Resguardo inicial

linux-7.2.3/tools/testing/selftests/arm64/signal/.gitignore

@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0-only
+mangle_*
+fake_sigreturn_*
+fpmr_*
+poe_*
+gcs_*
+sme_*
+ssve_*
+sve_*
+tpidr2_*
+za_*
+zt_*
+!*.[ch]

linux-7.2.3/tools/testing/selftests/arm64/signal/Makefile

@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2019 ARM Limited
+
+# Additional include paths needed by kselftest.h and local headers
+CFLAGS += -std=gnu99 -I.
+
+SRCS := $(filter-out testcases/testcases.c,$(wildcard testcases/*.c))
+PROGS := $(patsubst %.c,%,$(SRCS))
+
+# Generated binaries to be installed by top KSFT script
+TEST_GEN_PROGS := $(notdir $(PROGS))
+
+# Get Kernel headers installed and use them.
+
+# Including KSFT lib.mk here will also mangle the TEST_GEN_PROGS list
+# to account for any OUTPUT target-dirs optionally provided by
+# the toplevel makefile
+include ../../lib.mk
+
+$(TEST_GEN_PROGS): $(PROGS)
+	cp $(PROGS) $(OUTPUT)/
+
+# Common test-unit targets to build common-layout test-cases executables
+# Needs secondary expansion to properly include the testcase c-file in pre-reqs
+COMMON_SOURCES := test_signals.c test_signals_utils.c testcases/testcases.c \
+	signals.S sve_helpers.c
+COMMON_HEADERS := test_signals.h test_signals_utils.h testcases/testcases.h
+
+.SECONDEXPANSION:
+$(PROGS): $$@.c ${COMMON_SOURCES} ${COMMON_HEADERS}
+	$(CC) $(CFLAGS) ${@}.c ${COMMON_SOURCES} -o $@

linux-7.2.3/tools/testing/selftests/arm64/signal/README

@@ -0,0 +1,59 @@
+KSelfTest arm64/signal/
+=======================
+
+Signals Tests
++++++++++++++
+
+- Tests are built around a common main compilation unit: such shared main
+  enforces a standard sequence of operations needed to perform a single
+  signal-test (setup/trigger/run/result/cleanup)
+
+- The above mentioned ops are configurable on a test-by-test basis: each test
+  is described (and configured) using the descriptor signals.h::struct tdescr
+
+- Each signal testcase is compiled into its own executable: a separate
+  executable is used for each test since many tests complete successfully
+  by receiving some kind of fatal signal from the Kernel, so it's safer
+  to run each test unit in its own standalone process, so as to start each
+  test from a clean slate.
+
+- New tests can be simply defined in testcases/ dir providing a proper struct
+  tdescr overriding all the defaults we wish to change (as of now providing a
+  custom run method is mandatory though)
+
+- Signals' test-cases hereafter defined belong currently to two
+  principal families:
+
+  - 'mangle_' tests: a real signal (SIGUSR1) is raised and used as a trigger
+    and then the test case code modifies the signal frame from inside the
+    signal handler itself.
+
+  - 'fake_sigreturn_' tests: a brand new custom artificial sigframe structure
+    is placed on the stack and a sigreturn syscall is called to simulate a
+    real signal return. This kind of tests does not use a trigger usually and
+    they are just fired using some simple included assembly trampoline code.
+
+ - Most of these tests are successfully passing if the process gets killed by
+   some fatal signal: usually SIGSEGV or SIGBUS. Since while writing this
+   kind of tests it is extremely easy in fact to end-up injecting other
+   unrelated SEGV bugs in the testcases, it becomes extremely tricky to
+   be really sure that the tests are really addressing what they are meant
+   to address and they are not instead falling apart due to unplanned bugs
+   in the test code.
+   In order to alleviate the misery of the life of such test-developer, a few
+   helpers are provided:
+
+   - a couple of ASSERT_BAD/GOOD_CONTEXT() macros to easily parse a ucontext_t
+     and verify if it is indeed GOOD or BAD (depending on what we were
+     expecting), using the same logic/perspective as in the arm64 Kernel signals
+     routines.
+
+   - a sanity mechanism to be used in 'fake_sigreturn_'-alike tests: enabled by
+     default it takes care to verify that the test-execution had at least
+     successfully progressed up to the stage of triggering the fake sigreturn
+     call.
+
+  In both cases test results are expected in terms of:
+   - some fatal signal sent by the Kernel to the test process
+  or
+  - analyzing some final regs state

