11 Aug, 2020
1 commit
-
commit 55c7549819e438f40a3ef1d8ac5c38b73390bcb7 upstream.
When running `make coccicheck` in report mode using the
add_namespace.cocci file, it will fail for files that contain
MODULE_LICENSE. Those match the replacement precondition, but spatch
errors out as virtual.ns is not set.In order to fix that, add the virtual rule nsdeps and only do search and
replace if that rule has been explicitly requested.In order to make spatch happy in report mode, we also need a dummy rule,
as otherwise it errors out with "No rules apply". Using a script:python
rule appears unrelated and odd, but this is the shortest I could come up
with.Adjust scripts/nsdeps accordingly to set the nsdeps rule when run trough
`make nsdeps`.Suggested-by: Julia Lawall
Fixes: c7c4e29fb5a4 ("scripts: add_namespace: Fix coccicheck failed")
Cc: YueHaibing
Cc: jeyu@kernel.org
Cc: cocci@systeme.lip6.fr
Cc: stable@vger.kernel.org
Signed-off-by: Matthias Maennich
Reported-by: Shuah Khan
Acked-by: Julia Lawall
Link: https://lore.kernel.org/r/20200604164145.173925-1-maennich@google.com
Signed-off-by: Greg Kroah-Hartman
18 Oct, 2019
1 commit
-
While it is useful for new drivers to use devm_platform_ioremap_resource,
this script is currently used to spam maintainers, often updating very
old drivers. The net benefit is the removal of 2 lines of code in the
driver but the review load for the maintainers is huge. As of now, more
that 560 patches have been sent, some of them obviously broken, as in:https://lore.kernel.org/lkml/9bbcce19c777583815c92ce3c2ff2586@www.loen.fr/
Remove the script to reduce the spam.
Signed-off-by: Alexandre Belloni
Acked-by: Julia Lawall
Signed-off-by: Linus Torvalds
07 Oct, 2019
1 commit
-
Now all scripts in scripts/coccinelle to be automatically called
by coccicheck. However new adding add_namespace.cocci does not
support report mode, which make coccicheck failed.
This add "virtual report" to make the coccicheck go ahead smoothly.Fixes: eb8305aecb95 ("scripts: Coccinelle script for namespace dependencies.")
Acked-by: Julia Lawall
Acked-by: Matthias Maennich
Signed-off-by: YueHaibing
Signed-off-by: Jessica Yu
23 Sep, 2019
1 commit
-
Pull modules updates from Jessica Yu:
"The main bulk of this pull request introduces a new exported symbol
namespaces feature. The number of exported symbols is increasingly
growing with each release (we're at about 31k exports as of 5.3-rc7)
and we currently have no way of visualizing how these symbols are
"clustered" or making sense of this huge export surface.Namespacing exported symbols allows kernel developers to more
explicitly partition and categorize exported symbols, as well as more
easily limiting the availability of namespaced symbols to other parts
of the kernel. For starters, we have introduced the USB_STORAGE
namespace to demonstrate the API's usage. I have briefly summarized
the feature and its main motivations in the tag below.Summary:
- Introduce exported symbol namespaces.
This new feature allows subsystem maintainers to partition and
categorize their exported symbols into explicit namespaces. Module
authors are now required to import the namespaces they need.Some of the main motivations of this feature include: allowing
kernel developers to better manage the export surface, allow
subsystem maintainers to explicitly state that usage of some
exported symbols should only be limited to certain users (think:
inter-module or inter-driver symbols, debugging symbols, etc), as
well as more easily limiting the availability of namespaced symbols
to other parts of the kernel.With the module import requirement, it is also easier to spot the
misuse of exported symbols during patch review.Two new macros are introduced: EXPORT_SYMBOL_NS() and
EXPORT_SYMBOL_NS_GPL(). The API is thoroughly documented in
Documentation/kbuild/namespaces.rst.- Some small code and kbuild cleanups here and there"
* tag 'modules-for-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
module: Remove leftover '#undef' from export header
module: remove unneeded casts in cmp_name()
module: move CONFIG_UNUSED_SYMBOLS to the sub-menu of MODULES
module: remove redundant 'depends on MODULES'
module: Fix link failure due to invalid relocation on namespace offset
usb-storage: export symbols in USB_STORAGE namespace
usb-storage: remove single-use define for debugging
docs: Add documentation for Symbol Namespaces
scripts: Coccinelle script for namespace dependencies.
