Context tracking's state and dynticks counter are going to be merged
in a single field so that both updates can happen atomically and at the
same time. Prepare for that with converting the state into an atomic_t.
[ paulmck: Apply kernel test robot feedback. ]
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Some eqs functions are now only used internally by context tracking, so
their public declarations can be removed.
Also middle functions such as rcu_user_*() and rcu_idle_*()
which now directly call to rcu_eqs_enter() and rcu_eqs_exit() can be
wiped out as well.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Move the core RCU eqs/dynticks functions to context tracking so that
we can later merge all that code within context tracking.
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
To prepare for migrating the RCU eqs accounting code to context tracking,
split the last-resort deferred nocb resched from rcu_user_enter() and
move it into a separate call from context tracking.
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
The RCU eqs tracking is going to be performed by the context tracking
subsystem. The related nesting counters thus need to be moved to the
context tracking structure.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
The RCU eqs tracking is going to be performed by the context tracking
subsystem. The related nesting counters thus need to be moved to the
context tracking structure.
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
In order to prepare for merging RCU dynticks counter into the context
tracking state, move the rcu_data's dynticks field to the context
tracking structure. It will later be mixed within the context tracking
state itself.
[ paulmck: Move enum ctx_state into global scope. ]
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Now rcu_irq_enter/exit() is an unnecessary middle call between
ct_irq_enter/exit() and nmi_irq_enter/exit(). Take this opportunity
to remove the former functions and move the comments above them to the
new entrypoints.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
The RCU dynticks counter is going to be merged into the context tracking
subsystem. Prepare with moving the NMI extended quiescent states
entrypoints to context tracking. For now those are dumb redirection to
existing RCU calls.
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
The RCU dynticks counter is going to be merged into the context tracking
subsystem. Prepare with moving the IRQ extended quiescent states
entrypoints to context tracking. For now those are dumb redirection to
existing RCU calls.
[ paulmck: Apply Stephen Rothwell feedback from -next. ]
[ paulmck: Apply Nathan Chancellor feedback. ]
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
The RCU dynticks counter is going to be merged into the context tracking
subsystem. Start with moving the idle extended quiescent states
entrypoints to context tracking. For now those are dumb redirections to
existing RCU calls.
[ paulmck: Apply kernel test robot feedback. ]
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Context tracking is going to be used not only to track user transitions
but also idle/IRQs/NMIs. The user tracking part will then become a
separate feature. Prepare Kconfig for that.
[ frederic: Apply Max Filippov feedback. ]
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
context_tracking_cpu_set() is called in order to tell a CPU to track
user/kernel transitions. Since context tracking is going to expand in
to also track transitions from/to idle/IRQ/NMIs, the scope
of this function name becomes too broad and needs to be made more
specific. Also shorten the prefix to align with the new namespace.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
context_tracking_enter() and context_tracking_exit() have confusing
names that don't explain the fact they are referring to user/guest state.
Use more self-explanatory names and shrink to the new context tracking
prefix instead.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
context_tracking_user_enter() and context_tracking_user_exit() are
ASM callable versions of user_enter() and user_exit() for architectures
that didn't manage to check the context tracking static key from ASM.
Change those function names to better reflect their purpose.
[ frederic: Apply Max Filippov feedback. ]
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
The context tracking namespace is going to expand and some new functions
will require even longer names. Start shrinking the context_tracking
prefix to "ct" as is already the case for some existing macros, this
will make the introduction of new functions easier.
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Some context tracking functions enter or exit into/from RCU idle mode
while using trace-able and lockdep-aware IRQs (un-)masking. As a result
those functions can't get tagged as noinstr. This is unlikely to be
fixed since these are obsolete APIs. Drop a note about this matter.
[ paulmck: Apply Peter Zijlstra feedback. ]
Reported-by: Peter Zijlstra <peterz@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
This commit applies the "noinstr" tag to the rcu_idle_enter() and
rcu_idle_exit() functions, which are invoked from portions of the idle
loop that cannot be instrumented. These tags require reworking the
rcu_eqs_enter() and rcu_eqs_exit() functions that these two functions
invoke in order to cause them to use normal assertions rather than
lockdep. In addition, within rcu_idle_exit(), the raw versions of
local_irq_save() and local_irq_restore() are used, again to avoid issues
with lockdep in uninstrumented code.
This patch is based in part on an earlier patch by Jiri Olsa, discussions
with Peter Zijlstra and Frederic Weisbecker, earlier changes by Thomas
Gleixner, and off-list discussions with Yonghong Song.
