123 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 9c225f2655e3 ("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 9c225f2655e3 -
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 a7c1b990f715 ("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

    https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1406
    https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1438-L1477
    https://github.com/libfuse/osspd/blob/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:

    https://lab.nexedi.com/kirr/wendelin.core/blob/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
Nicholas Mc Guire
c8990359d4 Coccinelle: flag conditions with no effect
Report code constructs where the if and else branch are functionally
identical. In cases where this is intended it really should be
documented - most reported cases probably are bugs.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-10-11 09:57:17 +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
Luis R. Rodriguez
cc65e82336 scripts/coccinelle: require coccinelle >= 1.0.4 on device_node_continue.cocci
Make use of the new Requires: tag to be able to specify coccinelle binary
version requirements. The cocci file device_node_continue.cocci requires at
least coccinelle 1.0.4.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Acked-by: Nicolas Palix <nicolas.palix@imag.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-07-22 12:13:39 +02:00
Yann Droneaud
b7b2ee41f3 coccinelle: catch krealloc() on devm_*() allocated memory
krealloc() must not be used against devm_*() allocated
memory regions:

- if a bigger memory is to be allocated, krealloc() and
  __krealloc() could return a different pointer than the
  one given to them, creating a memory region which is not
  managed, thus it will not be automatically released on
  device removal.

- if a bigger memory is to be allocated, krealloc() could
  kfree() the managed memory region which is passed to it.
  The old pointer is left registered as a resource for the
  device. On device removal, this dangling pointer will be
  used and an unrelated memory region could be released.

- if the requested size is equal to 0, krealloc() can also
  just behave like kfree(). Here too, the old pointer is
  kept associated with the device. On device removal, this
  invalid pointer will be used and an unrelated memory
  region could be released.

For all these reasons, krealloc() must not be used on a
pointer returned by devm_*() functions.

Cc: Tejun Heo <tj@kernel.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-06-21 11:43:32 +02:00
Yann Droneaud
a720c0644d coccinelle: recognize more devm_* memory allocation functions
Updates free/devm_free.cocci to recognize functions added by:

- commit 64c862a839a8 ('devres: add kernel standard devm_k.alloc functions')
- commit e31108cad3de ('devres: introduce API "devm_kstrdup"')
- commit 3046365bb470 ('devres: introduce API "devm_kmemdup')
- commit 43339bed7010 ('devres: Add devm_get_free_pages API')
- commit 75f2a4ead5d5 ('devres: Add devm_kasprintf and devm_kvasprintf API')

See also Documentation/driver-model/devres.txt

Cc: Joe Perches <joe@perches.com>
Cc: Manish Badarkhe <badarkhe.manish@gmail.com>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Eli Billauer <eli.billauer@gmail.com>
Cc: Himangi Saraogi <himangi774@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-06-21 11:43:32 +02:00
Yann Droneaud
6dd9379e8f coccinelle: also catch kzfree() issues
Since commit 3ef0e5ba4673 ('slab: introduce kzfree()'),
kfree() is no more the only function to be considered:
kzfree() should be recognized too.

In particular, kzfree() must not be called on memory
allocated through devm_*() functions.

Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-06-21 11:43:32 +02:00
Vaishali Thakkar
bf56cc04ef Coccinelle: noderef: Add new rules and correct the old rule
Add new rules to detect the cases where sizeof is used in
function calls as a argument.

Also, for the patch mode third rule should behave same as
second rule with arguments reversed. So, change that as well.

