Commit 40a8e87b authored by Mark Brown's avatar Mark Brown Committed by Catalin Marinas
Browse files

arm64/sme: Disable ZA and streaming mode when handling signals 



The ABI requires that streaming mode and ZA are disabled when invoking
signal handlers, do this in setup_return() when we prepare the task state
for the signal handler.

Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-18-broonie@kernel.org


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 8bd7f91c

arch/arm64/kernel/signal.c

+7 −0
Original line number Diff line number Diff line
@@ -759,6 +759,13 @@ static void setup_return(struct pt_regs *regs, struct k_sigaction *ka, 
	/* TCO (Tag Check Override) always cleared for signal handlers */

	regs->pstate &= ~PSR_TCO_BIT;



	/* Signal handlers are invoked with ZA and streaming mode disabled */

	if (system_supports_sme()) {

		current->thread.svcr &= ~(SYS_SVCR_EL0_ZA_MASK |

					  SYS_SVCR_EL0_SM_MASK);

		sme_smstop();

	}



	if (ka->sa.sa_flags & SA_RESTORER)

		sigtramp = ka->sa.sa_restorer;

	else