modpost: add support for generating namespace dependencies
export: allow definition default namespaces in Makefiles or sources
module: add config option MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
modpost: add support for symbol namespaces
module: add support for symbol namespaces.
export: explicitly align struct kernel_symbol
module: support reading multiple values per modinfo tag
19 Sep, 2019
1 commit
-
Pull driver core updates from Greg Kroah-Hartman:
"Here is the big driver core update for 5.4-rc1.There was a bit of a churn in here, with a number of core and OF
platform patches being added to the tree, and then after much
discussion and review and a day-long in-person meeting, they were
decided to be reverted and a new set of patches is currently being
reviewed on the mailing list.Other than that churn, there are two "persistent" branches in here
that other trees will be pulling in as well during the merge window.
One branch to add support for drivers to have the driver core
automatically add sysfs attribute files when a driver is bound to a
device so that the driver doesn't have to manually do it (and then
clean it up, as it always gets it wrong).There's another branch in here for generic lookup helpers for the
driver core that lots of busses are starting to use. That's the
majority of the non-driver-core changes in this patch series.There's also some on-going debugfs file creation cleanup that has been
slowly happening over the past few releases, with the goal to
hopefully get that done sometime next year.All of these have been in linux-next for a while now with no reported
issues"[ Note that the above-mentioned generic lookup helpers branch was
already brought in by the LED merge (commit 4feaab05dc1e) that had
shared it.Also note that that common branch introduced an i2c bug due to a bad
conversion, which got fixed here. - Linus ]* tag 'driver-core-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (49 commits)
coccinelle: platform_get_irq: Fix parse error
driver-core: add include guard to linux/container.h
sysfs: add BIN_ATTR_WO() macro
driver core: platform: Export platform_get_irq_optional()
hwmon: pwm-fan: Use platform_get_irq_optional()
driver core: platform: Introduce platform_get_irq_optional()
Revert "driver core: Add support for linking devices during device addition"
Revert "driver core: Add edit_links() callback for drivers"
Revert "of/platform: Add functional dependency link from DT bindings"
Revert "driver core: Add sync_state driver/bus callback"
Revert "of/platform: Pause/resume sync state during init and of_platform_populate()"
Revert "of/platform: Create device links for all child-supplier depencencies"
Revert "of/platform: Don't create device links for default busses"
Revert "of/platform: Fix fn definitons for of_link_is_valid() and of_link_property()"
Revert "of/platform: Fix device_links_supplier_sync_state_resume() warning"
Revert "of/platform: Disable generic device linking code for PowerPC"
devcoredump: fix typo in comment
devcoredump: use memory_read_from_buffer
of/platform: Disable generic device linking code for PowerPC
device.h: Fix warnings for mismatched parameter names in comments
...
10 Sep, 2019
1 commit
-
A script that uses the '.ns_deps' files generated by modpost to
automatically add the required symbol namespace dependencies to each
module.Usage:
1) Move some symbols to a namespace with EXPORT_SYMBOL_NS() or define
DEFAULT_SYMBOL_NAMESPACE
2) Run 'make' (or 'make modules') and get warnings about modules not
importing that namespace.