linux-7.2.3/tools/testing/selftests/arm64/signal/signals.S

@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2019 ARM Limited */
+
+#include <asm/unistd.h>
+
+.section        .rodata, "a"
+call_fmt:
+	.asciz "Calling sigreturn with fake sigframe sized:%zd at SP @%08lX\n"
+
+.text
+
+.globl fake_sigreturn
+
+/*	fake_sigreturn	x0:&sigframe,  x1:sigframe_size,  x2:misalign_bytes */
+fake_sigreturn:
+	stp	x29, x30, [sp, #-16]!
+	mov	x29, sp
+
+	mov	x20, x0
+	mov	x21, x1
+	mov	x22, x2
+
+	/* create space on the stack for fake sigframe 16 bytes-aligned */
+	add	x0, x21, x22
+	add	x0, x0, #15
+	bic	x0, x0, #15 /* round_up(sigframe_size + misalign_bytes, 16) */
+	sub	sp, sp, x0
+	add	x23, sp, x22 /* new sigframe base with misaligment if any */
+
+	ldr	x0, =call_fmt
+	mov	x1, x21
+	mov	x2, x23
+	bl	printf
+
+	/* memcpy the provided content, while still keeping SP aligned */
+	mov	x0, x23
+	mov	x1, x20
+	mov	x2, x21
+	bl	memcpy
+
+	/*
+	 * Here saving a last minute SP to current->token acts as a marker:
+	 * if we got here, we are successfully faking a sigreturn; in other
+	 * words we are sure no bad fatal signal has been raised till now
+	 * for unrelated reasons, so we should consider the possibly observed
+	 * fatal signal like SEGV coming from Kernel restore_sigframe() and
+	 * triggered as expected from our test-case.
+	 * For simplicity this assumes that current field 'token' is laid out
+	 * as first in struct tdescr
+	 */
+	ldr	x0, current
+	str	x23, [x0]
+	/* finally move SP to misaligned address...if any requested */
+	mov	sp, x23
+
+	mov	x8, #__NR_rt_sigreturn
+	svc	#0
+
+	/*
+	 * Above sigreturn should not return...looping here leads to a timeout
+	 * and ensure proper and clean test failure, instead of jumping around
+	 * on a potentially corrupted stack.
+	 */
+	b	.

linux-7.2.3/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;
+}

linux-7.2.3/tools/testing/selftests/arm64/signal/sve_helpers.h

@@ -0,0 +1,34 @@
+/* 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);
+
+static inline uint64_t get_svcr(void)
+{
+	uint64_t val;
+
+	asm volatile (
+		"mrs	%0, S3_3_C4_C2_2\n"
+		: "=r"(val)
+		:
+		: "cc");
+
+	return val;
+}
+
+#endif

linux-7.2.3/tools/testing/selftests/arm64/signal/test_signals.c

@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 ARM Limited
+ *
+ * Generic test wrapper for arm64 signal tests.
+ *
+ * Each test provides its own tde struct tdescr descriptor to link with
+ * this wrapper. Framework provides common helpers.
+ */
+
+#include <sys/auxv.h>
+#include <sys/prctl.h>
+
+#include <kselftest.h>
+
+#include "test_signals.h"
+#include "test_signals_utils.h"
+
+struct tdescr *current = &tde;
+
+int main(int argc, char *argv[])
+{
+	/*
+	 * Ensure GCS is at least enabled throughout the tests if
+	 * supported, otherwise the inability to return from the
+	 * function that enabled GCS makes it very inconvenient to set
+	 * up test cases.  The prctl() may fail if GCS was locked by
+	 * libc setup code.
+	 */
+	if (getauxval(AT_HWCAP) & HWCAP_GCS)
+		gcs_set_state(PR_SHADOW_STACK_ENABLE);
+
+	ksft_print_msg("%s :: %s\n", current->name, current->descr);
+	if (test_setup(current) && test_init(current)) {
+		test_run(current);
+		test_cleanup(current);
+	}
+	test_result(current);
+
+	/* Do not return in case GCS was enabled */
+	exit(current->result);
+}

