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: e986a0d6cb61e02392d3
2022-08-25 11:18:31 +02:00
locking/atomic: Make test_and_*_bit() ordered on failure
2022-08-25 11:18:31 +02:00
lib/vdso: Make __arch_update_vdso_data() logic understandable
2020-03-05 16:43:49 +01:00
mm: make the __PAGETABLE_PxD_FOLDED defines non-empty
2018-11-02 08:31:52 +01:00
include/asm-generic/5level-fixup.h: fix variable 'p4d' set but not used
2019-08-13 16:06:52 -07:00
locking/atomics: Check atomic headers with sha1sum
2019-02-13 08:07:31 +01:00
locking/atomics: Check atomic headers with sha1sum
2019-02-13 08:07:31 +01:00
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36
2019-05-24 17:27:11 +02:00
locking/atomic: Use s64 for atomic64
2019-06-03 12:32:56 +02:00
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36
2019-05-24 17:27:11 +02:00
asm-generic, x86: add bitops instrumentation for KASAN
2019-07-12 11:05:42 -07:00
bug: move WARN_ON() "cut here" into exception handler
2019-09-25 17:51:41 -07:00
asm-generic/nds32: don't redefine cacheflush primitives
2020-01-17 19:48:43 +01:00
asm-generic: Move common compat types to asm-generic/compat.h
2018-08-29 15:42:20 +02:00
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428
2019-06-05 17:37:16 +02:00
asm-generic changes for v5.4
2019-09-17 14:30:30 -07:00
dma-mapping: bypass indirect calls for dma-direct
2018-12-13 21:06:18 +01:00
error-injection: Consolidate override function definition
2019-08-07 13:52:43 +01:00
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36
2019-05-24 17:27:11 +02:00
module: Remove leftover '#undef' from export header
2019-09-12 15:29:46 +02:00
mm: introduce common STRUCT_PAGE_MAX_SHIFT define
2018-12-14 15:05:45 -08:00
binfmt_flat: remove the persistent argument from flat_get_addr_from_rp
2019-06-24 09:16:47 +10:00
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
2019-06-19 17:09:55 +02:00
futex: Cleanup generic SMP variant of arch_futex_atomic_op_inuser()
2019-07-22 11:20:10 +02:00
asm-generic: fix -Wtype-limits compiler warnings
2019-08-03 07:02:01 -07:00
hugetlb: allow to free gigantic pages regardless of the configuration
2019-05-14 09:47:47 -07:00
asm-generic: don't provide __ioremap
2019-08-30 21:46:27 +02:00
iomap: introduce io{read|write}64_{lo_hi|hi_lo}
2019-01-22 13:39:59 +01:00
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
2019-05-30 11:26:32 -07:00
asm-generic: make simd.h a mandatory include/asm header
2019-07-31 21:29:24 +10:00
x86/mpx, mm/core: Fix recursive munmap() corruption
2019-05-09 10:37:17 +02:00
asm-generic/mmiowb: Allow mmiowb_set_pending() when preemptible()
2020-07-29 10:18:40 +02:00
asm-generic/mmiowb: Add generic implementation of mmiowb() tracking
2019-04-08 11:59:39 +01:00
x86/Hyper-V: Report crash data in die() when panic_on_oops is set
2020-04-23 10:36:24 +02:00
asm-generic/page.h: fix typo in #error text requiring a real asm/page.h
2019-02-22 21:53:25 +01:00
percpu: remove PER_CPU_DEF_ATTRIBUTES macro
2018-10-31 08:54:14 -07:00
mm: treewide: clarify pgtable_page_{ctor,dtor}() naming
2019-09-26 10:10:44 -07:00
x86/mm: Validate kernel_physical_mapping_init() PTE population
2018-12-05 09:03:06 +01:00
x86/mm: Validate kernel_physical_mapping_init() PTE population
2018-12-05 09:03:06 +01:00
mm: make the __PAGETABLE_PxD_FOLDED defines non-empty
2018-11-02 08:31:52 +01:00
x86/mm: Validate kernel_physical_mapping_init() PTE population
2018-12-05 09:03:06 +01:00
arch: pgtable: define MAX_POSSIBLE_PHYSMEM_BITS where needed
2020-12-02 08:49:50 +01:00
sched/preempt: Use CONFIG_PREEMPTION where appropriate
2019-07-31 19:03:34 +02:00
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
2019-05-30 11:26:37 -07:00
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
2019-05-30 11:26:37 -07:00
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
2019-05-30 11:26:37 -07:00
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
2019-06-19 17:09:55 +02:00
vmlinux.lds.h: Create section for protection against instrumentation
2021-02-17 10:35:16 +01:00
treewide: remove SPDX "WITH Linux-syscall-note" from kernel-space headers
2019-05-14 19:52:48 -07:00
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36
2019-05-24 17:27:11 +02:00
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193
2019-05-30 11:29:21 -07:00
tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry
2022-04-20 09:19:37 +02:00
include/asm-generic/topology.h: guard cpumask_of_node() macro argument
2020-06-03 08:21:27 +02:00
asm-generic: optimize generic uaccess for 8-byte loads and stores
2019-04-23 21:51:41 +02:00
module/ftrace: handle patchable-function-entry
2022-02-23 11:59:56 +01:00
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 47
2019-05-24 17:27:13 +02:00
d0c4307aea