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>
2016-06-20 17:20:13 +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
Wolfram Sang
f931362b38 scripts: coccinelle: remove check to move constants to right
The header mentions this check depends on personal taste. I agree.
Running coccicheck on patches before I apply them, this SmPL produced
enough false positives for me that I'd rather see it removed.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-04-20 09:53:27 +02:00
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: c5eda8fd10c6 ("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
f75621c6ec coccinelle: bugon: reduce rule applicability
Rule r is only use 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 22:09:40 +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
Julia Lawall
c7eaa8873b Coccinelle: array_size: reduce rule applicability
Rule r is only use 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 22:06:28 +01:00
Julia Lawall
8f551befa2 Coccinelle: reduce rule applicability
Rule r is only use 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 22:05:30 +01:00
Julia Lawall
1b669e713f scripts/coccinelle: modernize &
& is no longer allowed in column 0, since Coccinelle 1.0.4.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Tested-by: Nishanth Menon <nm@ti.com>
Cc: stable@vger.kernel.org
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-02-18 11:49:30 +01:00
Andrzej Hajda
3f984cb399 coccinelle: tests: unsigned value cannot be lesser than zero
Unsigned expressions cannot be lesser than zero. Presence of comparisons
'unsigned (<|<=|>|>=) 0' often indicates a bug, usually wrong type of variable.
The patch beside finding such comparisons tries to eliminate false positives,
mainly by bypassing range checks.

gcc can detect such comparisons also using -Wtype-limits switch, but it warns
also in correct cases, making too much noise.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-01-12 17:47:47 +01:00
Daniel Granat
67afc2110a coccinelle: Improve checking for missing NULL terminators
Extend checking on tables containing structures which are initialized
without specifying member name. Added new tables for checking:
i2c_device_id and platform_device_id.

Signed-off-by: Daniel Granat <d.granat@samsung.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-10-26 22:44:51 +01:00
Julia Lawall
4743775c6d coccinelle: ifnullfree: handle various destroy functions
Extend ifnullfree to the various destroy functions that were recently
extended to tolerate NULL arguments.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-10-26 22:41:18 +01:00
Julia Lawall
ca047e715c coccinelle: ifnullfree: various cleanups
Adjust tests to compare against NULL, to match cases that explicitly make
that comparison.

Remove removal and re-addition of freeing functions.

Add position variable on usb_free_urb in the non-patch case.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-10-26 22:41:13 +01:00
Julia Lawall
41167d072b cocinelle: iterators: semantic patch to delete unneeded of_node_put
Device node iterators perform an of_node_put on each iteration, so putting
an of_node_put before a continue results in a double put.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-10-26 22:39:11 +01:00
Julia Lawall
7c2aa6116b scripts/coccinelle: fix typos
Fix a couple spelling mistakes.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-10-26 22:26:23 +01:00
Johan Hovold
1a617a8475 coccinelle: misc: remove "complex return code" warnings
This effectively reverts 932058a5d5f9 ("coccinelle: misc: semantic patch
to delete overly complex return code processing").

There can be both symmetry and readability reasons for not wanting to do
the final function call as part of the return statement and to maintain
a clear separation of success and error paths.

Since this is in no way mandated by the coding standard, let's just
remove this semantic patch to avoid having "clean up" patches being
posted over and over in response to these Coccinelle warnings.

Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-10-26 22:10:01 +01:00
Julia Lawall
02da7b4277 coccinelle: tests: improve odd_ptr_err.cocci
The original version only considered the case where the then branch
contains only one call to PTR_ERR.  Reimplement the whole thing to allow
multiple calls, with potentially different arguments.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-10-26 20:54:28 +01:00
Julia Lawall
74a8478f9e coccinelle: misc: move constants to the right
Move constants to the right in binary operators.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2015-10-26 20:39:44 +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
Fabio Estevam
f94c56f4f3 coccinelle: simple_return: Add a 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>
2015-06-03 10:23:33 +02:00
Fabio Estevam
9473a62f77 coccinelle: irqf_oneshot.cocci: Improve the generated commit log
Improve the commit log of the generated patch by mentioning the commit
log that makes threaded IRQs without a primary handler to be requested
with the IRQF_ONESHOT flag.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked- by: Valentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-05-25 16:23:07 +08:00
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
74de120d80 scripts/coccinelle/misc/irqf_oneshot.cocci: Fix grammar
Correct form is 'always requested'.

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>
2015-05-21 14:14:45 +08:00
Fabio Estevam
4341f6e5ce scripts/coccinelle/misc/semicolon.cocci: 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>
2015-05-21 14:14:41 +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
dd494ac0de coccinelle: ifaddr: Fix the sentence
Make the sentence sensible.

