Merge branch 'for-next/selftests' into for-next/core

* for-next/selftests:
  kselftest/arm64: Fix build warnings for ptrace
  kselftest/arm64: Actually test SME vector length changes via sigreturn
  kselftest/arm64: signal: fix/refactor SVE vector length enumeration

Author: willdeacon

tools/testing/selftests/arm64/abi/ptrace.c

@@ -163,10 +163,10 @@ static void test_hw_debug(pid_t child, int type, const char *type_name)
 static int do_child(void)
 {
 	if (ptrace(PTRACE_TRACEME, -1, NULL, NULL))
-		ksft_exit_fail_msg("PTRACE_TRACEME", strerror(errno));
+		ksft_exit_fail_perror("PTRACE_TRACEME");
 
 	if (raise(SIGSTOP))
-		ksft_exit_fail_msg("raise(SIGSTOP)", strerror(errno));
+		ksft_exit_fail_perror("raise(SIGSTOP)");
 
 	return EXIT_SUCCESS;
 }

tools/testing/selftests/arm64/signal/Makefile

@@ -23,7 +23,7 @@ $(TEST_GEN_PROGS): $(PROGS)
 # Common test-unit targets to build common-layout test-cases executables
 # Needs secondary expansion to properly include the testcase c-file in pre-reqs
 COMMON_SOURCES := test_signals.c test_signals_utils.c testcases/testcases.c \
-	signals.S
+	signals.S sve_helpers.c
 COMMON_HEADERS := test_signals.h test_signals_utils.h testcases/testcases.h
 
 .SECONDEXPANSION:

tools/testing/selftests/arm64/signal/sve_helpers.c

@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2024 ARM Limited
+ *
+ * Common helper functions for SVE and SME functionality.
+ */
+
+#include <stdbool.h>
+#include <kselftest.h>
+#include <asm/sigcontext.h>
+#include <sys/prctl.h>
+
+unsigned int vls[SVE_VQ_MAX];
+unsigned int nvls;
+
+int sve_fill_vls(bool use_sme, int min_vls)
+{
+	int vq, vl;
+	int pr_set_vl = use_sme ? PR_SME_SET_VL : PR_SVE_SET_VL;
+	int len_mask = use_sme ? PR_SME_VL_LEN_MASK : PR_SVE_VL_LEN_MASK;
+
+	/*
+	 * Enumerate up to SVE_VQ_MAX vector lengths
+	 */
+	for (vq = SVE_VQ_MAX; vq > 0; --vq) {
+		vl = prctl(pr_set_vl, vq * 16);
+		if (vl == -1)
+			return KSFT_FAIL;
+
+		vl &= len_mask;
+
+		/*
+		 * Unlike SVE, SME does not require the minimum vector length
+		 * to be implemented, or the VLs to be consecutive, so any call
+		 * to the prctl might return the single implemented VL, which
+		 * might be larger than 16. So to avoid this loop never
+		 * terminating,  bail out here when we find a higher VL than
+		 * we asked for.
+		 * See the ARM ARM, DDI 0487K.a, B1.4.2: I_QQRNR and I_NWYBP.
+		 */
+		if (vq < sve_vq_from_vl(vl))
+			break;
+
+		/* Skip missing VLs */
+		vq = sve_vq_from_vl(vl);
+
+		vls[nvls++] = vl;
+	}
+
+	if (nvls < min_vls) {
+		fprintf(stderr, "Only %d VL supported\n", nvls);
+		return KSFT_SKIP;
+	}
+
+	return KSFT_PASS;
+}

tools/testing/selftests/arm64/signal/sve_helpers.h

@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2024 ARM Limited
+ *
+ * Common helper functions for SVE and SME functionality.
+ */
+
+#ifndef __SVE_HELPERS_H__
+#define __SVE_HELPERS_H__
+
+#include <stdbool.h>
+
+#define VLS_USE_SVE	false
+#define VLS_USE_SME	true
+
+extern unsigned int vls[];
+extern unsigned int nvls;
+
+int sve_fill_vls(bool use_sme, int min_vls);
+
+#endif

tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_sme_change_vl.c

@@ -6,75 +6,59 @@
  * handler, this is not supported and is expected to segfault.
  */
 
+#include <kselftest.h>
 #include <signal.h>
 #include <ucontext.h>
 #include <sys/prctl.h>
 
 #include "test_signals_utils.h"
+#include "sve_helpers.h"
 #include "testcases.h"
 
 struct fake_sigframe sf;
-static unsigned int vls[SVE_VQ_MAX];
-unsigned int nvls = 0;
 
 static bool sme_get_vls(struct tdescr *td)
 {
-	int vq, vl;
+	int res = sve_fill_vls(VLS_USE_SME, 2);
 
-	/*
-	 * Enumerate up to SVE_VQ_MAX vector lengths
-	 */
-	for (vq = SVE_VQ_MAX; vq > 0; --vq) {
-		vl = prctl(PR_SVE_SET_VL, vq * 16);
-		if (vl == -1)
-			return false;
+	if (!res)
+		return true;
 
-		vl &= PR_SME_VL_LEN_MASK;
+	if (res == KSFT_SKIP)
+		td->result = KSFT_SKIP;
 
-		/* Skip missing VLs */
-		vq = sve_vq_from_vl(vl);
-
-		vls[nvls++] = vl;
-	}
-
-	/* We need at least two VLs */
-	if (nvls < 2) {
-		fprintf(stderr, "Only %d VL supported\n", nvls);
-		return false;
-	}
-
-	return true;
+	return false;
 }
 
 static int fake_sigreturn_ssve_change_vl(struct tdescr *td,
 					 siginfo_t *si, ucontext_t *uc)
 {
 	size_t resv_sz, offset;
 	struct _aarch64_ctx *head = GET_SF_RESV_HEAD(sf);
-	struct sve_context *sve;
+	struct za_context *za;
 
 	/* Get a signal context with a SME ZA frame in it */
 	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
 		return 1;
 
 	resv_sz = GET_SF_RESV_SIZE(sf);
-	head = get_header(head, SVE_MAGIC, resv_sz, &offset);
+	head = get_header(head, ZA_MAGIC, resv_sz, &offset);
 	if (!head) {
-		fprintf(stderr, "No SVE context\n");
+		fprintf(stderr, "No ZA context\n");
 		return 1;
 	}
 
-	if (head->size != sizeof(struct sve_context)) {
+	if (head->size != sizeof(struct za_context)) {
 		fprintf(stderr, "Register data present, aborting\n");
 		return 1;
 	}
 
-	sve = (struct sve_context *)head;
+	za = (struct za_context *)head;
 
 	/* No changes are supported; init left us at minimum VL so go to max */
 	fprintf(stderr, "Attempting to change VL from %d to %d\n",
-		sve->vl, vls[0]);
-	sve->vl = vls[0];
+		za->vl, vls[0]);
+	za->vl = vls[0];
 
 	fake_sigreturn(&sf, sizeof(sf), 0);
 

tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_sve_change_vl.c

@@ -12,40 +12,22 @@
 #include <sys/prctl.h>
 
 #include "test_signals_utils.h"
+#include "sve_helpers.h"
 #include "testcases.h"
 
 struct fake_sigframe sf;
-static unsigned int vls[SVE_VQ_MAX];
-unsigned int nvls = 0;
 
 static bool sve_get_vls(struct tdescr *td)
 {
-	int vq, vl;
+	int res = sve_fill_vls(VLS_USE_SVE, 2);
 
-	/*
-	 * Enumerate up to SVE_VQ_MAX vector lengths
-	 */
-	for (vq = SVE_VQ_MAX; vq > 0; --vq) {
-		vl = prctl(PR_SVE_SET_VL, vq * 16);
-		if (vl == -1)
-			return false;
+	if (!res)
+		return true;
 
-		vl &= PR_SVE_VL_LEN_MASK;
-
-		/* Skip missing VLs */
-		vq = sve_vq_from_vl(vl);
-
-		vls[nvls++] = vl;
-	}
-
-	/* We need at least two VLs */
-	if (nvls < 2) {
-		fprintf(stderr, "Only %d VL supported\n", nvls);
+	if (res == KSFT_SKIP)
 		td->result = KSFT_SKIP;
-		return false;
-	}
 
-	return true;
+	return false;
 }
 
 static int fake_sigreturn_sve_change_vl(struct tdescr *td,

tools/testing/selftests/arm64/signal/testcases/ssve_regs.c

@@ -6,51 +6,31 @@
  * set up as expected.
  */
 
+#include <kselftest.h>
 #include <signal.h>
 #include <ucontext.h>
 #include <sys/prctl.h>
 
 #include "test_signals_utils.h"
+#include "sve_helpers.h"
 #include "testcases.h"
 
 static union {
 	ucontext_t uc;
 	char buf[1024 * 64];
 } context;
-static unsigned int vls[SVE_VQ_MAX];
-unsigned int nvls = 0;
 
 static bool sme_get_vls(struct tdescr *td)
 {
-	int vq, vl;
+	int res = sve_fill_vls(VLS_USE_SME, 1);
 
-	/*
-	 * Enumerate up to SVE_VQ_MAX vector lengths
-	 */
-	for (vq = SVE_VQ_MAX; vq > 0; --vq) {
-		vl = prctl(PR_SME_SET_VL, vq * 16);
-		if (vl == -1)
-			return false;
-
-		vl &= PR_SME_VL_LEN_MASK;
-
-		/* Did we find the lowest supported VL? */
-		if (vq < sve_vq_from_vl(vl))
-			break;
+	if (!res)
+		return true;
 
-		/* Skip missing VLs */
-		vq = sve_vq_from_vl(vl);
-
-		vls[nvls++] = vl;
-	}
-
-	/* We need at least one VL */
-	if (nvls < 1) {
-		fprintf(stderr, "Only %d VL supported\n", nvls);
-		return false;
-	}
+	if (res == KSFT_SKIP)
+		td->result = KSFT_SKIP;
 
-	return true;
+	return false;
 }
 
 static void setup_ssve_regs(void)

tools/testing/selftests/arm64/signal/testcases/ssve_za_regs.c

@@ -6,51 +6,31 @@
  * signal frames is set up as expected when enabled simultaneously.
  */
 
+#include <kselftest.h>
 #include <signal.h>
 #include <ucontext.h>
 #include <sys/prctl.h>
 
 #include "test_signals_utils.h"
+#include "sve_helpers.h"
 #include "testcases.h"
 
 static union {
 	ucontext_t uc;
 	char buf[1024 * 128];
 } context;
-static unsigned int vls[SVE_VQ_MAX];
-unsigned int nvls = 0;
 
 static bool sme_get_vls(struct tdescr *td)
 {
-	int vq, vl;
+	int res = sve_fill_vls(VLS_USE_SME, 1);
 
-	/*
-	 * Enumerate up to SVE_VQ_MAX vector lengths
-	 */
-	for (vq = SVE_VQ_MAX; vq > 0; --vq) {
-		vl = prctl(PR_SME_SET_VL, vq * 16);
-		if (vl == -1)
-			return false;
-
-		vl &= PR_SME_VL_LEN_MASK;
-
-		/* Did we find the lowest supported VL? */
-		if (vq < sve_vq_from_vl(vl))
-			break;
+	if (!res)
+		return true;
 
-		/* Skip missing VLs */
-		vq = sve_vq_from_vl(vl);
-
-		vls[nvls++] = vl;
-	}
-
-	/* We need at least one VL */
-	if (nvls < 1) {
-		fprintf(stderr, "Only %d VL supported\n", nvls);
-		return false;
-	}
+	if (res == KSFT_SKIP)
+		td->result = KSFT_SKIP;
 
-	return true;
+	return false;
 }
 
 static void setup_regs(void)