Paul E. McKenney [Mon, 5 Apr 2021 16:51:05 +0000 (09:51 -0700)]
rcu: Reject RCU_LOCKDEP_WARN() false positives
If another lockdep report runs concurrently with an RCU lockdep report
from RCU_LOCKDEP_WARN(), the following sequence of events can occur:
1. debug_lockdep_rcu_enabled() sees that lockdep is enabled
when called from (say) synchronize_rcu().
2. Lockdep is disabled by a concurrent lockdep report.
3. debug_lockdep_rcu_enabled() evaluates its lockdep-expression
argument, for example, lock_is_held(&rcu_bh_lock_map).
4. Because lockdep is now disabled, lock_is_held() plays it safe and
returns the constant 1.
5. But in this case, the constant 1 is not safe, because invoking
synchronize_rcu() under rcu_read_lock_bh() is disallowed.
6. debug_lockdep_rcu_enabled() wrongly invokes lockdep_rcu_suspicious(),
resulting in a false-positive splat.
This commit therefore changes RCU_LOCKDEP_WARN() to check
debug_lockdep_rcu_enabled() after checking the lockdep expression,
so that any "safe" returns from lock_is_held() are rejected by
debug_lockdep_rcu_enabled(). This requires memory ordering, which is
supplied by READ_ONCE(debug_locks). The resulting volatile accesses
prevent the compiler from reordering and the fact that only one variable
is being accessed prevents the underlying hardware from reordering.
The combination works for IA64, which can reorder reads to the same
location, but this is defeated by the volatile accesses, which compile
to load instructions that provide ordering.
Reported-by: syzbot+dde0cc33951735441301@syzkaller.appspotmail.com Reported-by: Matthew Wilcox <willy@infradead.org> Reported-by: syzbot+88e4f02896967fe1ab0d@syzkaller.appspotmail.com Reported-by: Thomas Gleixner <tglx@linutronix.de> Suggested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Mon, 5 Apr 2021 16:47:59 +0000 (09:47 -0700)]
lockdep: Explicitly flag likely false-positive report
The reason that lockdep_rcu_suspicious() prints the value of debug_locks
is because a value of zero indicates a likely false positive. This can
work, but is a bit obtuse. This commit therefore explicitly calls out
the possibility of a false positive.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
doc: Fix diagram references in memory-ordering document
The three diagrams describing rcu_gp_init() all spuriously refer to
the same figure, probably due to a copy/paste issue. This commit fixes
these references.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
srcu: Remove superfluous ssp initialization for early callbacks
Pre-srcu_init() invocations of call_srcu() initialize the srcu_struct
structure in question, so there is no need to check this initialization
in srcu_init() when initiating grace periods for srcu_struct structures
that had early call_srcu() invocations. This commit therefore drops
the calls to check_init_srcu_struct() in srcu_init().
Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Uladzislau Rezki <urezki@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
srcu: Remove superfluous sdp->srcu_lock_count zero filling
Because alloc_percpu() zeroes out the allocated memory, there is no need
to zero-fill newly allocated per-CPU memory. This commit therefore removes
the loop zeroing the ->srcu_lock_count and ->srcu_unlock_count arrays
from init_srcu_struct_nodes(). This is the only use of that function's
is_static parameter, which this commit also removes.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Uladzislau Rezki <urezki@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 1 Apr 2021 22:26:56 +0000 (15:26 -0700)]
torture: Set kvm.sh language to English
Some of the code invoked directly and indirectly from kvm.sh parses
the output of commands. This parsing assumes English, which can cause
failures if the user has set some other language. In a few cases,
there are language-independent commands available, but this is not
always the case. Therefore, as an alternative to polyglot parsing,
this commit sets the LANG environment variable to en_US.UTF-8.
Reported-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 31 Mar 2021 17:59:05 +0000 (10:59 -0700)]
rcu: Invoke rcu_spawn_core_kthreads() from rcu_spawn_gp_kthread()
Currently, rcu_spawn_core_kthreads() is invoked via an early_initcall(),
which works, except that rcu_spawn_gp_kthread() is also invoked via an
early_initcall() and rcu_spawn_core_kthreads() relies on adjustments to
kthread_prio that are carried out by rcu_spawn_gp_kthread(). There is
no guaranttee of ordering among early_initcall() handlers, and thus no
guarantee that kthread_prio will be properly checked and range-limited
at the time that rcu_spawn_core_kthreads() needs it.
In most cases, this bug is harmless. After all, the only reason that
rcu_spawn_gp_kthread() adjusts the value of kthread_prio is if the user
specified a nonsensical value for this boot parameter, which experience
indicates is rare.
Nevertheless, a bug is a bug. This commit therefore causes the
rcu_spawn_core_kthreads() function to be invoked directly from
rcu_spawn_gp_kthread() after any needed adjustments to kthread_prio have
been carried out.
Fixes: 48d07c04b4cc ("rcu: Enable elimination of Tree-RCU softirq processing") Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Tue, 30 Mar 2021 23:30:32 +0000 (16:30 -0700)]
rcutorture: Judge RCU priority boosting on grace periods, not callbacks
Currently, rcutorture's testing of RCU priority boosting insists not
only that grace periods complete, but also that callbacks be invoked.
Although this is in fact what the user would want, ensuring that there
is sufficient CPU bandwidth devoted to callback execution is in fact
the user's responsibility. One could argue that rcutorture can take on
that responsibility, which is true in theory. But in practice, ensuring
sufficient CPU bandwidth to ksoftirqd, any rcuc kthreads, and any rcuo
kthreads is not particularly consistent with rcutorture's main job,
that of stress-testing RCU. In addition, if the system administrator
(say) makes very poor choices when pinning rcuo kthreads and then runs
rcutorture, there really isn't much rcutorture can do.
Besides, RCU priority boosting only boosts lagging readers, not all the
machinery required to invoke callbacks in a timely fashion.
This commit therefore switches rcutorture's evaluation of RCU priority
boosting from callback execution to grace-period completion by using
the new start_poll_synchronize_rcu() and poll_state_synchronize_rcu()
functions. When rcutorture is built in (as in when there is no innocent
workload to inconvenience), the ksoftirqd ktheads are boosted to real-time
priority 2 in order to allow timeouts to work properly in the face of
rcutorture's testing of RCU priority boosting.
Indeed, it is not as easy as it looks to create a reliable test of RCU
priority boosting without destroying the rest of the kernel!
