diff options
Diffstat (limited to 'kernel/events/uprobes.c')
| -rw-r--r-- | kernel/events/uprobes.c | 35 |
1 files changed, 23 insertions, 12 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 4b7e590dc428..2ec796e2f055 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -103,8 +103,7 @@ struct xol_area { atomic_t slot_count; /* number of in-use slots */ unsigned long *bitmap; /* 0 = free slot */ - struct vm_special_mapping xol_mapping; - struct page *pages[2]; + struct page *page; /* * We keep the vma's vm_start rather than a pointer to the vma * itself. The probed process or a naughty kernel module could make @@ -1466,6 +1465,21 @@ void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned lon set_bit(MMF_RECALC_UPROBES, &vma->vm_mm->flags); } +static vm_fault_t xol_fault(const struct vm_special_mapping *sm, + struct vm_area_struct *vma, struct vm_fault *vmf) +{ + struct xol_area *area = vma->vm_mm->uprobes_state.xol_area; + + vmf->page = area->page; + get_page(vmf->page); + return 0; +} + +static const struct vm_special_mapping xol_mapping = { + .name = "[uprobes]", + .fault = xol_fault, +}; + /* Slot allocation for XOL */ static int xol_add_vma(struct mm_struct *mm, struct xol_area *area) { @@ -1492,7 +1506,7 @@ static int xol_add_vma(struct mm_struct *mm, struct xol_area *area) vma = _install_special_mapping(mm, area->vaddr, PAGE_SIZE, VM_EXEC|VM_MAYEXEC|VM_DONTCOPY|VM_IO, - &area->xol_mapping); + &xol_mapping); if (IS_ERR(vma)) { ret = PTR_ERR(vma); goto fail; @@ -1531,12 +1545,9 @@ static struct xol_area *__create_xol_area(unsigned long vaddr) if (!area->bitmap) goto free_area; - area->xol_mapping.name = "[uprobes]"; - area->xol_mapping.pages = area->pages; - area->pages[0] = alloc_page(GFP_HIGHUSER); - if (!area->pages[0]) + area->page = alloc_page(GFP_HIGHUSER); + if (!area->page) goto free_bitmap; - area->pages[1] = NULL; area->vaddr = vaddr; init_waitqueue_head(&area->wq); @@ -1544,12 +1555,12 @@ static struct xol_area *__create_xol_area(unsigned long vaddr) set_bit(0, area->bitmap); atomic_set(&area->slot_count, 1); insns = arch_uprobe_trampoline(&insns_size); - arch_uprobe_copy_ixol(area->pages[0], 0, insns, insns_size); + arch_uprobe_copy_ixol(area->page, 0, insns, insns_size); if (!xol_add_vma(mm, area)) return area; - __free_page(area->pages[0]); + __free_page(area->page); free_bitmap: kfree(area->bitmap); free_area: @@ -1591,7 +1602,7 @@ void uprobe_clear_state(struct mm_struct *mm) if (!area) return; - put_page(area->pages[0]); + put_page(area->page); kfree(area->bitmap); kfree(area); } @@ -1658,7 +1669,7 @@ static unsigned long xol_get_insn_slot(struct uprobe *uprobe) if (unlikely(!xol_vaddr)) return 0; - arch_uprobe_copy_ixol(area->pages[0], xol_vaddr, + arch_uprobe_copy_ixol(area->page, xol_vaddr, &uprobe->arch.ixol, sizeof(uprobe->arch.ixol)); return xol_vaddr; |