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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 09:54:46 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 09:54:46 -0700 |
commit | a5ad5742f671de906adbf29fbedf0a04705cebad (patch) | |
tree | 88d1a4c18e2025a5a8335dbbc9dea8bebeba5789 /fs/userfaultfd.c | |
parent | 013b2deba9a6b80ca02f4fafd7dedf875e9b4450 (diff) | |
parent | 4fa7252338a56fbc90220e6330f136a379175a7a (diff) | |
download | linux-a5ad5742f671de906adbf29fbedf0a04705cebad.tar.gz linux-a5ad5742f671de906adbf29fbedf0a04705cebad.tar.bz2 linux-a5ad5742f671de906adbf29fbedf0a04705cebad.zip |
Merge branch 'akpm' (patches from Andrew)
Merge even more updates from Andrew Morton:
- a kernel-wide sweep of show_stack()
- pagetable cleanups
- abstract out accesses to mmap_sem - prep for mmap_sem scalability work
- hch's user acess work
Subsystems affected by this patch series: debug, mm/pagemap, mm/maccess,
mm/documentation.
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (93 commits)
include/linux/cache.h: expand documentation over __read_mostly
maccess: return -ERANGE when probe_kernel_read() fails
x86: use non-set_fs based maccess routines
maccess: allow architectures to provide kernel probing directly
maccess: move user access routines together
maccess: always use strict semantics for probe_kernel_read
maccess: remove strncpy_from_unsafe
tracing/kprobes: handle mixed kernel/userspace probes better
bpf: rework the compat kernel probe handling
bpf:bpf_seq_printf(): handle potentially unsafe format string better
bpf: handle the compat string in bpf_trace_copy_string better
bpf: factor out a bpf_trace_copy_string helper
maccess: unify the probe kernel arch hooks
maccess: remove probe_read_common and probe_write_common
maccess: rename strnlen_unsafe_user to strnlen_user_nofault
maccess: rename strncpy_from_unsafe_strict to strncpy_from_kernel_nofault
maccess: rename strncpy_from_unsafe_user to strncpy_from_user_nofault
maccess: update the top of file comment
maccess: clarify kerneldoc comments
maccess: remove duplicate kerneldoc comments
...
Diffstat (limited to 'fs/userfaultfd.c')
-rw-r--r-- | fs/userfaultfd.c | 46 |
1 files changed, 23 insertions, 23 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index e39fdec8a0b0..52de29000c7e 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; - VM_BUG_ON(!rwsem_is_locked(&mm->mmap_sem)); + mmap_assert_locked(mm); 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; - VM_BUG_ON(!rwsem_is_locked(&mm->mmap_sem)); + mmap_assert_locked(mm); pgd = pgd_offset(mm, address); if (!pgd_present(*pgd)) @@ -369,13 +369,13 @@ static inline bool userfaultfd_signal_pending(unsigned int flags) * FAULT_FLAG_KILLABLE are not straightforward. The "Caution" * recommendation in __lock_page_or_retry is not an understatement. * - * If FAULT_FLAG_ALLOW_RETRY is set, the mmap_sem must be released + * If FAULT_FLAG_ALLOW_RETRY is set, the mmap_lock must be released * before returning VM_FAULT_RETRY only if FAULT_FLAG_RETRY_NOWAIT is * not set. * * If FAULT_FLAG_ALLOW_RETRY is set but FAULT_FLAG_KILLABLE is not * set, VM_FAULT_RETRY can still be returned if and only if there are - * fatal_signal_pending()s, and the mmap_sem must be released before + * fatal_signal_pending()s, and the mmap_lock must be released before * returning it. */ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason) @@ -396,16 +396,16 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason) * FOLL_DUMP case, anon memory also checks for FOLL_DUMP with * the no_page_table() helper in follow_page_mask(), but the * shmem_vm_ops->fault method is invoked even during - * coredumping without mmap_sem and it ends up here. + * coredumping without mmap_lock and it ends up here. */ if (current->flags & (PF_EXITING|PF_DUMPCORE)) goto out; /* - * Coredumping runs without mmap_sem so we can only check that - * the mmap_sem is held, if PF_DUMPCORE was not set. + * Coredumping runs without mmap_lock so we can only check that + * the mmap_lock is held, if PF_DUMPCORE was not set. */ - WARN_ON_ONCE(!rwsem_is_locked(&mm->mmap_sem)); + mmap_assert_locked(mm); ctx = vmf->vma->vm_userfaultfd_ctx.ctx; if (!ctx) @@ -422,7 +422,7 