Commit graph

39 commits

Author SHA1 Message Date
Kirill Smelkov
9c829b6e3f fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock
commit 10dce8af34226d90fa56746a934f8da5dcdba3df upstream.

Commit 9c225f2655 ("vfs: atomic f_pos accesses as per POSIX") added
locking for file.f_pos access and in particular made concurrent read and
write not possible - now both those functions take f_pos lock for the
whole run, and so if e.g. a read is blocked waiting for data, write will
deadlock waiting for that read to complete.

This caused regression for stream-like files where previously read and
write could run simultaneously, but after that patch could not do so
anymore. See e.g. commit 581d21a2d02a ("xenbus: fix deadlock on writes
to /proc/xen/xenbus") which fixes such regression for particular case of
/proc/xen/xenbus.

The patch that added f_pos lock in 2014 did so to guarantee POSIX thread
safety for read/write/lseek and added the locking to file descriptors of
all regular files. In 2014 that thread-safety problem was not new as it
was already discussed earlier in 2006.

However even though 2006'th version of Linus's patch was adding f_pos
locking "only for files that are marked seekable with FMODE_LSEEK (thus
avoiding the stream-like objects like pipes and sockets)", the 2014
version - the one that actually made it into the tree as 9c225f2655 -
is doing so irregardless of whether a file is seekable or not.

See

    https://lore.kernel.org/lkml/53022DB1.4070805@gmail.com/
    https://lwn.net/Articles/180387
    https://lwn.net/Articles/180396

for historic context.

The reason that it did so is, probably, that there are many files that
are marked non-seekable, but e.g. their read implementation actually
depends on knowing current position to correctly handle the read. Some
examples:

	kernel/power/user.c		snapshot_read
	fs/debugfs/file.c		u32_array_read
	fs/fuse/control.c		fuse_conn_waiting_read + ...
	drivers/hwmon/asus_atk0110.c	atk_debugfs_ggrp_read
	arch/s390/hypfs/inode.c		hypfs_read_iter
	...

Despite that, many nonseekable_open users implement read and write with
pure stream semantics - they don't depend on passed ppos at all. And for
those cases where read could wait for something inside, it creates a
situation similar to xenbus - the write could be never made to go until
read is done, and read is waiting for some, potentially external, event,
for potentially unbounded time -> deadlock.

Besides xenbus, there are 14 such places in the kernel that I've found
with semantic patch (see below):

	drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write()
	drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write()
	drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write()
	drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write()
	net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write()
	drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write()
	drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write()
	drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write()
	net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write()
	drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write()
	drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write()
	drivers/input/misc/uinput.c:400:1-17: ERROR: uinput_fops: .read() can deadlock .write()
	drivers/infiniband/core/user_mad.c:985:7-23: ERROR: umad_fops: .read() can deadlock .write()
	drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write()

In addition to the cases above another regression caused by f_pos
locking is that now FUSE filesystems that implement open with
FOPEN_NONSEEKABLE flag, can no longer implement bidirectional
stream-like files - for the same reason as above e.g. read can deadlock
write locking on file.f_pos in the kernel.

FUSE's FOPEN_NONSEEKABLE was added in 2008 in a7c1b990f7 ("fuse:
implement nonseekable open") to support OSSPD. OSSPD implements /dev/dsp
in userspace with FOPEN_NONSEEKABLE flag, with corresponding read and
write routines not depending on current position at all, and with both
read and write being potentially blocking operations:

See

    https://github.com/libfuse/osspd
    https://lwn.net/Articles/308445

    14a9cff0/osspd.c (L1406)
    14a9cff0/osspd.c (L1438-L1477)
    14a9cff0/osspd.c (L1479-L1510)

Corresponding libfuse example/test also describes FOPEN_NONSEEKABLE as
"somewhat pipe-like files ..." with read handler not using offset.
However that test implements only read without write and cannot exercise
the deadlock scenario:

    https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L124-L131
    https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L146-L163
    https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L209-L216

I've actually hit the read vs write deadlock for real while implementing
my FUSE filesystem where there is /head/watch file, for which open
creates separate bidirectional socket-like stream in between filesystem
and its user with both read and write being later performed
simultaneously. And there it is semantically not easy to split the
stream into two separate read-only and write-only channels:

    f13aa600/wcfs/wcfs.go (L88-169)

Let's fix this regression. The plan is:

1. We can't change nonseekable_open to include &~FMODE_ATOMIC_POS -
   doing so would break many in-kernel nonseekable_open users which
   actually use ppos in read/write handlers.

