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Commit fcbc5a97 authored by Stephen Rothwell's avatar Stephen Rothwell Committed by Paul Mackerras
Browse files

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: default avatarStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 3420b5da

arch/powerpc/kernel/signal_64.c

+12 −12
Original line number Diff line number Diff line
@@ -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;