After commit 831830b5a2 aka
"restrict reading from /proc/<pid>/maps to those who share ->mm or can ptrace"
sysctl stopped being relevant because commit moved security checks from ->show
time to ->start time (mm_for_maps()).
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Kees Cook <kees.cook@canonical.com>
Make process personality flags visible in /proc. Since a process's
personality is potentially sensitive (e.g. READ_IMPLIES_EXEC), make this
file only readable by the process owner.
Signed-off-by: Kees Cook <kees.cook@canonical.com>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
lock_task_sighand() make sure task->sighand is being protected,
so we do not need rcu_read_lock().
[ exec() will get task->sighand->siglock before change task->sighand! ]
But code using rcu_read_lock() _just_ to protect lock_task_sighand()
only appear in procfs. (and some code in procfs use lock_task_sighand()
without such redundant protection.)
Other subsystem may put lock_task_sighand() into rcu_read_lock()
critical region, but these rcu_read_lock() are used for protecting
"for_each_process()", "find_task_by_vpid()" etc. , not for protecting
lock_task_sighand().
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
[ok from Oleg]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
This is debatable, but while we're debating it, let's disallow the
combination of splice and an O_APPEND destination.
It's not entirely clear what the semantics of O_APPEND should be, and
POSIX apparently expects pwrite() to ignore O_APPEND, for example. So
we could make up any semantics we want, including the old ones.
But Miklos convinced me that we should at least give it some thought,
and that accepting writes at arbitrary offsets is wrong at least for
IS_APPEND() files (which always have O_APPEND set, even if the reverse
isn't true: you can obviously have O_APPEND set on a regular file).
So disallow O_APPEND entirely for now. I doubt anybody cares, and this
way we have one less gray area to worry about.
Reported-and-argued-for-by: Miklos Szeredi <miklos@szeredi.hu>
Acked-by: Jens Axboe <ens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix kernel-doc in new functions:
Error(mmotm-2008-1002-1617//fs/block_dev.c:895): duplicate section name 'Description'
Error(mmotm-2008-1002-1617//fs/block_dev.c:924): duplicate section name 'Description'
Warning(mmotm-2008-1002-1617//fs/block_dev.c:1282): No description found for parameter 'pathname'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
cc: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Since all bio_split calls refer the same single bio_split_pool, the bio_split
function can use bio_split_pool directly instead of the mempool_t parameter;
then the mempool_t parameter can be removed from bio_split param list, and
bio_split_pool is only referred in fs/bio.c file, can be marked static.
Signed-off-by: Denis ChengRq <crquan@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Helper function to find the sector offset in a bio given bvec index
and page offset.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
A filesystem might supply its own integrity metadata. Introduce a
flag that indicates whether the filesystem or the block layer owns the
integrity buffer.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Don't put functions that are only used in fs/bio-integrity.c in
blkdev.h, it's much cleaner to just keep it in there. Also kill
completely unused bdev_get_tag_size()
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Not all callers need (or want!) the mempool backing guarentee, it
essentially means that you can only use bio_alloc() for short allocations
and not for preallocating some bio's at setup or init time.
So add bio_kmalloc() which does the same thing as bio_alloc(), except
it just uses kmalloc() as the backing instead of the bio mempools.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
We call flush_disk() to make sure the buffer cache for the disk is
flushed after a disk resize. There are two resize cases, growing and
shrinking. Given that users can shrink/then grow a disk before
revalidate_disk() is called, we treat the grow case identically to
shrinking. We need to flush the buffer cache after an online shrink
because, as James Bottomley puts it,
The two use cases for shrinking I can see are
1. planned: the fs is already shrunk to within the new boundaries
and all data is relocated, so invalidate is fine (any dirty
buffers that might exist in the shrunk region are there only
because they were relocated but not yet written to their
original location).
2. unplanned: In this case, the fs is probably toast, so whether
we invalidate or not isn't going to make a whole lot of
difference; it's still going to try to read or write from
sectors beyond the new size and get I/O errors.
Immediately invalidating shrunk disks will cause errors for outstanding
I/Os for reads/write beyond the new end of the disk to be generated
earlier then if we waited for the normal buffer cache operation. It also
removes a potential security hole where we might keep old data around
from beyond the end of the shrunk disk if the disk was not invalidated.
Signed-off-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
We need to be able to flush the buffer cache for for more than
just when a disk is changed, so we factor out common cache flush code
in check_disk_change() to an internal flush_disk() routine. This
routine will then be used for both disk changes and disk resizes (in a
later patch).
Include the disk name in the text indicating that there are busy
inodes on the device and increase the KERN severity of the message.
Signed-off-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Check for device resize in the rescan_partitions() routine. If the device
has been resized, the bdev size is set to match. The rescan_partitions()
routine is called when opening the device and when calling the
BLKRRPART ioctl.
Signed-off-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
The revalidate_disk routine now checks if a disk has been resized by
comparing the gendisk capacity to the bdev inode size. If they are
different (usually because the disk has been resized underneath the kernel)
the bdev inode size is adjusted to match the capacity.
Signed-off-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This is a wrapper for the lower-level revalidate_disk call-backs such
as sd_revalidate_disk(). It allows us to perform pre and post
operations when calling them.
We will use this wrapper in a later patch to adjust block device sizes
after an online resize (a _post_ operation).
Signed-off-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch changes blk_rq_map_user to accept a NULL user-space buffer
with a READ command if rq_map_data is not NULL. Thus a caller can pass
page frames to lk_rq_map_user to just set up a request and bios with
page frames propely. bio_uncopy_user (called via blk_rq_unmap_user)
doesn't copy data to user space with such request.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Alexey Dobriyan
Kees Cook
Lai Jiangshan
Adrian Bunk
Linus Torvalds
Randy Dunlap
Denis ChengRq
Martin K. Petersen
Jens Axboe
Andrew Patterson
FUJITA Tomonori