This is another fine warning, related to the 'zero-length-bounds' one,
but hitting the same historical code in the kernel.
Because C didn't historically support flexible array members, we have
code that instead uses a one-sized array, the same way we have cases of
zero-sized arrays.
The one-sized arrays come from either not wanting to use the gcc
zero-sized array extension, or from a slight convenience-feature, where
particularly for strings, the size of the structure now includes the
allocation for the final NUL character.
So with a "char name[1];" at the end of a structure, you can do things
like
v = my_malloc(sizeof(struct vendor) + strlen(name));
and avoid the "+1" for the terminator.
Yes, the modern way to do that is with a flexible array, and using
'offsetof()' instead of 'sizeof()', and adding the "+1" by hand. That
also technically gets the size "more correct" in that it avoids any
alignment (and thus padding) issues, but this is another long-term
cleanup thing that will not happen for 5.7.
So disable the warning for now, even though it's potentially quite
useful. Having a slew of warnings that then hide more urgent new issues
is not an improvement.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a fine warning, but we still have a number of zero-length arrays
in the kernel that come from the traditional gcc extension. Yes, they
are getting converted to flexible arrays, but in the meantime the gcc-10
warning about zero-length bounds is very verbose, and is hiding other
issues.
I missed one actual build failure because it was hidden among hundreds
of lines of warning. Thankfully I caught it on the second go before
pushing things out, but it convinced me that I really need to disable
the new warnings for now.
We'll hopefully be all done with our conversion to flexible arrays in
the not too distant future, and we can then re-enable this warning.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have some rather random rules about when we accept the
"maybe-initialized" warnings, and when we don't.
For example, we consider it unreliable for gcc versions < 4.9, but also
if -O3 is enabled, or if optimizing for size. And then various kernel
config options disabled it, because they know that they trigger that
warning by confusing gcc sufficiently (ie PROFILE_ALL_BRANCHES).
And now gcc-10 seems to be introducing a lot of those warnings too, so
it falls under the same heading as 4.9 did.
At the same time, we have a very straightforward way to _enable_ that
warning when wanted: use "W=2" to enable more warnings.
So stop playing these ad-hoc games, and just disable that warning by
default, with the known and straight-forward "if you want to work on the
extra compiler warnings, use W=123".
Would it be great to have code that is always so obvious that it never
confuses the compiler whether a variable is used initialized or not?
Yes, it would. In a perfect world, the compilers would be smarter, and
our source code would be simpler.
That's currently not the world we live in, though.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge tag 'io_uring-5.7-2020-05-08' of git://git.kernel.dk/linux-block
Pull io_uring fixes from Jens Axboe:
- Fix finish_wait() balancing in file cancelation (Xiaoguang)
- Ensure early cleanup of resources in ring map failure (Xiaoguang)
- Ensure IORING_OP_SLICE does the right file mode checks (Pavel)
- Remove file opening from openat/openat2/statx, it's not needed and
messes with O_PATH
* tag 'io_uring-5.7-2020-05-08' of git://git.kernel.dk/linux-block:
io_uring: don't use 'fd' for openat/openat2/statx
splice: move f_mode checks to do_{splice,tee}()
io_uring: handle -EFAULT properly in io_uring_setup()
io_uring: fix mismatched finish_wait() calls in io_uring_cancel_files()
Four minor fixes, all in drivers (qla2xxx, ibmvfc, ibmvscsi)
Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>
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Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"Four minor fixes, all in drivers (qla2xxx, ibmvfc, ibmvscsi)"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: ibmvscsi: Fix WARN_ON during event pool release
scsi: ibmvfc: Don't send implicit logouts prior to NPIV login
scsi: qla2xxx: Delete all sessions before unregister local nvme port
scsi: qla2xxx: Fix hang when issuing nvme disconnect-all in NPIV
big-endian arches, a spammy log message and a couple error paths.
Also included a MAINTAINERS update.
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Merge tag 'ceph-for-5.7-rc5' of git://github.com/ceph/ceph-client
Pull ceph fixes from Ilya Dryomov:
"Fixes for an endianness handling bug that prevented mounts on
big-endian arches, a spammy log message and a couple error paths.
Also included a MAINTAINERS update"
* tag 'ceph-for-5.7-rc5' of git://github.com/ceph/ceph-client:
ceph: demote quotarealm lookup warning to a debug message
MAINTAINERS: remove myself as ceph co-maintainer
ceph: fix double unlock in handle_cap_export()
ceph: fix special error code in ceph_try_get_caps()
ceph: fix endianness bug when handling MDS session feature bits
A misconfigured cephx can easily result in having the kernel client
flooding the logs with:
ceph: Can't lookup inode 1 (err: -13)
Change this message to debug level.
Cc: stable@vger.kernel.org
URL: https://tracker.ceph.com/issues/44546
Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Here are some small driver fixes for 5.7-rc5 that resolve a number of
minor reported issues:
- mhi bus driver fixes found as people actually use the code
- phy driver fixes and compat string additions
- most driver fix due to link order changing when the core moved
out of staging
- mei driver fix
- interconnect build warning fix
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-5.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver fixes from Greg KH:
"Here are some small driver fixes for 5.7-rc5 that resolve a number of
minor reported issues:
- mhi bus driver fixes found as people actually use the code
- phy driver fixes and compat string additions
- most driver fix due to link order changing when the core moved out
of staging
- mei driver fix
- interconnect build warning fix
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-5.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
bus: mhi: core: Fix channel device name conflict
bus: mhi: core: Fix typo in comment
bus: mhi: core: Offload register accesses to the controller
bus: mhi: core: Remove link_status() callback
bus: mhi: core: Make sure to powerdown if mhi_sync_power_up fails
bus: mhi: Fix parsing of mhi_flags
mei: me: disable mei interface on LBG servers.
phy: qualcomm: usb-hs-28nm: Prepare clocks in init
MAINTAINERS: Add Vinod Koul as Generic PHY co-maintainer
interconnect: qcom: Move the static keyword to the front of declaration
most: core: use function subsys_initcall()
bus: mhi: core: Fix a NULL vs IS_ERR check in mhi_create_devices()
phy: qcom-qusb2: Re add "qcom,sdm845-qusb2-phy" compat string
phy: tegra: Select USB_COMMON for usb_get_maximum_speed()
Here are a number of small driver core fixes for 5.7-rc5 to resolve a
bunch of reported issues with the current tree.