Link: https://lore.kernel.org/lkml/20220515203653.4039075-1-jolsa@kernel.org/
Reported-by: Jiri Olsa <jolsa@kernel.org>
Reported-by: Alexei Starovoitov <ast@kernel.org>
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Yonghong Song <yhs@fb.com>
If the rcutree.use_softirq kernel boot parameter is disabled, then it is
possible that a RCU CPU stall is due to the rcuc kthreads being starved of
CPU time. There is currently no easy way to infer this from the RCU CPU
stall warning output. This commit therefore adds a string of the form "
rcuc=%ld jiffies(starved)" to a given CPU's output if the corresponding
rcuc kthread has been starved for more than two seconds.
[ paulmck: Eliminate extraneous space characters. ]
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
balance_push(). sched_setscheduler() spliced the balance callbacks accross
a lock break which makes an interleaving schedule() observe an empty list.
-----BEGIN PGP SIGNATURE-----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=k54w
-----END PGP SIGNATURE-----
Merge tag 'sched-urgent-2022-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Thomas Gleixner:
"A single scheduler fix plugging a race between sched_setscheduler()
and balance_push().
sched_setscheduler() spliced the balance callbacks accross a lock
break which makes it possible for an interleaving schedule() to
observe an empty list"
* tag 'sched-urgent-2022-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Fix balance_push() vs __sched_setscheduler()
worked until prandom_u32() was switched to the real random generator, which
takes a spinlock for extraction, which does not work on RT when invoked
from atomic contexts. lockdep has no requirement for real random numbers
and it turns out sched_clock() is good enough to create the cookie. That
works everywhere and is faster.
-----BEGIN PGP SIGNATURE-----
iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmKvHPcTHHRnbHhAbGlu
dXRyb25peC5kZQAKCRCmGPVMDXSYoW73D/9fVCl4iwazRZQ/srOivetw1tT1LVvV
v4HZpwjKbmokXf4Y9XMb0IvLJQro8Qr+YHkmEdZ3gpPWskYOcYpUko9TLgm5NKlH
T5PLqXa9mjMfBP1cHQETKUe/fFvNzwj2sp4QX4/Iydu/VrZRgeID4EDZuByz7Vyn
fGYIC7W2ADugxdFAQ0/Zswf5N+Dfyd2T0+5AYcfkxhBJZNnYiInzE5ae+6sLPsO9
h4mE5+nw6sNGNTZ4IHcr8Ff9V8ppxBMbOqFWaEa0nvnnnH483GzXRbXsdjFrAtNz
GoJuDhhNmkVAO49wnCGIt755w7Ay1mFG1IjP4jxDWAwQGd1z/sY3PIZtqUPtB6Ou
ldVApDJvS3wVB6rxEcoRjuZ6xgbA/6W6tPJ+KIP4Gbwgwm1Y8TekS2Qzc5BNqS9I
AuXB6CFWxRZj4078ZwYM59ctKi8dOrGp7VRbU+J/xPZ7KcFvItzuCyITSoHOAg+S
0RH3mZdggqIRViv25WYpr93+yS6yYzwZxhIVJ3H6IxHAqM0JGac8WjTDozGqbBI2
GT7UX+1tngHSM+U9t1VZSC44omeBI7j3ZWh2V3OELhqP4xdUr1QXk5/MNGgYMXlt
yqqfvVx4qCP7yIH9adwb++jkicbQbvrdICJL/gouW6zL03JWVv5zPZ+LUm4dss9o
BvtiF6tjaOkWsA==
=iuyB
-----END PGP SIGNATURE-----
Merge tag 'locking-urgent-2022-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull lockdep fix from Thomas Gleixner:
"A RT fix for lockdep.
lockdep invokes prandom_u32() to create cookies. This worked until
prandom_u32() was switched to the real random generator, which takes a
spinlock for extraction, which does not work on RT when invoked from
atomic contexts.
lockdep has no requirement for real random numbers and it turns out
sched_clock() is good enough to create the cookie. That works
everywhere and is faster"
* tag 'locking-urgent-2022-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/lockdep: Use sched_clock() for random numbers
-----BEGIN PGP SIGNATURE-----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=iiXX
-----END PGP SIGNATURE-----
Merge tag 'printk-for-5.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk fixes from Petr Mladek:
"Make the global console_sem available for CPU that is handling panic()
or shutdown.
