From da1c55f1b272f4bd54671d459b39ea7b54944ef9 Mon Sep 17 00:00:00 2001 From: Michel Lespinasse Date: Mon, 8 Jun 2020 21:33:47 -0700 Subject: [PATCH] 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: Michel Lespinasse Signed-off-by: Andrew Morton Reviewed-by: Vlastimil Babka Reviewed-by: Davidlohr Bueso Reviewed-by: Daniel Jordan Cc: David Rientjes Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: Jerome Glisse Cc: John Hubbard Cc: Laurent Dufour Cc: Liam Howlett Cc: Matthew Wilcox Cc: Peter Zijlstra Cc: Ying Han Link: http://lkml.kernel.org/r/20200520052908.204642-11-walken@google.com Signed-off-by: Linus Torvalds --- arch/ia64/mm/fault.c | 4 +-- arch/x86/mm/fault.c | 2 +- drivers/gpu/drm/etnaviv/etnaviv_gem.c | 2 +- include/linux/mm_types.h | 2 +- include/linux/mmap_lock.h | 38 +++++++++++++-------------- mm/gup.c | 2 +- mm/memory.c | 2 +- mm/mmap.c | 4 +-- mm/mmu_notifier.c | 2 +- 9 files changed, 29 insertions(+), 29 deletions(-) diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c index 245545b43a4c..e9ce969c8b73 100644 --- a/arch/ia64/mm/fault.c +++ b/arch/ia64/mm/fault.c @@ -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.. diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 8e7e4c2bd527..c23bcd027ae1 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1359,7 +1359,7 @@ dotraplinkage void do_page_fault(struct pt_regs *regs, unsigned long hw_error_code, unsigned long address) { - prefetchw(¤t->mm->mmap_sem); + prefetchw(¤t->mm->mmap_lock); /* * KVM has two types of events that are, logically, interrupts, but * are unfortunately delivered using the #PF vector. These events are diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c index dc9ef302f517..701f3995f621 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c @@ -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(¤t->mm->mmap_sem); + might_lock_read(¤t->mm->mmap_lock); if (userptr->mm != current->mm) return -EPERM; diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index ef6d3aface8a..b6639b30a83b 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -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 diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h index 43ef914e6468..0707671851a8 100644 --- a/include/linux/mmap_lock.h +++ b/include/linux/mmap_lock.h @@ -4,67 +4,67 @@ #include #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 */ diff --git a/mm/gup.c b/mm/gup.c index 279739fbd09a..762fb9f733b2 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2750,7 +2750,7 @@ static int internal_get_user_pages_fast(unsigned long start, int nr_pages, return -EINVAL; if (!(gup_flags & FOLL_FAST_ONLY)) - might_lock_read(¤t->mm->mmap_sem); + might_lock_read(¤t->mm->mmap_lock); start = untagged_addr(start) & PAGE_MASK; addr = start; diff --git a/mm/memory.c b/mm/memory.c index 533293faaaf5..823982a8f0b0 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4804,7 +4804,7 @@ void __might_fault(const char *file, int line) __might_sleep(file, line, 0); #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) if (current->mm) - might_lock_read(¤t->mm->mmap_sem); + might_lock_read(¤t->mm->mmap_lock); #endif } EXPORT_SYMBOL(__might_fault); diff --git a/mm/mmap.c b/mm/mmap.c index 7ed7cfca451e..a28778da76a3 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -3474,7 +3474,7 @@ static void vm_lock_anon_vma(struct mm_struct *mm, struct anon_vma *anon_vma) * The LSB of head.next can't change from under us * because we hold the mm_all_locks_mutex. */ - down_write_nest_lock(&anon_vma->root->rwsem, &mm->mmap_sem); + down_write_nest_lock(&anon_vma->root->rwsem, &mm->mmap_lock); /* * We can safely modify head.next after taking the * anon_vma->root->rwsem. If some other vma in this mm shares @@ -3504,7 +3504,7 @@ static void vm_lock_mapping(struct mm_struct *mm, struct address_space *mapping) */ if (test_and_set_bit(AS_MM_ALL_LOCKS, &mapping->flags)) BUG(); - down_write_nest_lock(&mapping->i_mmap_rwsem, &mm->mmap_sem); + down_write_nest_lock(&mapping->i_mmap_rwsem, &mm->mmap_lock); } } diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index 24eb9d1ed0a7..2f348b6c9c9a 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -983,7 +983,7 @@ int mmu_interval_notifier_insert(struct mmu_interval_notifier *interval_sub, struct mmu_notifier_subscriptions *subscriptions; int ret; - might_lock(&mm->mmap_sem); + might_lock(&mm->mmap_lock); subscriptions = smp_load_acquire(&mm->notifier_subscriptions); if (!subscriptions || !subscriptions->has_itree) {