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Tue, 30 Mar 2021 20:23:49 +0000 (13:23 -0700)]
rcu: Remove the unused rcu_irq_exit_preempt() function
Commit 9ee01e0f69a9 ("x86/entry: Clean up idtentry_enter/exit()
leftovers") left the rcu_irq_exit_preempt() in place in order to avoid
conflicts with the -rcu tree. Now that this change has long since hit
mainline, this commit removes the no-longer-used rcu_irq_exit_preempt()
function.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Fri, 26 Mar 2021 02:39:14 +0000 (19:39 -0700)]
torture: Make kvm-find-errors.sh account for kvm-remote.sh
Currently, kvm-find-errors.sh assumes that if "--buildonly" appears in
the log file, then the run did builds but ran no kernels. This breaks
with kvm-remote.sh, which uses kvm.sh to do a build, then kvm-again.sh
to run the kernels built on remote systems. This commit therefore adds
a check for a kvm-remote.sh run.
While in the area, this commit checks for "--build-only" as well as
"--build-only".
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 25 Mar 2021 00:08:48 +0000 (17:08 -0700)]
rcu-tasks: Make ksoftirqd provide RCU Tasks quiescent states
Heavy networking load can cause a CPU to execute continuously and
indefinitely within ksoftirqd, in which case there will be no voluntary
task switches and thus no RCU-tasks quiescent states. This commit
therefore causes the exiting rcu_softirq_qs() to provide an RCU-tasks
quiescent state.
This of course means that __do_softirq() and its callers cannot be
invoked from within a tracing trampoline.
Reported-by: Toke Høiland-Jørgensen <toke@redhat.com> Tested-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Masami Hiramatsu <mhiramat@kernel.org>
Ingo Molnar [Tue, 23 Mar 2021 05:29:10 +0000 (22:29 -0700)]
rcu: Fix various typos in comments
Fix ~12 single-word typos in RCU code comments.
[ paulmck: Apply feedback from Randy Dunlap. ] Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Fri, 19 Mar 2021 23:30:15 +0000 (16:30 -0700)]
doc: Fix statement of RCU's memory-ordering requirements
The sentence defining the relationship of accesses before a grace
period to read-side accesses following that same grace period was
missing a small word: "not". This commit therefore adds it.
Reported-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The reason is that the object address was not adjusted for the red zone.
With this fix, the backtrace is correct:
/ # cat /proc/meminfo
[ 14.870782] slab kmalloc-64 start c8ab0140 data offset 64 pointer offset 128 size 64 allocated at meminfo_proc_show+0x40/0x4f4
[ 14.871817] meminfo_proc_show+0x40/0x4f4
[ 14.872035] seq_read_iter+0x18c/0x4c4
[ 14.872229] proc_reg_read_iter+0x84/0xac
[ 14.872433] generic_file_splice_read+0xe8/0x17c
[ 14.872621] splice_direct_to_actor+0xb8/0x290
[ 14.872747] do_splice_direct+0xa0/0xe0
[ 14.872896] do_sendfile+0x2d0/0x438
[ 14.873044] sys_sendfile64+0x12c/0x140
[ 14.873229] ret_fast_syscall+0x0/0x58
[ 14.873372] 0xbe861de4
Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Vaneet Narang <v.narang@samsung.com> Signed-off-by: Maninder Singh <maninder1.s@samsung.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 18 Mar 2021 21:00:59 +0000 (14:00 -0700)]
torture: Make the build machine control N in "make -jN"
Given remote rcutorture runs, it is quite possible that the build system
will have fewer CPUs than the system(s) running the actual test scenarios.
In such cases, using the number of CPUs on the test systems can overload
the build system, slowing down the build or, worse, OOMing the build
system. This commit therefore uses the build system's CPU count to set
N in "make -jN", and by tradition sets "N" to double the CPU count.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 17 Mar 2021 20:21:41 +0000 (13:21 -0700)]
torture: Make kvm.sh use abstracted kvm-end-run-stats.sh
This commit reduces duplicate code by making kvm.sh use the new
kvm-end-run-stats.sh script rather than taking its historical approach
of open-coding it.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Frederic Weisbecker [Tue, 23 Feb 2021 00:10:11 +0000 (01:10 +0100)]
rcu/nocb: Unify timers
Now that ->nocb_timer and ->nocb_bypass_timer have become quite similar,
this commit merges them together. A new RCU_NOCB_WAKE_BYPASS wake level
is introduced. As a result, timers perform all kinds of deferred wake
ups but other deferred wakeup callsites only handle non-bypass wakeups
in order not to wake up rcuo too early.
The timer also unconditionally executes a full barrier so as to order
timer_pending() and callback enqueue although the path performing
RCU_NOCB_WAKE_FORCE that makes use of it is debatable. It should also
test against the rdp leader instead of the current rdp.
This unconditional full barrier shouldn't bring visible overhead since
these timers almost never fire.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Frederic Weisbecker [Tue, 23 Feb 2021 00:10:10 +0000 (01:10 +0100)]
rcu/nocb: Prepare for fine-grained deferred wakeup
Tuning the deferred wakeup level must be done from a safe wakeup
point. Currently those sites are:
* ->nocb_timer
* user/idle/guest entry
* CPU down
* softirq/rcuc
All of these sites perform the wake up for both RCU_NOCB_WAKE and
RCU_NOCB_WAKE_FORCE.
In order to merge ->nocb_timer and ->nocb_bypass_timer together, we plan
to add a new RCU_NOCB_WAKE_BYPASS that really should be deferred until
a timer fires so that we don't wake up the NOCB-gp kthread too early.
To prepare for that, this commit specifies the per-callsite wakeup
level/limit.
Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
[ paulmck: Fix non-NOCB rcu_nocb_need_deferred_wakeup() definition. ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Frederic Weisbecker [Tue, 23 Feb 2021 00:10:08 +0000 (01:10 +0100)]
rcu/nocb: Delete bypass_timer upon nocb_gp wakeup
A NOCB-gp wake p can safely delete the ->nocb_bypass_timer because
nocb_gp_wait() will recheck again the bypass state and rearm the bypass
timer if necessary. This commit therefore deletes this timer.
Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Frederic Weisbecker [Tue, 23 Feb 2021 00:10:07 +0000 (01:10 +0100)]
rcu/nocb: Cancel nocb_timer upon nocb_gp wakeup
When waking up in nocb_gp_wait(), there is no need to keep the nocb_timer
around because this function will traverse the whole rdp list. Any
update performed before the timer was armed will now be visible after
the ->nocb_gp_lock acquire.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Frederic Weisbecker [Tue, 23 Feb 2021 00:10:06 +0000 (01:10 +0100)]
rcu/nocb: Allow de-offloading rdp leader
The only thing that prevented an rdp leader from being de-offloaded was
the nocb_bypass_timer that used to lock the nocb_lock of the rdp leader.
If an rdp gets de-offloaded, it will subtlely ignore rcu_nocb_lock()
calls and do its job in the timer unsafely. Worse yet: If it gets
re-offloaded in the middle of the timer, rcu_nocb_unlock() would try to
unlock, leaving it imbalanced.
Now that the nocb_bypass_timer doesn't use the nocb_lock anymore,
de-offloading the rdp leader is now safe. This commit therefore allows
the rdp leader to be de-offloaded.
