diff options
Diffstat (limited to 'kernel/events/uprobes.c')
| -rw-r--r-- | kernel/events/uprobes.c | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 96d4bee83489..8aef47ee7bfa 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -171,11 +171,11 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr, .address = addr, }; int err; - /* For mmu_notifiers */ - const unsigned long mmun_start = addr; - const unsigned long mmun_end = addr + PAGE_SIZE; + struct mmu_notifier_range range; struct mem_cgroup *memcg; + mmu_notifier_range_init(&range, mm, addr, addr + PAGE_SIZE); + VM_BUG_ON_PAGE(PageTransHuge(old_page), old_page); err = mem_cgroup_try_charge(new_page, vma->vm_mm, GFP_KERNEL, &memcg, @@ -186,7 +186,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr, /* For try_to_free_swap() and munlock_vma_page() below */ lock_page(old_page); - mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end); + mmu_notifier_invalidate_range_start(&range); err = -EAGAIN; if (!page_vma_mapped_walk(&pvmw)) { mem_cgroup_cancel_charge(new_page, memcg, false); @@ -220,7 +220,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr, err = 0; unlock: - mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); + mmu_notifier_invalidate_range_end(&range); unlock_page(old_page); return err; } @@ -572,7 +572,9 @@ static void put_uprobe(struct uprobe *uprobe) * gets called, we don't get a chance to remove uprobe from * delayed_uprobe_list from remove_breakpoint(). Do it here. */ + mutex_lock(&delayed_uprobe_lock); delayed_uprobe_remove(uprobe, NULL); + mutex_unlock(&delayed_uprobe_lock); kfree(uprobe); } } @@ -829,7 +831,7 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file, BUG_ON((uprobe->offset & ~PAGE_MASK) + UPROBE_SWBP_INSN_SIZE > PAGE_SIZE); - smp_wmb(); /* pairs with rmb() in find_active_uprobe() */ + smp_wmb(); /* pairs with the smp_rmb() in handle_swbp() */ set_bit(UPROBE_COPY_INSN, &uprobe->flags); out: @@ -2178,10 +2180,18 @@ static void handle_swbp(struct pt_regs *regs) * After we hit the bp, _unregister + _register can install the * new and not-yet-analyzed uprobe at the same address, restart. */ - smp_rmb(); /* pairs with wmb() in install_breakpoint() */ if (unlikely(!test_bit(UPROBE_COPY_INSN, &uprobe->flags))) goto out; + /* + * Pairs with the smp_wmb() in prepare_uprobe(). + * + * Guarantees that if we see the UPROBE_COPY_INSN bit set, then + * we must also see the stores to &uprobe->arch performed by the + * prepare_uprobe() call. + */ + smp_rmb(); + /* Tracing handlers use ->utask to communicate with fetch methods */ if (!get_utask()) goto out; |