This is an old problem when an existing console lock owner might block
console output, but it became more visible with the kthreads"
* tag 'printk-for-5.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
printk: Wait for the global console lock when the system is going down
printk: Block console kthreads when direct printing will be required
-----BEGIN PGP SIGNATURE-----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=K9Im
-----END PGP SIGNATURE-----
Merge tag 'audit-pr-20220616' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit
Pull audit fix from Paul Moore:
"A single audit patch to fix a problem where we were not properly
freeing memory allocated when recording information related to a
module load"
* tag 'audit-pr-20220616' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
audit: free module name
Reset the type of the record last as the helper `audit_free_module()`
depends on it.
unreferenced object 0xffff888153b707f0 (size 16):
comm "modprobe", pid 1319, jiffies 4295110033 (age 1083.016s)
hex dump (first 16 bytes):
62 69 6e 66 6d 74 5f 6d 69 73 63 00 6b 6b 6b a5 binfmt_misc.kkk.
backtrace:
[<ffffffffa07dbf9b>] kstrdup+0x2b/0x50
[<ffffffffa04b0a9d>] __audit_log_kern_module+0x4d/0xf0
[<ffffffffa03b6664>] load_module+0x9d4/0x2e10
[<ffffffffa03b8f44>] __do_sys_finit_module+0x114/0x1b0
[<ffffffffa1f47124>] do_syscall_64+0x34/0x80
[<ffffffffa200007e>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
Cc: stable@vger.kernel.org
Fixes: 12c5e81d3f ("audit: prepare audit_context for use in calling contexts beyond syscalls")
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
There are reports that the console kthreads block the global console
lock when the system is going down, for example, reboot, panic.
First part of the solution was to block kthreads in these problematic
system states so they stopped handling newly added messages.
Second part of the solution is to wait when for the kthreads when
they are actively printing. It solves the problem when a message
was printed before the system entered the problematic state and
the kthreads managed to step in.
A busy waiting has to be used because panic() can be called in any
context and in an unknown state of the scheduler.
There must be a timeout because the kthread might get stuck or sleeping
and never release the lock. The timeout 10s is an arbitrary value
inspired by the softlockup timeout.
Link: https://lore.kernel.org/r/20220610205038.GA3050413@paulmck-ThinkPad-P17-Gen-1
Link: https://lore.kernel.org/r/CAMdYzYpF4FNTBPZsEFeWRuEwSies36QM_As8osPWZSr2q-viEA@mail.gmail.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20220615162805.27962-3-pmladek@suse.com
There are known situations when the console kthreads are not
reliable or does not work in principle, for example, early boot,
panic, shutdown.
For these situations there is the direct (legacy) mode when printk() tries
to get console_lock() and flush the messages directly. It works very well
during the early boot when the console kthreads are not available at all.
It gets more complicated in the other situations when console kthreads
might be actively printing and block console_trylock() in printk().
The same problem is in the legacy code as well. Any console_lock()
owner could block console_trylock() in printk(). It is solved by
a trick that the current console_lock() owner is responsible for
printing all pending messages. It is actually the reason why there
is the risk of softlockups and why the console kthreads were
introduced.
The console kthreads use the same approach. They are responsible
for printing the messages by definition. So that they handle
the messages anytime when they are awake and see new ones.
The global console_lock is available when there is nothing
to do.
It should work well when the problematic context is correctly
detected and printk() switches to the direct mode. But it seems
that it is not enough in practice. There are reports that
the messages are not printed during panic() or shutdown()
even though printk() tries to use the direct mode here.
The problem seems to be that console kthreads become active in these
situation as well. They steel the job before other CPUs are stopped.
Then they are stopped in the middle of the job and block the global
console_lock.
First part of the solution is to block console kthreads when
the system is in a problematic state and requires the direct
printk() mode.
Link: https://lore.kernel.org/r/20220610205038.GA3050413@paulmck-ThinkPad-P17-Gen-1
Link: https://lore.kernel.org/r/CAMdYzYpF4FNTBPZsEFeWRuEwSies36QM_As8osPWZSr2q-viEA@mail.gmail.com
Suggested-by: John Ogness <john.ogness@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220615162805.27962-2-pmladek@suse.com
RCU_NONIDLE usage during __cfi_slowpath_diag can result in an invalid
RCU state in the cpuidle code path:
WARNING: CPU: 1 PID: 0 at kernel/rcu/tree.c:613 rcu_eqs_enter+0xe4/0x138
...
Call trace:
rcu_eqs_enter+0xe4/0x138
rcu_idle_enter+0xa8/0x100
cpuidle_enter_state+0x154/0x3a8
cpuidle_enter+0x3c/0x58
do_idle.llvm.6590768638138871020+0x1f4/0x2ec
cpu_startup_entry+0x28/0x2c
secondary_start_kernel+0x1b8/0x220
__secondary_switched+0x94/0x98
Instead, call rcu_irq_enter/exit to wake up RCU only when needed and
disable interrupts for the entire CFI shadow/module check when we do.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20220531175910.890307-1-samitolvanen@google.com
Fixes: cf68fffb66 ("add support for Clang CFI")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Since the rewrote of prandom_u32(), in the commit mentioned below, the
function uses sleeping locks which extracing random numbers and filling
the batch.
