powerpc: Explicitly copy elements of pt_regs

Gcc 4.3 produced this warning:

arch/powerpc/kernel/signal_64.c: In function 'restore_sigcontext':
arch/powerpc/kernel/signal_64.c:161: warning: array subscript is above array bounds

This is caused by us copying to aliases of elements of the pt_regs
structure.  Make those explicit.

This adds one extra __get_user and unrolls a loop.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 12 insertions, 12 deletions

diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 34f37e59bacc..6e6b01a6db5f 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -170,29 +170,29 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
 #endif
         unsigned long err = 0;
         unsigned long save_r13 = 0;
-        elf_greg_t *gregs = (elf_greg_t *)regs;
         unsigned long msr;
-        int i;
 
         /* If this is not a signal return, we preserve the TLS in r13 */
         if (!sig)
                 save_r13 = regs->gpr[13];
 
-        /* copy everything before MSR */
-        err |= __copy_from_user(regs, &sc->gp_regs,
-                                PT_MSR*sizeof(unsigned long));
-
+        /* copy the GPRs */
+        err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr));
+        err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]);
         /* get MSR separately, transfer the LE bit if doing signal return */
         err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
         if (sig)
                 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
-
+        err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]);
+        err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]);
+        err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]);
+        err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]);
+        err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]);
         /* skip SOFTE */
-        for (i = PT_MSR+1; i <= PT_RESULT; i++) {
-                if (i == PT_SOFTE)
-                        continue;
-                err |= __get_user(gregs[i], &sc->gp_regs[i]);
-        }
+        err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]);
+        err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
+        err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
+        err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
 
         if (!sig)
                 regs->gpr[13] = save_r13;