2. Add stream_open() to kernel to open stream-like non-seekable file
   descriptors. Read and write on such file descriptors would never use
   nor change ppos. And with that property on stream-like files read and
   write will be running without taking f_pos lock - i.e. read and write
   could be running simultaneously.

3. With semantic patch search and convert to stream_open all in-kernel
   nonseekable_open users for which read and write actually do not
   depend on ppos and where there is no other methods in file_operations
   which assume @offset access.

4. Add FOPEN_STREAM to fs/fuse/ and open in-kernel file-descriptors via
   steam_open if that bit is present in filesystem open reply.

   It was tempting to change fs/fuse/ open handler to use stream_open
   instead of nonseekable_open on just FOPEN_NONSEEKABLE flags, but
   grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE,
   and in particular GVFS which actually uses offset in its read and
   write handlers

	https://codesearch.debian.net/search?q=-%3Enonseekable+%3D
	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080
	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346
	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481

   so if we would do such a change it will break a real user.

5. Add stream_open and FOPEN_STREAM handling to stable kernels starting
   from v3.14+ (the kernel where 9c225f2655 first appeared).

   This will allow to patch OSSPD and other FUSE filesystems that
   provide stream-like files to return FOPEN_STREAM | FOPEN_NONSEEKABLE
   in their open handler and this way avoid the deadlock on all kernel
   versions. This should work because fs/fuse/ ignores unknown open
   flags returned from a filesystem and so passing FOPEN_STREAM to a
   kernel that is not aware of this flag cannot hurt. In turn the kernel
   that is not aware of FOPEN_STREAM will be < v3.14 where just
   FOPEN_NONSEEKABLE is sufficient to implement streams without read vs
   write deadlock.

This patch adds stream_open, converts /proc/xen/xenbus to it and adds
semantic patch to automatically locate in-kernel places that are either
required to be converted due to read vs write deadlock, or that are just
safe to be converted because read and write do not use ppos and there
are no other funky methods in file_operations.

Regarding semantic patch I've verified each generated change manually -
that it is correct to convert - and each other nonseekable_open instance
left - that it is either not correct to convert there, or that it is not
converted due to current stream_open.cocci limitations.

The script also does not convert files that should be valid to convert,
but that currently have .llseek = noop_llseek or generic_file_llseek for
unknown reason despite file being opened with nonseekable_open (e.g.
drivers/input/mousedev.c)

Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yongzhi Pan <panyongzhi@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Tejun Heo <tj@kernel.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Nikolaus Rath <Nikolaus@rath.org>
Cc: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-11 12:22:49 +02:00
Julia Lawall
d97629f168 Coccinelle: pm_runtime: ensure relevance of pm_runtime reports
pm_runtime.cocci starts with one rule that searches for a variety of
functions calls, followed by various rules that report errors.  Previously,
the only connection between the first rule and the rest was to check that
the first rule had matched somewhere.  Change the rules to propagate a
position from the first rule to the others, to make sure that the sites
reported on are the same as the sites that were identified as having the
relevant functions.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-10-01 23:03:41 +02:00
Julia Lawall
43d96390d5 Coccinelle: limit memdup_user transformation to GFP_KERNEL case
Memdup_user encapsulates a memory allocation with the flag GFP_KERNEL, so
only allow this flag in the original code.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-10-01 23:03:09 +02:00
Linus Torvalds
dc03c0f9d1 Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull misc kbuild updates from Michal Marek:
 "This is the non-critical part of kbuild:

   - Coccinelle fixes, one semantic patch less in this round [Vaishali
     Thakkar, Wolfram Sang, Kees Cook]

   - rpm-pkg support for (open)SUSE's update-bootloader [Jiří Kosian]

   - rpm-pkg restored support for $RPMOPTS [Srinivas Pandruvada]

   - deb-pkg fixes for the linux-headers package [Bjørn Mork, Azriel
     Samson]"

