Hector Martin d0c4307aea locking/atomic: Make test_and_*_bit() ordered on failure ... commit 415d832497098030241605c52ea83d4e2cfa7879 upstream. These operations are documented as always ordered in include/asm-generic/bitops/instrumented-atomic.h, and producer-consumer type use cases where one side needs to ensure a flag is left pending after some shared data was updated rely on this ordering, even in the failure case. This is the case with the workqueue code, which currently suffers from a reproducible ordering violation on Apple M1 platforms (which are notoriously out-of-order) that ends up causing the TTY layer to fail to deliver data to userspace properly under the right conditions. This change fixes that bug. Change the documentation to restrict the "no order on failure" story to the _lock() variant (for which it makes sense), and remove the early-exit from the generic implementation, which is what causes the missing barrier semantics in that case. Without this, the remaining atomic op is fully ordered (including on ARM64 LSE, as of recent versions of the architecture spec). Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: stable@vger.kernel.org Fixes: e986a0d6cb ("locking/atomics, asm-generic/bitops/atomic.h: Rewrite using atomic_*() APIs") Fixes: 61e02392d3 ("locking/atomic/bitops: Document and clarify ordering semantics for failed test_and_{}_bit()") Signed-off-by: Hector Martin <marcan@marcan.st> Acked-by: Will Deacon <will@kernel.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2022-08-25 11:18:31 +02:00
..
ABI	iio: adc: vf610: fix conversion mode sysfs node name	2022-06-29 08:58:47 +02:00
accounting	psi: Fix uaf issue when psi trigger is destroyed while being polled	2022-02-05 12:35:36 +01:00
admin-guide	x86: Handle idle=nomwait cmdline properly for x86_idle	2022-08-25 11:17:28 +02:00
arm	ARM: 9012/1: move device tree mapping out of linear region	2021-05-19 10:08:32 +02:00
arm64	userfaultfd: do not untag user pointers	2021-07-28 13:31:01 +02:00
block	docs: block: null_blk: enhance document style	2019-09-11 16:04:22 -06:00
bpf	bpf/flow_dissector: document flags	2019-07-25 18:00:41 -07:00
cdrom	docs: add some directories to the main documentation index	2019-07-15 11:03:03 -03:00
core-api	XArray: add xas_split	2021-06-10 13:37:14 +02:00
cpu-freq	Documentation: cpufreq: Update policy notifier documentation	2019-09-02 22:44:05 +02:00
crypto	Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6	2019-09-18 12:11:14 -07:00
dev-tools	mm, page_owner: decouple freeing stack trace from debug_pagealloc	2019-10-14 15:04:00 -07:00
devicetree	dt-bindings: arm: qcom: fix MSM8916 MTP compatibles	2022-08-25 11:18:25 +02:00
doc-guide	docs: remove extra conf.py files	2019-07-17 06:57:52 -03:00
driver-api	Documentation: fix firewire.rst ABI file path error	2022-01-27 09:19:52 +01:00
EDID	docs: driver-api: add a series of orphaned documents	2019-07-15 11:03:02 -03:00
fault-injection	docs: add some directories to the main documentation index	2019-07-15 11:03:03 -03:00
fb	fbdev: fix numbering of fbcon options	2020-02-24 08:36:42 +01:00
features	It's a somewhat calmer cycle for docs this time, as the churn of the mass	2019-09-17 16:22:26 -07:00
filesystems	ext4, doc: fix incorrect h_reserved size	2022-04-27 13:50:50 +02:00
firmware_class
firmware-guide	Documentation: ACPI: EINJ: Fix obsolete example	2022-08-25 11:18:21 +02:00
fpga	Documentation: fpga: dfl: add descriptions for virtualization and new interfaces.	2019-09-03 19:35:42 -07:00
gpu	Merge drm/drm-next into drm-intel-next-queued	2019-08-22 00:10:36 -07:00
hid	docs: add some documentation dirs to the driver-api book	2019-07-15 11:03:02 -03:00
hwmon	Revert "hwmon: Make chip parameter for with_info API mandatory"	2022-06-25 12:44:36 +02:00