Biggest here are the reverts and patches from John Stultz to resolve a
bunch of deferred probe regressions we have been seeing in 5.7-rc right
now.
Along with those are some other smaller fixes:
- coredump crash fix
- devlink fix for when permissive mode was enabled
- amba and platform device dma_parms fixes
- component error silenced for when deferred probe happens
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core fixes from Greg KH:
"Here are a number of small driver core fixes for 5.7-rc5 to resolve a
bunch of reported issues with the current tree.
Biggest here are the reverts and patches from John Stultz to resolve a
bunch of deferred probe regressions we have been seeing in 5.7-rc
right now.
Along with those are some other smaller fixes:
- coredump crash fix
- devlink fix for when permissive mode was enabled
- amba and platform device dma_parms fixes
- component error silenced for when deferred probe happens
All of these have been in linux-next for a while with no reported
issues"
* tag 'driver-core-5.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
regulator: Revert "Use driver_deferred_probe_timeout for regulator_init_complete_work"
driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires
driver core: Use dev_warn() instead of dev_WARN() for deferred_probe_timeout warnings
driver core: Revert default driver_deferred_probe_timeout value to 0
component: Silence bind error on -EPROBE_DEFER
driver core: Fix handling of fw_devlink=permissive
coredump: fix crash when umh is disabled
amba: Initialize dma_parms for amba devices
driver core: platform: Initialize dma_parms for platform devices
Here are 3 small driver fixes for 5.7-rc5.
Two of these are documentation fixes:
- MAINTAINERS update due to removed driver
- removing Wolfram from the ks7010 driver TODO file
The other patch is a real fix:
- fix gasket driver to proper check the return value of a call
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'staging-5.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging driver fixes from Greg KH:
"Here are three small driver fixes for 5.7-rc5.
Two of these are documentation fixes:
- MAINTAINERS update due to removed driver
- removing Wolfram from the ks7010 driver TODO file
The other patch is a real fix:
- fix gasket driver to proper check the return value of a call
All of these have been in linux-next for a while with no reported
issues"
* tag 'staging-5.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
staging: gasket: Check the return value of gasket_get_bar_index()
staging: ks7010: remove me from CC list
MAINTAINERS: remove entry after hp100 driver removal
Here are 3 small TTY/Serial/VT fixes for 5.7-rc5:
- revert for the bcm63xx driver "fix" that was incorrect
- vt unicode console bugfix
- xilinx_uartps console driver fix
All of these have been in linux next with no reported issues
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-5.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial fixes from Greg KH:
"Here are three small TTY/Serial/VT fixes for 5.7-rc5:
- revert for the bcm63xx driver "fix" that was incorrect
- vt unicode console bugfix
- xilinx_uartps console driver fix
All of these have been in linux next with no reported issues"
* tag 'tty-5.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
tty: xilinx_uartps: Fix missing id assignment to the console
vt: fix unicode console freeing with a common interface
Revert "tty: serial: bcm63xx: fix missing clk_put() in bcm63xx_uart"
Here are some small USB fixes for 5.7-rc5 to resolve some reported
issues:
- syzbot found problems fixed
- usbfs dma mapping fix
- typec bugfixs
- chipidea bugfix
- usb4/thunderbolt fix
- new device ids/quirks
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'usb-5.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB fixes from Greg KH:
"Here are some small USB fixes for 5.7-rc5 to resolve some reported
issues:
- syzbot found problems fixed
- usbfs dma mapping fix
- typec bugfixs
- chipidea bugfix
- usb4/thunderbolt fix
- new device ids/quirks
All of these have been in linux-next for a while with no reported
issues"
* tag 'usb-5.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: chipidea: msm: Ensure proper controller reset using role switch API
usb: typec: mux: intel: Handle alt mode HPD_HIGH
usb: usbfs: correct kernel->user page attribute mismatch
usb: typec: intel_pmc_mux: Fix the property names
USB: core: Fix misleading driver bug report
USB: serial: qcserial: Add DW5816e support
USB: uas: add quirk for LaCie 2Big Quadra
thunderbolt: Check return value of tb_sw_read() in usb4_switch_op()
USB: serial: garmin_gps: add sanity checking for data length
hdcp:
- fix HDCP regression
amdgpu:
- Runtime PM fixes
- DC fix for PPC
- Misc DC fixes
virtio:
- fix context ordering issue
sun4i:
- old gcc warning fix
ingenic-drm:
- missing module support
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Merge tag 'drm-fixes-2020-05-08' of git://anongit.freedesktop.org/drm/drm
Pull drm fixes from Dave Airlie:
"Another pretty normal week. I didn't get any i915 fixes yet, so next
week I'd expect double the usual i915, but otherwise a bunch of amdgpu
and some scattered other fixes.
hdcp:
- fix HDCP regression
amdgpu:
- Runtime PM fixes
- DC fix for PPC
- Misc DC fixes
virtio:
- fix context ordering issue
sun4i:
- old gcc warning fix
ingenic-drm:
- missing module support"
* tag 'drm-fixes-2020-05-08' of git://anongit.freedesktop.org/drm/drm:
drm/amd/display: Prevent dpcd reads with passive dongles
drm/amd/display: fix counter in wait_for_no_pipes_pending
drm/amd/display: Update DCN2.1 DV Code Revision
drm: Fix HDCP failures when SRM fw is missing
sun6i: dsi: fix gcc-4.8
drm: ingenic-drm: add MODULE_DEVICE_TABLE
drm/virtio: create context before RESOURCE_CREATE_2D in 3D mode
drm/amd/display: work around fp code being emitted outside of DC_FP_START/END
drm/amdgpu/dc: Use WARN_ON_ONCE for ASSERT
drm/amdgpu: drop redundant cg/pg ungate on runpm enter
drm/amdgpu: move kfd suspend after ip_suspend_phase1
Merge misc fixes from Andrew Morton:
"14 fixes and one selftest to verify the ipc fixes herein"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm: limit boost_watermark on small zones
ubsan: disable UBSAN_ALIGNMENT under COMPILE_TEST
mm/vmscan: remove unnecessary argument description of isolate_lru_pages()
epoll: atomically remove wait entry on wake up
kselftests: introduce new epoll60 testcase for catching lost wakeups
percpu: make pcpu_alloc() aware of current gfp context
mm/slub: fix incorrect interpretation of s->offset
scripts/gdb: repair rb_first() and rb_last()
eventpoll: fix missing wakeup for ovflist in ep_poll_callback
arch/x86/kvm/svm/sev.c: change flag passed to GUP fast in sev_pin_memory()
scripts/decodecode: fix trapping instruction formatting
kernel/kcov.c: fix typos in kcov_remote_start documentation
mm/page_alloc: fix watchdog soft lockups during set_zone_contiguous()
mm, memcg: fix error return value of mem_cgroup_css_alloc()
ipc/mqueue.c: change __do_notify() to bypass check_kill_permission()
in sun4i, a probe issue in ingenic-drm and a regression in the HDCP
support.