* 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  coccicheck: Fix missing 0 index in kill loop
  scripts/package/Makefile: rpmbuild add support of RPMOPTS
  builddeb: fix missing headers in linux-headers package
  builddeb: include objtool binary in headers package
  kbuild/mkspec: support 'update-bootloader'-based systems
  scripts: coccinelle: remove check to move constants to right
  Coccinelle: setup_timer: Add space in front of parentheses
2016-05-26 22:32:05 -07:00
Vaishali Thakkar
531f50388f Coccinelle: setup_timer: Add space in front of parentheses
Add space in front of the offending parentheses to silent the
parse error for older Coccinelle versions. This makes the rule
usable with all Coccinelle versions.

Reported-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Vaishali Thakkar <vaishali.thakkar@oracle.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Fixes: c5eda8fd10 ("Coccinelle: Add api/setup_timer.cocci")
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-04-20 09:50:53 +02:00
Nicolai Stange
5103068eac debugfs, coccinelle: check for obsolete DEFINE_SIMPLE_ATTRIBUTE() usage
In order to protect against file removal races, debugfs files created via
debugfs_create_file() now get wrapped by a struct file_operations at their
opening.

If the original struct file_operations are known to be safe against removal
races by themselves already, the proxy creation may be bypassed by creating
the files through debugfs_create_file_unsafe().

In order to help debugfs users who use the common
  DEFINE_SIMPLE_ATTRIBUTE() + debugfs_create_file()
idiom to transition to removal safe struct file_operations, the helper
macro DEFINE_DEBUGFS_ATTRIBUTE() has been introduced.

Thus, the preferred strategy is to use
  DEFINE_DEBUGFS_ATTRIBUTE() + debugfs_create_file_unsafe()
now.

Introduce a Coccinelle script that searches for
DEFINE_SIMPLE_ATTRIBUTE()-defined struct file_operations handed into
debugfs_create_file(). Suggest to turn these usages into the
  DEFINE_DEBUGFS_ATTRIBUTE() + debugfs_create_file_unsafe()
pattern.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Acked-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12 14:14:21 -07:00
Vaishali Thakkar
c5eda8fd10 Coccinelle: Add api/setup_timer.cocci
Use the timer API function setup_timer instead of structure field
assignments to initialize a timer.

Signed-off-by: Vaishali Thakkar <vaishali.thakkar@oracle.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-02-18 22:17:30 +01:00
Julia Lawall
79ff2b3dea Coccinelle: pm_runtime: reduce rule applicability
Rule r is only used in org or report mode, so only execute it in those
cases.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-02-18 22:08:09 +01:00
Linus Torvalds
f6f7a63692 Merge branch 'akpm' (patches from Andrew)
Merge second patch-bomb from Andrew Morton:
 "Almost all of the rest of MM.  There was an unusually large amount of
  MM material this time"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (141 commits)
  zpool: remove no-op module init/exit
  mm: zbud: constify the zbud_ops
  mm: zpool: constify the zpool_ops
  mm: swap: zswap: maybe_preload & refactoring
  zram: unify error reporting
  zsmalloc: remove null check from destroy_handle_cache()
  zsmalloc: do not take class lock in zs_shrinker_count()
  zsmalloc: use class->pages_per_zspage
  zsmalloc: consider ZS_ALMOST_FULL as migrate source
  zsmalloc: partial page ordering within a fullness_list
  zsmalloc: use shrinker to trigger auto-compaction
  zsmalloc: account the number of compacted pages
  zsmalloc/zram: introduce zs_pool_stats api
  zsmalloc: cosmetic compaction code adjustments
  zsmalloc: introduce zs_can_compact() function
  zsmalloc: always keep per-class stats
  zsmalloc: drop unused variable `nr_to_migrate'
  mm/memblock.c: fix comment in __next_mem_range()
  mm/page_alloc.c: fix type information of memoryless node
  memory-hotplug: fix comments in zone_spanned_pages_in_node() and zone_spanned_pages_in_node()
  ...
2015-09-08 17:52:23 -07:00
Sean O. Stalley
1fc524d74c coccinelle: mm: scripts/coccinelle/api/alloc/pool_zalloc-simple.cocci
add [pci|dma]_pool_zalloc coccinelle check.
replaces instances of [pci|dma]_pool_alloc() followed by memset(0)
with [pci|dma]_pool_zalloc().