i2c	docs: i2c: convert to ReST and add to driver-api bookset	2019-07-31 13:25:27 -06:00
ia64	docs: add SPDX tags to new index files	2019-07-15 11:03:03 -03:00
ide	docs: add some directories to the main documentation index	2019-07-15 11:03:03 -03:00
iio	docs: add some documentation dirs to the driver-api book	2019-07-15 11:03:02 -03:00
infiniband	Documentation/infiniband: update name of some functions	2019-09-13 16:55:55 -03:00
input	Input: docs: fix spelling mistake "potocol" -> "protocol"	2019-08-06 11:24:49 -06:00
ioctl	fs-verity: add UAPI header	2019-07-28 16:59:16 -07:00
isdn	docs: isdn: convert to ReST and add to kAPI bookset	2019-07-31 13:30:25 -06:00
kbuild	kbuild: support LLVM=1 to switch the default tools to Clang/LLVM	2020-08-26 10:40:47 +02:00
kernel-hacking	docs: Add documentation for Symbol Namespaces	2019-09-10 10:30:49 +02:00
leds	leds: core: Add support for composing LED class device names	2019-07-25 20:07:52 +02:00
livepatch	docs: add some directories to the main documentation index	2019-07-15 11:03:03 -03:00
locking	doc🔒 remove reference to clever use of read-write lock	2019-09-14 01:53:27 -06:00
m68k	docs: README.buddha: convert to ReST and add to m68k book	2019-07-31 13:30:10 -06:00
maintainer	docs: Fix typo on pull requests guide	2019-08-12 15:14:14 -06:00
media	media: videodev2.h: RGB BT2020 and HSV are always full range	2020-11-05 11:43:15 +01:00
mic	docs: driver-api: add remaining converted dirs to it	2019-07-15 11:03:03 -03:00
mips	Main MIPS changes for v5.4:	2019-09-22 09:30:30 -07:00
misc-devices	Docs: misc: xilinx_sdfec: Add documentation	2019-08-15 17:54:38 +02:00
netlabel	docs: add some directories to the main documentation index	2019-07-15 11:03:03 -03:00
networking	Documentation: fix sctp_wmem in ip-sysctl.rst	2022-08-03 11:59:40 +02:00
nios2	docs: nios2: add it to the main Documentation body	2019-07-31 13:31:51 -06:00
openrisc	docs: openrisc: convert to ReST and add to documentation body	2019-07-31 13:30:20 -06:00
parisc	docs: parisc: convert to ReST and add to documentation body	2019-07-31 13:30:15 -06:00
PCI	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2019-08-27 14:23:31 -07:00
pcmcia	docs: add some directories to the main documentation index	2019-07-15 11:03:03 -03:00
power	Merge branches 'pm-opp', 'pm-qos', 'acpi-pm', 'pm-domains' and 'pm-tools'	2019-09-17 09:49:19 +02:00
powerpc	docs: powerpc: Add missing documentation reference	2019-09-17 23:59:34 +10:00
process	docs: submitting-patches: Fix crossref to 'The canonical patch format'	2022-06-06 08:33:51 +02:00
RCU	Merge branches 'consolidate.2019.08.01b', 'fixes.2019.08.12a', 'lists.2019.08.13a' and 'torture.2019.08.01b' into HEAD	2019-08-13 14:30:30 -07:00
riscv	It's a somewhat calmer cycle for docs this time, as the churn of the mass	2019-09-17 16:22:26 -07:00
s390	Documentation/s390: remove outdated debugging390 documentation	2019-08-21 12:41:43 +02:00
scheduler	sched/fair: Fix low cpu usage with high throttling by removing expiration of cpu-local slices	2019-08-08 09:09:30 +02:00
scsi	scsi: smartpqi: Update attribute name to driver_version	2020-01-17 19:48:27 +01:00
security	Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity	2019-09-27 19:37:27 -07:00
sh	docs: remove extra conf.py files	2019-07-17 06:57:52 -03:00
sound	ALSA: hda/realtek: Add alc256-samsung-headphone fixup	2022-04-15 14:18:25 +02:00
sparc	docs: add arch doc directories to the index	2019-07-15 11:03:01 -03:00
sphinx	tweewide: Fix most Shebang lines	2021-05-22 11:38:30 +02:00
sphinx-static
spi	spi: docs: convert to ReST and add it to the kABI bookset	2019-07-31 14:13:13 -06:00
target	tweewide: Fix most Shebang lines	2021-05-22 11:38:30 +02:00
timers	docs: add some directories to the main documentation index	2019-07-15 11:03:03 -03:00
