Messages in this thread | | | Date | Tue, 31 Jan 2017 16:44:42 +0100 | From | Oleg Nesterov <> | Subject | Re: [PATCHv3 01/12] uprobes: split THPs before trying replace them |
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On 01/29, Kirill A. Shutemov wrote: > > For THPs page_check_address() always fails. It leads to endless loop in > uprobe_write_opcode(). > > Testcase with huge-tmpfs (not sure if it's possible to trigger this > uprobe codepath for anon memory):
No, you can't probe the anonymous memory,
> --- a/kernel/events/uprobes.c > +++ b/kernel/events/uprobes.c > @@ -300,8 +300,8 @@ int uprobe_write_opcode(struct mm_struct *mm, unsigned long vaddr, > > retry: > /* Read the page with vaddr into memory */ > - ret = get_user_pages_remote(NULL, mm, vaddr, 1, FOLL_FORCE, &old_page, > - &vma, NULL); > + ret = get_user_pages_remote(NULL, mm, vaddr, 1, > + FOLL_FORCE | FOLL_SPLIT, &old_page, &vma, NULL); > if (ret <= 0) > return ret;
Thanks,
Acked-by: Oleg Nesterov <oleg@redhat.com>
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