Signed-off-by: Sean O. Stalley <sean.stalley@intel.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Gilles Muller <Gilles.Muller@lip6.fr>
Cc: Nicolas Palix <nicolas.palix@imag.fr>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08 15:35:28 -07:00
Krzysztof Kozlowski
bec8a5a226 coccinelle: api: extend spatch for dropping unnecessary owner
i2c_add_driver (through i2c_register_driver) sets the owner field so we
can drop it also from i2c drivers, just like from platform drivers.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2015-08-19 17:23:45 +02:00
Dmitry Kalinkin
4c8f20bb8e coccinelle: api: add vma_pages.cocci
This semantic patch replaces explicit computations of vma page count
with explicit function call.

Signed-off-by: Dmitry Kalinkin <dmitry.kalinkin@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-05-21 19:19:13 +08:00
Fabio Estevam
ca34cba431 coccinelle: simple_open: Use imperative mood
According to Documentation/SubmittingPatches:

"Describe your changes in imperative mood, e.g. "make xyzzy do frotz"
instead of "[This patch] makes xyzzy do frotz" or "[I] changed xyzzy
to do frotz", as if you are giving orders to the codebase to change
its behaviour."

So do as recommended.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-05-20 14:01:41 +08:00
Fabio Estevam
f9beafc9d8 coccinelle: pm_runtime: Insert blank line
Insert a blank line in order to improve the readability of the
generated patch and also make it consistent with the other
.cocci files.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-05-20 14:01:41 +08:00
Wolfram Sang
1f648f88ce coccinelle: api: add spatch to prevent unnecessary .owner
There are calls which silently set the owner of a module. This is the
preferred way [1], so avoid setting it manually. Currently, we only care
about platform drivers, but there might be more calls to be added later.

[1] https://lkml.org/lkml/2014/10/12/87

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-06 15:16:02 -08:00
Linus Torvalds
899552d6e8 Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull misc kbuild updates from Michal Marek:
 "This is the non-critical part of kbuild for 3.17-rc1:

   - make help hint to use make -s with make kernelrelease et al.
   - moved a kbuild document to Documentation/kbuild where it belongs
   - four new Coccinelle scripts, one dropped and one fixed
   - new make kselftest target to run various tests on the kernel"

* 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild: kselftest - new make target to build and run kernel selftests
  Coccinelle: Script to replace if and BUG with BUG_ON
  Coccinelle: Script to detect incorrect argument to sizeof
  Coccinelle: Script to use ARRAY_SIZE instead of division of two sizeofs
  Coccinelle: Script to detect cast after memory allocation
  coccinelle/null: solve parse error
  Documentation: headers_install.txt is part of kbuild
  kbuild: make -s should be used with kernelrelease/kernelversion/image_name
2014-08-14 11:14:29 -06:00
Himangi Saraogi
99fcec30e8 Coccinelle: Script to detect cast after memory allocation
This script detects cases of use of cast for the value returned by
kmalloc, kzalloc, kcalloc, kmem_cache_alloc, kmem_cache_zalloc,
kmem_cache_alloc_node, kmalloc_node and kzalloc_node and removes
the cast as it is not useful. This Coccinelle script replaces
drop_kmalloc_cast.cocci as it removes the casting in more limited
cases of kmalloc, kzalloc and kcalloc.

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-08-06 12:10:17 +02:00
Jingoo Han
c9d53c0f2d devres: remove devm_request_and_ioremap()
devm_request_and_ioremap() was obsoleted by the commit 7509657
("lib: devres: Introduce devm_ioremap_resource()") and has been
deprecated for a long time. So, let's remove this function.
In addition, all usages of devm_request_and_ioremap() are also
removed.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-19 20:01:36 -07:00
Sachin Kamat
f23a9fa7e8 scripts/coccinelle: Use PTR_ERR_OR_ZERO
PTR_RET is deprecated. Do not recommend its usage anymore.
Use PTR_ERR_OR_ZERO instead.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-04-08 17:27:01 +02:00
Nishanth Menon
79f0345fef scripts: Coccinelle script for pm_runtime_* return checks with IS_ERR_VALUE
As indicated by Sekhar in [1], there seems to be a tendency to use
IS_ERR_VALUE to check the error result for pm_runtime_* functions which
make no sense considering commit c48cd65 (ARM: OMAP: use consistent
error checking) - the error values can either be < 0 for error OR
0, 1 in cases where we have success.