3) Run 'make nsdeps' to automatically add required import statements
to said modules.This makes it easer for subsystem maintainers to introduce and maintain
symbol namespaces into their codebase.Co-developed-by: Martijn Coenen
Signed-off-by: Martijn Coenen
Acked-by: Julia Lawall
Reviewed-by: Greg Kroah-Hartman
Signed-off-by: Matthias Maennich
Signed-off-by: Jessica Yu
06 Sep, 2019
1 commit
-
When do coccicheck, I get this error:
spatch -D report --no-show-diff --very-quiet --cocci-file
./scripts/coccinelle/api/platform_get_irq.cocci --include-headers
--dir . -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
--include ./include/linux/kconfig.h --jobs 192 --chunksize 1
minus: parse error:
File "./scripts/coccinelle/api/platform_get_irq.cocci", line 24, column 9, charpos = 355
around = '\(',
whole content = if ( ret \( < \|
Reviewed-by: Stephen Boyd
Acked-by: Julia Lawall
Link: https://lore.kernel.org/r/20190906033006.17616-1-yuehaibing@huawei.com
Signed-off-by: Greg Kroah-Hartman
31 Jul, 2019
1 commit
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Add the missing GPLv2 SPDX license identifier.
It appears this single file was missing from 7f904d7e1f3e ("treewide:
Replace GPLv2 boilerplate/reference with SPDX - rule 505"), which
addressed all other files in scripts/coccinelle. Hence I added
GPL-2.0-only consitently with the mentioned patch.Cc: linux-spdx@vger.kernel.org
Cc: Elena Reshetova
Signed-off-by: Matthias Maennich
Acked-by: Julia Lawall
Signed-off-by: Greg Kroah-Hartman
30 Jul, 2019
1 commit
-
Add a coccinelle script to check for the usage of dev_err() after a call
to platform_get_irq{,_byname}() as it's redundant now that the function
already prints an error when it fails.Cc: Greg Kroah-Hartman
Cc: Rob Herring
Cc: Bartlomiej Zolnierkiewicz
Cc: Javier Martinez Canillas
Cc: Andrzej Hajda
Cc: Mark Brown
Cc: Russell King - ARM Linux
Cc: Marek Szyprowski
Cc: Rafael J. Wysocki
Cc: Andy Shevchenko
Cc: Markus Elfring
Signed-off-by: Stephen Boyd
Link: https://lore.kernel.org/r/20190730053845.126834-4-swboyd@chromium.org
Signed-off-by: Greg Kroah-Hartman
21 Jul, 2019
1 commit
-
Pull more Kbuild updates from Masahiro Yamada:
- match the directory structure of the linux-libc-dev package to that
of Debian-based distributions- fix incorrect include/config/auto.conf generation when Kconfig
creates it along with the .config file- remove misleading $(AS) from documents
- clean up precious tag files by distclean instead of mrproper
- add a new coccinelle patch for devm_platform_ioremap_resource
migration- refactor module-related scripts to read modules.order instead of
$(MODVERDIR)/*.mod files to get the list of created modules- remove MODVERDIR
- update list of header compile-test
- add -fcf-protection=none flag to avoid conflict with the retpoline
flags when CONFIG_RETPOLINE=y- misc cleanups
* tag 'kbuild-v5.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits)
kbuild: add -fcf-protection=none when using retpoline flags
kbuild: update compile-test header list for v5.3-rc1
kbuild: split out *.mod out of {single,multi}-used-m rules
kbuild: remove 'prepare1' target
kbuild: remove the first line of *.mod files
kbuild: create *.mod with full directory path and remove MODVERDIR
kbuild: export_report: read modules.order instead of .tmp_versions/*.mod
kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod
kbuild: modsign: read modules.order instead of $(MODVERDIR)/*.mod
kbuild: modinst: read modules.order instead of $(MODVERDIR)/*.mod
scsi: remove pointless $(MODVERDIR)/$(obj)/53c700.ver
kbuild: remove duplication from modules.order in sub-directories
kbuild: get rid of kernel/ prefix from in-tree modules.{order,builtin}
kbuild: do not create empty modules.order in the prepare stage
coccinelle: api: add devm_platform_ioremap_resource script
kbuild: compile-test headers listed in header-test-m as well
kbuild: remove unused hostcc-option
kbuild: remove tag files by distclean instead of mrproper
kbuild: add --hash-style= and --build-id unconditionally
kbuild: get rid of misleading $(AS) from documents
...
