Messages in this thread Patch in this message | | | Date | Sun, 24 Jun 2012 17:00:02 +0200 | From | Oleg Nesterov <> | Subject | [PATCH v2 1/5] uprobes: don't recheck vma/f_mapping in write_opcode() |
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write_opcode() rechecks valid_vma() and ->f_mapping, this is pointless. The caller, register_for_each_vma() or uprobe_mmap(), has already done these checks under mmap_sem.
To clarify, uprobe_mmap() checks valid_vma() only, but we can rely on build_probe_list(vm_file->f_mapping->host).
Signed-off-by: Oleg Nesterov <oleg@redhat.com> --- kernel/events/uprobes.c | 19 +------------------ 1 files changed, 1 insertions(+), 18 deletions(-)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index f935327..a2b32a5 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -206,33 +206,16 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_t opcode) { struct page *old_page, *new_page; - struct address_space *mapping; void *vaddr_old, *vaddr_new; struct vm_area_struct *vma; - struct uprobe *uprobe; 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) return ret; - ret = -EINVAL; - - /* - * We are interested in text pages only. Our pages of interest - * should be mapped for read and execute only. We desist from - * adding probes in write mapped pages since the breakpoints - * might end up in the file copy. - */ - if (!valid_vma(vma, is_swbp_insn(&opcode))) - goto put_out; - - uprobe = container_of(auprobe, struct uprobe, arch); - mapping = uprobe->inode->i_mapping; - if (mapping != vma->vm_file->f_mapping) - goto put_out; - ret = -ENOMEM; new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vaddr); if (!new_page) -- 1.5.5.1
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