This breaks lockdep on PREEMPT_RT because lock_pin_lock() disables
interrupts while calling __lock_pin_lock(). This can't be moved earlier
because the main user of the function (rq_pin_lock()) invokes that
function after disabling interrupts in order to acquire the lock.
The cookie does not require random numbers as its goal is to provide a
random value in order to notice unexpected "unlock + lock" sites.
Use sched_clock() to provide random numbers.
Fixes: a0103f4d86f88 ("random32: use real rng for non-deterministic randomness")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/YoNn3pTkm5+QzE5k@linutronix.de
The purpose of balance_push() is to act as a filter on task selection
in the case of CPU hotplug, specifically when taking the CPU out.
It does this by (ab)using the balance callback infrastructure, with
the express purpose of keeping all the unlikely/odd cases in a single
place.
In order to serve its purpose, the balance_push_callback needs to be
(exclusively) on the callback list at all times (noting that the
callback always places itself back on the list the moment it runs,
also noting that when the CPU goes down, regular balancing concerns
are moot, so ignoring them is fine).
And here-in lies the problem, __sched_setscheduler()'s use of
splice_balance_callbacks() takes the callbacks off the list across a
lock-break, making it possible for, an interleaving, __schedule() to
see an empty list and not get filtered.
Fixes: ae79270232 ("sched: Optimize finish_lock_switch()")
Reported-by: Jing-Ting Wu <jing-ting.wu@mediatek.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Jing-Ting Wu <jing-ting.wu@mediatek.com>
Link: https://lkml.kernel.org/r/20220519134706.GH2578@worktop.programming.kicks-ass.net
Tetsuo's patch to trigger build warnings if system-wide wq's are flushed
along with a TP type update and trivial comment update.
-----BEGIN PGP SIGNATURE-----
iIQEABYIACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCYqUyqQ4cdGpAa2VybmVs
Lm9yZwAKCRCxYfJx3gVYGQPtAQCQZuNFoWhCtdpjW/MWuGdY1pGGPMVl+60xwvew
Ad8gegD/eoAsXP1XAzJ9Z1BPqr/IxncfOgGGDGHbR1Ll39qLlwE=
=i3Sx
-----END PGP SIGNATURE-----
Merge tag 'wq-for-5.19-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fixes from Tejun Heo:
"Tetsuo's patch to trigger build warnings if system-wide wq's are
flushed along with a TP type update and trivial comment update"
* tag 'wq-for-5.19-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: Switch to new kerneldoc syntax for named variable macro argument
workqueue: Fix type of cpu in trace event
workqueue: Wrap flush_workqueue() using a macro
- Fix CPUIDLE_FLAG_IRQ_ENABLE handling in intel_idle (Peter Zijlstra).
- Allow all platforms to use the global poweroff handler and make
non-syscall poweroff code paths work again (Dmitry Osipenko).
-----BEGIN PGP SIGNATURE-----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=2OMR
-----END PGP SIGNATURE-----
Merge tag 'pm-5.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki:
"These fix an intel_idle issue introduced during the 5.16 development
cycle and two recent regressions in the system reboot/poweroff code.
Specifics:
- Fix CPUIDLE_FLAG_IRQ_ENABLE handling in intel_idle (Peter Zijlstra)
- Allow all platforms to use the global poweroff handler and make
non-syscall poweroff code paths work again (Dmitry Osipenko)"
* tag 'pm-5.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE
kernel/reboot: Fix powering off using a non-syscall code paths
kernel/reboot: Use static handler for register_platform_power_off()
Merge fixes for regressions introduced by the recent rework of the
system reboot/poweroff code.