17 Jul, 2019
1 commit
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Use recently introduced devm_platform_ioremap_resource
helper which wraps platform_get_resource() and
devm_ioremap_resource() together. This helps produce much
cleaner code and remove local `struct resource` declaration.Signed-off-by: Himanshu Jha
Signed-off-by: Julia Lawall
Signed-off-by: Masahiro Yamada
15 Jul, 2019
2 commits
-
The audience for the Kernel driver-model is clearly Kernel hackers.
Signed-off-by: Mauro Carvalho Chehab
Acked-by: Jeff Kirsher # ice driver changes -
Pull stream_open() updates from Kirill Smelkov:
"This time on stream_open front it is only two small changes:- the first one converts stream_open.cocci to treat all functions
that start with wait_.* as blocking. Previously it was only
wait_event_.* functions that were considered as blocking, but this
was falsely reporting several deadlock cases as only warning.This was picked by linux-kbuild and entered mainline as commit
0c4ab18fc33b ("coccinelle: api/stream_open: treat all wait_.*()
calls as blocking"), and already merged earlier.- the second one teaches stream_open.cocci to consider files as being
stream-like even if they use noop_llseek. It results in two more
drivers being converted to stream_open() (mousedev.c and
hid-sensor-custom.c)"* tag 'stream_open-5.3' of https://lab.nexedi.com/kirr/linux:
*: convert stream-like files -> stream_open, even if they use noop_llseek
14 Jul, 2019
1 commit
-
This patch continues 10dce8af3422 (fs: stream_open - opener for
stream-like files so that read and write can run simultaneously without
deadlock) and c5bf68fe0c86 (*: convert stream-like files from
nonseekable_open -> stream_open) and teaches steam_open.cocci to
consider files as being stream-like not only if they have
.llseek=no_llseek, but also if they have .llseek=noop_llseek.This is safe to do: the comment about noop_llseek says
This is an implementation of ->llseek useable for the rare special case when
userspace expects the seek to succeed but the (device) file is actually not
able to perform the seek. In this case you use noop_llseek() instead of
falling back to the default implementation of ->llseek.and in general noop_llseek was massively added to drivers in 6038f373a3dc
(llseek: automatically add .llseek fop) when changing default for NULL .llseek
from NOP to no_llseek with the idea to avoid breaking compatibility, if
maybe some user-space program was using lseek on a device without caring
about the result, but caring if it was an error or not.Amended semantic patch produces two changes when applied tree-wide:
drivers/hid/hid-sensor-custom.c:690:8-24: WARNING: hid_sensor_custom_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
drivers/input/mousedev.c:564:1-17: ERROR: mousedev_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.Cc: Julia Lawall
Cc: Jan Blunck
Cc: Arnd Bergmann
Cc: Jiri Kosina
Cc: Jonathan Cameron
Cc: Srinivas Pandruvada
Cc: Benjamin Tissoires
Cc: Dmitry Torokhov
Signed-off-by: Kirill Smelkov
13 Jul, 2019
2 commits
-
Pull Kbuild updates from Masahiro Yamada:
- remove headers_{install,check}_all targets
- remove unreasonable 'depends on !UML' from CONFIG_SAMPLES
- re-implement 'make headers_install' more cleanly
- add new header-test-y syntax to compile-test headers
- compile-test exported headers to ensure they are compilable in
user-space- compile-test headers under include/ to ensure they are self-contained
- remove -Waggregate-return, -Wno-uninitialized, -Wno-unused-value
flags- add -Werror=unknown-warning-option for Clang
- add 128-bit built-in types support to genksyms
- fix missed rebuild of modules.builtin
- propagate 'No space left on device' error in fixdep to Make
