[patch 55/96] powerpc: Fix load/store float double alignment handler

Greg KH
2009-03-14T00:37:50Z

[-- Attachment #1: powerpc-fix-load-store-float-double-alignment-handler.patch --]
[-- Type: text/plain, Size: 2008 bytes --]

2.6.27-stable review patch. If anyone has any objections, please let us know.

------------------

From: Michael Neuling <mikey@neuling.org>

commit 49f297f8df9adb797334155470ea9ca68bdb041e upstream.

When we introduced VSX, we changed the way FPRs are stored in the
thread_struct. Unfortunately we missed the load/store float double
alignment handler code when updating how we access FPRs in the
thread_struct.

Below fixes this and merges the little/big endian case.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
arch/powerpc/kernel/align.c | 29 +++++++++++++----------------
1 file changed, 13 insertions(+), 16 deletions(-)

--- a/arch/powerpc/kernel/align.c
+++ b/arch/powerpc/kernel/align.c
@@ -367,27 +367,24 @@ static int emulate_multiple(struct pt_re
static int emulate_fp_pair(unsigned char __user *addr, unsigned int reg,
unsigned int flags)
{
- char *ptr = (char *) &current->thread.TS_FPR(reg);
- int i, ret;
+ char *ptr0 = (char *) &current->thread.TS_FPR(reg);
+ char *ptr1 = (char *) &current->thread.TS_FPR(reg+1);
+ int i, ret, sw = 0;

if (!(flags & F))
return 0;
if (reg & 1)
return 0; /* invalid form: FRS/FRT must be even */
- if (!(flags & SW)) {
- /* not byte-swapped - easy */
- if (!(flags & ST))
- ret = __copy_from_user(ptr, addr, 16);
- else
- ret = __copy_to_user(addr, ptr, 16);
- } else {
- /* each FPR value is byte-swapped separately */
- ret = 0;
- for (i = 0; i < 16; ++i) {
- if (!(flags & ST))
- ret |= __get_user(ptr[i^7], addr + i);
- else
- ret |= __put_user(ptr[i^7], addr + i);
+ if (flags & SW)
+ sw = 7;
+ ret = 0;
+ for (i = 0; i < 8; ++i) {
+ if (!(flags & ST)) {
+ ret |= __get_user(ptr0[i^sw], addr + i);
+ ret |= __get_user(ptr1[i^sw], addr + i + 8);
+ } else {
+ ret |= __put_user(ptr0[i^sw], addr + i);
+ ret |= __put_user(ptr1[i^sw], addr + i + 8);
}
}
if (ret)