Reported-by: Paul E. McKenney <paulmck@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Frederic Weisbecker [Tue, 23 Feb 2021 00:10:05 +0000 (01:10 +0100)]
rcu/nocb: Directly call __wake_nocb_gp() from bypass timer
The bypass timer calls __call_rcu_nocb_wake() instead of directly
calling __wake_nocb_gp(). The only difference here is that
rdp->qlen_last_fqs_check gets overriden. But resetting the deferred
force quiescent state base shouldn't be relevant for that timer. In fact
the bypass queue in question can be for any rdp from the group and not
necessarily the rdp leader on which the bypass timer is attached.
This commit therefore calls __wake_nocb_gp() directly. This way we
don't even need to lock the ->nocb_lock.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Frederic Weisbecker [Tue, 23 Feb 2021 00:10:03 +0000 (01:10 +0100)]
rcu/nocb: Use the rcuog CPU's ->nocb_timer
Currently each CPU has its own ->nocb_timer queued when the nocb_gp
wakeup must be deferred. This approach has many drawbacks, compared to
a solution based on a single timer per NOCB group:
* There are a lot of timers to maintain.
* The per-rdp ->nocb_lock must be held to queue and cancel the timer
and this lock can already be heavily contended.
* One timer firing doesn't cancel the other timers in the same group:
- These other timers can thus cause spurious wakeups
- Each rdp that queued a timer must lock both ->nocb_lock and then
->nocb_gp_lock upon exit from the kernel to idle/user/guest mode.
* We can't cancel all of them if we detect an unflushed bypass in
nocb_gp_wait(). In fact currently we only ever cancel the ->nocb_timer
of the leader group.
* The leader group's nocb_timer is cancelled without locking ->nocb_lock
in nocb_gp_wait(). This currently appears to be safe but is an
accident waiting to happen.
* Since the timer acquires ->nocb_lock, it requires extra care in the
NOCB (de-)offloading process, requiring that it be either enabled or
disabled and then flushed.
This commit instead uses the rcuog kthread's CPU's ->nocb_timer instead.
It is protected by nocb_gp_lock, which is _way_ less contended and
remains so even after this change. As a matter of fact, the nocb_timer
almost never fires and the deferred wakeup is mostly carried out upon
idle/user/guest entry. Now the early check performed at this point in
do_nocb_deferred_wakeup() is done on rdp_gp->nocb_defer_wakeup, which
is of course racy. However, this raciness is harmless because we only
need the guarantee that the timer is queued if we were the last one to
queue it. Any other situation (another CPU has queued it and we either
see it or not) is fine.
This solves all the issues listed above.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Sun, 14 Mar 2021 22:19:59 +0000 (15:19 -0700)]
torture: Fix grace-period rate output
The kvm-again.sh script relies on shell comments added to the qemu-cmd
file, but this means that code extracting values from the QEMU command in
this file must grep out those commment. Which kvm-recheck-rcu.sh failed
to do, which destroyed its grace-period-per-second calculation. This
commit therefore adds the needed "grep -v '^#'" to kvm-recheck-rcu.sh.
Fixes: 315957cad445 ("torture: Prepare for splitting qemu execution from kvm-test-1-run.sh") Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Sun, 14 Mar 2021 04:05:31 +0000 (20:05 -0800)]
rcutorture: Abstract read-lock-held checks
This commit adds a (*readlock_held)() function pointer to the
rcu_torture_ops structure in order to make the rcu_torture_one_read()
function's rcu_dereference_check() lockdep expression more appropriate
for a given run.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 11 Mar 2021 02:02:36 +0000 (18:02 -0800)]
refscale: Add acqrel, lock, and lock-irq
This commit adds scale_type of acqrel, lock, and lock-irq to
test acquisition and release. Note that the refscale.nreaders=1
module parameter is required if you wish to test uncontended locking.
In contrast, acqrel uses a per-CPU variable, so should be just fine with
large values of the refscale.nreaders=1 module parameter.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Thomas Gleixner [Tue, 9 Mar 2021 08:55:58 +0000 (09:55 +0100)]
rcu: Prevent false positive softirq warning on RT
Soft interrupt disabled sections can legitimately be preempted or schedule
out when blocking on a lock on RT enabled kernels so the RCU preempt check
warning has to be disabled for RT kernels.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Thomas Gleixner [Tue, 9 Mar 2021 08:55:57 +0000 (09:55 +0100)]
tick/sched: Prevent false positive softirq pending warnings on RT
On RT a task which has soft interrupts disabled can block on a lock and
schedule out to idle while soft interrupts are pending. This triggers the
warning in the NOHZ idle code which complains about going idle with pending
soft interrupts. But as the task is blocked soft interrupt processing is
temporarily blocked as well which means that such a warning is a false
positive.
To prevent that check the per CPU state which indicates that a scheduled
out task has soft interrupts disabled.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Thomas Gleixner [Tue, 9 Mar 2021 08:55:56 +0000 (09:55 +0100)]
softirq: Make softirq control and processing RT aware
Provide a local lock based serialization for soft interrupts on RT which
allows the local_bh_disabled() sections and servicing soft interrupts to be
preemptible.
Provide the necessary inline helpers which allow to reuse the bulk of the
softirq processing code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Thomas Gleixner [Tue, 9 Mar 2021 08:55:55 +0000 (09:55 +0100)]
softirq: Move various protections into inline helpers
To allow reuse of the bulk of softirq processing code for RT and to avoid
#ifdeffery all over the place, split protections for various code sections
out into inline helpers so the RT variant can just replace them in one go.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Thomas Gleixner [Tue, 9 Mar 2021 08:55:54 +0000 (09:55 +0100)]
irqtime: Make accounting correct on RT
vtime_account_irq and irqtime_account_irq() base checks on preempt_count()
which fails on RT because preempt_count() does not contain the softirq
accounting which is seperate on RT.
These checks do not need the full preempt count as they only operate on the
hard and softirq sections.
Use irq_count() instead which provides the correct value on both RT and non
RT kernels. The compiler is clever enough to fold the masking for !RT:
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Thomas Gleixner [Tue, 9 Mar 2021 08:55:53 +0000 (09:55 +0100)]
softirq: Add RT specific softirq accounting
RT requires the softirq processing and local bottomhalf disabled regions to
be preemptible. Using the normal preempt count based serialization is
therefore not possible because this implicitely disables preemption.
RT kernels use a per CPU local lock to serialize bottomhalfs. As
local_bh_disable() can nest the lock can only be acquired on the outermost
invocation of local_bh_disable() and released when the nest count becomes
zero. Tasks which hold the local lock can be preempted so its required to
keep track of the nest count per task.
