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authorMark Brown <broonie@kernel.org>2022-04-19 12:22:25 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2022-04-22 18:51:08 +0100
commit40a8e87bb32855b39839d35b5b5b125494b3a604 (patch)
treefd4d7f65eb19a306cd43192eb8ca582ae99843c5 /arch/arm64/kernel
parent8bd7f91c03d886f41d35f6108078d20be5a4a1bd (diff)
downloadlinux-40a8e87bb32855b39839d35b5b5b125494b3a604.tar.bz2
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 <broonie@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20220419112247.711548-18-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel')
-rw-r--r--arch/arm64/kernel/signal.c7
1 files changed, 7 insertions, 0 deletions
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