* pm-sysoff:
kernel/reboot: Fix powering off using a non-syscall code paths
kernel/reboot: Use static handler for register_platform_power_off()
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQRTLbB6QfY48x44uB6AXGG7T9hjvgUCYqLLcQAKCRCAXGG7T9hj
vggVAP0Wjf81TxvIGrwtcn1q2LW7xyNp5TQk1T6GYx40sHXWlQD/SCKl5iorSGn+
+g1eXYmOpnSIAcMX3B3T4Ra8uo3mnA8=
=PnB/
-----END PGP SIGNATURE-----
Merge tag 'for-linus-5.19a-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen updates from Juergen Gross:
- a small cleanup removing "export" of an __init function
- a small series adding a new infrastructure for platform flags
- a series adding generic virtio support for Xen guests (frontend side)
* tag 'for-linus-5.19a-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: unexport __init-annotated xen_xlate_map_ballooned_pages()
arm/xen: Assign xen-grant DMA ops for xen-grant DMA devices
xen/grant-dma-ops: Retrieve the ID of backend's domain for DT devices
xen/grant-dma-iommu: Introduce stub IOMMU driver
dt-bindings: Add xen,grant-dma IOMMU description for xen-grant DMA ops
xen/virtio: Enable restricted memory access using Xen grant mappings
xen/grant-dma-ops: Add option to restrict memory access under Xen
xen/grants: support allocating consecutive grants
arm/xen: Introduce xen_setup_dma_ops()
virtio: replace arch_has_restricted_virtio_memory_access()
kernel: add platform_has() infrastructure
When requesting an interrupt, we correctly call into the runtime
PM framework to guarantee that the underlying interrupt controller
is up and running.
However, we fail to do so for chained interrupt controllers, as
the mux interrupt is not requested along the same path.
Augment __irq_do_set_handler() to call into the runtime PM code
in this case, making sure the PM flow is the same for all interrupts.
Reported-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Liu Ying <victor.liu@nxp.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/26973cddee5f527ea17184c0f3fccb70bc8969a0.camel@pengutronix.de
* Fix TDP MMU performance issue with disabling dirty logging
* Fix 5.14 regression with SVM TSC scaling
* Fix indefinite stall on applying live patches
* Fix unstable selftest
* Fix memory leak from wrong copy-and-paste
* Fix missed PV TLB flush when racing with emulation
-----BEGIN PGP SIGNATURE-----
iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmKglysUHHBib256aW5p
QHJlZGhhdC5jb20ACgkQv/vSX3jHroOJDAgArpPcAnJbeT2VQTQcp94e4tp9k1Sf
gmUewajco4zFVB/sldE0fIporETkaX+FYYPiaNDdNgJ2lUw/HUJBN7KoFEYTZ37N
Xx/qXiIXQYFw1bmxTnacLzIQtD3luMCzOs/6/Q7CAFZIBpUtUEjkMlQOBuxoKeG0
B0iLCTJSw0taWcN170aN8G6T+5+bdR3AJW1k2wkgfESfYF9NfJoTUHQj9WTMzM2R
aBRuXvUI/rWKvQY3DfoRmgg9Ig/SirSC+abbKIs4H08vZIEUlPk3WOZSKpsN/Wzh
3XDnVRxgnaRLx6NI/ouI2UYJCmjPKbNcueGCf5IfUcHvngHjAEG/xxe4Qw==
=zQ9u
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
- syzkaller NULL pointer dereference
- TDP MMU performance issue with disabling dirty logging
- 5.14 regression with SVM TSC scaling
- indefinite stall on applying live patches
- unstable selftest
- memory leak from wrong copy-and-paste
- missed PV TLB flush when racing with emulation
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86: do not report a vCPU as preempted outside instruction boundaries
KVM: x86: do not set st->preempted when going back to user space
KVM: SVM: fix tsc scaling cache logic
KVM: selftests: Make hyperv_clock selftest more stable
KVM: x86/MMU: Zap non-leaf SPTEs when disabling dirty logging
x86: drop bogus "cc" clobber from __try_cmpxchg_user_asm()
KVM: x86/mmu: Check every prev_roots in __kvm_mmu_free_obsolete_roots()
entry/kvm: Exit to user mode when TIF_NOTIFY_SIGNAL is set
KVM: Don't null dereference ops->destroy
There are other methods of powering off machine than the reboot syscall.
Previously we missed to cover those methods and it created power-off
regression for some machines, like the PowerPC e500.
Fix this problem by moving the legacy sys-off handler registration to
the latest phase of power-off process and making the kernel_can_power_off()
check the legacy pm_power_off presence.
Tested-by: Michael Ellerman <mpe@ellerman.id.au> # ppce500
Reported-by: Michael Ellerman <mpe@ellerman.id.au> # ppce500
Fixes: da007f171f ("kernel/reboot: Change registration order of legacy power-off handler")
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The verifier allows programs to call global functions as long as their
argument types match, using BTF to check the function arguments. One of the
allowed argument types to such global functions is PTR_TO_CTX; however the
check for this fails on BPF_PROG_TYPE_EXT functions because the verifier
uses the wrong type to fetch the vmlinux BTF ID for the program context
type. This failure is seen when an XDP program is loaded using
libxdp (which loads it as BPF_PROG_TYPE_EXT and attaches it to a global XDP
type program).
