diff options
| author | James Bottomley <JBottomley@Parallels.com> | 2012-05-16 11:10:27 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-06-01 15:12:53 +0800 |
| commit | 63ce590e41683a7ba1895a1d79b29a62b06c7613 (patch) | |
| tree | 896d37da279ae651d74bc75daa84d3b9fb8bfcfe | |
| parent | 2952561d79919e78efee8d43b499aa4d21453f03 (diff) | |
PARISC: fix panic on prefetch(NULL) on PA7300LC
commit b3cb8674811d1851bbf1486a73d62b90c119b994 upstream.
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.
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/parisc/include/asm/prefetch.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/parisc/include/asm/prefetch.h b/arch/parisc/include/asm/prefetch.h index c5edc60c059..1ee7c82672c 100644 --- a/arch/parisc/include/asm/prefetch.h +++ b/arch/parisc/include/asm/prefetch.h @@ -21,7 +21,12 @@ #define ARCH_HAS_PREFETCH static inline void prefetch(const void *addr) { - __asm__("ldw 0(%0), %%r0" : : "r" (addr)); + __asm__( +#ifndef CONFIG_PA20 + /* Need to avoid prefetch of NULL on PA7300LC */ + " extrw,u,= %0,31,32,%%r0\n" +#endif + " ldw 0(%0), %%r0" : : "r" (addr)); } /* LDD is a PA2.0 addition. */ |