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Merge tag 'drm-misc-fixes-2020-05-07' of git://anongit.freedesktop.org/drm/drm-misc into drm-fixes
A few minor fixes for an ordering issue in virtio, an (old) gcc warning
in sun4i, a probe issue in ingenic-drm and a regression in the HDCP
support.
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20200507160130.id64niqgf5wsha4u@gilmour.lan
Pull security subsystem fix from James Morris:
"Fix the default value of fs_context_parse_param hook"
* 'for-v5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
security: Fix the default value of fs_context_parse_param hook
Commit 1c30844d2d ("mm: reclaim small amounts of memory when an
external fragmentation event occurs") adds a boost_watermark() function
which increases the min watermark in a zone by at least
pageblock_nr_pages or the number of pages in a page block.
On Arm64, with 64K pages and 512M huge pages, this is 8192 pages or
512M. It does this regardless of the number of managed pages managed in
the zone or the likelihood of success.
This can put the zone immediately under water in terms of allocating
pages from the zone, and can cause a small machine to fail immediately
due to OoM. Unlike set_recommended_min_free_kbytes(), which
substantially increases min_free_kbytes and is tied to THP,
boost_watermark() can be called even if THP is not active.
The problem is most likely to appear on architectures such as Arm64
where pageblock_nr_pages is very large.
It is desirable to run the kdump capture kernel in as small a space as
possible to avoid wasting memory. In some architectures, such as Arm64,
there are restrictions on where the capture kernel can run, and
therefore, the space available. A capture kernel running in 768M can
fail due to OoM immediately after boost_watermark() sets the min in zone
DMA32, where most of the memory is, to 512M. It fails even though there
is over 500M of free memory. With boost_watermark() suppressed, the
capture kernel can run successfully in 448M.
This patch limits boost_watermark() to boosting a zone's min watermark
only when there are enough pages that the boost will produce positive
results. In this case that is estimated to be four times as many pages
as pageblock_nr_pages.
Mel said:
: There is no harm in marking it stable. Clearly it does not happen very
: often but it's not impossible. 32-bit x86 is a lot less common now
: which would previously have been vulnerable to triggering this easily.
: ppc64 has a larger base page size but typically only has one zone.
: arm64 is likely the most vulnerable, particularly when CMA is
: configured with a small movable zone.
Fixes: 1c30844d2d ("mm: reclaim small amounts of memory when an external fragmentation event occurs")
Signed-off-by: Henry Willard <henry.willard@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/1588294148-6586-1-git-send-email-henry.willard@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The documentation for UBSAN_ALIGNMENT already mentions that it should
not be used on all*config builds (and for efficient-unaligned-access
architectures), so just refactor the Kconfig to correctly implement this
so randconfigs will stop creating insane images that freak out objtool
under CONFIG_UBSAN_TRAP (due to the false positives producing functions
that never return, etc).
Link: http://lkml.kernel.org/r/202005011433.C42EA3E2D@keescook
Fixes: 0887a7ebc9 ("ubsan: add trap instrumentation option")
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/linux-next/202004231224.D6B3B650@keescook/
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit a9e7c39fa9 ("mm/vmscan.c: remove 7th argument of
isolate_lru_pages()"), the explanation of 'mode' argument has been
unnecessary. Let's remove it.
Signed-off-by: Qiwu Chen <chenqiwu@xiaomi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200501090346.2894-1-chenqiwu@xiaomi.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch does two things:
- fixes a lost wakeup introduced by commit 339ddb53d3 ("fs/epoll:
remove unnecessary wakeups of nested epoll")
- improves performance for events delivery.
The description of the problem is the following: if N (>1) threads are
waiting on ep->wq for new events and M (>1) events come, it is quite
likely that >1 wakeups hit the same wait queue entry, because there is
quite a big window between __add_wait_queue_exclusive() and the
following __remove_wait_queue() calls in ep_poll() function.
This can lead to lost wakeups, because thread, which was woken up, can
handle not all the events in ->rdllist. (in better words the problem is
described here: https://lkml.org/lkml/2019/10/7/905)
The idea of the current patch is to use init_wait() instead of
init_waitqueue_entry().
Internally init_wait() sets autoremove_wake_function as a callback,
which removes the wait entry atomically (under the wq locks) from the
list, thus the next coming wakeup hits the next wait entry in the wait
queue, thus preventing lost wakeups.
Problem is very well reproduced by the epoll60 test case [1].