Add a RT only counter to task struct and adjust the relevant macros in
preempt.h.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Fri, 5 Mar 2021 21:59:54 +0000 (13:59 -0800)]
torture: Add kvm-remote.sh script for distributed rcutorture test runs
This commit adds a kvm-remote.sh script that prepares a tarball that
is then downloaded to the remote system(s) and executed. The user is
responsible for having set up the remote systems to run qemu, but all the
kernel builds are done on the system running the kvm-remote.sh script.
The user is also responsible for setting up the remote systems so that
ssh can be run non-interactively, given that ssh is used to poll the
remote systems in order to detect completion of each batch.
See the script's header comment for usage information.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Fri, 5 Mar 2021 21:15:31 +0000 (13:15 -0800)]
rcuscale: Allow CPU hotplug to be enabled
It is no longer possible to disable CPU hotplug in many configurations,
which means that the CONFIG_HOTPLUG_CPU=n lines in rcuscale's Kconfig
options are just a source of useless diagnostics. In addition, rcuscale
doesn't do CPU-hotplug operations in any case. This commit therefore
changes these lines to read CONFIG_HOTPLUG_CPU=y.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Fri, 5 Mar 2021 21:12:36 +0000 (13:12 -0800)]
refscale: Allow CPU hotplug to be enabled
It is no longer possible to disable CPU hotplug in many configurations,
which means that the CONFIG_HOTPLUG_CPU=n lines in refscale's Kconfig
options are just a source of useless diagnostics. In addition, refscale
doesn't do CPU-hotplug operations in any case. This commit therefore
changes these lines to read CONFIG_HOTPLUG_CPU=y.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
A misspelled git-grep regex revealed that smp_mb__after_spinlock()
was misspelled in explanation.txt. This commit adds the missing "_".
Fixes: 1c27b644c0fd ("Automate memory-barriers.txt; provide Linux-kernel memory model")
[ paulmck: Apply Alan Stern commit-log feedback. ] Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Fri, 5 Mar 2021 01:52:59 +0000 (17:52 -0800)]
torture: Make kvm-again.sh use "scenarios" rather than "batches" file
This commit saves a few lines of code by making kvm-again.sh use the
"scenarios" file rather than the "batches" file, both of which are
generated by kvm.sh.
This results in a break point because new versions of kvm-again.sh cannot
handle "res" directories produced by old versions of kvm.sh, which lack
the "scenarios" file. In the unlikely event that this becomes a problem,
a trivial script suffices to convert the "batches" file to a "scenarios"
file, and this script may be easily extracted from kvm.sh.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Fri, 5 Mar 2021 00:04:09 +0000 (16:04 -0800)]
kcsan: Add pointer to access-marking.txt to data_race() bullet
This commit references tools/memory-model/Documentation/access-marking.txt
in the bullet introducing data_race(). The access-marking.txt file
gives advice on when data_race() should and should not be used.
Suggested-by: Akira Yokosawa <akiyks@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 4 Mar 2021 22:46:59 +0000 (14:46 -0800)]
rcu-tasks: Add block comment laying out RCU Rude design
This commit adds a block comment that gives a high-level overview of
how RCU Rude grace periods progress. It also gives an overview of the
memory ordering.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 4 Mar 2021 22:41:47 +0000 (14:41 -0800)]
rcu-tasks: Add block comment laying out RCU Tasks design
This commit adds a block comment that gives a high-level overview of how
RCU tasks grace periods progress. It also adds a note about how exiting
tasks are handled, plus it gives an overview of the memory ordering.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 4 Mar 2021 22:15:00 +0000 (14:15 -0800)]
torture: Fix remaining erroneous torture.sh instance of $*
Although "eval" was removed from torture.sh, that commit failed to
update the KCSAN instance of $* to "$@". This results in failures when
(for example) --bootargs is given more than one argument. This commit
therefore makes this change.
There is one remaining instance of $* in torture.sh, but this
is used only in the "echo" command, where quoting doesn't matter
so much.
Fixes: 197220d4a334 ("torture: Remove use of "eval" in torture.sh") Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Tue, 22 Dec 2020 21:23:46 +0000 (13:23 -0800)]
clocksource: Do pairwise clock-desynchronization checking
Although smp_call_function() has the advantage of simplicity, using
it to check for cross-CPU clock desynchronization means that any CPU
being slow reduces the sensitivity of the checking across all CPUs.
And it is not uncommon for smp_call_function() latencies to be in the
hundreds of microseconds.
This commit therefore switches to smp_call_function_single(), so that
delays from a given CPU affect only those measurements involving that
particular CPU.
Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mark Rutland <Mark.Rutland@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Reported-by: Chris Mason <clm@fb.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Tue, 22 Dec 2020 01:31:18 +0000 (17:31 -0800)]
clocksource: Provide a module parameter to fuzz per-CPU clock checking
Code that checks for clock desynchronization must itself be tested, so
this commit creates a new clocksource.inject_delay_shift_percpu= kernel
boot parameter that adds or subtracts a large value from the check read,
using the specified bit of the CPU ID to determine whether to add or
to subtract.
Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mark Rutland <Mark.Rutland@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Reported-by: Chris Mason <clm@fb.com>
[ paulmck: Apply Randy Dunlap feedback. ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Mon, 21 Dec 2020 23:40:47 +0000 (15:40 -0800)]
clocksource: Check per-CPU clock synchronization when marked unstable
Some sorts of per-CPU clock sources have a history of going out of
synchronization with each other. However, this problem has purportedy
been solved in the past ten years. Except that it is all too possible
that the problem has instead simply been made less likely, which might
mean that some of the occasional "Marking clocksource 'tsc' as unstable"
messages might be due to desynchronization. How would anyone know?
This commit therefore adds CPU-to-CPU synchronization checking
for newly unstable clocksource that are marked with the new
CLOCK_SOURCE_VERIFY_PERCPU flag. Lists of desynchronized CPUs are
printed, with the caveat that if it is the reporting CPU that is itself
desynchronized, it will appear that all the other clocks are wrong.
Just like in real life.
Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mark Rutland <Mark.Rutland@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Reported-by: Chris Mason <clm@fb.com>
[ paulmck: Add "static" to clocksource_verify_one_cpu() per kernel test robot feedback. ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 17 Dec 2020 01:32:25 +0000 (17:32 -0800)]
clocksource: Retry clock read if long delays detected
When the clocksource watchdog marks a clock as unstable, this might
be due to that clock being unstable or it might be due to delays that
happen to occur between the reads of the two clocks. Yes, interrupts are
disabled across those two reads, but there are no shortage of things that
can delay interrupts-disabled regions of code ranging from SMI handlers
to vCPU preemption. It would be good to have some indication as to why
the clock was marked unstable.
This commit therefore re-reads the watchdog clock on either side of
the read from the clock under test. If the watchdog clock shows an
excessive time delta between its pair of reads, the reads are retried.
