Paul E. McKenney
1f3ebc8253
rcu: Restore barrier() to rcu_read_lock() and rcu_read_unlock()
...
Commit bb73c52bad ("rcu: Don't disable preemption for Tiny and Tree
RCU readers") removed the barrier() calls from rcu_read_lock() and
rcu_write_lock() in CONFIG_PREEMPT=n&&CONFIG_PREEMPT_COUNT=n kernels.
Within RCU, this commit was OK, but it failed to account for things like
get_user() that can pagefault and that can be reordered by the compiler.
Lack of the barrier() calls in rcu_read_lock() and rcu_read_unlock()
can cause these page faults to migrate into RCU read-side critical
sections, which in CONFIG_PREEMPT=n kernels could result in too-short
grace periods and arbitrary misbehavior. Please see commit 386afc9114
("spinlocks and preemption points need to be at least compiler barriers")
and Linus's commit 66be4e66a7 ("rcu: locking and unlocking need to
always be at least barriers"), this last of which restores the barrier()
call to both rcu_read_lock() and rcu_read_unlock().
This commit removes barrier() calls that are no longer needed given that
the addition of them in Linus's commit noted above. The combination of
this commit and Linus's commit effectively reverts commit bb73c52bad
("rcu: Don't disable preemption for Tiny and Tree RCU readers").
Reported-by: Herbert Xu <herbert@gondor.apana.org.au>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
[ paulmck: Fix embarrassing typo located by Alan Stern. ]
2019-08-01 14:05:51 -07:00
..
bpf
Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2019-07-20 10:45:15 -07:00
cgroup
Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2019-07-19 10:42:02 -07:00
configs
debug
treewide: Add SPDX license identifier - Makefile/Kconfig
2019-05-21 10:50:46 +02:00
dma
dma-mapping fixes for 5.3-rc1
2019-07-20 12:09:52 -07:00
events
perf/core: Fix creating kernel counters for PMUs that override event->cpu
2019-07-25 15:41:31 +02:00
gcov
gcov: no need to check return value of debugfs_create functions
2019-06-03 16:18:12 +02:00
irq
Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2019-07-08 11:22:57 -07:00
livepatch
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching
2019-07-11 15:30:05 -07:00
locking
lockdep: Make print_lock() address visible
2019-08-01 14:05:51 -07:00
power
pci-v5.3-changes
2019-07-15 20:44:49 -07:00
printk
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13
2019-05-21 11:28:45 +02:00
rcu
rcu: Restore barrier() to rcu_read_lock() and rcu_read_unlock()
2019-08-01 14:05:51 -07:00
sched
time/tick-broadcast: Fix tick_broadcast_offline() lockdep complaint
2019-08-01 14:05:51 -07:00
time
timekeeping/vsyscall: Use __iter_div_u64_rem()
2019-07-10 20:37:49 +02:00
trace
Eiichi Tsukata found a small bug from the fixup of the stack code
2019-07-19 12:18:46 -07:00
.gitignore
Provide in-kernel headers to make extending kernel easier
2019-04-29 16:48:03 +02:00
acct.c
acct_on(): don't mess with freeze protection
2019-04-04 21:04:13 -04:00
async.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441
2019-06-05 17:37:17 +02:00
audit.c
audit/stable-5.3 PR 20190702
2019-07-08 18:55:42 -07:00
audit.h
audit/stable-5.3 PR 20190702
2019-07-08 18:55:42 -07:00
audit_fsnotify.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
2019-05-30 11:26:37 -07:00
audit_tree.c
fsnotify: switch send_to_group() and ->handle_event to const struct qstr *
2019-04-26 13:51:03 -04:00
audit_watch.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
2019-05-30 11:26:35 -07:00
auditfilter.c
audit/stable-5.3 PR 20190702
2019-07-08 18:55:42 -07:00
auditsc.c
audit: enforce op for string fields
2019-05-28 17:46:43 -04:00
backtracetest.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441