- allow Clang to use its integrated assembler
- improve some coccinelle scripts
- add a new flag KBUILD_ABS_SRCTREE to request Kbuild to use absolute
path for $(srctree).- do not ignore errors when compression utility is missing
- misc cleanups
* tag 'kbuild-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (49 commits)
kbuild: use -- separater intead of $(filter-out ...) for cc-cross-prefix
kbuild: Inform user to pass ARCH= for make mrproper
kbuild: fix compression errors getting ignored
kbuild: add a flag to force absolute path for srctree
kbuild: replace KBUILD_SRCTREE with boolean building_out_of_srctree
kbuild: remove src and obj from the top Makefile
scripts/tags.sh: remove unused environment variables from comments
scripts/tags.sh: drop SUBARCH support for ARM
kbuild: compile-test kernel headers to ensure they are self-contained
kheaders: include only headers into kheaders_data.tar.xz
kheaders: remove meaningless -R option of 'ls'
kbuild: support header-test-pattern-y
kbuild: do not create wrappers for header-test-y
kbuild: compile-test exported headers to ensure they are self-contained
init/Kconfig: add CONFIG_CC_CAN_LINK
kallsyms: exclude kasan local symbols on s390
kbuild: add more hints about SUBDIRS replacement
coccinelle: api/stream_open: treat all wait_.*() calls as blocking
coccinelle: put_device: Add a cast to an expression for an assignment
coccinelle: put_device: Adjust a message construction
... -
Pull driver core and debugfs updates from Greg KH:
"Here is the "big" driver core and debugfs changes for 5.3-rc1It's a lot of different patches, all across the tree due to some api
changes and lots of debugfs cleanups.Other than the debugfs cleanups, in this set of changes we have:
- bus iteration function cleanups
- scripts/get_abi.pl tool to display and parse Documentation/ABI
entries in a simple way- cleanups to Documenatation/ABI/ entries to make them parse easier
due to typos and other minor things- default_attrs use for some ktype users
- driver model documentation file conversions to .rst
- compressed firmware file loading
- deferred probe fixes
All of these have been in linux-next for a while, with a bunch of
merge issues that Stephen has been patient with me for"* tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits)
debugfs: make error message a bit more verbose
orangefs: fix build warning from debugfs cleanup patch
ubifs: fix build warning after debugfs cleanup patch
driver: core: Allow subsystems to continue deferring probe
drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT
arch_topology: Remove error messages on out-of-memory conditions
lib: notifier-error-inject: no need to check return value of debugfs_create functions
swiotlb: no need to check return value of debugfs_create functions
ceph: no need to check return value of debugfs_create functions
sunrpc: no need to check return value of debugfs_create functions
ubifs: no need to check return value of debugfs_create functions
orangefs: no need to check return value of debugfs_create functions
nfsd: no need to check return value of debugfs_create functions
lib: 842: no need to check return value of debugfs_create functions
debugfs: provide pr_fmt() macro
debugfs: log errors when something goes wrong
drivers: s390/cio: Fix compilation warning about const qualifiers
drivers: Add generic helper to match by of_node
driver_find_device: Unify the match function with class_find_device()
bus_find_device: Unify the match callback with class_find_device
...
08 Jul, 2019
4 commits
-
Previously steam_open.cocci was treating only wait_event_.* - e.g.
wait_event_interruptible - as a blocking operation. However e.g.
