[v4,10/10] mmap locking API: rename mmap_sem to mmap_lock

Message ID	20200415004353.130248-11-walken@google.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=Lua+=57=kvack.org=owner-linux-mm@kernel.org> DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 312D22064A Date: Tue, 14 Apr 2020 17:43:53 -0700 In-Reply-To: <20200415004353.130248-1-walken@google.com> Message-Id: <20200415004353.130248-11-walken@google.com> Mime-Version: 1.0 References: <20200415004353.130248-1-walken@google.com> Subject: [PATCH v4 10/10] mmap locking API: rename mmap_sem to mmap_lock From: Michel Lespinasse <walken@google.com> To: Andrew Morton <akpm@linux-foundation.org>, linux-mm <linux-mm@kvack.org> Cc: LKML <linux-kernel@vger.kernel.org>, Peter Zijlstra <peterz@infradead.org>, Laurent Dufour <ldufour@linux.ibm.com>, Vlastimil Babka <vbabka@suse.cz>, Matthew Wilcox <willy@infradead.org>, Liam Howlett <Liam.Howlett@oracle.com>, Jerome Glisse <jglisse@redhat.com>, Davidlohr Bueso <dave@stgolabs.net>, David Rientjes <rientjes@google.com>, Hugh Dickins <hughd@google.com>, Ying Han <yinghan@google.com>, Jason Gunthorpe <jgg@ziepe.ca>, Daniel Jordan <daniel.m.jordan@oracle.com>, Michel Lespinasse <walken@google.com> Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org Precedence: bulk
Series	Add a new mmap locking API wrapping mmap_sem calls \| expand [v4,00/10] Add a new mmap locking API wrapping mmap_sem calls [v4,01/10] mmap locking API: initial implementation as rwsem wrappers [v4,02/10] MMU notifier: use the new mmap locking API [v4,03/10] DMA reservations: use the new mmap locking API [v4,04/10] mmap locking API: use coccinelle to convert mmap_sem rwsem call sites [v4,05/10] mmap locking API: convert mmap_sem call sites missed by coccinelle [v4,06/10] mmap locking API: convert nested write lock sites [v4,07/10] mmap locking API: add mmap_read_trylock_non_owner() [v4,08/10] mmap locking API: add MMAP_LOCK_INITIALIZER [v4,09/10] mmap locking API: use lockdep_assert_held [v4,10/10] mmap locking API: rename mmap_sem to mmap_lock

diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c index 693f00b117e1..9b95050c2048 100644 --- a/arch/ia64/mm/fault.c +++ b/arch/ia64/mm/fault.c @@ -70,8 +70,8 @@ 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/events/core.c b/arch/x86/events/core.c index a619763e96e1..eda117ca1c43 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -2179,10 +2179,10 @@ static void x86_pmu_event_mapped(struct perf_event *event, struct mm_struct *mm) * userspace with CR4.PCE clear while another task is still * doing on_each_cpu_mask() to propagate CR4.PCE. * - * For now, this can't happen because all callers hold mmap_sem + * For now, this can't happen because all callers hold mmap_lock * for write. If this changes, we'll need a different solution. */ - lockdep_assert_held_write(&mm->mmap_sem); + lockdep_assert_held_write(&mm->mmap_lock); if (atomic_inc_return(&mm->context.perf_rdpmc_allowed) == 1) on_each_cpu_mask(mm_cpumask(mm), refresh_pce, NULL, 1); diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c index 4b79335624b1..4792e8778b28 100644 --- a/arch/x86/kernel/tboot.c +++ b/arch/x86/kernel/tboot.c @@ -90,7 +90,7 @@ static struct mm_struct tboot_mm = { .pgd = swapper_pg_dir, .mm_users = ATOMIC_INIT(2), .mm_count = ATOMIC_INIT(1), - .mmap_sem = MMAP_LOCK_INITIALIZER(init_mm.mmap_sem), + .mmap_lock = MMAP_LOCK_INITIALIZER(init_mm.mmap_lock), .