kernel/linux.git/lib/iov_iter.c, branch v4.9.125

new privimitive: iov_iter_revert()

2017-04-21T07:31:21+00:00

commit 27c0e3748e41ca79171ffa3e97415a20af6facd0 upstream. opposite to iov_iter_advance(); the caller is responsible for never using it to move back past the initial position. Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

fix a fencepost error in pipe_advance()

2017-01-19T19:18:02+00:00

commit b9dc6f65bc5e232d1c05fe34b5daadc7e8bbf1fb upstream. The logics in pipe_advance() used to release all buffers past the new position failed in cases when the number of buffers to release was equal to pipe->buffers. If that happened, none of them had been released, leaving pipe full. Worse, it was trivial to trigger and we end up with pipe full of uninitialized pages. IOW, it's an infoleak. Reported-by: "Alan J. Wylie" Tested-by: "Alan J. Wylie" Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

fix iov_iter_advance() for ITER_PIPE

2016-11-17T05:00:48+00:00

iov_iter_advance() needs to decrement iter->count by the number of bytes we'd moved beyond. Normal flavours do that, but ITER_PIPE doesn't and ITER_PIPE generic_file_read_iter() for O_DIRECT files ends up with a bogus fallback to page cache read, resulting in incorrect values for file offset and bytes read. Signed-off-by: Abhi Das Signed-off-by: Al Viro

iov_iter: kernel-doc import_iovec() and rw_copy_check_uvector()

2016-10-15T00:00:34+00:00

Both import_iovec() and rw_copy_check_uvector() take an array (typically small and on-stack) which is used to hold an iovec array copy from userspace. This is to avoid an expensive memory allocation in the fast path (i.e. few iovec elements). The caller may have to check whether these functions actually used the provided buffer or allocated a new one -- but this differs between the too. Let's just add a kernel doc to clarify what the semantics are for each function. Signed-off-by: Vegard Nossum Signed-off-by: Al Viro

Fix off-by-one in __pipe_get_pages()

2016-10-11T17:40:01+00:00

it actually worked only when requested area ended on the page boundary... Reported-by: Marco Grassi Signed-off-by: Al Viro Signed-off-by: Linus Torvalds

Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2016-10-10T20:04:49+00:00

Pull misc vfs updates from Al Viro: "Assorted misc bits and pieces. There are several single-topic branches left after this (rename2 series from Miklos, current_time series from Deepa Dinamani, xattr series from Andreas, uaccess stuff from from me) and I'd prefer to send those separately" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits) proc: switch auxv to use of __mem_open() hpfs: support FIEMAP cifs: get rid of unused arguments of CIFSSMBWrite() posix_acl: uapi header split posix_acl: xattr representation cleanups fs/aio.c: eliminate redundant loads in put_aio_ring_file fs/internal.h: add const to ns_dentry_operations declaration compat: remove compat_printk() fs/buffer.c: make __getblk_slow() static proc: unsigned file descriptors fs/file: more unsigned file descriptors fs: compat: remove redundant check of nr_segs cachefiles: Fix attempt to read i_blocks after deleting file [ver #2] cifs: don't use memcpy() to copy struct iov_iter get rid of separate multipage fault-in primitives fs: Avoid premature clearing of capabilities fs: Give dentry to inode_change_ok() instead of inode fuse: Propagate dentry down to inode_change_ok() ceph: Propagate dentry down to inode_change_ok() xfs: Propagate dentry down to inode_change_ok() ...

pipe: add pipe_buf_release() helper

2016-10-05T22:23:58+00:00

Signed-off-by: Miklos Szeredi Signed-off-by: Al Viro

new iov_iter flavour: pipe-backed

2016-10-05T22:23:36+00:00

iov_iter variant for passing data into pipe. copy_to_iter() copies data into page(s) it has allocated and stuffs them into the pipe; copy_page_to_iter() stuffs there a reference to the page given to it. Both will try to coalesce if possible. iov_iter_zero() is similar to copy_to_iter(); iov_iter_get_pages() and friends will do as copy_to_iter() would have and return the pages where the data would've been copied. iov_iter_advance() will truncate everything past the spot it has advanced to. New primitive: iov_iter_pipe(), used for initializing those. pipe should be locked all along. Running out of space acts as fault would for iovec-backed ones; in other words, giving it to ->read_iter() may result in short read if the pipe overflows, or -EFAULT if it happens with nothing copied there. In other words, ->read_iter() on those acts pretty much like ->splice_read(). Moreover, all generic_file_splice_read() users, as well as many other ->splice_read() instances can be switched to that scheme - that'll happen in the next commit. Signed-off-by: Al Viro

get rid of separate multipage fault-in primitives

2016-09-27T22:12:24+00:00

* the only remaining callers of "short" fault-ins are just as happy with generic variants (both in lib/iov_iter.c); switch them to multipage variants, kill the "short" ones * rename the multipage variants to now available plain ones. * get rid of compat macro defining iov_iter_fault_in_multipage_readable by expanding it in its only user. Signed-off-by: Al Viro

fix iov_iter_fault_in_readable()

2016-09-17T21:05:30+00:00

... by turning it into what used to be multipages counterpart Cc: stable@vger.kernel.org Signed-off-by: Al Viro Signed-off-by: Linus Torvalds