wait_for_completion_interruptible is also blocking, and so from this
point of view it would be more logical to treat all wait_.* as a
blocking point.The logic of this change actually came up for real when
drivers/pci/switch/switchtec.c changed from using
wait_event_interruptible to wait_for_completion_interruptible:https://lore.kernel.org/linux-pci/20190413170056.GA11293@deco.navytux.spb.ru/
https://lore.kernel.org/linux-pci/20190415145456.GA15280@deco.navytux.spb.ru/
https://lore.kernel.org/linux-pci/20190415154102.GB17661@deco.navytux.spb.ru/For a driver that uses nonseekable_open with read/write having stream
semantic and read also calling e.g. wait_for_completion_interruptible,
running stream_open.cocci before this patch would produce:WARNING: _fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
while after this patch it will report:
ERROR: _fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
Signed-off-by: Kirill Smelkov
Acked-by: Julia Lawall
Signed-off-by: Masahiro Yamada -
Extend a when constraint in a SmPL rule so that an additional cast
is optionally excluded from source code searches for an expression
in assignments.Signed-off-by: Markus Elfring
Suggested-by: Julia Lawall
Link: https://lore.kernel.org/lkml/alpine.DEB.2.21.1902160934400.3212@hadrien/
Link: https://systeme.lip6.fr/pipermail/cocci/2019-February/005592.html
Acked-by: Julia Lawall
Signed-off-by: Masahiro Yamada -
The Linux coding style tolerates long string literals so that
the provided information can be easier found also by search tools
like grep.
Thus simplify a message construction in a SmPL rule by concatenating text
with two plus operators less.Signed-off-by: Markus Elfring
Signed-off-by: Masahiro Yamada -
Replace 'kstrdep' with 'kstrdup' in warning messages.
Signed-off-by: Rikard Falkeborn
Acked-by: Julia Lawall
Signed-off-by: Masahiro Yamada
21 Jun, 2019
1 commit
-
Convert the various documents at the driver-model, preparing
them to be part of the driver-api book.The conversion is actually:
- add blank lines and identation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.Signed-off-by: Mauro Carvalho Chehab
Acked-by: Jeff Kirsher # ice
Signed-off-by: Greg Kroah-Hartman
19 Jun, 2019
1 commit
-
Based on 1 normalized pattern(s):
gplv2
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 58 file(s).
Signed-off-by: Thomas Gleixner
Reviewed-by: Enrico Weigelt
Reviewed-by: Allison Randal
Reviewed-by: Kate Stewart
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081207.556988620@linutronix.de
Signed-off-by: Greg Kroah-Hartman
05 Jun, 2019
1 commit
-
Based on 1 normalized pattern(s):
gpl v2
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 19 file(s).
Signed-off-by: Thomas Gleixner
Reviewed-by: Allison Randal
Reviewed-by: Richard Fontana
Reviewed-by: Steve Winslow
Reviewed-by: Kate Stewart
Reviewed-by: Alexios Zavras
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141333.108140152@linutronix.de
Signed-off-by: Greg Kroah-Hartman
07 Apr, 2019
1 commit
-
…multaneously without deadlock
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/180396for 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/308445https://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-L1510Corresponding 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-L216I'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 handlershttps://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#L1399-1481so 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>
28 Mar, 2019
2 commits
-
Summary was copy and pasted from array_size.cocci.
Signed-off-by: Michael Stefaniuc
Acked-by: Julia Lawall
Signed-off-by: Masahiro Yamada -
Don't complain about a return when this function returns "&pdev->dev".
Fixes: da9cfb87a44d ("coccinelle: semantic code search for missing put_device()")
Reported-by: Julia Lawall
Signed-off-by: Wen Yang
Acked-by: Julia Lawall
Signed-off-by: Masahiro Yamada
17 Mar, 2019
1 commit
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The of_find_device_by_node() takes a reference to the underlying device
structure, we should release that reference.
The implementation of this semantic code search is:
In a function, for a local variable returned by calling
of_find_device_by_node(),
a, if it is released by a function such as
put_device()/of_dev_put()/platform_device_put() after the last use,
it is considered that there is no reference leak;
b, if it is passed back to the caller via
dev_get_drvdata()/platform_get_drvdata()/get_device(), etc., the
reference will be released in other functions, and the current function
also considers that there is no reference leak;
c, for the rest of the situation, the current function should release the
reference by calling put_device, this code search will report the
corresponding error message.By using this semantic code search, we have found some object reference leaks,
such as:
commit 11907e9d3533 ("ASoC: fsl-asoc-card: fix object reference leaks in
fsl_asoc_card_probe")
commit a12085d13997 ("mtd: rawnand: atmel: fix possible object reference leak")
commit 11493f26856a ("mtd: rawnand: jz4780: fix possible object reference leak")There are still dozens of reference leaks in the current kernel code.
