Messages in this thread | | | Subject | mlock behavior across fork, as broken as it looks? | Date | Mon, 28 Feb 2000 13:56:18 +0100 | From | Olaf Titz <> |
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According to the mlock(2) manpage, "Child processes do not inherit page locks across a fork." Even if I call mlock() for the critical pages again just after the fork(), in my understanding there is a small time window when the pages can, theoretically, be swapped out. (Increase this window for a potential exploit with the usual high load, high mem pressure attack.)
So is it really impossible to guarantee that locked pages will never be swapped out if the process holding them does fork? This would be a severe limitation for the case of cryptographic keys, as it in effect means "fork() is forbidden for such applications". If so, this is a deficiency which should be fixed.
Olaf
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