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>

diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 34f37e59bacc6ca219b87d7300cc06ca78002b9a..6e6b01a6db5fff1b70c99c1e16030af33fc116e0 100644 (file)
--- 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;