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock), .mmlist = LIST_HEAD_INIT(init_mm.mmlist), }; diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 181f66b9049f..35f530f9dfc0 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1522,7 +1522,7 @@ 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); trace_page_fault_entries(regs, hw_error_code, address); if (unlikely(kmmio_fault(regs, address))) diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 4bac9d7a48a6..b124fdbc1492 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -54,7 +54,7 @@ struct mm_struct efi_mm = { .mm_rb = RB_ROOT, .mm_users = ATOMIC_INIT(2), .mm_count = ATOMIC_INIT(1), - .mmap_sem = MMAP_LOCK_INITIALIZER(efi_mm.mmap_sem), + .mmap_lock = MMAP_LOCK_INITIALIZER(efi_mm.mmap_lock), .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock), .mmlist = LIST_HEAD_INIT(efi_mm.mmlist), .cpu_bitmap = { [BITS_TO_LONGS(NR_CPUS)] = 0}, 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(&current->mm->mmap_sem); + might_lock_read(&current->mm->mmap_lock); if (userptr->mm != current->mm) return -EPERM; diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 81ae8315f1e6..2d1be141757a 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -234,7 +234,7 @@ static inline bool userfaultfd_huge_must_wait(struct userfaultfd_ctx *ctx, pte_t *ptep, pte; bool ret = true; - lockdep_assert_held(&mm->mmap_sem); + lockdep_assert_held(&mm->mmap_lock); ptep = huge_pte_offset(mm, address, vma_mmu_pagesize(vma)); @@ -286,7 +286,7 @@ static inline bool userfaultfd_must_wait(struct userfaultfd_ctx *ctx, pte_t *pte; bool ret = true; - lockdep_assert_held(&mm->mmap_sem); + lockdep_assert_held(&mm->mmap_lock); pgd = pgd_offset(mm, address); if (!pgd_present(*pgd)) @@ -405,7 +405,7 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason) * Coredumping runs without mmap_sem so we can only check that * the mmap_sem is held, if PF_DUMPCORE was not set. */ - lockdep_assert_held(&mm->mmap_sem); + lockdep_assert_held(&mm->mmap_lock); ctx = vmf->vma->vm_userfaultfd_ctx.ctx; if (!ctx) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 4aba6c0c2ba8..d13b90399c16 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -436,7 +436,7 @@ 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 07efa379664a..fc156433216d 100644 --- a/include/linux/mmap_lock.h +++ b/include/linux/mmap_lock.h @@ -5,63 +5,63 @@ 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_downgrade_write_lock(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; @@ -69,7 +69,7 @@ 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); } #endif /* _LINUX_MMAP_LOCK_H */ diff --git a/mm/gup.c b/mm/gup.c index dd8f045b047b..e2fdf296a1a8 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1403,7 +1403,7 @@ long populate_vma_page_range(struct vm_area_struct *vma, VM_BUG_ON(end & ~PAGE_MASK); VM_BUG_ON_VMA(start < vma->vm_start, vma); VM_BUG_ON_VMA(end > vma->vm_end, vma); - lockdep_assert_held(&mm->mmap_sem); + lockdep_assert_held(&mm->mmap_lock); gup_flags = FOLL_TOUCH | FOLL_POPULATE | FOLL_MLOCK; if (vma->vm_flags & VM_LOCKONFAULT) diff --git a/mm/hmm.c b/mm/hmm.c index 280585833adf..8660aec6aafa 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -581,7 +581,7 @@ long hmm_range_fault(struct hmm_range *range) struct mm_struct *mm = range->notifier->mm; int ret; - lockdep_assert_held(&mm->mmap_sem); + lockdep_assert_held(&mm->mmap_lock); do { /* If range is no longer valid force retry. */ diff --git a/mm/init-mm.c b/mm/init-mm.c index 3c128bd6a30c..2b16924419b4 100644 --- a/mm/init-mm.c +++ b/mm/init-mm.c @@ -31,7 +31,7 @@ struct mm_struct init_mm = { .pgd = swapper_pg_dir, .mm_users = ATOMIC_INIT(2), .mm_count = ATOMIC_INIT(1), - .mmap_sem = MMAP_LOCK_INITIALIZER(init_mm.mmap_sem), + .mmap_lock = MMAP_LOCK_INITIALIZER(init_mm.mmap_lock), .