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason) /* * If it's already released don't get it. This avoids to loop * in __get_user_pages if userfaultfd_release waits on the - * caller of handle_userfault to release the mmap_sem. + * caller of handle_userfault to release the mmap_lock. */ if (unlikely(READ_ONCE(ctx->released))) { /* @@ -481,7 +481,7 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason) if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT) goto out; - /* take the reference before dropping the mmap_sem */ + /* take the reference before dropping the mmap_lock */ userfaultfd_ctx_get(ctx); init_waitqueue_func_entry(&uwq.wq, userfaultfd_wake_function); @@ -514,7 +514,7 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason) must_wait = userfaultfd_huge_must_wait(ctx, vmf->vma, vmf->address, vmf->flags, reason); - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); if (likely(must_wait && !READ_ONCE(ctx->released) && !userfaultfd_signal_pending(vmf->flags))) { @@ -637,7 +637,7 @@ static void userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx, struct mm_struct *mm = release_new_ctx->mm; /* the various vma->vm_userfaultfd_ctx still points to it */ - down_write(&mm->mmap_sem); + mmap_write_lock(mm); /* no task can run (and in turn coredump) yet */ VM_WARN_ON(!mmget_still_valid(mm)); for (vma = mm->mmap; vma; vma = vma->vm_next) @@ -645,7 +645,7 @@ static void userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx, vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; vma->vm_flags &= ~(VM_UFFD_WP | VM_UFFD_MISSING); } - up_write(&mm->mmap_sem); + mmap_write_unlock(mm); userfaultfd_ctx_put(release_new_ctx); } @@ -799,7 +799,7 @@ bool userfaultfd_remove(struct vm_area_struct *vma, userfaultfd_ctx_get(ctx); WRITE_ONCE(ctx->mmap_changing, true); - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); msg_init(&ewq.msg); @@ -890,11 +890,11 @@ static int userfaultfd_release(struct inode *inode, struct file *file) * Flush page faults out of all CPUs. NOTE: all page faults * must be retried without returning VM_FAULT_SIGBUS if * userfaultfd_ctx_get() succeeds but vma->vma_userfault_ctx - * changes while handle_userfault released the mmap_sem. So + * changes while handle_userfault released the mmap_lock. So * it's critical that released is set to true (above), before - * taking the mmap_sem for writing. + * taking the mmap_lock for writing. */ - down_write(&mm->mmap_sem); + mmap_write_lock(mm); still_valid = mmget_still_valid(mm); prev = NULL; for (vma = mm->mmap; vma; vma = vma->vm_next) { @@ -920,7 +920,7 @@ static int userfaultfd_release(struct inode *inode, struct file *file) vma->vm_flags = new_flags; vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; } - up_write(&mm->mmap_sem); + mmap_write_unlock(mm); mmput(mm); wakeup: /* @@ -1248,7 +1248,7 @@ static __always_inline void wake_userfault(struct userfaultfd_ctx *ctx, /* * To be sure waitqueue_active() is not reordered by the CPU * before the pagetable update, use an explicit SMP memory - * barrier here. PT lock release or up_read(mmap_sem) still + * barrier here. PT lock release or mmap_read_unlock(mm) still * have release semantics that can allow the * waitqueue_active() to be reordered before the pte update. */ @@ -1345,7 +1345,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, if (!mmget_not_zero(mm)) goto out; - down_write(&mm->mmap_sem); + mmap_write_lock(mm); if (!mmget_still_valid(mm)) goto out_unlock; vma = find_vma_prev(mm, start, &prev); @@ -1492,7 +1492,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, vma = vma->vm_next; } while (vma && vma->vm_start < end); out_unlock: - up_write(&mm->mmap_sem); + mmap_write_unlock(mm); mmput(mm); if (!ret) { __u64 ioctls_out; @@ -1547,7 +1547,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx, if (!mmget_not_zero(mm)) goto out; - down_write(&mm->mmap_sem); + mmap_write_lock(mm); if (!mmget_still_valid(mm)) goto out_unlock; vma = find_vma_prev(mm, start, &prev); @@ -1664,7 +1664,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx, vma = vma->vm_next; } while (vma && vma->vm_start < end); out_unlock: - up_write(&mm->mmap_sem); + mmap_write_unlock(mm); mmput(mm); out: return ret; |