Commit 08334222 authored Oct 29, 2008 by Kurt Garloff Committed by Linus Torvalds Oct 30, 2008

mm: increase the default mlock limit from 32k to 64k



By default, non-privileged tasks can only mlock() a small amount of
memory to avoid a DoS attack by ordinary users.  The Linux kernel
defaulted to 32k (on a 4k page size system) to accommodate the needs of
gpg.

However, newer gpg2 needs 64k in various circumstances and otherwise
fails miserably, see bnc#329675.

Change the default to 64k, and make it more agnostic to PAGE_SIZE.

Signed-off-by: Kurt Garloff <garloff@suse.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent e946217e

include/linux/resource.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -59,10 +59,10 @@ struct rlimit {
		#define _STK_LIM (810241024)

		/*
		* GPG wants 32kB of mlocked memory, to make sure pass phrases
		* GPG2 wants 64kB of mlocked memory, to make sure pass phrases
		* and other sensitive information are never written to disk.
		*/
		#define MLOCK_LIMIT (8 * PAGE_SIZE)
		#define MLOCK_LIMIT ((PAGE_SIZE > 641024) ? PAGE_SIZE : 641024)

		/*
		* Due to binary compatibility, the actual resource numbers

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