]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
pipe: simplify round_pipe_size()
authorEric Biggers <ebiggers@google.com>
Tue, 6 Feb 2018 23:42:05 +0000 (15:42 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 7 Feb 2018 02:32:48 +0000 (18:32 -0800)
commitc4fed5a91fadc8a277b1eda474317b501651dd3e
tree6194bd7d003a2527f675dee2ab3fbb03332a8e19
parent96e99be40e4cff870a83233731121ec0f7f95075
pipe: simplify round_pipe_size()

round_pipe_size() calculates the number of pages the requested size
corresponds to, then rounds the page count up to the next power of 2.

However, it also rounds everything < PAGE_SIZE up to PAGE_SIZE.
Therefore, there's no need to actually translate the size into a page
count; we just need to round the size up to the next power of 2.

We do need to verify the size isn't greater than (1 << 31), since on
32-bit systems roundup_pow_of_two() would be undefined in that case.  But
that can just be combined with the UINT_MAX check which we need anyway
now.

Finally, update pipe_set_size() to not redundantly check the return value
of round_pipe_size() for the "invalid size" case twice.

Link: http://lkml.kernel.org/r/20180111052902.14409-7-ebiggers3@gmail.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "Luis R . Rodriguez" <mcgrof@kernel.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/pipe.c