Wait entry removal on wakeup has also performance benefits, because
there is no need to take a ep->lock and remove wait entry from the queue
after the successful wakeup. Here is the timing output of the epoll60
test case:
With explicit wakeup from ep_scan_ready_list() (the state of the
code prior 339ddb53d3):
real 0m6.970s
user 0m49.786s
sys 0m0.113s
After this patch:
real 0m5.220s
user 0m36.879s
sys 0m0.019s
The other testcase is the stress-epoll [2], where one thread consumes
all the events and other threads produce many events:
With explicit wakeup from ep_scan_ready_list() (the state of the
code prior 339ddb53d3):
threads events/ms run-time ms
8 5427 1474
16 6163 2596
32 6824 4689
64 7060 9064
128 6991 18309
After this patch:
threads events/ms run-time ms
8 5598 1429
16 7073 2262
32 7502 4265
64 7640 8376
128 7634 16767
(number of "events/ms" represents event bandwidth, thus higher is
better; number of "run-time ms" represents overall time spent
doing the benchmark, thus lower is better)
[1] tools/testing/selftests/filesystems/epoll/epoll_wakeup_test.c
[2] https://github.com/rouming/test-tools/blob/master/stress-epoll.c
Signed-off-by: Roman Penyaev <rpenyaev@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jason Baron <jbaron@akamai.com>
Cc: Khazhismel Kumykov <khazhy@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Heiher <r@hev.cc>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200430130326.1368509-2-rpenyaev@suse.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This test case catches lost wake up introduced by commit 339ddb53d3
("fs/epoll: remove unnecessary wakeups of nested epoll")
The test is simple: we have 10 threads and 10 event fds. Each thread
can harvest only 1 event. 1 producer fires all 10 events at once and
waits that all 10 events will be observed by 10 threads.
In case of lost wakeup epoll_wait() will timeout and 0 will be returned.
Test case catches two sort of problems: forgotten wakeup on event, which
hits the ->ovflist list, this problem was fixed by:
5a2513239750 ("eventpoll: fix missing wakeup for ovflist in ep_poll_callback")
the other problem is when several sequential events hit the same waiting
thread, thus other waiters get no wakeups. Problem is fixed in the
following patch.
Signed-off-by: Roman Penyaev <rpenyaev@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Khazhismel Kumykov <khazhy@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Heiher <r@hev.cc>
Cc: Jason Baron <jbaron@akamai.com>
Link: http://lkml.kernel.org/r/20200430130326.1368509-1-rpenyaev@suse.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since 5.7-rc1, on btrfs we have a percpu counter initialization for
which we always pass a GFP_KERNEL gfp_t argument (this happens since
commit 2992df7326 ("btrfs: Implement DREW lock")).
That is safe in some contextes but not on others where allowing fs
reclaim could lead to a deadlock because we are either holding some
btrfs lock needed for a transaction commit or holding a btrfs
transaction handle open. Because of that we surround the call to the
function that initializes the percpu counter with a NOFS context using
memalloc_nofs_save() (this is done at btrfs_init_fs_root()).
However it turns out that this is not enough to prevent a possible
deadlock because percpu_alloc() determines if it is in an atomic context
by looking exclusively at the gfp flags passed to it (GFP_KERNEL in this
case) and it is not aware that a NOFS context is set.
Because percpu_alloc() thinks it is in a non atomic context it locks the
pcpu_alloc_mutex. This can result in a btrfs deadlock when
pcpu_balance_workfn() is running, has acquired that mutex and is waiting
for reclaim, while the btrfs task that called percpu_counter_init() (and
therefore percpu_alloc()) is holding either the btrfs commit_root
semaphore or a transaction handle (done fs/btrfs/backref.c:
iterate_extent_inodes()), which prevents reclaim from finishing as an
attempt to commit the current btrfs transaction will deadlock.
Lockdep reports this issue with the following trace:
======================================================
WARNING: possible circular locking dependency detected
5.6.0-rc7-btrfs-next-77 #1 Not tainted
------------------------------------------------------
kswapd0/91 is trying to acquire lock:
ffff8938a3b3fdc8 (&delayed_node->mutex){+.+.}, at: __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs]
but task is already holding lock:
ffffffffb4f0dbc0 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x5/0x30
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (fs_reclaim){+.+.}:
fs_reclaim_acquire.part.0+0x25/0x30
__kmalloc+0x5f/0x3a0
pcpu_create_chunk+0x19/0x230
pcpu_balance_workfn+0x56a/0x680
process_one_work+0x235/0x5f0
worker_thread+0x50/0x3b0
kthread+0x120/0x140
ret_from_fork+0x3a/0x50
-> #3 (pcpu_alloc_mutex){+.+.}:
__mutex_lock+0xa9/0xaf0
pcpu_alloc+0x480/0x7c0
__percpu_counter_init+0x50/0xd0
btrfs_drew_lock_init+0x22/0x70 [btrfs]
btrfs_get_fs_root+0x29c/0x5c0 [btrfs]
resolve_indirect_refs+0x120/0xa30 [btrfs]
find_parent_nodes+0x50b/0xf30 [btrfs]
btrfs_find_all_leafs+0x60/0xb0 [btrfs]
iterate_extent_inodes+0x139/0x2f0 [btrfs]
iterate_inodes_from_logical+0xa1/0xe0 [btrfs]
btrfs_ioctl_logical_to_ino+0xb4/0x190 [btrfs]
btrfs_ioctl+0x165a/0x3130 [btrfs]
ksys_ioctl+0x87/0xc0
__x64_sys_ioctl+0x16/0x20
do_syscall_64+0x5c/0x260
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #2 (&fs_info->commit_root_sem){++++}:
down_write+0x38/0x70
btrfs_cache_block_group+0x2ec/0x500 [btrfs]
find_free_extent+0xc6a/0x1600 [btrfs]
btrfs_reserve_extent+0x9b/0x180 [btrfs]
btrfs_alloc_tree_block+0xc1/0x350 [btrfs]
alloc_tree_block_no_bg_flush+0x4a/0x60 [btrfs]
__btrfs_cow_block+0x122/0x5a0 [btrfs]
btrfs_cow_block+0x106/0x240 [btrfs]
commit_cowonly_roots+0x55/0x310 [btrfs]
btrfs_commit_transaction+0x509/0xb20 [btrfs]
sync_filesystem+0x74/0x90