The maximum number of retries is specified by a new kernel boot
parameter clocksource.max_read_retries, which defaults to three, that
is, up to four reads, one initial and up to three retries. If retries
were required, a message is printed on the console. If the number of
retries is exceeded, the clock under test will be marked unstable.
However, the probability of this happening due to various sorts of
delays is quite small. In addition, the reason (clock-read delays)
for the unstable marking will be apparent.
Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mark Rutland <Mark.Rutland@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Reported-by: Chris Mason <clm@fb.com>
[ paulmck: Per-clocksource retries per Neeraj Upadhyay feedback. ]
[ paulmck: Don't reset injectfail per Neeraj Upadhyay feedback. ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 17 Dec 2020 00:44:53 +0000 (16:44 -0800)]
clocksource: Provide module parameters to inject delays in watchdog
When the clocksource watchdog marks a clock as unstable, this might be due
to that clock being unstable or it might be due to delays that happen to
occur between the reads of the two clocks. Yes, interrupts are disabled
across those two reads, but there are no shortage of things that can
delay interrupts-disabled regions of code ranging from SMI handlers to
vCPU preemption. It would be good to have some indication as to why
the clock was marked unstable.
The first step is a way of injecting such delays, and this
commit therefore provides a clocksource.inject_delay_freq and
clocksource.inject_delay_run kernel boot parameters that specify that
sufficient delay be injected to cause the clocksource_watchdog()
function to mark a clock unstable. This delay is injected every
Nth set of M calls to clocksource_watchdog(), where N is the value
specified for the inject_delay_freq boot parameter and M is the value
specified for the inject_delay_run boot parameter. Values of zero or
less for either parameter disable delay injection, and the default for
clocksource.inject_delay_freq is zero, that is, disabled. The default for
clocksource.inject_delay_run is the value one, that is single-call runs.
This facility is intended for diagnostic use only, and should be avoided
on production systems.
Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mark Rutland <Mark.Rutland@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Andi Kleen <ak@linux.intel.com>
[ paulmck: Apply Rik van Riel feedback. ] Reported-by: Chris Mason <clm@fb.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Linus Torvalds [Sun, 28 Mar 2021 20:22:54 +0000 (13:22 -0700)]
Merge tag 'perf-tools-fixes-for-v5.12-2020-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux
Pull perf tooling fixes from Arnaldo Carvalho de Melo:
- Avoid write of uninitialized memory when generating PERF_RECORD_MMAP*
records.
- Fix 'perf top' BPF support related crash with perf_event_paranoid=3 +
kptr_restrict.
- Validate raw event with sysfs exported format bits.
- Fix waipid on SIGCHLD delivery bugs in 'perf daemon'.
- Change to use bash for daemon test on Debian, where the default is
dash and thus fails for use of bashisms in this test.
- Fix memory leak in vDSO found using ASAN.
- Remove now useless (due to the fact that BPF now supports static
vars) failing sub test "BPF relocation checker".
- Fix auxtrace queue conflict.
- Sync linux/kvm.h with the kernel sources.
* tag 'perf-tools-fixes-for-v5.12-2020-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
perf test: Change to use bash for daemon test
perf record: Fix memory leak in vDSO found using ASAN
perf test: Remove now useless failing sub test "BPF relocation checker"
perf daemon: Return from kill functions
perf daemon: Force waipid for all session on SIGCHLD delivery
perf top: Fix BPF support related crash with perf_event_paranoid=3 + kptr_restrict
perf pmu: Validate raw event with sysfs exported format bits
perf synthetic events: Avoid write of uninitialized memory when generating PERF_RECORD_MMAP* records
tools headers UAPI: Sync linux/kvm.h with the kernel sources
perf synthetic-events: Fix uninitialized 'kernel_thread' variable
perf auxtrace: Fix auxtrace queue conflict
Linus Torvalds [Sun, 28 Mar 2021 19:19:16 +0000 (12:19 -0700)]
Merge tag 'x86-urgent-2021-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"Two fixes:
- Fix build failure on Ubuntu with new GCC packages that turn
on -fcf-protection
- Fix SME memory encryption PTE encoding bug - AFAICT the code
worked on 4K page sizes (level 1) but had the wrong shift at
higher page level orders (level 2 and higher)"
* tag 'x86-urgent-2021-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/build: Turn off -fcf-protection for realmode targets
x86/mem_encrypt: Correct physical address calculation in __set_clr_pte_enc()
Linus Torvalds [Sun, 28 Mar 2021 19:12:22 +0000 (12:12 -0700)]
Merge tag 'locking-urgent-2021-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fix from Ingo Molnar:
"Fix the non-debug mutex_lock_io_nested() method to map to
mutex_lock_io() instead of mutex_lock().
Right now nothing uses this API explicitly, but this is an
accident waiting to happen"
* tag 'locking-urgent-2021-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/mutex: Fix non debug version of mutex_lock_io_nested()
Linus Torvalds [Sun, 28 Mar 2021 19:06:21 +0000 (12:06 -0700)]
Merge tag '5.12-rc4-smb3' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs fixes from Steve French:
"Five cifs/smb3 fixes, two for stable.
Includes an important fix for encryption and an ACL fix, as well as a
fix for possible reflink data corruption"
* tag '5.12-rc4-smb3' of git://git.samba.org/sfrench/cifs-2.6:
smb3: fix cached file size problems in duplicate extents (reflink)
cifs: Silently ignore unknown oplock break handle
cifs: revalidate mapping when we open files for SMB1 POSIX
cifs: Fix chmod with modefromsid when an older ACE already exists.
cifs: Adjust key sizes and key generation routines for AES256 encryption
Linus Torvalds [Sun, 28 Mar 2021 18:42:05 +0000 (11:42 -0700)]
Merge tag 'io_uring-5.12-2021-03-27' of git://git.kernel.dk/linux-block
Pull io_uring fixes from Jens Axboe:
- Use thread info versions of flag testing, as discussed last week.
- The series enabling PF_IO_WORKER to just take signals, instead of
needing to special case that they do not in a bunch of places. Ends
up being pretty trivial to do, and then we can revert all the special
casing we're currently doing.