Fix the issue by passing in the target program type instead of the
BPF_PROG_TYPE_EXT type to bpf_prog_get_ctx() when checking function
argument compatibility.
The first Fixes tag refers to the latest commit that touched the code in
question, while the second one points to the code that first introduced
the global function call verification.
v2:
- Use resolve_prog_type()
Fixes: 3363bd0cfb ("bpf: Extend kfunc with PTR_TO_CTX, PTR_TO_MEM argument support")
Fixes: 51c39bb1d5 ("bpf: Introduce function-by-function verification")
Reported-by: Simon Sundberg <simon.sundberg@kau.se>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20220606075253.28422-1-toke@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The kvmalloc_array() function is safer because it has a check for
integer overflows. These sizes come from the user and I was not
able to see any bounds checking so an integer overflow seems like a
realistic concern.
Fixes: 0dcac27254 ("bpf: Add multi kprobe link")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/Yo9VRVMeHbALyjUH@kili
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Since flush operation synchronously waits for completion, flushing
system-wide WQs (e.g. system_wq) might introduce possibility of deadlock
due to unexpected locking dependency. Tejun Heo commented at [1] that it
makes no sense at all to call flush_workqueue() on the shared WQs as the
caller has no idea what it's gonna end up waiting for.
Although there is flush_scheduled_work() which flushes system_wq WQ with
"Think twice before calling this function! It's very easy to get into
trouble if you don't take great care." warning message, syzbot found a
circular locking dependency caused by flushing system_wq WQ [2].
Therefore, let's change the direction to that developers had better use
their local WQs if flush_scheduled_work()/flush_workqueue(system_*_wq) is
inevitable.
Steps for converting system-wide WQs into local WQs are explained at [3],
and a conversion to stop flushing system-wide WQs is in progress. Now we
want some mechanism for preventing developers who are not aware of this
conversion from again start flushing system-wide WQs.
Since I found that WARN_ON() is complete but awkward approach for teaching
developers about this problem, let's use __compiletime_warning() for
incomplete but handy approach. For completeness, we will also insert
WARN_ON() into __flush_workqueue() after all in-tree users stopped calling
flush_scheduled_work().
Link: https://lore.kernel.org/all/YgnQGZWT%2Fn3VAITX@slm.duckdns.org/ [1]
Link: https://syzkaller.appspot.com/bug?extid=bde0f89deacca7c765b8 [2]
Link: https://lkml.kernel.org/r/49925af7-78a8-a3dd-bce6-cfc02e1a9236@I-love.SAKURA.ne.jp [3]
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Tejun Heo <tj@kernel.org>
A livepatch transition may stall indefinitely when a kvm vCPU is heavily
loaded. To the host, the vCPU task is a user thread which is spending a
very long time in the ioctl(KVM_RUN) syscall. During livepatch
transition, set_notify_signal() will be called on such tasks to
interrupt the syscall so that the task can be transitioned. This
interrupts guest execution, but when xfer_to_guest_mode_work() sees that
TIF_NOTIFY_SIGNAL is set but not TIF_SIGPENDING it concludes that an
exit to user mode is unnecessary, and guest execution is resumed without
transitioning the task for the livepatch.
This handling of TIF_NOTIFY_SIGNAL is incorrect, as set_notify_signal()
is expected to break tasks out of interruptible kernel loops and cause
them to return to userspace. Change xfer_to_guest_mode_work() to handle
TIF_NOTIFY_SIGNAL the same as TIF_SIGPENDING, signaling to the vCPU run
loop that an exit to userpsace is needed. Any pending task_work will be
run when get_signal() is called from exit_to_user_mode_loop(), so there
is no longer any need to run task work from xfer_to_guest_mode_work().
Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Petr Mladek <pmladek@suse.com>
Signed-off-by: Seth Forshee <sforshee@digitalocean.com>
Message-Id: <20220504180840.2907296-1-sforshee@digitalocean.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- fix a regressin in setting swiotlb ->force_bounce (me)
- make dma-debug less chatty (Rob Clark)
-----BEGIN PGP SIGNATURE-----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=JdkI
-----END PGP SIGNATURE-----
Merge tag 'dma-mapping-5.19-2022-06-06' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping fixes from Christoph Hellwig:
- fix a regressin in setting swiotlb ->force_bounce (me)
- make dma-debug less chatty (Rob Clark)
* tag 'dma-mapping-5.19-2022-06-06' of git://git.infradead.org/users/hch/dma-mapping:
swiotlb: fix setting ->force_bounce
dma-debug: make things less spammy under memory pressure
Add a simple infrastructure for setting, resetting and querying
platform feature flags.
