[PARISC] fix panic on prefetch(NULL) on PA7300LC
authorJames Bottomley <JBottomley@Parallels.com>
Wed, 16 May 2012 10:10:27 +0000 (11:10 +0100)
committerJames Bottomley <JBottomley@Parallels.com>
Wed, 16 May 2012 12:15:21 +0000 (13:15 +0100)
commitb3cb8674811d1851bbf1486a73d62b90c119b994
treec2158cee689175a1fae57767ab8b4c955d0a237c
parent207f583d7179f707f402c36a7bda5ca1fd03ad5b
[PARISC] fix panic on prefetch(NULL) on PA7300LC

Due to an errata, the PA7300LC generates a TLB miss interruption even on the
prefetch instruction.  This means that prefetch(NULL), which is supposed to be
a nop on linux actually generates a NULL deref fault.  Fix this by testing the
address of prefetch against NULL before doing the prefetch.

Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
arch/parisc/include/asm/prefetch.h