Commit ad65f490 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/signal32: Switch handle_signal32() to user_access_begin() logic 



Replace the access_ok() by user_access_begin() and change all user
accesses to unsafe_ version.

Move flush_icache_range() outside the user access block.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a27797f781aa00da96f8284c898173d18e952361.1597770847.git.christophe.leroy@csgroup.eu
parent 8d33001d

arch/powerpc/kernel/signal_32.c

+16 −13
Original line number Diff line number Diff line
@@ -840,35 +840,35 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, 
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM

	tm_mctx = &frame->mctx_transact;

#endif

	if (!access_ok(frame, sizeof(*frame)))

	if (!user_write_access_begin(frame, sizeof(*frame)))

		goto badframe;

	sc = (struct sigcontext __user *) &frame->sctx;



#if _NSIG != 64

#error "Please adjust handle_signal()"

#endif

	if (__put_user(to_user_ptr(ksig->ka.sa.sa_handler), &sc->handler)

	    || __put_user(oldset->sig[0], &sc->oldmask)

	unsafe_put_user(to_user_ptr(ksig->ka.sa.sa_handler), &sc->handler, failed);

	unsafe_put_user(oldset->sig[0], &sc->oldmask, failed);

#ifdef CONFIG_PPC64

	    || __put_user((oldset->sig[0] >> 32), &sc->_unused[3])

	unsafe_put_user((oldset->sig[0] >> 32), &sc->_unused[3], failed);

#else

	    || __put_user(oldset->sig[1], &sc->_unused[3])

	unsafe_put_user(oldset->sig[1], &sc->_unused[3], failed);

#endif

	    || __put_user(to_user_ptr(mctx), &sc->regs)

	    || __put_user(ksig->sig, &sc->signal))

		goto badframe;

	unsafe_put_user(to_user_ptr(mctx), &sc->regs, failed);

	unsafe_put_user(ksig->sig, &sc->signal, failed);



	if (vdso32_sigtramp && tsk->mm->context.vdso_base) {

		tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;

	} else {

		tramp = (unsigned long)mctx->mc_pad;

		/* Set up the sigreturn trampoline: li r0,sigret; sc */

		if (__put_user(PPC_INST_ADDI + __NR_sigreturn, &mctx->mc_pad[0]))

			goto badframe;

		if (__put_user(PPC_INST_SC, &mctx->mc_pad[1]))

			goto badframe;

		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));

		unsafe_put_user(PPC_INST_ADDI + __NR_sigreturn, &mctx->mc_pad[0], failed);

		unsafe_put_user(PPC_INST_SC, &mctx->mc_pad[1], failed);

	}

	user_write_access_end();



	if (tramp == (unsigned long)mctx->mc_pad)

		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));



#ifdef CONFIG_PPC_TRANSACTIONAL_MEM

	if (MSR_TM_ACTIVE(msr)) {
@@ -901,6 +901,9 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, 
	regs->msr &= ~MSR_LE;

	return 0;



failed:

	user_write_access_end();



badframe:

	signal_fault(tsk, regs, "handle_signal32", frame);