- Kill dead pointer assignment
- Fix hashed part of async work queue trace
- Fix sign extension issue for IORING_OP_PROVIDE_BUFFERS
- Fix a link completion ordering regression in this merge window
- Cancellation fixes
* tag 'io_uring-5.12-2021-03-27' of git://git.kernel.dk/linux-block:
io_uring: remove unsued assignment to pointer io
io_uring: don't cancel extra on files match
io_uring: don't cancel-track common timeouts
io_uring: do post-completion chore on t-out cancel
io_uring: fix timeout cancel return code
Revert "signal: don't allow STOP on PF_IO_WORKER threads"
Revert "kernel: freezer should treat PF_IO_WORKER like PF_KTHREAD for freezing"
Revert "kernel: treat PF_IO_WORKER like PF_KTHREAD for ptrace/signals"
Revert "signal: don't allow sending any signals to PF_IO_WORKER threads"
kernel: stop masking signals in create_io_thread()
io_uring: handle signals for IO threads like a normal thread
kernel: don't call do_exit() for PF_IO_WORKER threads
io_uring: maintain CQE order of a failed link
io-wq: fix race around pending work on teardown
io_uring: do ctx sqd ejection in a clear context
io_uring: fix provide_buffers sign extension
io_uring: don't skip file_end_write() on reissue
io_uring: correct io_queue_async_work() traces
io_uring: don't use {test,clear}_tsk_thread_flag() for current
Linus Torvalds [Sun, 28 Mar 2021 18:37:42 +0000 (11:37 -0700)]
Merge tag 'block-5.12-2021-03-27' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
- Fix regression from this merge window with the xarray partition
change, which allowed partition counts that overflow the u8 that
holds the partition number (Ming)
- Fix zone append warning (Johannes)
- Segmentation count fix for multipage bvecs (David)
- Partition scan fix (Chris)
* tag 'block-5.12-2021-03-27' of git://git.kernel.dk/linux-block:
block: don't create too many partitions
block: support zone append bvecs
block: recalculate segment count for multi-segment discards correctly
block: clear GD_NEED_PART_SCAN later in bdev_disk_changed
Linus Torvalds [Sun, 28 Mar 2021 18:34:47 +0000 (11:34 -0700)]
Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"Seven fixes, all in drivers (qla2xxx, mkt3sas, qedi, target,
ibmvscsi).
The most serious are the target pscsi oom and the qla2xxx revert which
can otherwise cause a use after free"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: target: pscsi: Clean up after failure in pscsi_map_sg()
scsi: target: pscsi: Avoid OOM in pscsi_map_sg()
scsi: mpt3sas: Fix error return code of mpt3sas_base_attach()
scsi: qedi: Fix error return code of qedi_alloc_global_queues()
scsi: Revert "qla2xxx: Make sure that aborted commands are freed"
scsi: ibmvfc: Make ibmvfc_wait_for_ops() MQ aware
scsi: ibmvfc: Fix potential race in ibmvfc_wait_for_ops()
Pavel Begunkov [Thu, 25 Mar 2021 18:32:45 +0000 (18:32 +0000)]
io_uring: don't cancel extra on files match
As tasks always wait and kill their io-wq on exec/exit, files are of no
more concern to us, so we don't need to specifically cancel them by hand
in those cases. Moreover we should not, because io_match_task() looks at
req->task->files now, which is always true and so leads to extra
cancellations, that wasn't a case before per-task io-wq.
Pavel Begunkov [Thu, 25 Mar 2021 18:32:44 +0000 (18:32 +0000)]
io_uring: don't cancel-track common timeouts
Don't account usual timeouts (i.e. not linked) as REQ_F_INFLIGHT but
keep behaviour prior to dd59a3d595cc1 ("io_uring: reliably cancel linked
timeouts").
Pavel Begunkov [Thu, 25 Mar 2021 18:32:43 +0000 (18:32 +0000)]
io_uring: do post-completion chore on t-out cancel
Don't forget about io_commit_cqring() + io_cqring_ev_posted() after
exit/exec cancelling timeouts. Both functions declared only after
io_kill_timeouts(), so to avoid tons of forward declarations move
it down.
Before IO threads accepted signals, the freezer using take signals to wake
up an IO thread would cause them to loop without any way to clear the
pending signal. That is no longer the case, so stop special casing
PF_IO_WORKER in the freezer.
The IO threads do allow signals now, including SIGSTOP, and we can allow
ptrace attach. Attaching won't reveal anything interesting for the IO
threads, but it will allow eg gdb to attach to a task with io_urings
and IO threads without complaining. And once attached, it will allow
the usual introspection into regular threads.
Jens Axboe [Fri, 26 Mar 2021 15:05:22 +0000 (09:05 -0600)]
kernel: stop masking signals in create_io_thread()
This is racy - move the blocking into when the task is created and
we're marking it as PF_IO_WORKER anyway. The IO threads are now
prepared to handle signals like SIGSTOP as well, so clear that from
the mask to allow proper stopping of IO threads.
Jens Axboe [Fri, 26 Mar 2021 00:16:06 +0000 (18:16 -0600)]
io_uring: handle signals for IO threads like a normal thread
We go through various hoops to disallow signals for the IO threads, but
there's really no reason why we cannot just allow them. The IO threads
never return to userspace like a normal thread, and hence don't go through
normal signal processing. Instead, just check for a pending signal as part
of the work loop, and call get_signal() to handle it for us if anything
is pending.
With that, we can support receiving signals, including special ones like
SIGSTOP.
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Sat, 27 Mar 2021 07:13:09 +0000 (15:13 +0800)]
block: don't create too many partitions
Commit a33df75c6328 ("block: use an xarray for disk->part_tbl") drops the
check on max supported number of partitionsr, and allows partition with
bigger partition numbers to be added. However, ->bd_partno is defined as
u8, so partition index of xarray table may not match with ->bd_partno.
Then delete_partition() may delete one unmatched partition, and caused
use-after-free.
Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reported-by: syzbot+8fede7e30c7cee0de139@syzkaller.appspotmail.com Fixes: a33df75c6328 ("block: use an xarray for disk->part_tbl") Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Steve French [Fri, 26 Mar 2021 23:41:55 +0000 (18:41 -0500)]
smb3: fix cached file size problems in duplicate extents (reflink)
There were two problems (one of which could cause data corruption)
that were noticed with duplicate extents (ie reflink)
when debugging why various xfstests were being incorrectly skipped
(e.g. generic/138, generic/140, generic/142). First, we were not
updating the file size locally in the cache when extending a
file due to reflink (it would refresh after actimeo expires)
but xfstest was checking the size immediately which was still
0 so caused the test to be skipped. Second, we were setting
the target file size (which could shrink the file) in all cases
to the end of the reflinked range rather than only setting the
target file size when reflink would extend the file.
CC: <stable@vger.kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
Vincent Whitchurch [Fri, 19 Mar 2021 13:57:11 +0000 (14:57 +0100)]
cifs: Silently ignore unknown oplock break handle
Make SMB2 not print out an error when an oplock break is received for an
unknown handle, similar to SMB1. The debug message which is printed for
these unknown handles may also be misleading, so fix that too.
The SMB2 lease break path is not affected by this patch.
Without this, a program which writes to a file from one thread, and
opens, reads, and writes the same file from another thread triggers the
below errors several times a minute when run against a Samba server
configured with "smb2 leases = no".
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Reviewed-by: Tom Talpey <tom@talpey.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
Under SMB1 + POSIX, if an inode is reused on a server after we have read and
cached a part of a file, when we then open the new file with the
re-cycled inode there is a chance that we may serve the old data out of cache
to the application.
