From: Oleg Nesterov Date: Sun, 29 Jul 2012 18:22:36 +0000 (+0200) Subject: uprobes: Remove copy_vma()->uprobe_mmap() X-Git-Tag: v3.6-rc1~32^2~6 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6dab3cc078e3da0d26534410bc9e018a17031d95;p=platform%2Fkernel%2Flinux-exynos.git uprobes: Remove copy_vma()->uprobe_mmap() Remove copy_vma()->uprobe_mmap(new_vma), it is absolutely wrong. This new_vma was just initialized to represent the new unmapped area, [vm_start, vm_end) was returned by get_unmapped_area() in the caller. This means that uprobe_mmap()->get_user_pages() will fail for sure, simply because find_vma() can never succeed. And I verified that sys_mremap()->mremap_to() indeed always fails with the wrong ENOMEM code if [addr, addr+old_len] is probed. And why this uprobe_mmap() was added? I believe the intent was wrong. Note that the caller is going to do move_page_tables(), all registered uprobes are already faulted in, we only change the virtual addresses. NOTE: However, somehow we need to close the race with uprobe_register() which relies on map_info->vaddr. This needs another fix I'll try to do later. Probably we need uprobe_mmap() in move_vma() but we can not do this right now, this can confuse uprobes_state.counter (which I still hope we are going to kill). Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju Cc: Anton Arapov Cc: Srikar Dronamraju Link: http://lkml.kernel.org/r/20120729182236.GA20342@redhat.com Signed-off-by: Ingo Molnar --- diff --git a/mm/mmap.c b/mm/mmap.c index 3edfcdf..e5a4614 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2418,9 +2418,6 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap, if (new_vma->vm_file) { get_file(new_vma->vm_file); - if (uprobe_mmap(new_vma)) - goto out_free_mempol; - if (vma->vm_flags & VM_EXECUTABLE) added_exe_file_vma(mm); }