2019-06-05 17:37:17 +02:00
bounds.c
capability.c
compat.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
2019-06-19 17:09:55 +02:00
configs.c
kernel/configs: use .incbin directive to embed config_data.gz
2019-03-07 18:32:02 -08:00
context_tracking.c
treewide: Add SPDX license identifier for missed files
2019-05-21 10:50:45 +02:00
cpu.c
Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2019-07-08 10:39:56 -07:00
cpu_pm.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282
2019-06-05 17:36:37 +02:00
crash_core.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 230
2019-06-19 17:09:06 +02:00
crash_dump.c
treewide: Add SPDX license identifier for missed files
2019-05-21 10:50:45 +02:00
cred.c
Merge branch 'access-creds'
2019-07-25 08:36:29 -07:00
delayacct.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 25
2019-05-21 11:52:39 +02:00
dma.c
elfcore.c
exec_domain.c
exit.c
pidfd: fix a poll race when setting exit_state
2019-07-22 16:02:03 +02:00
extable.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
2019-05-30 11:26:35 -07:00
fail_function.c
fail_function: no need to check return value of debugfs_create functions
2019-06-03 15:49:06 +02:00
fork.c
sched/fair: Don't free p->numa_faults with concurrent readers
2019-07-25 15:37:04 +02:00
freezer.c
treewide: Add SPDX license identifier for missed files
2019-05-21 10:50:45 +02:00
futex.c
Linux 5.2-rc3
2019-06-03 11:50:18 +02:00
gen_kheaders.sh
kheaders: include only headers into kheaders_data.tar.xz
2019-07-09 10:10:52 +09:00
groups.c
hung_task.c
treewide: Add SPDX license identifier for missed files
2019-05-21 10:50:45 +02:00
iomem.c
mm/nvdimm: add is_ioremap_addr and use that to check ioremap address
2019-07-12 11:05:40 -07:00
irq_work.c
treewide: Add SPDX license identifier for missed files
2019-05-21 10:50:45 +02:00
jump_label.c
jump_label: Batch updates if arch supports it
2019-06-17 12:09:22 +02:00
kallsyms.c
treewide: Add SPDX license identifier for missed files
2019-05-21 10:50:45 +02:00
kcmp.c
Kconfig.freezer
treewide: Add SPDX license identifier - Makefile/Kconfig
2019-05-21 10:50:46 +02:00
Kconfig.hz
treewide: Add SPDX license identifier - Makefile/Kconfig
2019-05-21 10:50:46 +02:00
Kconfig.locks
treewide: Add SPDX license identifier - Makefile/Kconfig
2019-05-21 10:50:46 +02:00
Kconfig.preempt
sched/rt, Kconfig: Unbreak def/oldconfig with CONFIG_PREEMPT=y
2019-07-22 18:05:11 +02:00
kcov.c
kcov: convert kcov.refcount to refcount_t
2019-03-07 18:32:02 -08:00
kexec.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 230
2019-06-19 17:09:06 +02:00
kexec_core.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 230
2019-06-19 17:09:06 +02:00
kexec_file.c
Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
2019-07-08 20:28:59 -07:00
kexec_internal.h
kheaders.c
kheaders: Move from proc to sysfs
2019-05-24 20:16:01 +02:00
kmod.c
kprobes.c
The main changes in this release include:
2019-07-18 11:51:00 -07:00
ksysfs.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 170
2019-05-30 11:26:39 -07:00
kthread.c
treewide: Add SPDX license identifier for missed files
2019-05-21 10:50:45 +02:00
latencytop.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441
2019-06-05 17:37:17 +02:00
Makefile
kheaders: Move from proc to sysfs
2019-05-24 20:16:01 +02:00
memremap.c
mm/devm_memremap_pages: enable sub-section remap
2019-07-18 17:08:07 -07:00
module-internal.h
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36
2019-05-24 17:27:11 +02:00
module.c
Modules updates for v5.3
2019-07-18 12:06:57 -07:00
module_signing.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36
2019-05-24 17:27:11 +02:00