Further, for the case of b, the object returned to other functions may also
have a reference leak, we will continue to develop other cocci scripts to
further check the reference leak.Signed-off-by: Wen Yang
Reviewed-by: Julia Lawall
Reviewed-by: Markus Elfring
Signed-off-by: Masahiro Yamada
08 Jan, 2019
1 commit
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dma_zalloc_coherent() is no longer needed as it has no users because
dma_alloc_coherent() already zeroes out memory for us.The Coccinelle grammar rule that used to check for dma_alloc_coherent()
+ memset() is modified so that it just tells the user that the memset is
not needed anymore.Suggested-by: Christoph Hellwig
Signed-off-by: Luis Chamberlain
Signed-off-by: Christoph Hellwig
06 Jan, 2019
2 commits
-
Coccinelle doesn't always have access to the values of named
(#define) constants, and they may likely often be bound to true
and false values anyway, resulting in false positives. So stop
warning about them.Signed-off-by: Julia Lawall
Signed-off-by: Masahiro Yamada -
Avoid reporting on the use of an iterator index variable when
the variable is redeclared.Signed-off-by: Julia Lawall
Signed-off-by: Masahiro Yamada
30 Dec, 2018
1 commit
-
Pull Kbuild updates from Masahiro Yamada:
"Kbuild core:
- remove unneeded $(call cc-option,...) switches
- consolidate Clang compiler flags into CLANG_FLAGS
- announce the deprecation of SUBDIRS
- fix single target build for external module
- simplify the dependencies of 'prepare' stage targets
- allow fixdep to directly write to .*.cmd files
- simplify dependency generation for CONFIG_TRIM_UNUSED_KSYMS
- change if_changed_rule to accept multi-line recipe
- move .SECONDARY special target to scripts/Kbuild.include
- remove redundant 'set -e'
- improve parallel execution for CONFIG_HEADERS_CHECK
- misc cleanupsTreewide fixes and cleanups
- set Clang flags correctly for PowerPC boot images
- fix UML build error with CONFIG_GCC_PLUGINS
- remove unneeded patterns from .gitignore files
- refactor firmware/Makefile
- remove unneeded rules for *offsets.s
- avoid unneeded regeneration of intermediate .s files
- clean up ./KbuildModpost:
- remove unused -M, -K options
- fix false positive warnings about section mismatch
- use simple devtable lookup instead of linker magic
- misc cleanupsCoccinelle:
- relax boolinit.cocci checks for overall consistency
- fix warning messages of boolinit.cocciOther tools:
- improve -dirty check of scripts/setlocalversion
- add a tool to generate compile_commands.json from .*.cmd files"* tag 'kbuild-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (51 commits)
kbuild: remove unused cmd_gentimeconst
kbuild: remove $(obj)/ prefixes in ./Kbuild
treewide: add intermediate .s files to targets
treewide: remove explicit rules for *offsets.s
firmware: refactor firmware/Makefile
firmware: remove unnecessary patterns from .gitignore
scripts: remove unnecessary ihex2fw and check-lc_ctypes from .gitignore
um: remove unused filechk_gen_header in Makefile
scripts: add a tool to produce a compile_commands.json file
kbuild: add -Werror=implicit-int flag unconditionally
kbuild: add -Werror=strict-prototypes flag unconditionally
kbuild: add -fno-PIE flag unconditionally
scripts: coccinelle: Correct warning message
scripts: coccinelle: only suggest true/false in files that already use them
kbuild: handle part-of-module correctly for *.ll and *.symtypes
kbuild: refactor part-of-module
kbuild: refactor quiet_modtag
kbuild: remove redundant quiet_modtag for $(obj-m)
kbuild: refactor Makefile.asm-generic
user/Makefile: Fix typo and capitalization in comment section
...