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock), .arg_lock = __SPIN_LOCK_UNLOCKED(init_mm.arg_lock), .mmlist = LIST_HEAD_INIT(init_mm.mmlist), diff --git a/mm/memory.c b/mm/memory.c index 66baf5142e6b..8ae378527248 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1214,7 +1214,7 @@ static inline unsigned long zap_pud_range(struct mmu_gather *tlb, next = pud_addr_end(addr, end); if (pud_trans_huge(*pud) || pud_devmap(*pud)) { if (next - addr != HPAGE_PUD_SIZE) { - lockdep_assert_held(&tlb->mm->mmap_sem); + lockdep_assert_held(&tlb->mm->mmap_lock); split_huge_pud(vma, pud, addr); } else if (zap_huge_pud(tlb, vma, pud, addr)) goto next; @@ -4811,7 +4811,7 @@ 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(&current->mm->mmap_sem); + might_lock_read(&current->mm->mmap_lock); #endif } EXPORT_SYMBOL(__might_fault); diff --git a/mm/mmap.c b/mm/mmap.c index 79597ec2366d..5b3b94ad20e2 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 cfd0a03bf5cc..6717278d6d49 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -599,7 +599,7 @@ void __mmu_notifier_invalidate_range(struct mm_struct *mm, } /* - * Same as mmu_notifier_register but here the caller must hold the mmap_sem in + * Same as mmu_notifier_register but here the caller must hold the mmap_lock in * write mode. A NULL mn signals the notifier is being registered for itree * mode. */ @@ -609,7 +609,7 @@ int __mmu_notifier_register(struct mmu_notifier *subscription, struct mmu_notifier_subscriptions *subscriptions = NULL; int ret; - lockdep_assert_held_write(&mm->mmap_sem); + lockdep_assert_held_write(&mm->mmap_lock); BUG_ON(atomic_read(&mm->mm_users) <= 0); if (IS_ENABLED(CONFIG_LOCKDEP)) { @@ -623,7 +623,7 @@ int __mmu_notifier_register(struct mmu_notifier *subscription, /* * kmalloc cannot be called under mm_take_all_locks(), but we * know that mm->notifier_subscriptions can't change while we - * hold the write side of the mmap_sem. + * hold the write side of the mmap_lock. */ subscriptions = kzalloc( sizeof(struct mmu_notifier_subscriptions), GFP_KERNEL); @@ -655,7 +655,7 @@ int __mmu_notifier_register(struct mmu_notifier *subscription, * readers. acquire can only be used while holding the mmgrab or * mmget, and is safe because once created the * mmu_notifier_subscriptions is not freed until the mm is destroyed. - * As above, users holding the mmap_sem or one of the + * As above, users holding the mmap_lock or one of the * mm_take_all_locks() do not need to use acquire semantics. */ if (subscriptions) @@ -689,7 +689,7 @@ EXPORT_SYMBOL_GPL(__mmu_notifier_register); * @mn: The notifier to attach * @mm: The mm to attach the notifier to * - * Must not hold mmap_sem nor any other VM related lock when calling + * Must not hold mmap_lock nor any other VM related lock when calling * this registration function. Must also ensure mm_users can't go down * to zero while this runs to avoid races with mmu_notifier_release, * so mm has to be current->mm or the mm should be pinned safely such @@ -750,7 +750,7 @@ find_get_mmu_notifier(struct mm_struct *mm, const struct mmu_notifier_ops *ops) * are the same. * * Each call to mmu_notifier_get() must be paired with a call to - * mmu_notifier_put(). The caller must hold the write side of mm->mmap_sem. + * mmu_notifier_put(). The caller must hold the write side of mm->mmap_lock. * * While the caller has a mmu_notifier get the mm pointer will remain valid, * and can be converted to an active mm pointer via mmget_not_zero(). @@ -761,7 +761,7 @@ struct mmu_notifier *mmu_notifier_get_locked(const struct