linux-toradex.git/kernel/locking/mutex.c, branch v5.15-rc5 Linux kernel for Apalis and Colibri modules locking/ww_mutex: Initialize waiter.ww_ctx properly 2021-08-20T10:15:54+00:00 Sebastian Andrzej Siewior bigeasy@linutronix.de 2021-08-19T19:30:30+00:00 b857174e68e26f9c4f0796971e11eb63ad5a3eb6 The consolidation of the debug code for mutex waiter intialization sets waiter::ww_ctx to a poison value unconditionally. For regular mutexes this is intended to catch the case where waiter_ww_ctx is dereferenced accidentally. For ww_mutex the poison value has to be overwritten either with a context pointer or NULL for ww_mutexes without context. The rework broke this as it made the store conditional on the context pointer instead of the argument which signals whether ww_mutex code should be compiled in or optiized out. As a result waiter::ww_ctx ends up with the poison pointer for contextless ww_mutexes which causes a later dereference of the poison pointer because it is != NULL. Use the build argument instead so for ww_mutex the poison value is always overwritten. Fixes: c0afb0ffc06e6 ("locking/ww_mutex: Gather mutex_waiter initialization") Reported-by: Guenter Roeck <linux@roeck-us.net> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210819193030.zpwrpvvrmy7xxxiy@linutronix.de 
The consolidation of the debug code for mutex waiter intialization sets
waiter::ww_ctx to a poison value unconditionally. For regular mutexes this
is intended to catch the case where waiter_ww_ctx is dereferenced
accidentally.

For ww_mutex the poison value has to be overwritten either with a context
pointer or NULL for ww_mutexes without context.

The rework broke this as it made the store conditional on the context
pointer instead of the argument which signals whether ww_mutex code should
be compiled in or optiized out. As a result waiter::ww_ctx ends up with the
poison pointer for contextless ww_mutexes which causes a later dereference of
the poison pointer because it is != NULL.

Use the build argument instead so for ww_mutex the poison value is always
overwritten.

Fixes: c0afb0ffc06e6 ("locking/ww_mutex: Gather mutex_waiter initialization")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210819193030.zpwrpvvrmy7xxxiy@linutronix.de
locking/rtmutex: Add mutex variant for RT 2021-08-17T17:05:29+00:00 Thomas Gleixner tglx@linutronix.de 2021-08-15T21:29:01+00:00 bb630f9f7a7d43869e4e7f5e4c002207396aea59 Add the necessary defines, helpers and API functions for replacing struct mutex on a PREEMPT_RT enabled kernel with an rtmutex based variant. No functional change when CONFIG_PREEMPT_RT=n Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20210815211305.081517417@linutronix.de 
Add the necessary defines, helpers and API functions for replacing struct mutex on
a PREEMPT_RT enabled kernel with an rtmutex based variant.

No functional change when CONFIG_PREEMPT_RT=n

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.081517417@linutronix.de
locking/ww_mutex: Split out the W/W implementation logic into kernel/locking/ww_mutex.h 2021-08-17T17:04:46+00:00 Peter Zijlstra (Intel) peterz@infradead.org 2021-08-17T14:31:54+00:00 2674bd181f3338dc2c58a59caa766dc9d5779784 Split the W/W mutex helper functions out into a separate header file, so they can be shared with a rtmutex based variant later. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20210815211304.396893399@linutronix.de 
Split the W/W mutex helper functions out into a separate header file, so
they can be shared with a rtmutex based variant later.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.396893399@linutronix.de
locking/ww_mutex: Split up ww_mutex_unlock() 2021-08-17T17:04:44+00:00 Peter Zijlstra (Intel) peterz@infradead.org 2021-08-17T14:19:04+00:00 aaa77de10b7c86fa779b2108802fa9e785fbe2e9 Split the ww related part out into a helper function so it can be reused for a rtmutex based ww_mutex implementation. [ mingo: Fixed bisection failure. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20210815211304.340166556@linutronix.de 
Split the ww related part out into a helper function so it can be reused
for a rtmutex based ww_mutex implementation.

[ mingo: Fixed bisection failure. ]

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.340166556@linutronix.de
locking/ww_mutex: Gather mutex_waiter initialization 2021-08-17T17:04:41+00:00 Peter Zijlstra peterz@infradead.org 2021-08-15T21:28:39+00:00 c0afb0ffc06e6b4e492a3b711f1fb32074f9949c Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20210815211304.281927514@linutronix.de 
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.281927514@linutronix.de
locking/ww_mutex: Simplify lockdep annotations 2021-08-17T17:04:28+00:00 Peter Zijlstra peterz@infradead.org 2021-08-15T21:28:38+00:00 cf702eddcd03dca3184947170930bf284aea27e9 No functional change. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20210815211304.222921634@linutronix.de 
No functional change.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.222921634@linutronix.de
locking/mutex: Make mutex::wait_lock raw 2021-08-17T17:03:33+00:00 Thomas Gleixner tglx@linutronix.de 2021-08-15T21:28:36+00:00 ebf4c55c1ddbabaea120fe8d48ce25b4f5da93a1 The wait_lock of mutex is really a low level lock. Convert it to a raw_spinlock like the wait_lock of rtmutex. [ mingo: backmerged the test_lockup.c build fix by bigeasy. ] Co-developed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20210815211304.166863404@linutronix.de 
The wait_lock of mutex is really a low level lock. Convert it to a
raw_spinlock like the wait_lock of rtmutex.

[ mingo: backmerged the test_lockup.c build fix by bigeasy. ]

Co-developed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.166863404@linutronix.de
locking/mutex: Consolidate core headers, remove kernel/locking/mutex-debug.h 2021-08-17T16:24:22+00:00 Thomas Gleixner tglx@linutronix.de 2021-08-17T14:17:38+00:00 a321fb9038b335f3c447d1810b97d5f7eec152ac Having two header files which contain just the non-debug and debug variants is mostly waste of disc space and has no real value. Stick the debug variants into the common mutex.h file as counterpart to the stubs for the non-debug case. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20210815211303.995350521@linutronix.de 
Having two header files which contain just the non-debug and debug variants
is mostly waste of disc space and has no real value. Stick the debug
variants into the common mutex.h file as counterpart to the stubs for the
non-debug case.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.995350521@linutronix.de
Merge tag 'v5.14-rc6' into locking/core, to pick up fixes 2021-08-17T14:16:29+00:00 Ingo Molnar mingo@kernel.org 2021-08-17T14:16:29+00:00 c87866ede44ad7da6b296d732221dc34ce1b154d Signed-off-by: Ingo Molnar <mingo@kernel.org> 
Signed-off-by: Ingo Molnar <mingo@kernel.org>
locking/mutex: Add MUTEX_WARN_ON 2021-07-07T11:53:25+00:00 Peter Zijlstra peterz@infradead.org 2021-06-30T15:35:20+00:00 e6b4457b05f36bb9e371f29ab1dd2d97272a1540 Cleanup some #ifdef'fery. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Waiman Long <longman@redhat.com> Reviewed-by: Yanfei Xu <yanfei.xu@windriver.com> Link: https://lore.kernel.org/r/20210630154115.020298650@infradead.org 
Cleanup some #ifdef'fery.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Waiman Long <longman@redhat.com>
Reviewed-by: Yanfei Xu <yanfei.xu@windriver.com>
Link: https://lore.kernel.org/r/20210630154115.020298650@infradead.org