Commit 3e71f016 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'locking-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull locking updates from Ingo Molnar:

 - Disable preemption in rwsem_write_trylock()'s attempt to take the
   rwsem, to avoid RT tasks hogging the CPU, which managed to preempt
   this function after the owner has been cleared but before a new owner
   is set. Also add debug checks to enforce this.

 - Add __lockfunc to more slow path functions and add __sched to
   semaphore functions.

 - Mark spinlock APIs noinline when the respective CONFIG_INLINE_SPIN_*
   toggles are disabled, to reduce LTO text size.

 - Print more debug information when lockdep gets confused in
   look_up_lock_class().

 - Improve header file abuse checks.

 - Misc cleanups

* tag 'locking-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/lockdep: Print more debug information - report name and key when look_up_lock_class() got confused
  locking: Add __sched to semaphore functions
  locking/rwsem: Disable preemption while trying for rwsem lock
  locking: Detect includes rwlock.h outside of spinlock.h
  locking: Add __lockfunc to slow path functions
  locking/spinlocks: Mark spinlocks noinline when inline spinlocks are disabled
  selftests: futex: Fix 'the the' typo in comment
parents 3871d93b 76e64c73

arch/x86/include/asm/qspinlock_paravirt.h

+7 −6
Original line number Diff line number Diff line
@@ -12,7 +12,7 @@ 
 */

#ifdef CONFIG_64BIT



PV_CALLEE_SAVE_REGS_THUNK(__pv_queued_spin_unlock_slowpath);

__PV_CALLEE_SAVE_REGS_THUNK(__pv_queued_spin_unlock_slowpath, ".spinlock.text");

#define __pv_queued_spin_unlock	__pv_queued_spin_unlock

#define PV_UNLOCK		"__raw_callee_save___pv_queued_spin_unlock"

#define PV_UNLOCK_SLOWPATH	"__raw_callee_save___pv_queued_spin_unlock_slowpath"
@@ -20,9 +20,10 @@ PV_CALLEE_SAVE_REGS_THUNK(__pv_queued_spin_unlock_slowpath); 
/*

 * Optimized assembly version of __raw_callee_save___pv_queued_spin_unlock

 * which combines the registers saving trunk and the body of the following

 * C code:

 * C code.  Note that it puts the code in the .spinlock.text section which

 * is equivalent to adding __lockfunc in the C code:

 *

 * void __pv_queued_spin_unlock(struct qspinlock *lock)

 * void __lockfunc __pv_queued_spin_unlock(struct qspinlock *lock)

 * {

 *	u8 lockval = cmpxchg(&lock->locked, _Q_LOCKED_VAL, 0);

 *
@@ -36,7 +37,7 @@ PV_CALLEE_SAVE_REGS_THUNK(__pv_queued_spin_unlock_slowpath); 
 *   rsi = lockval           (second argument)

 *   rdx = internal variable (set to 0)

 */

asm    (".pushsection .text;"

asm    (".pushsection .spinlock.text;"

	".globl " PV_UNLOCK ";"

	".type " PV_UNLOCK ", @function;"

	".align 4,0x90;"
@@ -65,8 +66,8 @@ asm (".pushsection .text;" 


#else /* CONFIG_64BIT */



extern void __pv_queued_spin_unlock(struct qspinlock *lock);

PV_CALLEE_SAVE_REGS_THUNK(__pv_queued_spin_unlock);

extern void __lockfunc __pv_queued_spin_unlock(struct qspinlock *lock);

__PV_CALLEE_SAVE_REGS_THUNK(__pv_queued_spin_unlock, ".spinlock.text");



#endif /* CONFIG_64BIT */

#endif

include/linux/rwlock.h

+1 −1
Original line number Diff line number Diff line 
#ifndef __LINUX_RWLOCK_H

#define __LINUX_RWLOCK_H



#ifndef __LINUX_SPINLOCK_H

#ifndef __LINUX_INSIDE_SPINLOCK_H

# error "please don't include this file directly"

#endif

include/linux/spinlock.h

+2 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef __LINUX_SPINLOCK_H

#define __LINUX_SPINLOCK_H

#define __LINUX_INSIDE_SPINLOCK_H



/*

 * include/linux/spinlock.h - generic spinlock/rwlock declarations
@@ -492,4 +493,5 @@ int __alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *lock_mask, 


void free_bucket_spinlocks(spinlock_t *locks);



#undef __LINUX_INSIDE_SPINLOCK_H

#endif /* __LINUX_SPINLOCK_H */

include/linux/spinlock_api_smp.h

+1 −1
Original line number Diff line number Diff line 
#ifndef __LINUX_SPINLOCK_API_SMP_H

#define __LINUX_SPINLOCK_API_SMP_H



#ifndef __LINUX_SPINLOCK_H

#ifndef __LINUX_INSIDE_SPINLOCK_H

# error "please don't include this file directly"

#endif

include/linux/spinlock_api_up.h

+1 −1
Original line number Diff line number Diff line 
#ifndef __LINUX_SPINLOCK_API_UP_H

#define __LINUX_SPINLOCK_API_UP_H



#ifndef __LINUX_SPINLOCK_H

#ifndef __LINUX_INSIDE_SPINLOCK_H

# error "please don't include this file directly"

#endif