linux-7.2.3/tools/testing/selftests/arm64/signal/test_signals.h

@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2019 ARM Limited */
+
+#ifndef __TEST_SIGNALS_H__
+#define __TEST_SIGNALS_H__
+
+#include <signal.h>
+#include <stdbool.h>
+#include <ucontext.h>
+
+/*
+ * Using ARCH specific and sanitized Kernel headers from the tree.
+ */
+#include <asm/ptrace.h>
+#include <asm/hwcap.h>
+
+#define __stringify_1(x...)	#x
+#define __stringify(x...)	__stringify_1(x)
+
+#define get_regval(regname, out)			\
+{							\
+	asm volatile("mrs %0, " __stringify(regname)	\
+	: "=r" (out)					\
+	:						\
+	: "memory");					\
+}
+
+/*
+ * Feature flags used in tdescr.feats_required to specify
+ * any feature by the test
+ */
+enum {
+	FSSBS_BIT,
+	FSVE_BIT,
+	FSME_BIT,
+	FSME_FA64_BIT,
+	FSME2_BIT,
+	FGCS_BIT,
+	FPOE_BIT,
+	FMAX_END
+};
+
+#define FEAT_SSBS		(1UL << FSSBS_BIT)
+#define FEAT_SVE		(1UL << FSVE_BIT)
+#define FEAT_SME		(1UL << FSME_BIT)
+#define FEAT_SME_FA64		(1UL << FSME_FA64_BIT)
+#define FEAT_SME2		(1UL << FSME2_BIT)
+#define FEAT_GCS		(1UL << FGCS_BIT)
+#define FEAT_POE		(1UL << FPOE_BIT)
+
+/*
+ * A descriptor used to describe and configure a test case.
+ * Fields with a non-trivial meaning are described inline in the following.
+ */
+struct tdescr {
+	/* KEEP THIS FIELD FIRST for easier lookup from assembly */
+	void			*token;
+	/* when disabled token based sanity checking is skipped in handler */
+	bool			sanity_disabled;
+	/* just a name for the test-case; manadatory field */
+	char			*name;
+	char			*descr;
+	unsigned long		feats_required;
+	unsigned long		feats_incompatible;
+	/* bitmask of effectively supported feats: populated at run-time */
+	unsigned long		feats_supported;
+	bool			initialized;
+	unsigned int		minsigstksz;
+	/* signum used as a test trigger. Zero if no trigger-signal is used */
+	int			sig_trig;
+	/*
+	 * signum considered as a successful test completion.
+	 * Zero when no signal is expected on success
+	 */
+	int			sig_ok;
+	/*
+	 * expected si_code for sig_ok, or 0 to not check
+	 */
+	int			sig_ok_code;
+	/* signum expected on unsupported CPU features. */
+	int			sig_unsupp;
+	/* a timeout in second for test completion */
+	unsigned int		timeout;
+	bool			triggered;
+	bool			pass;
+	unsigned int		result;
+	/* optional sa_flags for the installed handler */
+	int			sa_flags;
+	ucontext_t		saved_uc;
+	/* used by get_current_ctx() */
+	size_t			live_sz;
+	ucontext_t		*live_uc;
+	volatile sig_atomic_t	live_uc_valid;
+	/* optional test private data */
+	void			*priv;
+
+	/* a custom setup: called alternatively to default_setup */
+	int (*setup)(struct tdescr *td);
+	/* a custom init: called by default test init after test_setup */
+	bool (*init)(struct tdescr *td);
+	/* a custom cleanup function called before test exits */
+	void (*cleanup)(struct tdescr *td);
+	/* an optional function to be used as a trigger for starting test */
+	int (*trigger)(struct tdescr *td);
+	/*
+	 * the actual test-core: invoked differently depending on the
+	 * presence of the trigger function above; this is mandatory
+	 */
+	int (*run)(struct tdescr *td, siginfo_t *si, ucontext_t *uc);
+	/* an optional function for custom results' processing */
+	void (*check_result)(struct tdescr *td);
+};
+
+extern struct tdescr tde;
+#endif