So, setup a coccinelle script to help identify the same.

[1] http://marc.info/?t=138472678100003&r=1&w=2

Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Reported-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-01-03 14:39:35 +01:00
Wolfram Sang
a690876385 scripts/coccinelle/api: remove devm_request_and_ioremap.cocci
Use of this function is discouraged in favour of
devm_ioremap_resource(). Don't advertise it.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2013-10-23 16:55:15 +02:00
Rusty Russell
8c6ffba0ed PTR_RET is now PTR_ERR_OR_ZERO(): Replace most.
Sweep of the simple cases.

Cc: netdev@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-15 11:25:01 +09:30
Nicolas Palix
93f1446849 Coccinelle: Update the options used to the new option scheme
spatch has changed its option scheme.
E.g., --no_show_diff is now --no-show-diff

This patch updates:
 - scripts/coccicheck
 - Semantic patches under scripts/coccinelle/

Signed-off-by: Nicolas Palix <nicolas.palix@imag.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2013-07-03 22:58:13 +02:00
Thierry Reding
75096579c3 lib: devres: Introduce devm_ioremap_resource()
The devm_request_and_ioremap() function is very useful and helps avoid a
whole lot of boilerplate. However, one issue that keeps popping up is
its lack of a specific error code to determine which of the steps that
it performs failed. Furthermore, while the function gives an example and
suggests what error code to return on failure, a wide variety of error
codes are used throughout the tree.

In an attempt to fix these problems, this patch adds a new function that
drivers can transition to. The devm_ioremap_resource() returns a pointer
to the remapped I/O memory on success or an ERR_PTR() encoded error code
on failure. Callers can check for failure using IS_ERR() and determine
its cause by extracting the error code using PTR_ERR().

devm_request_and_ioremap() is implemented as a wrapper around the new
API and return NULL on failure as before. This ensures that backwards
compatibility is maintained until all users have been converted to the
new API, at which point the old devm_request_and_ioremap() function
should be removed.

A semantic patch is included which can be used to convert from the old
devm_request_and_ioremap() API to the new devm_ioremap_resource() API.
Some non-trivial cases may require manual intervention, though.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-22 09:41:43 -08:00
Cyril Roelandt
af56e3f017 Coccinelle: add api/d_find_alias.cocci
Ensure that calls to d_find_alias() have a corresponding dput().

Signed-off-by: Cyril Roelandt <tipecaml@gmail.com>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Gilles Muller <Gilles.Muller@lip6.fr>
Cc: Nicolas Palix <nicolas.palix@imag.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 15:02:11 -08:00
Linus Torvalds
cbd8aca472 Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild misc changes from Michal Marek:
 "In the non-critical part of kbuild, I have
   - Some make coccicheck improvements and two new tests
   - Support for a cleaner html output in scripts/kernel-doc, named
     html5 (no, it does not play videos, yet)

  BTW, Randy wants to route further kernel-doc patches through the
  kbuild tree."

* 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  Update SmPL/Coccinelle section of MAINTAINERS
  coccicheck: Add the rep+ctxt mode
  scripts/coccinelle/tests/odd_ptr_err.cocci: semantic patch for IS_ERR/PTR_ERR inconsistency
  scripts/tags.sh: Add magic for pci access functions
  scripts/coccinelle: ptr_ret: Add ternary operator version
  scripts/kernel-doc: drop maintainer
  scripts/kernel-doc: added support for html5
2012-10-12 10:32:29 +09:00
Fengguang Wu
7c6c4d5c4a Coccinelle: fix typo in memdup_user.cocci
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-09-01 08:52:13 -07:00
Lars-Peter Clausen
3085897359 scripts/coccinelle: ptr_ret: Add ternary operator version
Add a ternary operator version of the open-coded PTR_RET().

