From 2b989c411ab98fa76b7bb3b87ba7a2a4c3b5e946 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Fri, 31 Jul 2026 21:50:52 +0100 Subject: [PATCH] kselftest/arm64: Don't write to P0 in irritator on SME only systems Commit 3e360ef0c0a1f ("kselftest/arm64: Corrupt P0 in the irritator when testing SSVE") added corruption of P0 to the sve-test case in order to ensure that the predicate registers were covered as part of the corruption. On SME only systems this results in an illegal instruction since signal handlers are run out of streaming mode and the predicate registers do not exist out of streaming mode without SVE. Switch to entering and exiting streaming mode in the irritator, this will reset all relevant registers to 0 if they somehow weren't already by the signal entry. Fixes: 3e360ef0c0a1f ("kselftest/arm64: Corrupt P0 in the irritator when testing SSVE") Reported-by: Mark Rutland Signed-off-by: Mark Brown Signed-off-by: Will Deacon --- tools/testing/selftests/arm64/fp/sve-test.S | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/arm64/fp/sve-test.S b/tools/testing/selftests/arm64/fp/sve-test.S index 80e072f221cd..7ef7835389e7 100644 --- a/tools/testing/selftests/arm64/fp/sve-test.S +++ b/tools/testing/selftests/arm64/fp/sve-test.S @@ -298,15 +298,20 @@ function irritator_handler add x0, x0, #1 str x0, [x2, #ucontext_regs + 8 * 23] +#ifndef SSVE // Corrupt some random Z-regs movi v0.8b, #1 movi v9.16b, #2 movi v31.8b, #3 // And P0 ptrue p0.d -#ifndef SSVE // And FFR wrffr p15.b +#else + // Enter and exit streaming mode, will reset all of the V, Z, P + // and FFR registers that the system has. + smstart_sm + smstop #endif ret