This only happens for SMB1 (deprecated) and when posix are used.
The simplest solution to avoid this race is to force a revalidate
on smb1-posix open.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
Shyam Prasad N [Fri, 26 Mar 2021 10:28:16 +0000 (10:28 +0000)]
cifs: Fix chmod with modefromsid when an older ACE already exists.
My recent fixes to cifsacl to maintain inherited ACEs had
regressed modefromsid when an older ACL already exists.
Found testing xfstest 495 with modefromsid mount option
Fixes: f5065508897a ("cifs: Retain old ACEs when converting between mode bits and ACL") Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
Jens Axboe [Fri, 26 Mar 2021 14:57:10 +0000 (08:57 -0600)]
kernel: don't call do_exit() for PF_IO_WORKER threads
Right now we're never calling get_signal() from PF_IO_WORKER threads, but
in preparation for doing so, don't handle a fatal signal for them. The
workers have state they need to cleanup when exiting, so just return
instead of calling do_exit() on their behalf. The threads themselves will
detect a fatal signal and do proper shutdown.
- Fix DM core's zoned model and zone sectors checks.
- Fix spurious "detected capacity change" pr_info() when creating new
DM device.
- Fix DM ioctl out of bounds array access in handling of
DM_LIST_DEVICES_CMD when no devices exist.
* tag 'for-5.12/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm ioctl: fix out of bounds array access when no devices
dm: don't report "detected capacity change" on device creation
dm table: Fix zoned model check and zone sectors check
dm verity: fix DM_VERITY_OPTS_MAX value
Mikulas Patocka [Fri, 26 Mar 2021 18:32:32 +0000 (14:32 -0400)]
dm ioctl: fix out of bounds array access when no devices
If there are not any dm devices, we need to zero the "dev" argument in
the first structure dm_name_list. However, this can cause out of
bounds write, because the "needed" variable is zero and len may be
less than eight.
Fix this bug by reporting DM_BUFFER_FULL_FLAG if the result buffer is
too small to hold the "nl->dev" value.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Linus Torvalds [Fri, 26 Mar 2021 18:33:39 +0000 (11:33 -0700)]
Merge tag 'acpi-5.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI fixes from Rafael Wysocki:
"These fix a memory management regression in ACPICA, repair an ACPI
blacklist entry damaged inadvertently during the 5.11 cycle and fix
the bookkeeping of devices with the same primary device ID in the ACPI
core.
Specifics:
- Make ACPICA use the same object cache consistently when allocating
and freeing objects (Vegard Nossum)
- Add a callback pointer removed inadvertently during the 5.11 cycle
to the ACPI backlight blacklist entry for Sony VPCEH3U1E (Chris
Chiu)
- Make the ACPI device enumeration core use IDA for creating names of
ACPI device objects with the same primary device ID to avoid using
duplicate device object names in some cases (Andy Shevchenko)"
* tag 'acpi-5.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPICA: Always create namespace nodes using acpi_ns_create_node()
ACPI: scan: Use unique number for instance_no
ACPI: video: Add missing callback back for Sony VPCEH3U1E
Linus Torvalds [Fri, 26 Mar 2021 18:29:36 +0000 (11:29 -0700)]
Merge tag 'pm-5.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki:
"These fix an issue related to device links in the runtime PM framework
and debugfs usage in the Energy Model code.
Specifics:
- Modify the runtime PM device suspend to avoid suspending supplier
devices before the consumer device's status changes to
RPM_SUSPENDED (Rafael Wysocki)
- Change the Energy Model code to prevent it from attempting to
create its main debugfs directory too early (Lukasz Luba)"
* tag 'pm-5.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM: EM: postpone creating the debugfs dir till fs_initcall
PM: runtime: Defer suspending suppliers
Linus Torvalds [Fri, 26 Mar 2021 18:19:38 +0000 (11:19 -0700)]
Merge tag 'soc-fixes-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Pull ARM SoC fixes from Arnd Bergmann:
"Too many fixes have accumulated in the soc tree, so this is a fairly
large set. As usual, most of the fixes are for devicetree files, but
there are also notable code changes for imx and omap regressions as
well as some maintainer file updates.
imx:
- Fix an Ethernet issue on imx6ul-14x14-evk board that is caused by
independent PHY reset.
- Add missing `dma-coherent` property for LayerScape device trees to
fix a kernel BUG report.
- Use IRQCHIP_DECLARE for AVIC driver to fix a boot issue on i.MX25
with fw_devlink=on.
- Add missing I2C pinctrl entry for imx8mp-phyboard-pollux-rdk board
to fix the broken I2C GPIO recovery support.
- Add `fsl,use-minimum-ecc` property for imx6ull-myir-mys-6ulx-eval
device tree to fix UBI filesystem mount failure.
at91:
- wrong phy address that blocks Ethernet use on boards with sama5d27
SoM1
- restrictive pin possibilities for sam9x60
omap:
- Fix ocp interconnect bus access error reporting for omap_l3_noc by
setting IRQF_NO_THREAD
- Fix changed mmc slot order regression by adding mmc aliases for
am335x
- Fix smartreflex init regression caused by dropped legacy data
- Fix ti-sysc driver warning on unbind if reset is not deasserted
- Fix flakey reset deassert for dra7 iva
stm32:
- MAINTAINER file updates
broadcom:
- brcmstb SoC ID build fix
- MAINTAINER file updates"
* tag 'soc-fixes-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
MAINTAINERS: Add Alain Volmat as STM32 I2C/SMBUS maintainer
MAINTAINERS: Remove Vincent Abriou for STM/STI DRM drivers.
MAINTAINERS: Update some st.com email addresses to foss.st.com
ARM: dts: imx6ull: fix ubi filesystem mount failed
ARM: imx6ul-14x14-evk: Do not reset the Ethernet PHYs independently
arm64: dts: imx8mp-phyboard-pollux-rdk: Add missing pinctrl entry
arm64: dts: ls1012a: mark crypto engine dma coherent
arm64: dts: ls1043a: mark crypto engine dma coherent
arm64: dts: ls1046a: mark crypto engine dma coherent
ARM: imx: avic: Convert to using IRQCHIP_DECLARE
ARM: dts: at91: sam9x60: fix mux-mask to match product's datasheet
ARM: dts: at91: sam9x60: fix mux-mask for PA7 so it can be set to A, B and C
ARM: dts: at91-sama5d27_som1: fix phy address to 7
soc: ti: omap-prm: Fix occasional abort on reset deassert for dra7 iva
bus: ti-sysc: Fix warning on unbind if reset is not deasserted
ARM: OMAP2+: Fix smartreflex init regression after dropping legacy data
soc: ti: omap-prm: Fix reboot issue with invalid pcie reset map for dra7
MAINTAINERS: rectify BROADCOM PMB (POWER MANAGEMENT BUS) DRIVER
ARM: dts: am33xx: add aliases for mmc interfaces
bus: omap_l3_noc: mark l3 irqs as IRQF_NO_THREAD
Linus Torvalds [Fri, 26 Mar 2021 18:15:25 +0000 (11:15 -0700)]
Merge tag 'for-linus-5.12b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross:
"This contains a small series with a more elegant fix of a problem
which was originally fixed in rc2"
* tag 'for-linus-5.12b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
Revert "xen: fix p2m size in dom0 for disabled memory hotplug case"
xen/x86: make XEN_BALLOON_MEMORY_HOTPLUG_LIMIT depend on MEMORY_HOTPLUG
Linus Torvalds [Fri, 26 Mar 2021 18:05:18 +0000 (11:05 -0700)]
Merge tag 'drm-fixes-2021-03-26' of git://anongit.freedesktop.org/drm/drm
Pull drm fixes from Dave Airlie:
"As expected last week things were overly quiet so this week things
seem to have caught up. It still isn't too major.