Flags can be either global or architecture specific.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Tested-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Arm64 only
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Juergen Gross <jgross@suse.com>
because,unusually, it has dependencies on both the mm-stable and
mm-nonmm-stable queues.
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCYpz3SAAKCRDdBJ7gKXxA
jou6AP9bY89NifR7Tc8U59Xu4c9amphXS9rTJv7Ysj3GxBMoRwEAuXvvJTet6mEn
UdmytDdb4BtAlx7Itd7IKu4S9JD6mQw=
=bAU1
-----END PGP SIGNATURE-----
Merge tag 'mm-nonmm-stable-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull delay-accounting update from Andrew Morton:
"A single featurette for delay accounting.
Delayed a bit because, unusually, it had dependencies on both the
mm-stable and mm-nonmm-stable queues"
* tag 'mm-nonmm-stable-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
delayacct: track delays from write-protect copy
-----BEGIN PGP SIGNATURE-----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=arj3
-----END PGP SIGNATURE-----
Merge tag 'sched-urgent-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Thomas Gleixner:
"Fix the fallout of sysctl code move which placed the init function
wrong"
* tag 'sched-urgent-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/autogroup: Fix sysctl move
- Make the ICL event constraints match reality
- Remove a unused local variable
-----BEGIN PGP SIGNATURE-----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=ZK+2
-----END PGP SIGNATURE-----
Merge tag 'perf-urgent-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
- Make the ICL event constraints match reality
- Remove a unused local variable
* tag 'perf-urgent-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Remove unused local variable
perf/x86/intel: Fix event constraints for ICL
The fix is usermode_driver.c one - once you've done kern_mount(), you
must kern_unmount(); simple mntput() will end up with a leak. Several
failure exits in there messed up that way... In practice you won't
hit those particular failure exits without fault injection, though.
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCYpvrWQAKCRBZ7Krx/gZQ
6z29AP9EZVSyIvnwXleehpa2mEZhsp+KAKgV/ENaKHMn7jiH0wD/bfgnhxIDNuc5
108E2R5RWEYTynW5k7nnP5PsTsMq5Qc=
=b3Wc
-----END PGP SIGNATURE-----
Merge tag 'pull-18-rc1-work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull mount handling updates from Al Viro:
"Cleanups (and one fix) around struct mount handling.
The fix is usermode_driver.c one - once you've done kern_mount(), you
must kern_unmount(); simple mntput() will end up with a leak. Several
failure exits in there messed up that way... In practice you won't hit
those particular failure exits without fault injection, though"
* tag 'pull-18-rc1-work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
move mount-related externs from fs.h to mount.h
blob_to_mnt(): kern_unmount() is needed to undo kern_mount()
m->mnt_root->d_inode->i_sb is a weird way to spell m->mnt_sb...
linux/mount.h: trim includes
uninline may_mount() and don't opencode it in fspick(2)/fsopen(2)
of Peter Zijlstra was encountering with ptrace in his freezer rewrite
I identified some cleanups to ptrace_stop that make sense on their own
and move make resolving the other problems much simpler.
The biggest issue is the habbit of the ptrace code to change task->__state
from the tracer to suppress TASK_WAKEKILL from waking up the tracee. No
other code in the kernel does that and it is straight forward to update
signal_wake_up and friends to make that unnecessary.
Peter's task freezer sets frozen tasks to a new state TASK_FROZEN and
then it stores them by calling "wake_up_state(t, TASK_FROZEN)" relying
on the fact that all stopped states except the special stop states can
tolerate spurious wake up and recover their state.
The state of stopped and traced tasked is changed to be stored in
task->jobctl as well as in task->__state. This makes it possible for
the freezer to recover tasks in these special states, as well as
serving as a general cleanup. With a little more work in that
direction I believe TASK_STOPPED can learn to tolerate spurious wake
ups and become an ordinary stop state.
The TASK_TRACED state has to remain a special state as the registers for
a process are only reliably available when the process is stopped in
the scheduler. Fundamentally ptrace needs acess to the saved
register values of a task.
There are bunch of semi-random ptrace related cleanups that were found
while looking at these issues.
One cleanup that deserves to be called out is from commit 57b6de08b5
("ptrace: Admit ptrace_stop can generate spuriuos SIGTRAPs"). This
makes a change that is technically user space visible, in the handling
of what happens to a tracee when a tracer dies unexpectedly.
According to our testing and our understanding of userspace nothing
cares that spurious SIGTRAPs can be generated in that case.
