Commit da1c55f1 authored by Michel Lespinasse's avatar Michel Lespinasse Committed by Linus Torvalds
Browse files

mmap locking API: rename mmap_sem to mmap_lock 



Rename the mmap_sem field to mmap_lock.  Any new uses of this lock should
now go through the new mmap locking api.  The mmap_lock is still
implemented as a rwsem, though this could change in the future.

[akpm@linux-foundation.org: fix it for mm-gup-might_lock_readmmap_sem-in-get_user_pages_fast.patch]

Signed-off-by: default avatarMichel Lespinasse <walken@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: default avatarVlastimil Babka <vbabka@suse.cz>
Reviewed-by: default avatarDavidlohr Bueso <dbueso@suse.de>
Reviewed-by: default avatarDaniel Jordan <daniel.m.jordan@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-11-walken@google.com


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 42fc5414

arch/ia64/mm/fault.c

+2 −2
Original line number Diff line number Diff line
@@ -74,8 +74,8 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re 
	mask = ((((isr >> IA64_ISR_X_BIT) & 1UL) << VM_EXEC_BIT)

		| (((isr >> IA64_ISR_W_BIT) & 1UL) << VM_WRITE_BIT));



	/* mmap_sem is performance critical.... */

	prefetchw(&mm->mmap_sem);

	/* mmap_lock is performance critical.... */

	prefetchw(&mm->mmap_lock);



	/*

	 * If we're in an interrupt or have no user context, we must not take the fault..

arch/x86/mm/fault.c

+1 −1
Original line number Diff line number Diff line
@@ -1359,7 +1359,7 @@ dotraplinkage void 
do_page_fault(struct pt_regs *regs, unsigned long hw_error_code,

		unsigned long address)

{

	prefetchw(&current->mm->mmap_sem);

	prefetchw(&current->mm->mmap_lock);

	/*

	 * KVM has two types of events that are, logically, interrupts, but

	 * are unfortunately delivered using the #PF vector.  These events are

drivers/gpu/drm/etnaviv/etnaviv_gem.c

+1 −1
Original line number Diff line number Diff line
@@ -661,7 +661,7 @@ static int etnaviv_gem_userptr_get_pages(struct etnaviv_gem_object *etnaviv_obj) 
	struct etnaviv_gem_userptr *userptr = &etnaviv_obj->userptr;

	int ret, pinned = 0, npages = etnaviv_obj->base.size >> PAGE_SHIFT;



	might_lock_read(&current->mm->mmap_sem);

	might_lock_read(&current->mm->mmap_lock);



	if (userptr->mm != current->mm)

		return -EPERM;

include/linux/mm_types.h

+1 −1
Original line number Diff line number Diff line
@@ -440,7 +440,7 @@ struct mm_struct { 
		spinlock_t page_table_lock; /* Protects page tables and some

					     * counters

					     */

		struct rw_semaphore mmap_sem;

		struct rw_semaphore mmap_lock;



		struct list_head mmlist; /* List of maybe swapped mm's.	These

					  * are globally strung together off

include/linux/mmap_lock.h

+19 −19
Original line number Diff line number Diff line
@@ -4,67 +4,67 @@ 
#include <linux/mmdebug.h>



#define MMAP_LOCK_INITIALIZER(name) \

	.mmap_sem = __RWSEM_INITIALIZER((name).mmap_sem),

	.mmap_lock = __RWSEM_INITIALIZER((name).mmap_lock),



static inline void mmap_init_lock(struct mm_struct *mm)

{

	init_rwsem(&mm->mmap_sem);

	init_rwsem(&mm->mmap_lock);

}



static inline void mmap_write_lock(struct mm_struct *mm)

{

	down_write(&mm->mmap_sem);

	down_write(&mm->mmap_lock);

}



static inline void mmap_write_lock_nested(struct mm_struct *mm, int subclass)

{

	down_write_nested(&mm->mmap_sem, subclass);

	down_write_nested(&mm->mmap_lock, subclass);

}



static inline int mmap_write_lock_killable(struct mm_struct *mm)

{

	return down_write_killable(&mm->mmap_sem);

	return down_write_killable(&mm->mmap_lock);

}



static inline bool mmap_write_trylock(struct mm_struct *mm)

{

	return down_write_trylock(&mm->mmap_sem) != 0;

	return down_write_trylock(&mm->mmap_lock) != 0;

}



static inline void mmap_write_unlock(struct mm_struct *mm)

{

	up_write(&mm->mmap_sem);

	up_write(&mm->mmap_lock);

}



static inline void mmap_write_downgrade(struct mm_struct *mm)

{

	downgrade_write(&mm->mmap_sem);

	downgrade_write(&mm->mmap_lock);

}



static inline void mmap_read_lock(struct mm_struct *mm)

{

	down_read(&mm->mmap_sem);

	down_read(&mm->mmap_lock);

}



static inline int mmap_read_lock_killable(struct mm_struct *mm)

{

	return down_read_killable(&mm->mmap_sem);

	return down_read_killable(&mm->mmap_lock);

}



static inline bool mmap_read_trylock(struct mm_struct *mm)

{

	return down_read_trylock(&mm->mmap_sem) != 0;

	return down_read_trylock(&mm->mmap_lock) != 0;

}



static inline void mmap_read_unlock(struct mm_struct *mm)

{

	up_read(&mm->mmap_sem);

	up_read(&mm->mmap_lock);

}



static inline bool mmap_read_trylock_non_owner(struct mm_struct *mm)

{

	if (down_read_trylock(&mm->mmap_sem)) {

		rwsem_release(&mm->mmap_sem.dep_map, _RET_IP_);

	if (down_read_trylock(&mm->mmap_lock)) {

		rwsem_release(&mm->mmap_lock.dep_map, _RET_IP_);

		return true;

	}

	return false;
@@ -72,19 +72,19 @@ static inline bool mmap_read_trylock_non_owner(struct mm_struct *mm) 


static inline void mmap_read_unlock_non_owner(struct mm_struct *mm)

{

	up_read_non_owner(&mm->mmap_sem);

	up_read_non_owner(&mm->mmap_lock);

}



static inline void mmap_assert_locked(struct mm_struct *mm)

{

	lockdep_assert_held(&mm->mmap_sem);

	VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_sem), mm);

	lockdep_assert_held(&mm->mmap_lock);

	VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);

}



static inline void mmap_assert_write_locked(struct mm_struct *mm)

{

	lockdep_assert_held_write(&mm->mmap_sem);

	VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_sem), mm);

	lockdep_assert_held_write(&mm->mmap_lock);

	VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);

}



#endif /* _LINUX_MMAP_LOCK_H */

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