powerpc: Fix load/store float double alignment handler

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>

1 files changed, 13 insertions, 16 deletions

diff --git a/arch/powerpc/kernel/align.c b/arch/powerpc/kernel/align.c
index ada06924a423..73cb6a3229ae 100644
--- a/arch/powerpc/kernel/align.c
+++ b/arch/powerpc/kernel/align.c
@@ -367,27 +367,24 @@ static int emulate_multiple(struct pt_regs *regs, unsigned char __user *addr,
 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)