The entire discussion can be found at:
https://lkml.kernel.org/r/87a6bv6dl6.fsf_-_@email.froward.int.ebiederm.org
Eric W. Biederman (11):
signal: Rename send_signal send_signal_locked
signal: Replace __group_send_sig_info with send_signal_locked
ptrace/um: Replace PT_DTRACE with TIF_SINGLESTEP
ptrace/xtensa: Replace PT_SINGLESTEP with TIF_SINGLESTEP
ptrace: Remove arch_ptrace_attach
signal: Use lockdep_assert_held instead of assert_spin_locked
ptrace: Reimplement PTRACE_KILL by always sending SIGKILL
ptrace: Document that wait_task_inactive can't fail
ptrace: Admit ptrace_stop can generate spuriuos SIGTRAPs
ptrace: Don't change __state
ptrace: Always take siglock in ptrace_resume
Peter Zijlstra (1):
sched,signal,ptrace: Rework TASK_TRACED, TASK_STOPPED state
arch/ia64/include/asm/ptrace.h | 4 --
arch/ia64/kernel/ptrace.c | 57 ----------------
arch/um/include/asm/thread_info.h | 2 +
arch/um/kernel/exec.c | 2 +-
arch/um/kernel/process.c | 2 +-
arch/um/kernel/ptrace.c | 8 +--
arch/um/kernel/signal.c | 4 +-
arch/x86/kernel/step.c | 3 +-
arch/xtensa/kernel/ptrace.c | 4 +-
arch/xtensa/kernel/signal.c | 4 +-
drivers/tty/tty_jobctrl.c | 4 +-
include/linux/ptrace.h | 7 --
include/linux/sched.h | 10 ++-
include/linux/sched/jobctl.h | 8 +++
include/linux/sched/signal.h | 20 ++++--
include/linux/signal.h | 3 +-
kernel/ptrace.c | 87 ++++++++---------------
kernel/sched/core.c | 5 +-
kernel/signal.c | 140 +++++++++++++++++---------------------
kernel/time/posix-cpu-timers.c | 6 +-
20 files changed, 140 insertions(+), 240 deletions(-)
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
-----BEGIN PGP SIGNATURE-----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=ZUuO
-----END PGP SIGNATURE-----
Merge tag 'ptrace_stop-cleanup-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull ptrace_stop cleanups from Eric Biederman:
"While looking at the ptrace problems with PREEMPT_RT and the problems
Peter Zijlstra was encountering with ptrace in his freezer rewrite I
identified some cleanups to ptrace_stop that make sense on their own
and move make resolving the other problems much simpler.
The biggest issue is the habit of the ptrace code to change
task->__state from the tracer to suppress TASK_WAKEKILL from waking up
the tracee. No other code in the kernel does that and it is straight
forward to update signal_wake_up and friends to make that unnecessary.
Peter's task freezer sets frozen tasks to a new state TASK_FROZEN and
then it stores them by calling "wake_up_state(t, TASK_FROZEN)" relying
on the fact that all stopped states except the special stop states can
tolerate spurious wake up and recover their state.
The state of stopped and traced tasked is changed to be stored in
task->jobctl as well as in task->__state. This makes it possible for
the freezer to recover tasks in these special states, as well as
serving as a general cleanup. With a little more work in that
direction I believe TASK_STOPPED can learn to tolerate spurious wake
ups and become an ordinary stop state.
The TASK_TRACED state has to remain a special state as the registers
for a process are only reliably available when the process is stopped
in the scheduler. Fundamentally ptrace needs acess to the saved
register values of a task.
There are bunch of semi-random ptrace related cleanups that were found
while looking at these issues.
One cleanup that deserves to be called out is from commit 57b6de08b5
("ptrace: Admit ptrace_stop can generate spuriuos SIGTRAPs"). This
makes a change that is technically user space visible, in the handling
of what happens to a tracee when a tracer dies unexpectedly. According
to our testing and our understanding of userspace nothing cares that
spurious SIGTRAPs can be generated in that case"
* tag 'ptrace_stop-cleanup-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
sched,signal,ptrace: Rework TASK_TRACED, TASK_STOPPED state
ptrace: Always take siglock in ptrace_resume
ptrace: Don't change __state
ptrace: Admit ptrace_stop can generate spuriuos SIGTRAPs
ptrace: Document that wait_task_inactive can't fail
ptrace: Reimplement PTRACE_KILL by always sending SIGKILL
signal: Use lockdep_assert_held instead of assert_spin_locked
ptrace: Remove arch_ptrace_attach
ptrace/xtensa: Replace PT_SINGLESTEP with TIF_SINGLESTEP
ptrace/um: Replace PT_DTRACE with TIF_SINGLESTEP
signal: Replace __group_send_sig_info with send_signal_locked
signal: Rename send_signal send_signal_locked