16 Dec, 2018
2 commits
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"Assignment" requires the assigned value before the place that
value is stored into.Signed-off-by: Julia Lawall
Signed-off-by: Masahiro Yamada -
Some code may overall use 0 and 1, so don't introduce occasional
uses of true and false in these cases.Signed-off-by: Julia Lawall
Signed-off-by: Masahiro Yamada
25 Nov, 2018
1 commit
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The coccinelle script was used to rename some (deprecated) functions
which no longer exist now.Signed-off-by: Fernando Ramos
Reviewed-by: Linus Walleij
Acked-by: Julia Lawall
Signed-off-by: Linus Walleij
Link: https://patchwork.freedesktop.org/patch/msgid/20181115221634.22715-9-greenfoo@gluegarage.com
22 Aug, 2018
1 commit
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Because pci_alloc_consistent has been deprecated. We prefer to use
dma_alloc_coherent directly. Therefore, we should remove pci_alloc_consistent
to increase the confidence.Acked-by: Julia Lawall
Acked-by: Himanshu Jha
Signed-off-by: zhong jiang
Signed-off-by: Masahiro Yamada
14 Aug, 2018
1 commit
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Ensure that the cited expression is not a function call or an
assignment to reduce the chance of false positives.Slightly modify the warning message to indicate another source
of false positves.Signed-off-by: Julia Lawall
Signed-off-by: Masahiro Yamada
18 Jul, 2018
1 commit
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atomic_as_refcounter.cocci script allows detecting
cases when refcount_t type and API should be used
instead of atomic_t.Signed-off-by: Elena Reshetova
Acked-by: Julia Lawall
Reviewed-by: Kees Cook
Signed-off-by: Masahiro Yamada
07 Jun, 2018
1 commit
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Pull Kbuild updates from Masahiro Yamada:
- improve fixdep to coalesce consecutive slashes in dep-files
- fix some issues of the maintainer string generation in deb-pkg script
- remove unused CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX and clean-up
several tools and linker scripts- clean-up modpost
- allow to enable the dead code/data elimination for PowerPC in EXPERT
mode- improve two coccinelle scripts for better performance
- pass endianness and machine size flags to sparse for all architecture
- misc fixes
* tag 'kbuild-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits)
kbuild: add machine size to CHECKFLAGS
kbuild: add endianness flag to CHEKCFLAGS
kbuild: $(CHECK) doesnt need NOSTDINC_FLAGS twice
scripts: Fixed printf format mismatch
scripts/tags.sh: use `find` for $ALLSOURCE_ARCHS generation
coccinelle: deref_null: improve performance
coccinelle: mini_lock: improve performance
powerpc: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selected
kbuild: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selectable if enabled
kbuild: LD_DEAD_CODE_DATA_ELIMINATION no -ffunction-sections/-fdata-sections for module build
kbuild: Fix asm-generic/vmlinux.lds.h for LD_DEAD_CODE_DATA_ELIMINATION
modpost: constify *modname function argument where possible
modpost: remove redundant is_vmlinux() test
modpost: use strstarts() helper more widely
modpost: pass struct elf_info pointer to get_modinfo()
checkpatch: remove VMLINUX_SYMBOL() check
vmlinux.lds.h: remove no-op macro VMLINUX_SYMBOL()
kbuild: remove CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
export.h: remove code for prefixing symbols with underscore
depmod.sh: remove symbol prefix support
...
22 May, 2018
2 commits
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Move rules looking for some special cases of safe dereferences before
the collection of NULL-tested values. The special cases are fairly
rare, but somewhat costly to find, because isomorphisms create many
variants of the rules. There is thus no need to search for them over
and over for each NULL tested expression. Collecting them just once
is sufficient and more efficient.Signed-off-by: Julia Lawall
Signed-off-by: Masahiro Yamada -
Replace by ... when any. is slow, and in some
obscure cases involving backward jumps it doesn't force the unlock to
actually come after the end of the if.Signed-off-by: Julia Lawall
Signed-off-by: Masahiro Yamada