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
fe8c46b632 coccinelle: returnvar: 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
Fabian Frederick
33236415ec scripts/coccinelle/misc/bugon.cocci: update bug_on conversion warning
if()/BUG conversion to BUG_ON must be avoided when there's side effect
in condition. The reason being BUG_ON won't execute the condition when
CONFIG_BUG is not defined.

Inspired-by: J. Bruce Fields <bfields@fieldses.org>
Suggested-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-04-15 14:21:31 +02:00
Valentin Rothberg
2c2b913d19 irqf_oneshot.cocci: add check of devm_request_threaded_irq()
Since commit 1c6c69525b40eb76de8adf039409722015927dc3 ("genirq: Reject
bogus threaded irq requests") threaded IRQs without a primary handler
need to be requested with IRQF_ONESHOT, otherwise the request will fail.

Until now, this coccinelle script only checked request_threaded_irq().
However, the counterpart devm function (see kernel/irq/devres.c) is also
affected by the missing flag which can be detected with this patch.

Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-03-25 11:58:10 +01:00
Linus Torvalds
787140ad6b Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull misc kbuild changes from Michal Marek:
 "There are only a few things in the misc branch:

   - Fix for bugon.cocci semantic patch
   - Kdevelop4 files are .gitignored
   - Put make binrpm-pkg on diet"

* 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  scripts/package: binrpm-pkg do not create source and devel package
  .gitignore: Add Kdevelop4 project files
  bugon.cocci: fix Options at the macro
2014-12-20 13:33:03 -08:00
Mauro Carvalho Chehab
7426977c8e bugon.cocci: fix Options at the macro
The comma after --no-includes makes coccinelle to not run the script:

/usr/bin/spatch -D report --very-quiet --no-show-diff --cocci-file ./scripts/coccinelle/misc/bugon.cocci --no-includes, --include-headers --patch . --dir drivers/media/platform/coda/ -I ./arch/x86/include -I arch/x86/include/generated -I include -I ./arch/x86/include/uapi -I arch/x86/include/generated/uapi -I ./include/uapi -I include/generated/uapi -I ./include/linux/kconfig.h
Usage: spatch.opt --sp-file <SP> <infile> [-o <outfile>] [--iso-file <iso>] [options]
Options are:
  --sp-file                    <file> the semantic patch file
  -o                           <file> the output file
  --in-place                   do the modification on the file directly
  --backup-suffix              suffix to use when making a backup for inplace
...

At least with Fedora 20 coccinelle package:
	coccinelle-1.0.0-0.rc20.1.fc21.x86_64

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Tested-by: Wolfram Sang <wsa@the-dreams.de>
Fixes: 5be1df66 (Coccinelle: Script to replace if and BUG with BUG_ON)
Cc: stable@vger.kernel.org
Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-11-24 22:04:27 +01:00
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
Julia Lawall
932058a5d5 coccinelle: misc: semantic patch to delete overly complex return code processing
This semantic patch simplifies cases where the effect of the processing of
a function call's return code is just to return the result of the function
directly.  It may also delete a local return flag variable, if this is no
longer used.

This was proposed by Uwe Kleine-König.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-09-26 13:42:31 +02:00
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
Fabian Frederick
45715f33d4 scripts/coccinelle/free/ifnullfree.cocci: add copyright information
All coccinelle scripts have a copyright in the header.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Suggested-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:27 -07:00
Fabian Frederick
791dfeb495 scripts/coccinelle/free: add NULL test before freeing functions
Warns or generates patch for NULL check before the following functions:

kfree
usb_free_urb
debugfs_remove
debugfs_remove_recursive

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Acked-by: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Gilles Muller <Gilles.Muller@lip6.fr>
Cc: Joe Perches <joe@perches.com>
Cc: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:26 -07:00
Himangi Saraogi
5be1df668a Coccinelle: Script to replace if and BUG with BUG_ON
This script detects cases where BUG() follows an if condition on an
expression and replaces the if condition and BUG() with a BUG_ON having
the conditional expression of the if statement as argument.

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