linux-7.2.3/tools/testing/selftests/arm64/signal/test_signals_utils.c

@@ -0,0 +1,424 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2019 ARM Limited */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <string.h>
+#include <unistd.h>
+#include <assert.h>
+#include <sys/auxv.h>
+#include <linux/auxvec.h>
+#include <ucontext.h>
+
+#include <asm/unistd.h>
+
+#include <kselftest.h>
+
+#include "test_signals.h"
+#include "test_signals_utils.h"
+#include "testcases/testcases.h"
+
+
+extern struct tdescr *current;
+
+static int sig_copyctx = SIGTRAP;
+
+static char const *const feats_names[FMAX_END] = {
+	" SSBS ",
+	" SVE ",
+	" SME ",
+	" FA64 ",
+	" SME2 ",
+	" GCS ",
+	" POE ",
+};
+
+#define MAX_FEATS_SZ	128
+static char feats_string[MAX_FEATS_SZ];
+
+static inline char *feats_to_string(unsigned long feats)
+{
+	size_t flen = MAX_FEATS_SZ - 1;
+
+	feats_string[0] = '\0';
+
+	for (int i = 0; i < FMAX_END; i++) {
+		if (feats & (1UL << i)) {
+			size_t tlen = strlen(feats_names[i]);
+
+			assert(flen > tlen);
+			flen -= tlen;
+			strncat(feats_string, feats_names[i], flen);
+		}
+	}
+
+	return feats_string;
+}
+
+static void unblock_signal(int signum)
+{
+	sigset_t sset;
+
+	sigemptyset(&sset);
+	sigaddset(&sset, signum);
+	sigprocmask(SIG_UNBLOCK, &sset, NULL);
+}
+
+static void default_result(struct tdescr *td, bool force_exit)
+{
+	if (td->result == KSFT_SKIP) {
+		fprintf(stderr, "==>> completed. SKIP.\n");
+	} else if (td->pass) {
+		fprintf(stderr, "==>> completed. PASS(1)\n");
+		td->result = KSFT_PASS;
+	} else {
+		fprintf(stdout, "==>> completed. FAIL(0)\n");
+		td->result = KSFT_FAIL;
+	}
+
+	if (force_exit)
+		exit(td->result);
+}
+
+/*
+ * The following handle_signal_* helpers are used by main default_handler
+ * and are meant to return true when signal is handled successfully:
+ * when false is returned instead, it means that the signal was somehow
+ * unexpected in that context and it was NOT handled; default_handler will
+ * take care of such unexpected situations.
+ */
+
+static bool handle_signal_unsupported(struct tdescr *td,
+				      siginfo_t *si, void *uc)
+{
+	if (feats_ok(td))
+		return false;
+
+	/* Mangling PC to avoid loops on original SIGILL */
+	((ucontext_t *)uc)->uc_mcontext.pc += 4;
+
+	if (!td->initialized) {
+		fprintf(stderr,
+			"Got SIG_UNSUPP @test_init. Ignore.\n");
+	} else {
+		fprintf(stderr,
+			"-- RX SIG_UNSUPP on unsupported feat...OK\n");
+		td->pass = 1;
+		default_result(current, 1);
+	}
+
+	return true;
+}
+
+static bool handle_signal_trigger(struct tdescr *td,
+				  siginfo_t *si, void *uc)
+{
+	td->triggered = 1;
+	/* ->run was asserted NON-NULL in test_setup() already */
+	td->run(td, si, uc);
+
+	return true;
+}
+
+static bool handle_signal_ok(struct tdescr *td,
+			     siginfo_t *si, void *uc)
+{
+	/*
+	 * it's a bug in the test code when this assert fail:
+	 * if sig_trig was defined, it must have been used before getting here.
+	 */
+	assert(!td->sig_trig || td->triggered);
+	fprintf(stderr,
