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 <[email protected]>
