From: "Michael Kerrisk (man-pages)" <mtk.manpages@xxxxxxxxx> Subject: pipe: move limit checking logic into pipe_set_size() This is a preparatory patch for following work. Move the F_SETPIPE_SZ limit-checking logic from pipe_fcntl() into pipe_set_size(). This simplifies the code a little, and allows for reworking required in a later patch that fixes the limit checking in pipe_set_size() Link: http://lkml.kernel.org/r/3701b2c5-2c52-2c3e-226d-29b9deb29b50@xxxxxxxxx Signed-off-by: Michael Kerrisk <mtk.manpages@xxxxxxxxx> Reviewed-by: Vegard Nossum <vegard.nossum@xxxxxxxxxx> Cc: Willy Tarreau <w@xxxxxx> Cc: <socketpair@xxxxxxxxx> Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/pipe.c | 41 ++++++++++++++++++----------------------- 1 file changed, 18 insertions(+), 23 deletions(-) diff -puN fs/pipe.c~pipe-move-limit-checking-logic-into-pipe_set_size fs/pipe.c --- a/fs/pipe.c~pipe-move-limit-checking-logic-into-pipe_set_size +++ a/fs/pipe.c @@ -1023,9 +1023,24 @@ static inline unsigned int round_pipe_si * 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 nr_pages) +static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long arg) { struct pipe_buffer *bufs; + unsigned int size, nr_pages; + + size = round_pipe_size(arg); + nr_pages = size >> PAGE_SHIFT; + + if (!nr_pages) + return -EINVAL; + + if (!capable(CAP_SYS_RESOURCE) && size > pipe_max_size) + return -EPERM; + + if ((too_many_pipe_buffers_hard(pipe->user) || + too_many_pipe_buffers_soft(pipe->user)) && + !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN)) + return -EPERM; /* * We can shrink the pipe, if arg >= pipe->nrbufs. Since we don't @@ -1109,28 +1124,9 @@ long pipe_fcntl(struct file *file, unsig __pipe_lock(pipe); switch (cmd) { - case F_SETPIPE_SZ: { - unsigned int size, nr_pages; - - size = round_pipe_size(arg); - nr_pages = size >> PAGE_SHIFT; - - ret = -EINVAL; - if (!nr_pages) - goto out; - - if (!capable(CAP_SYS_RESOURCE) && size > pipe_max_size) { - ret = -EPERM; - goto out; - } else if ((too_many_pipe_buffers_hard(pipe->user) || - too_many_pipe_buffers_soft(pipe->user)) && - !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN)) { - ret = -EPERM; - goto out; - } - ret = pipe_set_size(pipe, nr_pages); + case F_SETPIPE_SZ: + ret = pipe_set_size(pipe, arg); break; - } case F_GETPIPE_SZ: ret = pipe->buffers * PAGE_SIZE; break; @@ -1139,7 +1135,6 @@ long pipe_fcntl(struct file *file, unsig break; } -out: __pipe_unlock(pipe); return ret; } _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