generic_shutdown_super+0x22/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x93/0xc0
exit_to_usermode_loop+0xf9/0x100
do_syscall_64+0x20d/0x260
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #1 (&space_info->groups_sem){++++}:
down_read+0x3c/0x140
find_free_extent+0xef6/0x1600 [btrfs]
btrfs_reserve_extent+0x9b/0x180 [btrfs]
btrfs_alloc_tree_block+0xc1/0x350 [btrfs]
alloc_tree_block_no_bg_flush+0x4a/0x60 [btrfs]
__btrfs_cow_block+0x122/0x5a0 [btrfs]
btrfs_cow_block+0x106/0x240 [btrfs]
btrfs_search_slot+0x50c/0xd60 [btrfs]
btrfs_lookup_inode+0x3a/0xc0 [btrfs]
__btrfs_update_delayed_inode+0x90/0x280 [btrfs]
__btrfs_commit_inode_delayed_items+0x81f/0x870 [btrfs]
__btrfs_run_delayed_items+0x8e/0x180 [btrfs]
btrfs_commit_transaction+0x31b/0xb20 [btrfs]
iterate_supers+0x87/0xf0
ksys_sync+0x60/0xb0
__ia32_sys_sync+0xa/0x10
do_syscall_64+0x5c/0x260
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #0 (&delayed_node->mutex){+.+.}:
__lock_acquire+0xef0/0x1c80
lock_acquire+0xa2/0x1d0
__mutex_lock+0xa9/0xaf0
__btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs]
btrfs_evict_inode+0x40d/0x560 [btrfs]
evict+0xd9/0x1c0
dispose_list+0x48/0x70
prune_icache_sb+0x54/0x80
super_cache_scan+0x124/0x1a0
do_shrink_slab+0x176/0x440
shrink_slab+0x23a/0x2c0
shrink_node+0x188/0x6e0
balance_pgdat+0x31d/0x7f0
kswapd+0x238/0x550
kthread+0x120/0x140
ret_from_fork+0x3a/0x50
other info that might help us debug this:
Chain exists of:
&delayed_node->mutex --> pcpu_alloc_mutex --> fs_reclaim
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(fs_reclaim);
lock(pcpu_alloc_mutex);
lock(fs_reclaim);
lock(&delayed_node->mutex);
*** DEADLOCK ***
3 locks held by kswapd0/91:
#0: (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x5/0x30
#1: (shrinker_rwsem){++++}, at: shrink_slab+0x12f/0x2c0
#2: (&type->s_umount_key#43){++++}, at: trylock_super+0x16/0x50
stack backtrace:
CPU: 1 PID: 91 Comm: kswapd0 Not tainted 5.6.0-rc7-btrfs-next-77 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack+0x8f/0xd0
check_noncircular+0x170/0x190
__lock_acquire+0xef0/0x1c80
lock_acquire+0xa2/0x1d0
__mutex_lock+0xa9/0xaf0
__btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs]
btrfs_evict_inode+0x40d/0x560 [btrfs]
evict+0xd9/0x1c0
dispose_list+0x48/0x70
prune_icache_sb+0x54/0x80
super_cache_scan+0x124/0x1a0
do_shrink_slab+0x176/0x440
shrink_slab+0x23a/0x2c0
shrink_node+0x188/0x6e0
balance_pgdat+0x31d/0x7f0
kswapd+0x238/0x550
kthread+0x120/0x140
ret_from_fork+0x3a/0x50
This could be fixed by making btrfs pass GFP_NOFS instead of GFP_KERNEL
to percpu_counter_init() in contextes where it is not reclaim safe,
however that type of approach is discouraged since
memalloc_[nofs|noio]_save() were introduced. Therefore this change
makes pcpu_alloc() look up into an existing nofs/noio context before
deciding whether it is in an atomic context or not.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Link: http://lkml.kernel.org/r/20200430164356.15543-1-fdmanana@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In a couple of places in the slub memory allocator, the code uses
"s->offset" as a check to see if the free pointer is put right after the
object. That check is no longer true with commit 3202fa62fb ("slub:
relocate freelist pointer to middle of object").
As a result, echoing "1" into the validate sysfs file, e.g. of dentry,
may cause a bunch of "Freepointer corrupt" error reports like the
following to appear with the system in panic afterwards.
=============================================================================
BUG dentry(666:pmcd.service) (Tainted: G B): Freepointer corrupt
-----------------------------------------------------------------------------
To fix it, use the check "s->offset == s->inuse" in the new helper
function freeptr_outside_object() instead. Also add another helper
function get_info_end() to return the end of info block (inuse + free
pointer if not overlapping with object).
Fixes: 3202fa62fb ("slub: relocate freelist pointer to middle of object")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Rafael Aquini <aquini@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Vitaly Nikolenko <vnik@duasynt.com>
Cc: Silvio Cesare <silvio.cesare@gmail.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Markus Elfring <Markus.Elfring@web.de>
Cc: Changbin Du <changbin.du@gmail.com>
Link: http://lkml.kernel.org/r/20200429135328.26976-1-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current implementations of the rb_first() and rb_last() gdb
functions have a variable that references itself in its instanciation,
which causes the function to throw an error if a specific condition on
the argument is met. The original author rather intended to reference
the argument and made a typo. Referring the argument instead makes the
function work as intended.
Signed-off-by: Aymeric Agon-Rambosson <aymeric.agon@yandex.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Nikolay Borisov <n.borisov.lkml@gmail.com>
Cc: Jackie Liu <liuyun01@kylinos.cn>
Cc: Jason Wessel <jason.wessel@windriver.com>
Link: http://lkml.kernel.org/r/20200427051029.354840-1-aymeric.agon@yandex.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the event that we add to ovflist, before commit 339ddb53d3
("fs/epoll: remove unnecessary wakeups of nested epoll") we would be
woken up by ep_scan_ready_list, and did no wakeup in ep_poll_callback.
With that wakeup removed, if we add to ovflist here, we may never wake
up. Rather than adding back the ep_scan_ready_list wakeup - which was
resulting in unnecessary wakeups, trigger a wake-up in ep_poll_callback.
We noticed that one of our workloads was missing wakeups starting with
339ddb53d3 and upon manual inspection, this wakeup seemed missing to me.
With this patch added, we no longer see missing wakeups. I haven't yet
tried to make a small reproducer, but the existing kselftests in
filesystem/epoll passed for me with this patch.
