Messages in this thread | | | Date | Mon, 16 Mar 2015 19:18:03 +0300 | From | Konstantin Khlebnikov <> | Subject | Re: [PATCH] mm: rcu-protected get_mm_exe_file() |
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On 16.03.2015 17:50, Davidlohr Bueso wrote: > On Mon, 2015-03-16 at 15:07 +0100, Oleg Nesterov wrote: >> 3. and we can remove down_write(mmap_sem) from prctl paths. >> >> Actually we can do this even without xchg() above, but we might >> want to kill MMF_EXE_FILE_CHANGED and test_and_set_bit() check. > > Yeah I was waiting for security folks input about this, otherwise this > still doesn't do it for me as we still have to deal with mmap_sem. >
Why? mm->flags are updated atomically. mmap_sem isn't required here.
-- Konstantin
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