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authorAnton Blanchard <anton@samba.org>2013-08-07 02:01:19 +1000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-09-26 17:18:01 -0700
commitd8ba750f9a2feb07bb6f0448807907b674ca4525 (patch)
tree194f1095bd74b52ff88cebe514d0993a0a8568f4 /arch/powerpc
parent139653e11c9eec4d5eff614e688d6bec99b78d7f (diff)
downloadlinaro-lsk-d8ba750f9a2feb07bb6f0448807907b674ca4525.tar.gz
powerpc: Handle unaligned ldbrx/stdbrx
commit 230aef7a6a23b6166bd4003bfff5af23c9bd381f upstream. Normally when we haven't implemented an alignment handler for a load or store instruction the process will be terminated. The alignment handler uses the DSISR (or a pseudo one) to locate the right handler. Unfortunately ldbrx and stdbrx overlap lfs and stfs so we incorrectly think ldbrx is an lfs and stdbrx is an stfs. This bug is particularly nasty - instead of terminating the process we apply an incorrect fixup and continue on. With more and more overlapping instructions we should stop creating a pseudo DSISR and index using the instruction directly, but for now add a special case to catch ldbrx/stdbrx. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/kernel/align.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/align.c b/arch/powerpc/kernel/align.c
index ee5b690a0be..52e5758ea36 100644
--- a/arch/powerpc/kernel/align.c
+++ b/arch/powerpc/kernel/align.c
@@ -764,6 +764,16 @@ int fix_alignment(struct pt_regs *regs)
nb = aligninfo[instr].len;
flags = aligninfo[instr].flags;
+ /* ldbrx/stdbrx overlap lfs/stfs in the DSISR unfortunately */
+ if (IS_XFORM(instruction) && ((instruction >> 1) & 0x3ff) == 532) {
+ nb = 8;
+ flags = LD+SW;
+ } else if (IS_XFORM(instruction) &&
+ ((instruction >> 1) & 0x3ff) == 660) {
+ nb = 8;
+ flags = ST+SW;
+ }
+
/* Byteswap little endian loads and stores */
swiz = 0;
if (regs->msr & MSR_LE) {