[khazhy@google.com: use if/elif instead of goto + cleanup suggested by Roman]
Link: http://lkml.kernel.org/r/20200424190039.192373-1-khazhy@google.com
Fixes: 339ddb53d3 ("fs/epoll: remove unnecessary wakeups of nested epoll")
Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Roman Penyaev <rpenyaev@suse.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Roman Penyaev <rpenyaev@suse.de>
Cc: Heiher <r@hev.cc>
Cc: Jason Baron <jbaron@akamai.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200424025057.118641-1-khazhy@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When trying to lock read-only pages, sev_pin_memory() fails because
FOLL_WRITE is used as the flag for get_user_pages_fast().
Commit 73b0140bf0 ("mm/gup: change GUP fast to use flags rather than a
write 'bool'") updated the get_user_pages_fast() call sites to use
flags, but incorrectly updated the call in sev_pin_memory(). As the
original coding of this call was correct, revert the change made by that
commit.
Fixes: 73b0140bf0 ("mm/gup: change GUP fast to use flags rather than a write 'bool'")
Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Mike Marshall <hubcap@omnibond.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Link: http://lkml.kernel.org/r/20200423152419.87202-1-Janakarajan.Natarajan@amd.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the trapping instruction contains a ':', for a memory access through
segment registers for example, the sed substitution will insert the '*'
marker in the middle of the instruction instead of the line address:
2b: 65 48 0f c7 0f cmpxchg16b %gs:*(%rdi) <-- trapping instruction
I started to think I had forgotten some quirk of the assembly syntax
before noticing that it was actually coming from the script. Fix it to
add the address marker at the right place for these instructions:
28: 49 8b 06 mov (%r14),%rax
2b:* 65 48 0f c7 0f cmpxchg16b %gs:(%rdi) <-- trapping instruction
30: 0f 94 c0 sete %al
Fixes: 18ff44b189 ("scripts/decodecode: make faulting insn ptr more robust")
Signed-off-by: Ivan Delalande <colona@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20200419223653.GA31248@visor
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Without CONFIG_PREEMPT, it can happen that we get soft lockups detected,
e.g., while booting up.
watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:1]
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.6.0-next-20200331+ #4
Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014
RIP: __pageblock_pfn_to_page+0x134/0x1c0
Call Trace:
set_zone_contiguous+0x56/0x70
page_alloc_init_late+0x166/0x176
kernel_init_freeable+0xfa/0x255
kernel_init+0xa/0x106
ret_from_fork+0x35/0x40
The issue becomes visible when having a lot of memory (e.g., 4TB)
assigned to a single NUMA node - a system that can easily be created
using QEMU. Inside VMs on a hypervisor with quite some memory
overcommit, this is fairly easy to trigger.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Shile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Shile Zhang <shile.zhang@linux.alibaba.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200416073417.5003-1-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When I run my memcg testcase which creates lots of memcgs, I found
there're unexpected out of memory logs while there're still enough
available free memory. The error log is
mkdir: cannot create directory 'foo.65533': Cannot allocate memory
The reason is when we try to create more than MEM_CGROUP_ID_MAX memcgs,
an -ENOMEM errno will be set by mem_cgroup_css_alloc(), but the right
errno should be -ENOSPC "No space left on device", which is an
appropriate errno for userspace's failed mkdir.
As the errno really misled me, we should make it right. After this
patch, the error log will be
mkdir: cannot create directory 'foo.65533': No space left on device
[akpm@linux-foundation.org: s/EBUSY/ENOSPC/, per Michal]
[akpm@linux-foundation.org: s/EBUSY/ENOSPC/, per Michal]
Fixes: 73f576c04b ("mm: memcontrol: fix cgroup creation failure after many small jobs")
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Link: http://lkml.kernel.org/r/20200407063621.GA18914@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/1586192163-20099-1-git-send-email-laoar.shao@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Fix bootconfig causing kernels to fail with CONFIG_BLK_DEV_RAM enabled
- Fix allocation leaks in bootconfig tool
- Fix a double initialization of a variable
- Fix API bootconfig usage from kprobe boot time events
- Reject NULL location for kprobes
- Fix crash caused by preempt delay module not cleaning up kthread
correctly
- Add vmalloc_sync_mappings() to prevent x86_64 page faults from
recursively faulting from tracing page faults
- Fix comment in gpu/trace kerneldoc header
- Fix documentation of how to create a trace event class
- Make the local tracing_snapshot_instance_cond() function static
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Merge tag 'trace-v5.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix bootconfig causing kernels to fail with CONFIG_BLK_DEV_RAM
enabled
- Fix allocation leaks in bootconfig tool
- Fix a double initialization of a variable
- Fix API bootconfig usage from kprobe boot time events
- Reject NULL location for kprobes
- Fix crash caused by preempt delay module not cleaning up kthread
correctly
- Add vmalloc_sync_mappings() to prevent x86_64 page faults from
recursively faulting from tracing page faults
- Fix comment in gpu/trace kerneldoc header
- Fix documentation of how to create a trace event class
- Make the local tracing_snapshot_instance_cond() function static
* tag 'trace-v5.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tools/bootconfig: Fix resource leak in apply_xbc()
tracing: Make tracing_snapshot_instance_cond() static
tracing: Fix doc mistakes in trace sample
gpu/trace: Minor comment updates for gpu_mem_total tracepoint
tracing: Add a vmalloc_sync_mappings() for safe measure
tracing: Wait for preempt irq delay thread to finish
tracing/kprobes: Reject new event if loc is NULL
tracing/boottime: Fix kprobe event API usage
tracing/kprobes: Fix a double initialization typo
bootconfig: Fix to remove bootconfig data from initrd while boot
This Kselftest update for Linux 5.7-rc5 consists of ftrace test fixes
and fix to kvm Makefile for relocatable native/cross builds and installs.
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Merge tag 'linux-kselftest-5.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull kselftest fixes from Shuah Khan:
"ftrace test fixes and a fix to kvm Makefile for relocatable
native/cross builds and installs"
* tag 'linux-kselftest-5.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
selftests: fix kvm relocatable native/cross builds and installs
selftests/ftrace: Make XFAIL green color
ftrace/selftest: make unresolved cases cause failure if --fail-unresolved set
ftrace/selftests: workaround cgroup RT scheduling issues
We currently make some guesses as when to open this fd, but in reality
we have no business (or need) to do so at all. In fact, it makes certain
things fail, like O_PATH.
