diff options
Diffstat (limited to 'kernel/events/uprobes.c')
-rw-r--r-- | kernel/events/uprobes.c | 48 |
1 files changed, 25 insertions, 23 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index ece7e13f6e4a..bb0862873dba 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -162,14 +162,12 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr, }; int err; struct mmu_notifier_range range; - struct mem_cgroup *memcg; mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, addr, addr + PAGE_SIZE); if (new_page) { - err = mem_cgroup_try_charge(new_page, vma->vm_mm, GFP_KERNEL, - &memcg, false); + err = mem_cgroup_charge(new_page, vma->vm_mm, GFP_KERNEL); if (err) return err; } @@ -179,17 +177,13 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr, mmu_notifier_invalidate_range_start(&range); err = -EAGAIN; - if (!page_vma_mapped_walk(&pvmw)) { - if (new_page) - mem_cgroup_cancel_charge(new_page, memcg, false); + if (!page_vma_mapped_walk(&pvmw)) goto unlock; - } VM_BUG_ON_PAGE(addr != pvmw.address, old_page); if (new_page) { get_page(new_page); page_add_new_anon_rmap(new_page, vma, addr, false); - mem_cgroup_commit_charge(new_page, memcg, false, false); lru_cache_add_active_or_unevictable(new_page, vma); } else /* no new page, just dec_mm_counter for old_page */ @@ -463,7 +457,7 @@ static int update_ref_ctr(struct uprobe *uprobe, struct mm_struct *mm, * @vaddr: the virtual address to store the opcode. * @opcode: opcode to be written at @vaddr. * - * Called with mm->mmap_sem held for write. + * Called with mm->mmap_lock held for write. * Return 0 (success) or a negative errno. */ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, @@ -867,10 +861,6 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file, if (ret) goto out; - /* uprobe_write_opcode() assumes we don't cross page boundary */ - BUG_ON((uprobe->offset & ~PAGE_MASK) + - UPROBE_SWBP_INSN_SIZE > PAGE_SIZE); - smp_wmb(); /* pairs with the smp_rmb() in handle_swbp() */ set_bit(UPROBE_COPY_INSN, &uprobe->flags); @@ -1064,7 +1054,7 @@ register_for_each_vma(struct uprobe *uprobe, struct uprobe_consumer *new) if (err && is_register) goto free; - down_write(&mm->mmap_sem); + mmap_write_lock(mm); vma = find_vma(mm, info->vaddr); if (!vma || !valid_vma(vma, is_register) || file_inode(vma->vm_file) != uprobe->inode) @@ -1086,7 +1076,7 @@ register_for_each_vma(struct uprobe *uprobe, struct uprobe_consumer *new) } unlock: - up_write(&mm->mmap_sem); + mmap_write_unlock(mm); free: mmput(mm); info = free_map_info(info); @@ -1166,6 +1156,15 @@ static int __uprobe_register(struct inode *inode, loff_t offset, if (offset > i_size_read(inode)) return -EINVAL; + /* + * This ensures that copy_from_page(), copy_to_page() and + * __update_ref_ctr() can't cross page boundary. + */ + if (!IS_ALIGNED(offset, UPROBE_SWBP_INSN_SIZE)) + return -EINVAL; + if (!IS_ALIGNED(ref_ctr_offset, sizeof(short))) + return -EINVAL; + retry: uprobe = alloc_uprobe(inode, offset, ref_ctr_offset); if (!uprobe) @@ -1241,7 +1240,7 @@ static int unapply_uprobe(struct uprobe *uprobe, struct mm_struct *mm) struct vm_area_struct *vma; int err = 0; - down_read(&mm->mmap_sem); + mmap_read_lock(mm); for (vma = mm->mmap; vma; vma = vma->vm_next) { unsigned long vaddr; loff_t offset; @@ -1258,7 +1257,7 @@ static int unapply_uprobe(struct uprobe *uprobe, struct mm_struct *mm) vaddr = offset_to_vaddr(vma, uprobe->offset); err |= remove_breakpoint(uprobe, mm, vaddr); } - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); return err; } @@ -1355,7 +1354,7 @@ static int delayed_ref_ctr_inc(struct vm_area_struct *vma) } /* - * Called from mmap_region/vma_adjust with mm->mmap_sem acquired. + * Called from mmap_region/vma_adjust with mm->mmap_lock acquired. * * Currently we ignore all errors and always return 0, the callers * can't handle the failure anyway. @@ -1445,7 +1444,7 @@ static int xol_add_vma(struct mm_struct *mm, struct xol_area *area) struct vm_area_struct *vma; int ret; - if (down_write_killable(&mm->mmap_sem)) + if (mmap_write_lock_killable(mm)) return -EINTR; if (mm->uprobes_state.xol_area) { @@ -1475,7 +1474,7 @@ static int xol_add_vma(struct mm_struct *mm, struct xol_area *area) /* pairs with get_xol_area() */ smp_store_release(&mm->uprobes_state.xol_area, area); /* ^^^ */ fail: - up_write(&mm->mmap_sem); + mmap_write_unlock(mm); return ret; } @@ -1674,7 +1673,7 @@ void __weak arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr, copy_to_page(page, vaddr, src, len); /* - * We probably need flush_icache_user_range() but it needs vma. + * We probably need flush_icache_user_page() but it needs vma. * This should work on most of architectures by default. If * architecture needs to do something different it can define * its own version of the function. @@ -2014,6 +2013,9 @@ static int is_trap_at_addr(struct mm_struct *mm, unsigned long vaddr) uprobe_opcode_t opcode; int result; + if (WARN_ON_ONCE(!IS_ALIGNED(vaddr, UPROBE_SWBP_INSN_SIZE))) + return -EINVAL; + pagefault_disable(); result = __get_user(opcode, (uprobe_opcode_t __user *)vaddr); pagefault_enable(); @@ -2045,7 +2047,7 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp) struct uprobe *uprobe = NULL; struct vm_area_struct *vma; - down_read(&mm->mmap_sem); + mmap_read_lock(mm); vma = find_vma(mm, bp_vaddr); if (vma && vma->vm_start <= bp_vaddr) { if (valid_vma(vma, false)) { @@ -2063,7 +2065,7 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp) if (!uprobe && test_and_clear_bit(MMF_RECALC_UPROBES, &mm->flags)) mmf_recalc_uprobes(mm); - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); return uprobe; } |