msm and amdgpu lead the size here, the msm fixes are pretty varied
across the driver, the amdgpu one is mostly the S0ix fixes with some
other minor ones. Otherwise there are a few i915 fixes and one each
for nouveau, etnaviv and rcar-du.
i915:
- DisplayPort LTTPR fixes around link training and limiting it
according to supported spec version.
- Fix enabled_planes bitmask to really represent only logically
enabled planes.
- Fix DSS CTL registers for ICL DSI transcoders
- Fix the GT fence revocation runtime PM logic.
nouveau:
- cursor size regression fix
amdgpu:
- S0ix fixes
- Add PCI ID
- Polaris PCIe DPM fix
- Display fix for high refresh rate monitors"
* tag 'drm-fixes-2021-03-26' of git://anongit.freedesktop.org/drm/drm: (37 commits)
drm/nouveau/kms/nve4-nv108: Limit cursors to 128x128
drm/i915: Fix the GT fence revocation runtime PM logic
drm/amdgpu/display: restore AUX_DPHY_TX_CONTROL for DCN2.x
drm/amdgpu: Add additional Sienna Cichlid PCI ID
drm/amd/pm: workaround for audio noise issue
drm/i915/dsc: fix DSS CTL register usage for ICL DSI transcoders
drm/i915: Fix enabled_planes bitmask
drm/i915: Disable LTTPR support when the LTTPR rev < 1.4
drm/i915: Disable LTTPR support when the DPCD rev < 1.4
drm/i915/ilk-glk: Fix link training on links with LTTPRs
drm/msm/disp/dpu1: icc path needs to be set before dpu runtime resume
drm/amdgpu: skip kfd suspend/resume for S0ix
drm/amdgpu: drop S0ix checks around CG/PG in suspend
drm/amdgpu: skip CG/PG for gfx during S0ix
drm/amdgpu: update comments about s0ix suspend/resume
drm/amdgpu/swsmu: skip gfx cgpg on s0ix suspend
drm/amdgpu: re-enable suspend phase 2 for S0ix
drm/amdgpu: move s0ix check into amdgpu_device_ip_suspend_phase2 (v3)
drm/amdgpu: clean up non-DC suspend/resume handling
drm/amdgpu: don't evict vram on APUs for suspend to ram (v4)
...
Shyam Prasad N [Thu, 25 Mar 2021 12:34:54 +0000 (12:34 +0000)]
cifs: Adjust key sizes and key generation routines for AES256 encryption
For AES256 encryption (GCM and CCM), we need to adjust the size of a few
fields to 32 bytes instead of 16 to accommodate the larger keys.
Also, the L value supplied to the key generator needs to be changed from
to 256 when these algorithms are used.
Keeping the ioctl struct for dumping keys of the same size for now.
Will send out a different patch for that one.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> CC: <stable@vger.kernel.org> # v5.10+ Signed-off-by: Steve French <stfrench@microsoft.com>
Leo Yan [Sat, 20 Mar 2021 10:45:54 +0000 (18:45 +0800)]
perf test: Change to use bash for daemon test
When executing the daemon test on Arm64 and x86 with Debian (Buster)
distro, both skip the test case with the log:
# ./perf test -v 76
76: daemon operations :
--- start ---
test child forked, pid 11687
test daemon list
trap: SIGINT: bad trap
./tests/shell/daemon.sh: 173: local: cpu-clock: bad variable name
test child finished with -2
---- end ----
daemon operations: Skip
So the error happens for the variable expansion when use local variable
in the shell script. Since Debian Buster uses dash but not bash as
non-interactive shell, when execute the daemon testing, it hits a known
issue for dash which was reported [1].
To resolve this issue, one option is to add double quotes for all local
variables assignment, so need to change the code from:
local line=`perf daemon --config ${config} -x: | head -2 | tail -1`
... to:
local line="`perf daemon --config ${config} -x: | head -2 | tail -1`"
But the testing script has bunch of local variables, this leads to big
changes for whole script.
On the other hand, the testing script asks to use the "local" feature
which is bash-specific, so this patch explicitly uses "#!/bin/bash" to
ensure running the script with bash.
After:
# ./perf test -v 76
76: daemon operations :
--- start ---
test child forked, pid 11329
test daemon list
test daemon reconfig
test daemon stop
test daemon signal
signal 12 sent to session 'test [11596]'
signal 12 sent to session 'test [11596]'
test daemon ping
test daemon lock
test child finished with 0
---- end ----
daemon operations: Ok
Linus Torvalds [Thu, 25 Mar 2021 23:46:43 +0000 (16:46 -0700)]
Merge tag 'integrity-v5.12-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull integrity fix from Mimi Zohar:
"Just one patch to address a NULL ptr dereferencing when there is a
mismatch between the user enabled LSMs and IMA/EVM"
* tag 'integrity-v5.12-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
integrity: double check iint_cache was initialized
Linus Torvalds [Thu, 25 Mar 2021 22:38:22 +0000 (15:38 -0700)]
Merge tag 'for-5.12-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"Fixes for issues that have some user visibility and are simple enough
for this time of development cycle:
- a few fixes for rescue= mount option, adding more checks for
missing trees
- fix sleeping in atomic context on qgroup deletion
- fix subvolume deletion on mount
- fix build with M= syntax
- fix checksum mismatch error message for direct io"
* tag 'for-5.12-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix check_data_csum() error message for direct I/O
btrfs: fix sleep while in non-sleep context during qgroup removal
btrfs: fix subvolume/snapshot deletion not triggered on mount
btrfs: fix build when using M=fs/btrfs
btrfs: do not initialize dev replace for bad dev root
btrfs: initialize device::fs_info always
btrfs: do not initialize dev stats if we have no dev_root
btrfs: zoned: remove outdated WARN_ON in direct IO
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