+		"SIG_OK -- SP:0x%llX  si_addr@:%p  si_code:%d  token@:%p  offset:%ld\n",
+		((ucontext_t *)uc)->uc_mcontext.sp,
+		si->si_addr, si->si_code, td->token, td->token - si->si_addr);
+	/*
+	 * fake_sigreturn tests, which have sanity_enabled=1, set, at the very
+	 * last time, the token field to the SP address used to place the fake
+	 * sigframe: so token==0 means we never made it to the end,
+	 * segfaulting well-before, and the test is possibly broken.
+	 */
+	if (!td->sanity_disabled && !td->token) {
+		fprintf(stdout,
+			"current->token ZEROED...test is probably broken!\n");
+		abort();
+	}
+	if (td->sig_ok_code) {
+		if (si->si_code != td->sig_ok_code) {
+			fprintf(stdout, "si_code is %d not %d\n",
+				si->si_code, td->sig_ok_code);
+			abort();
+		}
+	} else {
+		/*
+		 * Trying to narrow down the SEGV to the ones
+		 * generated by Kernel itself via
+		 * arm64_notify_segfault(). This is a best-effort
+		 * check anyway, and the si_code check may need to
+		 * change if this aspect of the kernel ABI changes.
+		 */
+		if (td->sig_ok == SIGSEGV && si->si_code != SEGV_ACCERR) {
+			fprintf(stdout,
+				"si_code != SEGV_ACCERR...test is probably broken!\n");
+			abort();
+		}
+	}
+	td->pass = 1;
+	/*
+	 * Some tests can lead to SEGV loops: in such a case we want to
+	 * terminate immediately exiting straight away; some others are not
+	 * supposed to outlive the signal handler code, due to the content of
+	 * the fake sigframe which caused the signal itself.
+	 */
+	default_result(current, 1);
+
+	return true;
+}
+
+static bool handle_signal_copyctx(struct tdescr *td,
+				  siginfo_t *si, void *uc_in)
+{
+	ucontext_t *uc = uc_in;
+	struct _aarch64_ctx *head;
+	struct extra_context *extra, *copied_extra;
+	size_t offset = 0;
+	size_t to_copy;
+
+	ASSERT_GOOD_CONTEXT(uc);
+
+	/* Mangling PC to avoid loops on original BRK instr */
+	uc->uc_mcontext.pc += 4;
+
+	/*
+	 * Check for an preserve any extra data too with fixups.
+	 */
+	head = (struct _aarch64_ctx *)uc->uc_mcontext.__reserved;
+	head = get_header(head, EXTRA_MAGIC, td->live_sz, &offset);
+	if (head) {
+		extra = (struct extra_context *)head;
+
+		/*
+		 * The extra buffer must be immediately after the
+		 * extra_context and a 16 byte terminator. Include it
+		 * in the copy, this was previously validated in
+		 * ASSERT_GOOD_CONTEXT().
+		 */
+		to_copy = __builtin_offsetof(ucontext_t,
+					     uc_mcontext.__reserved);
+		to_copy += offset + sizeof(struct extra_context) + 16;
+		to_copy += extra->size;
+		copied_extra = (struct extra_context *)&(td->live_uc->uc_mcontext.__reserved[offset]);
+	} else {
+		copied_extra = NULL;
+		to_copy = sizeof(ucontext_t);
+	}
+
+	if (to_copy > td->live_sz) {
+		fprintf(stderr,
+			"Not enough space to grab context, %lu/%lu bytes\n",
+			td->live_sz, to_copy);
+		return false;
+	}
+
+	memcpy(td->live_uc, uc, to_copy);
+
+	/*
+	 * If there was any EXTRA_CONTEXT fix up the size to be the
+	 * struct extra_context and the following terminator record,
+	 * this means that the rest of the code does not need to have
