Subject: linux-next: manual merge of the keys tree with Linus' tree

From: Stephen Rothwell <[email-masked]>
Date: Thu, 20 Feb 2020 10:43:32 +1100

Hi all,

Today's linux-next merge of the keys tree got a conflict in:

  fs/pipe.c

between commit:

  6551d5c56eb0 ("pipe: make sure to wake up everybody when the last reader/writer closes")

from Linus' tree and commit:

  549d46d3827d ("pipe: Add general notification queue support")

from the keys tree.

I fixed it up (I think - see below) and can carry the fix as necessary.
This is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging.  You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

-- 
Cheers,
Stephen Rothwell

diff --cc fs/pipe.c
index 2144507447c5,238601a7ab24..000000000000
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@@ -1269,12 -1310,63 +1311,64 @@@ int pipe_resize_ring(struct pipe_inode_
  	kfree(pipe->bufs);
  	pipe->bufs = bufs;
  	pipe->ring_size = nr_slots;
- 	pipe->max_usage = nr_slots;
+ 	if (pipe->max_usage > nr_slots)
+ 		pipe->max_usage = nr_slots;
  	pipe->tail = tail;
  	pipe->head = head;
 -	wake_up_interruptible_all(&pipe->rd_wait);
 -	wake_up_interruptible_all(&pipe->wr_wait);
 +
 +	/* This might have made more room for writers */
 +	wake_up_interruptible(&pipe->wr_wait);
+ 	return 0;
+ }
+ 
+ /*
+  * Allocate a new array of pipe buffers and copy the info over. Returns the
+  * pipe size if successful, or return -ERROR on error.
+  */
+ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long arg)
+ {
+ 	unsigned long user_bufs;
+ 	unsigned int nr_slots, size;
+ 	long ret = 0;
+ 
+ #ifdef CONFIG_WATCH_QUEUE
+ 	if (pipe->watch_queue)
+ 		return -EBUSY;
+ #endif
+ 
+ 	size = round_pipe_size(arg);
+ 	nr_slots = size >> PAGE_SHIFT;
+ 
+ 	if (!nr_slots)
+ 		return -EINVAL;
+ 
+ 	/*
+ 	 * If trying to increase the pipe capacity, check that an
+ 	 * unprivileged user is not trying to exceed various limits
+ 	 * (soft limit check here, hard limit check just below).
+ 	 * Decreasing the pipe capacity is always permitted, even
+ 	 * if the user is currently over a limit.
+ 	 */
+ 	if (nr_slots > pipe->max_usage &&
+ 			size > pipe_max_size && !capable(CAP_SYS_RESOURCE))
+ 		return -EPERM;
+ 
+ 	user_bufs = account_pipe_buffers(pipe->user, pipe->nr_accounted, nr_slots);
+ 
+ 	if (nr_slots > pipe->max_usage &&
+ 			(too_many_pipe_buffers_hard(user_bufs) ||
+ 			 too_many_pipe_buffers_soft(user_bufs)) &&
+ 			pipe_is_unprivileged_user()) {
+ 		ret = -EPERM;
+ 		goto out_revert_acct;
+ 	}
+ 
+ 	ret = pipe_resize_ring(pipe, nr_slots);
+ 	if (ret < 0)
+ 		goto out_revert_acct;
+ 
+ 	pipe->max_usage = nr_slots;
+ 	pipe->nr_accounted = nr_slots;
  	return pipe->max_usage * PAGE_SIZE;
  
  out_revert_acct: