releases/6.2.3/kselftest-arm64-fix-syscall-abi-for-systems-without-.patch

From fb6959a1ba6659e8fe0de386522fa1f1c024cae9 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Tue, 27 Dec 2022 13:06:35 +0000
Subject: kselftest/arm64: Fix syscall-abi for systems without 128 bit SME

From: Mark Brown <broonie@kernel.org>

[ Upstream commit 97ec597b26df774a257e3f8e97353fd1b4471615 ]

SME does not mandate any specific VL so we may not have 128 bit SME but
the algorithm used for enumerating VLs assumes that we will. Add the
required check to ensure that the algorithm terminates.

Fixes: 43e3f85523e4 ("kselftest/arm64: Add SME support to syscall ABI test")
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20221223-arm64-syscall-abi-sme-only-v1-1-4fabfbd62087@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/arm64/abi/syscall-abi.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tools/testing/selftests/arm64/abi/syscall-abi.c b/tools/testing/selftests/arm64/abi/syscall-abi.c
index dd7ebe536d05f..ffe719b50c215 100644
--- a/tools/testing/selftests/arm64/abi/syscall-abi.c
+++ b/tools/testing/selftests/arm64/abi/syscall-abi.c
@@ -390,6 +390,10 @@ static void test_one_syscall(struct syscall_cfg *cfg)
 
 			sme_vl &= PR_SME_VL_LEN_MASK;
 
+			/* Found lowest VL */
+			if (sve_vq_from_vl(sme_vl) > sme_vq)
+				break;
+
 			if (sme_vq != sve_vq_from_vl(sme_vl))
 				sme_vq = sve_vq_from_vl(sme_vl);
 
@@ -461,6 +465,10 @@ int sme_count_vls(void)
 
 		vl &= PR_SME_VL_LEN_MASK;
 
+		/* Found lowest VL */
+		if (sve_vq_from_vl(vl) > vq)
+			break;
+
 		if (vq != sve_vq_from_vl(vl))
 			vq = sve_vq_from_vl(vl);
 
-- 
2.39.2