Remove the fd lookup from these opcodes, we're just passing the 'fd' to
generic helpers anyway. With that, we can also remove the special casing
of fd values in io_req_needs_file(), and the 'fd_non_neg' check that
we have. And we can ensure that we only read sqe->fd once.
This fixes O_PATH usage with openat/openat2, and ditto statx path side
oddities.
Cc: stable@vger.kernel.org: # v5.6
Reported-by: Max Kellermann <mk@cm4all.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Fix the @data and @fd allocations that are leaked in the error path of
apply_xbc().
Link: http://lkml.kernel.org/r/583a49c9-c27a-931d-e6c2-6f63a4b18bea@huawei.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fix the following sparse warning:
kernel/trace/trace.c:950:6: warning: symbol 'tracing_snapshot_instance_cond'
was not declared. Should it be static?
Link: http://lkml.kernel.org/r/1587614905-48692-1-git-send-email-zou_wei@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This change updates the improper comment for the 'size' attribute in the
tracepoint definition. Most gfx drivers pre-fault in physical pages
instead of making virtual allocations. So we drop the 'Virtual' keyword
here and leave this to the implementations.
Link: http://lkml.kernel.org/r/20200428220825.169606-1-zzyiwei@google.com
Signed-off-by: Yiwei Zhang <zzyiwei@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
x86_64 lazily maps in the vmalloc pages, and the way this works with per_cpu
areas can be complex, to say the least. Mappings may happen at boot up, and
if nothing synchronizes the page tables, those page mappings may not be
synced till they are used. This causes issues for anything that might touch
one of those mappings in the path of the page fault handler. When one of
those unmapped mappings is touched in the page fault handler, it will cause
another page fault, which in turn will cause a page fault, and leave us in
a loop of page faults.
Commit 763802b53a ("x86/mm: split vmalloc_sync_all()") split
vmalloc_sync_all() into vmalloc_sync_unmappings() and
vmalloc_sync_mappings(), as on system exit, it did not need to do a full
sync on x86_64 (although it still needed to be done on x86_32). By chance,
the vmalloc_sync_all() would synchronize the page mappings done at boot up
and prevent the per cpu area from being a problem for tracing in the page
fault handler. But when that synchronization in the exit of a task became a
nop, it caused the problem to appear.
Link: https://lore.kernel.org/r/20200429054857.66e8e333@oasis.local.home
Cc: stable@vger.kernel.org
Fixes: 737223fbca ("tracing: Consolidate buffer allocation code")
Reported-by: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
Suggested-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Running on a slower machine, it is possible that the preempt delay kernel
thread may still be executing if the module was immediately removed after
added, and this can cause the kernel to crash as the kernel thread might be
executing after its code has been removed.
There's no reason that the caller of the code shouldn't just wait for the
delay thread to finish, as the thread can also be created by a trigger in
the sysfs code, which also has the same issues.
Link: http://lore.kernel.org/r/5EA2B0C8.2080706@cn.fujitsu.com
Cc: stable@vger.kernel.org
Fixes: 793937236d ("lib: Add module for testing preemptoff/irqsoff latency tracers")
Reported-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Reviewed-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Reviewed-by: Joel Fernandes <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"Bugfixes, mostly for ARM and AMD, and more documentation.
Slightly bigger than usual because I couldn't send out what was
pending for rc4, but there is nothing worrisome going on. I have more
fixes pending for guest debugging support (gdbstub) but I will send
them next week"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (22 commits)
KVM: X86: Declare KVM_CAP_SET_GUEST_DEBUG properly
KVM: selftests: Fix build for evmcs.h
kvm: x86: Use KVM CPU capabilities to determine CR4 reserved bits
KVM: VMX: Explicitly clear RFLAGS.CF and RFLAGS.ZF in VM-Exit RSB path
docs/virt/kvm: Document configuring and running nested guests
KVM: s390: Remove false WARN_ON_ONCE for the PQAP instruction
kvm: ioapic: Restrict lazy EOI update to edge-triggered interrupts
KVM: x86: Fixes posted interrupt check for IRQs delivery modes
KVM: SVM: fill in kvm_run->debug.arch.dr[67]
KVM: nVMX: Replace a BUG_ON(1) with BUG() to squash clang warning
KVM: arm64: Fix 32bit PC wrap-around
KVM: arm64: vgic-v4: Initialize GICv4.1 even in the absence of a virtual ITS
KVM: arm64: Save/restore sp_el0 as part of __guest_enter
KVM: arm64: Delete duplicated label in invalid_vector
KVM: arm64: vgic-its: Fix memory leak on the error path of vgic_add_lpi()
KVM: arm64: vgic-v3: Retire all pending LPIs on vcpu destroy
KVM: arm: vgic-v2: Only use the virtual state when userspace accesses pending bits
KVM: arm: vgic: Only use the virtual state when userspace accesses enable bits
KVM: arm: vgic: Synchronize the whole guest on GIC{D,R}_I{S,C}ACTIVER read
KVM: arm64: PSCI: Forbid 64bit functions for 32bit guests
...
do_splice() is used by io_uring, as will be do_tee(). Move f_mode
checks from sys_{splice,tee}() to do_{splice,tee}(), so they're
enforced for io_uring as well.
Fixes: 7d67af2c01 ("io_uring: add splice(2) support")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The static analyzer in GCC 10 spotted that in huge_pte_alloc() we may
pass a NULL pmdp into pte_alloc_map() when pmd_alloc() returns NULL:
| CC arch/arm64/mm/pageattr.o
| CC arch/arm64/mm/hugetlbpage.o
| from arch/arm64/mm/hugetlbpage.c:10:
| arch/arm64/mm/hugetlbpage.c: In function ‘huge_pte_alloc’:
| ./arch/arm64/include/asm/pgtable-types.h:28:24: warning: dereference of NULL ‘pmdp’ [CWE-690] [-Wanalyzer-null-dereference]
| ./arch/arm64/include/asm/pgtable.h:436:26: note: in expansion of macro ‘pmd_val’
| arch/arm64/mm/hugetlbpage.c:242:10: note: in expansion of macro ‘pte_alloc_map’
| |arch/arm64/mm/hugetlbpage.c:232:10:
| |./arch/arm64/include/asm/pgtable-types.h:28:24:
| ./arch/arm64/include/asm/pgtable.h:436:26: note: in expansion of macro ‘pmd_val’
| arch/arm64/mm/hugetlbpage.c:242:10: note: in expansion of macro ‘pte_alloc_map’
This can only occur when the kernel cannot allocate a page, and so is
unlikely to happen in practice before other systems start failing.
