NULL callbacks, which makes sense as it wouldn't even create a file. Require non-NULL callbacks, and throw away the handling for NULL callbacks. Link: https://lkml.kernel.org/r/e40642f3b027d2bb6bc851ddb60e0a61ea51f5f8.1606153547.git.jani.nikula@intel.com Signed-off-by: Jani Nikula Suggested-by: Christoph Hellwig Reviewed-by: Christoph Hellwig Cc: Jens Axboe Cc: Kalle Valo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/relay.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-) diff --git a/kernel/relay.c b/kernel/relay.c index b51343642bf4..d9b8185161a8 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -291,13 +291,6 @@ static int remove_buf_file_default_callback(struct dentry *dentry) return -EINVAL; } -/* relay channel default callbacks */ -static struct rchan_callbacks default_channel_callbacks = { - .subbuf_start = subbuf_start_default_callback, - .create_buf_file = create_buf_file_default_callback, - .remove_buf_file = remove_buf_file_default_callback, -}; - /** * wakeup_readers - wake up readers waiting on a channel * @work: contains the channel buffer @@ -472,11 +465,6 @@ static void relay_close_buf(struct rchan_buf *buf) static void setup_callbacks(struct rchan *chan, struct rchan_callbacks *cb) { - if (!cb) { - chan->cb = &default_channel_callbacks; - return; - } - if (!cb->subbuf_start) cb->subbuf_start = subbuf_start_default_callback; if (!cb->create_buf_file) @@ -542,6 +530,8 @@ struct rchan *relay_open(const char *base_filename, return NULL; if (subbuf_size > UINT_MAX / n_subbufs) return NULL; + if (!cb) + return NULL; chan = kzalloc(sizeof(struct rchan), GFP_KERNEL); if (!chan)