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Subject[PATCH 1/2] fs/aio: Use kmap_local() instead of kmap()
Date
Originally, we used kmap() instead of kmap_atomic() for reading events
out of the completion ringbuffer because we're using copy_to_user(),
which can fault.

Now that kmap_local() is a thing, use that instead.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Benjamin LaHaise <bcrl@kvack.org
Cc: linux-aio@kvack.org
Cc: linux-fsdevel@vger.kernel.org
---
fs/aio.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index 5b2ff20ad3..3f795ed2a2 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1246,10 +1246,10 @@ static long aio_read_events_ring(struct kioctx *ctx,
avail = min(avail, nr - ret);
avail = min_t(long, avail, AIO_EVENTS_PER_PAGE - pos);

- ev = kmap(page);
+ ev = kmap_local_page(page);
copy_ret = copy_to_user(event + ret, ev + pos,
sizeof(*ev) * avail);
- kunmap(page);
+ kunmap_local(ev);

if (unlikely(copy_ret)) {
ret = -EFAULT;
--
2.39.0
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