We can avoid this by bailing out if pmd_alloc() fails, as we do earlier
in the function if pud_alloc() fails.
Fixes: 66b3923a1a ("arm64: hugetlb: add support for PTE contiguous bit")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Kyrill Tkachov <kyrylo.tkachov@arm.com>
Cc: <stable@vger.kernel.org> # 4.5.x-
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Currently we check to make sure there is no error state on the extcon
handle for VBUS when writing to the HS_PHY_GENCONFIG_2 register. When using
the USB role-switch API we still need to write to this register absent an
extcon handle.
This patch makes the appropriate update to ensure the write happens if
role-switching is true.
Fixes: 05559f10ed ("usb: chipidea: add role switch class support")
Cc: stable <stable@vger.kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: linux-usb@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Link: https://lore.kernel.org/r/20200507004918.25975-2-peter.chen@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull networking fixes from David Miller:
1) Fix reference count leaks in various parts of batman-adv, from Xiyu
Yang.
2) Update NAT checksum even when it is zero, from Guillaume Nault.
3) sk_psock reference count leak in tls code, also from Xiyu Yang.
4) Sanity check TCA_FQ_CODEL_DROP_BATCH_SIZE netlink attribute in
fq_codel, from Eric Dumazet.
5) Fix panic in choke_reset(), also from Eric Dumazet.
6) Fix VLAN accel handling in bnxt_fix_features(), from Michael Chan.
7) Disallow out of range quantum values in sch_sfq, from Eric Dumazet.
8) Fix crash in x25_disconnect(), from Yue Haibing.
9) Don't pass pointer to local variable back to the caller in
nf_osf_hdr_ctx_init(), from Arnd Bergmann.
10) Wireguard should use the ECN decap helper functions, from Toke
Høiland-Jørgensen.
11) Fix command entry leak in mlx5 driver, from Moshe Shemesh.
12) Fix uninitialized variable access in mptcp's
subflow_syn_recv_sock(), from Paolo Abeni.
13) Fix unnecessary out-of-order ingress frame ordering in macsec, from
Scott Dial.
14) IPv6 needs to use a global serial number for dst validation just
like ipv4, from David Ahern.
15) Fix up PTP_1588_CLOCK deps, from Clay McClure.
16) Missing NLM_F_MULTI flag in gtp driver netlink messages, from
Yoshiyuki Kurauchi.
17) Fix a regression in that dsa user port errors should not be fatal,
from Florian Fainelli.
18) Fix iomap leak in enetc driver, from Dejin Zheng.
19) Fix use after free in lec_arp_clear_vccs(), from Cong Wang.
20) Initialize protocol value earlier in neigh code paths when
generating events, from Roman Mashak.
21) netdev_update_features() must be called with RTNL mutex in macsec
driver, from Antoine Tenart.
22) Validate untrusted GSO packets even more strictly, from Willem de
Bruijn.
23) Wireguard decrypt worker needs a cond_resched(), from Jason
Donenfeld.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (111 commits)
net: flow_offload: skip hw stats check for FLOW_ACTION_HW_STATS_DONT_CARE
MAINTAINERS: put DYNAMIC INTERRUPT MODERATION in proper order
wireguard: send/receive: use explicit unlikely branch instead of implicit coalescing
wireguard: selftests: initalize ipv6 members to NULL to squelch clang warning
wireguard: send/receive: cond_resched() when processing worker ringbuffers
wireguard: socket: remove errant restriction on looping to self
wireguard: selftests: use normal kernel stack size on ppc64
net: ethernet: ti: am65-cpsw-nuss: fix irqs type
ionic: Use debugfs_create_bool() to export bool
net: dsa: Do not leave DSA master with NULL netdev_ops
net: dsa: remove duplicate assignment in dsa_slave_add_cls_matchall_mirred
net: stricter validation of untrusted gso packets
seg6: fix SRH processing to comply with RFC8754
net: mscc: ocelot: ANA_AUTOAGE_AGE_PERIOD holds a value in seconds, not ms
net: dsa: ocelot: the MAC table on Felix is twice as large
net: dsa: sja1105: the PTP_CLK extts input reacts on both edges
selftests: net: tcp_mmap: fix SO_RCVLOWAT setting
net: hsr: fix incorrect type usage for protocol variable
net: macsec: fix rtnl locking issue
net: mvpp2: cls: Prevent buffer overflow in mvpp2_ethtool_cls_rule_del()
...
This patch adds FLOW_ACTION_HW_STATS_DONT_CARE which tells the driver
that the frontend does not need counters, this hw stats type request
never fails. The FLOW_ACTION_HW_STATS_DISABLED type explicitly requests
the driver to disable the stats, however, if the driver cannot disable
counters, it bails out.
TCA_ACT_HW_STATS_* maintains the 1:1 mapping with FLOW_ACTION_HW_STATS_*
except by disabled which is mapped to FLOW_ACTION_HW_STATS_DISABLED
(this is 0 in tc). Add tc_act_hw_stats() to perform the mapping between
TCA_ACT_HW_STATS_* and FLOW_ACTION_HW_STATS_*.
Fixes: 319a1d1947 ("flow_offload: check for basic action hw stats type")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 9b038086f0 ("docs: networking: convert DIM to RST") added a new
file entry to DYNAMIC INTERRUPT MODERATION to the end, and not following
alphabetical order.
So, ./scripts/checkpatch.pl -f MAINTAINERS complains:
WARNING: Misordered MAINTAINERS entry - list file patterns in alphabetic
order
#5966: FILE: MAINTAINERS:5966:
+F: lib/dim/
+F: Documentation/networking/net_dim.rst
Reorder the file entries to keep MAINTAINERS nicely ordered.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Linus Torvalds