notifier.c
treewide: Add SPDX license identifier for missed files
2019-05-21 10:50:45 +02:00
nsproxy.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441
2019-06-05 17:37:17 +02:00
padata.c
padata: use smp_mb in padata_reorder to avoid orphaned padata jobs
2019-07-18 13:39:54 +08:00
panic.c
docs: admin-guide: move sysctl directory to it
2019-07-15 11:03:01 -03:00
params.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
2019-05-30 11:26:35 -07:00
pid.c
kernel/pid.c: convert struct pid count to refcount_t
2019-07-16 19:23:24 -07:00
pid_namespace.c
proc/sysctl: add shared variables for range check
2019-07-18 17:08:07 -07:00
profile.c
treewide: Add SPDX license identifier for missed files
2019-05-21 10:50:45 +02:00
ptrace.c
ptrace: add PTRACE_GET_SYSCALL_INFO request
2019-07-16 19:23:24 -07:00
range.c
reboot.c
treewide: Add SPDX license identifier for missed files
2019-05-21 10:50:45 +02:00
relay.c
Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2019-03-12 13:27:20 -07:00
resource.c
resource: avoid unnecessary lookups in find_next_iomem_res()
2019-07-18 17:08:06 -07:00
rseq.c
signal: Remove task parameter from force_sig
2019-05-27 09:36:28 -05:00
seccomp.c
signal: Remove the signal number and task parameters from force_sig_info
2019-05-29 09:31:44 -05:00
signal.c
signal: simplify set_user_sigmask/restore_user_sigmask
2019-07-16 19:23:24 -07:00
smp.c
smp: Warn on function calls from softirq context
2019-07-20 11:27:16 +02:00
smpboot.c
treewide: Add SPDX license identifier for missed files
2019-05-21 10:50:45 +02:00
smpboot.h
softirq.c
Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2019-07-08 11:01:13 -07:00
stackleak.c
stacktrace.c
stacktrace: Force USER_DS for stack_trace_save_user()
2019-07-18 16:47:24 +02:00
stop_machine.c
processor: get rid of cpu_relax_yield
2019-06-15 12:25:55 +02:00
sys.c
prctl_set_mm: downgrade mmap_sem to read lock
2019-06-01 15:51:31 -07:00
sys_ni.c
arch: handle arches who do not yet define clone3
2019-06-21 01:54:53 +02:00
sysctl.c
proc/sysctl: add shared variables for range check
2019-07-18 17:08:07 -07:00
sysctl_binary.c
task_work.c
taskstats.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
2019-05-30 11:26:37 -07:00
test_kprobes.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 25
2019-05-21 11:52:39 +02:00
torture.c
torture: Allow inter-stutter interval to be specified
2019-05-28 09:06:09 -07:00
tracepoint.c
The main changes in this release include:
2019-07-18 11:51:00 -07:00
tsacct.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
2019-05-30 11:26:37 -07:00
ucount.c
proc/sysctl: add shared variables for range check
2019-07-18 17:08:07 -07:00
uid16.c
uid16.h
umh.c
treewide: Add SPDX license identifier for missed files
2019-05-21 10:50:45 +02:00
up.c
smp: Remove smp_call_function() and on_each_cpu() return values
2019-06-23 14:26:26 +02:00
user-return-notifier.c
treewide: Add SPDX license identifier for missed files
2019-05-21 10:50:45 +02:00
user.c
Keyrings namespacing
2019-07-08 19:36:47 -07:00
user_namespace.c
Keyrings namespacing
2019-07-08 19:36:47 -07:00
utsname.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441
2019-06-05 17:37:17 +02:00
utsname_sysctl.c
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441
2019-06-05 17:37:17 +02:00
watchdog.c
watchdog: Fix typo in comment
2019-04-18 14:05:51 +02:00
watchdog_hld.c
kernel/watchdog_hld.c: hard lockup message should end with a newline
2019-04-19 09:46:05 -07:00
workqueue.c
workqueue: Remove GPF argument from alloc_workqueue_attrs()
2019-06-27 14:12:19 -07:00
workqueue_internal.h
sched/core, workqueues: Distangle worker accounting from rq lock
2019-04-16 16:55:15 +02:00