diff options
| -rw-r--r-- | fs/pipe.c | 37 |
1 files changed, 21 insertions, 16 deletions
diff --git a/fs/pipe.c b/fs/pipe.c index 01ca9fab95fa..bdd3f96054b9 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -1112,26 +1112,20 @@ SYSCALL_DEFINE1(pipe, int __user *, fildes) * 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) +static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long nr_pages) { struct pipe_buffer *bufs; /* - * Must be a power-of-2 currently - */ - if (!is_power_of_2(arg)) - return -EINVAL; - - /* * We can shrink the pipe, if arg >= pipe->nrbufs. Since we don't * expect a lot of shrink+grow operations, just free and allocate * again like we would do for growing. If the pipe currently * contains more buffers than arg, then return busy. */ - if (arg < pipe->nrbufs) + if (nr_pages < pipe->nrbufs) return -EBUSY; - bufs = kcalloc(arg, sizeof(struct pipe_buffer), GFP_KERNEL); + bufs = kcalloc(nr_pages, sizeof(struct pipe_buffer), GFP_KERNEL); if (unlikely(!bufs)) return -ENOMEM; @@ -1152,8 +1146,8 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long arg) pipe->curbuf = 0; kfree(pipe->bufs); pipe->bufs = bufs; - pipe->buffers = arg; - return arg; + pipe->buffers = nr_pages; + return nr_pages * PAGE_SIZE; } long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg) @@ -1168,19 +1162,30 @@ long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg) mutex_lock(&pipe->inode->i_mutex); switch (cmd) { - case F_SETPIPE_SZ: - if (!capable(CAP_SYS_ADMIN) && arg > pipe_max_pages) + case F_SETPIPE_SZ: { + unsigned long nr_pages; + + /* + * Currently the array must be a power-of-2 size, so adjust + * upwards if needed. + */ + nr_pages = (arg + PAGE_SIZE - 1) >> PAGE_SHIFT; + nr_pages = roundup_pow_of_two(nr_pages); + + if (!capable(CAP_SYS_ADMIN) && nr_pages > pipe_max_pages) return -EPERM; + /* * The pipe needs to be at least 2 pages large to * guarantee POSIX behaviour. */ - if (arg < 2) + if (nr_pages < 2) return -EINVAL; - ret = pipe_set_size(pipe, arg); + ret = pipe_set_size(pipe, nr_pages); break; + } case F_GETPIPE_SZ: - ret = pipe->buffers; + ret = pipe->buffers * PAGE_SIZE; break; default: ret = -EINVAL; |