trace	tracing/histogram: Rename "cpu" to "common_cpu"	2021-07-28 13:31:00 +02:00
translations	doc: arm64: fix grammar dtb placed in no attributes region	2019-09-06 08:44:34 -06:00
usb	USB: rio500: Remove Rio 500 kernel driver	2019-10-04 10:53:36 +02:00
userspace-api	Documentation: seccomp: Fix user notification documentation	2021-06-03 08:59:03 +02:00
virt	KVM: X86: MMU: Use the correct inherited permissions to get shadow page	2021-08-15 13:08:04 +02:00
virtual	cpuidle: add haltpoll governor	2019-07-30 17:27:37 +02:00
vm	arm: remove CONFIG_ARCH_HAS_HOLES_MEMORYMODEL	2022-05-15 19:54:46 +02:00
w1	docs: w1: convert to ReST and add to the kAPI group of docs	2019-07-31 14:16:17 -06:00
watchdog	linux-watchdog 5.4-rc1 tag	2019-09-27 11:17:38 -07:00
x86	x86/CPU/AMD: Save AMD NodeId as cpu_die_id	2020-12-30 11:51:47 +01:00
xtensa	xtensa: fix TLBTEMP area placement	2020-11-24 13:29:22 +01:00
.gitignore
asm-annotations.rst	linkage: Introduce new macros for assembler symbols	2020-11-10 12:37:24 +01:00
atomic_bitops.txt	locking/atomic: Make test_and_*_bit() ordered on failure	2022-08-25 11:18:31 +02:00
atomic_t.txt	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2019-07-08 16:12:03 -07:00
bus-virt-phys-mapping.txt
Changes
CodingStyle
conf.py	docs/conf.py: Cope with removal of language=None in Sphinx 5.0.0	2022-06-14 18:11:49 +02:00
COPYING-logo	docs: logo.txt: rename it to COPYING-logo	2019-07-15 09:20:27 -03:00
crc32.txt
debugging-modules.txt
debugging-via-ohci1394.txt
digsig.txt
DMA-API-HOWTO.txt	docs: DMA-API-HOWTO.txt: fix an unmarked code block	2019-07-15 09:20:24 -03:00
DMA-API.txt	dma-mapping: remove dma_release_declared_memory	2019-09-04 11:13:19 +02:00
DMA-attributes.txt	Reinstate some of "swiotlb: rework "fix info leak with DMA_FROM_DEVICE""	2022-05-25 09:14:38 +02:00
DMA-ISA-LPC.txt
docutils.conf	doc-rst: Add missing newline at end of file	2019-06-20 14:16:56 -06:00
dontdiff	kbuild: create *.mod with full directory path and remove MODVERDIR	2019-07-18 02:19:31 +09:00
futex-requeue-pi.txt
hwspinlock.txt	hwspinlock: add the 'in_atomic' API	2019-06-29 21:08:14 -07:00
index.rst	linkage: Introduce new macros for assembler symbols	2020-11-10 12:37:24 +01:00
io_ordering.txt
io-mapping.txt
IPMI.txt
IRQ-affinity.txt
IRQ-domain.txt
IRQ.txt
irqflags-tracing.txt
Kconfig	docs: Kbuild/Makefile: allow check for missing docs at build time	2019-06-07 11:33:16 -06:00
kobject.txt
kprobes.txt	Merge branch 'parisc-5.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux	2019-05-07 19:34:17 -07:00
kref.txt
logo.gif
lzo.txt	lib/lzo: fix ambiguous encoding bug in lzo-rle	2020-06-17 16:40:28 +02:00
mailbox.txt
Makefile	docs: Kbuild/Makefile: allow check for missing docs at build time	2019-06-07 11:33:16 -06:00
memory-barriers.txt	docs: fix broken doc references due to renames	2019-07-17 06:57:51 -03:00
nommu-mmap.txt
padata.txt	padata: allocate workqueue internally	2019-09-13 21:15:39 +10:00
percpu-rw-semaphore.txt
pi-futex.txt	docs: locking: convert docs to ReST and rename to *.rst	2019-07-15 08:53:27 -03:00
preempt-locking.txt	x86/fpu: Remove fpu__restore()	2019-04-09 19:27:42 +02:00
rbtree.txt	docs: rbtree.txt: fix Sphinx build warnings	2019-07-15 09:20:24 -03:00
remoteproc.txt	remoteproc: add vendor resources handling	2019-06-29 12:02:17 -07:00
robust-futex-ABI.txt
robust-futexes.txt	futex: Update comments and docs about return values of arch futex code	2019-04-26 13:57:55 +01:00
rpmsg.txt
speculation.txt	docs: speculation.txt: mark example blocks as such	2019-04-11 12:37:03 -06:00
static-keys.txt
SubmittingPatches
tee.txt	Documentation: tee: Grammar s/the its/its/	2019-06-07 11:23:38 -06:00
this_cpu_ops.txt
unaligned-memory-access.txt	docs: unaligned-memory-access.txt: use a lowercase title	2019-04-11 12:37:03 -06:00
xz.txt