mmu_notifier_ops *ops, struct mmu_notifier *subscription; int ret; - lockdep_assert_held_write(&mm->mmap_sem); + lockdep_assert_held_write(&mm->mmap_lock); if (mm->notifier_subscriptions) { subscription = find_get_mmu_notifier(mm, ops); @@ -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) { @@ -1006,7 +1006,7 @@ int mmu_interval_notifier_insert_locked( mm->notifier_subscriptions; int ret; - lockdep_assert_held_write(&mm->mmap_sem); + lockdep_assert_held_write(&mm->mmap_lock); if (!subscriptions || !subscriptions->has_itree) { ret = __mmu_notifier_register(NULL, mm); diff --git a/mm/pagewalk.c b/mm/pagewalk.c index 928df1638c30..d669a3146c0f 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -373,8 +373,9 @@ static int __walk_page_range(unsigned long start, unsigned long end, * caller-specific data to callbacks, @private should be helpful. * * Locking: - * Callers of walk_page_range() and walk_page_vma() should hold @mm->mmap_sem, - * because these function traverse vma list and/or access to vma's data. + * Callers of walk_page_range() and walk_page_vma() should hold + * @mm->mmap_lock, because these function traverse the vma list + * and/or access the vma's data. */ int walk_page_range(struct mm_struct *mm, unsigned long start, unsigned long end, const struct mm_walk_ops *ops, @@ -395,7 +396,7 @@ int walk_page_range(struct mm_struct *mm, unsigned long start, if (!walk.mm) return -EINVAL; - lockdep_assert_held(&walk.mm->mmap_sem); + lockdep_assert_held(&walk.mm->mmap_lock); vma = find_vma(walk.mm, start); do { @@ -453,7 +454,7 @@ int walk_page_range_novma(struct mm_struct *mm, unsigned long start, if (start >= end || !walk.mm) return -EINVAL; - lockdep_assert_held(&walk.mm->mmap_sem); + lockdep_assert_held(&walk.mm->mmap_lock); return __walk_page_range(start, end, &walk); } @@ -472,7 +473,7 @@ int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops, if (!walk.mm) return -EINVAL; - lockdep_assert_held(&walk.mm->mmap_sem); + lockdep_assert_held(&walk.mm->mmap_lock); err = walk_page_test(vma->vm_start, vma->vm_end, &walk); if (err > 0) @@ -498,11 +499,11 @@ int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops, * Also see walk_page_range() for additional information. * * Locking: - * This function can't require that the struct mm_struct::mmap_sem is held, + * This function can't require that the struct mm_struct::mmap_lock is held, * since @mapping may be mapped by multiple processes. Instead * @mapping->i_mmap_rwsem must be held. This might have implications in the * callbacks, and it's up tho the caller to ensure that the - * struct mm_struct::mmap_sem is not needed. + * struct mm_struct::mmap_lock is not needed. * * Also this means that a caller can't rely on the struct * vm_area_struct::vm_flags to be constant across a call, diff --git a/mm/util.c b/mm/util.c index ea2e15b21446..56c562f7ad19 100644 --- a/mm/util.c +++ b/mm/util.c @@ -425,7 +425,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) * @bypass_rlim: %true if checking RLIMIT_MEMLOCK should be skipped * * Assumes @task and @mm are valid (i.e. at least one reference on each), and - * that mmap_sem is held as writer. + * that mmap_lock is held as writer. * * Return: * * 0 on success @@ -437,7 +437,7 @@ int __account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc, unsigned long locked_vm, limit; int ret = 0; - lockdep_assert_held_write(&mm->mmap_sem); + lockdep_assert_held_write(&mm->mmap_lock); locked_vm = mm->locked_vm; if (inc) {

[v4,10/10] mmap locking API: rename mmap_sem to mmap_lock

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