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2012-08-31 16:55:15 +02:00
Linus Torvalds
5d32c88f0b Merge branch 'akpm' (Andrew's patch-bomb)
Merge batch of fixes from Andrew Morton:
 "The simple_open() cleanup was held back while I wanted for laggards to
  merge things.

  I still need to send a few checkpoint/restore patches.  I've been
  wobbly about merging them because I'm wobbly about the overall
  prospects for success of the project.  But after speaking with Pavel
  at the LSF conference, it sounds like they're further toward
  completion than I feared - apparently davem is at the "has stopped
  complaining" stage regarding the net changes.  So I need to go back
  and re-review those patchs and their (lengthy) discussion."

* emailed from Andrew Morton <akpm@linux-foundation.org>: (16 patches)
  memcg swap: use mem_cgroup_uncharge_swap fix
  backlight: add driver for DA9052/53 PMIC v1
  C6X: use set_current_blocked() and block_sigmask()
  MAINTAINERS: add entry for sparse checker
  MAINTAINERS: fix REMOTEPROC F: typo
  alpha: use set_current_blocked() and block_sigmask()
  simple_open: automatically convert to simple_open()
  scripts/coccinelle/api/simple_open.cocci: semantic patch for simple_open()
  libfs: add simple_open()
  hugetlbfs: remove unregister_filesystem() when initializing module
  drivers/rtc/rtc-88pm860x.c: fix rtc irq enable callback
  fs/xattr.c:setxattr(): improve handling of allocation failures
  fs/xattr.c:listxattr(): fall back to vmalloc() if kmalloc() failed
  fs/xattr.c: suppress page allocation failure warnings from sys_listxattr()
  sysrq: use SEND_SIG_FORCED instead of force_sig()
  proc: fix mount -t proc -o AAA
2012-04-05 15:30:34 -07:00
Julia Lawall
9b3ae64be6 scripts/coccinelle/api/simple_open.cocci: semantic patch for simple_open()
Find instances of an open-coded simple_open() and replace them with
calls to simple_open().

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reported-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-05 15:25:50 -07:00
Julia Lawall
468db96122 scripts/coccinelle/api/ptr_ret.cocci: semantic patch for ptr_err
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2012-03-26 22:51:24 +02:00
Julia Lawall
29a36d4dec scripts/coccinelle: improve the coverage of some semantic patches
This patch ensures that all semantic patches in the scripts/coccinelle
directory provide the report option.  Report messages that include line
numbers now have the line number preceded by "line" for easier subsequent
processing.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2012-01-15 00:05:46 +01:00
Julia Lawall
22e0059af3 coccinelle: semantic patches related to devm_ functions (part 1)
devm_ functions allocate memory that is to remain allocated until the
device is detached.  This patch checks for opportunities for using the
function devm_request_and_ioremap.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2012-01-14 22:39:53 +01:00
Nicolas Palix
be8fe9d451 Coccinelle: Move alloc directory into api directory
alloc contains various semantic patches related
to the allocation APIs

Signed-off-by: Nicolas Palix <npalix@diku.dk>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-08-31 11:43:13 +02:00
Nicolas Palix
77c272fb24 Coccinelle: Move resource_size.cocci to the api directory
Signed-off-by: Nicolas Palix <npalix@diku.dk>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-08-31 11:37:54 +02:00
Nicolas Palix
99d653d4bc Coccinelle: Move err_cast.cocci to the api directory
Signed-off-by: Nicolas Palix <npalix@diku.dk>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-08-31 11:37:54 +02:00
Nicolas Palix
034174598b Coccinelle: Add api/memdup_user
Use kmemdup_user rather than duplicating its implementation
This is a little bit restricted to reduce false positives

Signed-off-by: Nicolas Palix <npalix@diku.dk>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-08-31 11:37:54 +02:00
Nicolas Palix
0426a97c4b Coccinelle: Add api/memdup.cocci
Use kmemdup rather than duplicating its implementation

Signed-off-by: Nicolas Palix <npalix@diku.dk>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-08-31 11:37:54 +02:00
Nicolas Palix
998f552323 Coccinelle: Add api/kstrdup.cocci
Use kstrdup rather than duplicating its implementation

Signed-off-by: Nicolas Palix <npalix@diku.dk>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-08-31 11:37:53 +02:00