From 40a8e87bb32855b39839d35b5b5b125494b3a604 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Tue, 19 Apr 2022 12:22:25 +0100 Subject: [PATCH] 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: Mark Brown Reviewed-by: Catalin Marinas Link: https://lore.kernel.org/r/20220419112247.711548-18-broonie@kernel.org Signed-off-by: Catalin Marinas --- arch/arm64/kernel/signal.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 4a4122ef6f39..42efa464e46e 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -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 -- 2.11.0