diff options
Diffstat (limited to 'kernel/events/uprobes.c')
-rw-r--r-- | kernel/events/uprobes.c | 41 |
1 files changed, 13 insertions, 28 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 604930bf9c92..3ccdb29ee8d6 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -129,33 +129,17 @@ static loff_t vma_address(struct vm_area_struct *vma, loff_t offset) static int __replace_page(struct vm_area_struct *vma, struct page *page, struct page *kpage) { struct mm_struct *mm = vma->vm_mm; - pgd_t *pgd; - pud_t *pud; - pmd_t *pmd; - pte_t *ptep; - spinlock_t *ptl; unsigned long addr; - int err = -EFAULT; + spinlock_t *ptl; + pte_t *ptep; addr = page_address_in_vma(page, vma); if (addr == -EFAULT) - goto out; - - pgd = pgd_offset(mm, addr); - if (!pgd_present(*pgd)) - goto out; - - pud = pud_offset(pgd, addr); - if (!pud_present(*pud)) - goto out; + return -EFAULT; - pmd = pmd_offset(pud, addr); - if (!pmd_present(*pmd)) - goto out; - - ptep = pte_offset_map_lock(mm, pmd, addr, &ptl); + ptep = page_check_address(page, mm, addr, &ptl, 0); if (!ptep) - goto out; + return -EAGAIN; get_page(kpage); page_add_new_anon_rmap(kpage, vma, addr); @@ -174,10 +158,8 @@ static int __replace_page(struct vm_area_struct *vma, struct page *page, struct try_to_free_swap(page); put_page(page); pte_unmap_unlock(ptep, ptl); - err = 0; -out: - return err; + return 0; } /** @@ -222,9 +204,10 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, void *vaddr_old, *vaddr_new; struct vm_area_struct *vma; struct uprobe *uprobe; + unsigned long pgoff; loff_t addr; int ret; - +retry: /* Read the page with vaddr into memory */ ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &old_page, &vma); if (ret <= 0) @@ -269,9 +252,9 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, memcpy(vaddr_new, vaddr_old, PAGE_SIZE); /* poke the new insn in, ASSUMES we don't cross page boundary */ - vaddr &= ~PAGE_MASK; - BUG_ON(vaddr + UPROBE_SWBP_INSN_SIZE > PAGE_SIZE); - memcpy(vaddr_new + vaddr, &opcode, UPROBE_SWBP_INSN_SIZE); + pgoff = (vaddr & ~PAGE_MASK); + BUG_ON(pgoff + UPROBE_SWBP_INSN_SIZE > PAGE_SIZE); + memcpy(vaddr_new + pgoff, &opcode, UPROBE_SWBP_INSN_SIZE); kunmap_atomic(vaddr_new); kunmap_atomic(vaddr_old); @@ -291,6 +274,8 @@ unlock_out: put_out: put_page(old_page); + if (unlikely(ret == -EAGAIN)) + goto retry; return ret; } |