+	 * special handling for the record and we don't need to fix up
+	 * datap for the new location.
+	 */
+	if (copied_extra)
+		copied_extra->head.size = sizeof(*copied_extra) + 16;
+
+	td->live_uc_valid = 1;
+	fprintf(stderr,
+		"%lu byte GOOD CONTEXT grabbed from sig_copyctx handler\n",
+		to_copy);
+
+	return true;
+}
+
+static void default_handler(int signum, siginfo_t *si, void *uc)
+{
+	if (current->sig_unsupp && signum == current->sig_unsupp &&
+	    handle_signal_unsupported(current, si, uc)) {
+		fprintf(stderr, "Handled SIG_UNSUPP\n");
+	} else if (current->sig_trig && signum == current->sig_trig &&
+		   handle_signal_trigger(current, si, uc)) {
+		fprintf(stderr, "Handled SIG_TRIG\n");
+	} else if (current->sig_ok && signum == current->sig_ok &&
+		   handle_signal_ok(current, si, uc)) {
+		fprintf(stderr, "Handled SIG_OK\n");
+	} else if (signum == sig_copyctx && current->live_uc &&
+		   handle_signal_copyctx(current, si, uc)) {
+		fprintf(stderr, "Handled SIG_COPYCTX\n");
+	} else {
+		if (signum == SIGALRM && current->timeout) {
+			fprintf(stderr, "-- Timeout !\n");
+		} else {
+			fprintf(stderr,
+				"-- RX UNEXPECTED SIGNAL: %d code %d address %p\n",
+				signum, si->si_code, si->si_addr);
+		}
+		default_result(current, 1);
+	}
+}
+
+static int default_setup(struct tdescr *td)
+{
+	struct sigaction sa;
+
+	sa.sa_sigaction = default_handler;
+	sa.sa_flags = SA_SIGINFO | SA_RESTART;
+	sa.sa_flags |= td->sa_flags;
+	sigemptyset(&sa.sa_mask);
+	/* uncatchable signals naturally skipped ... */
+	for (int sig = 1; sig < 32; sig++)
+		sigaction(sig, &sa, NULL);
+	/*
+	 * RT Signals default disposition is Term but they cannot be
+	 * generated by the Kernel in response to our tests; so just catch
+	 * them all and report them as UNEXPECTED signals.
+	 */
+	for (int sig = SIGRTMIN; sig <= SIGRTMAX; sig++)
+		sigaction(sig, &sa, NULL);
+
+	/* just in case...unblock explicitly all we need */
+	if (td->sig_trig)
+		unblock_signal(td->sig_trig);
+	if (td->sig_ok)
+		unblock_signal(td->sig_ok);
+	if (td->sig_unsupp)
+		unblock_signal(td->sig_unsupp);
+
+	if (td->timeout) {
+		unblock_signal(SIGALRM);
+		alarm(td->timeout);
+	}
+	fprintf(stderr, "Registered handlers for all signals.\n");
+
+	return 1;
+}
+
+static inline int default_trigger(struct tdescr *td)
+{
+	return !raise(td->sig_trig);
+}
+
+int test_init(struct tdescr *td)
+{
+	if (td->sig_trig == sig_copyctx) {
+		fprintf(stdout,
+			"Signal %d is RESERVED, cannot be used as a trigger. Aborting\n",
+			sig_copyctx);
+		return 0;
+	}
+	/* just in case */
+	unblock_signal(sig_copyctx);
+
+	td->minsigstksz = getauxval(AT_MINSIGSTKSZ);
+	if (!td->minsigstksz)
+		td->minsigstksz = MINSIGSTKSZ;
+	fprintf(stderr, "Detected MINSTKSIGSZ:%d\n", td->minsigstksz);
+
+	if (td->feats_required || td->feats_incompatible) {
+		td->feats_supported = 0;
+		/*
+		 * Checking for CPU required features using both the
+		 * auxval and the arm64 MRS Emulation to read sysregs.
+		 */
+		if (getauxval(AT_HWCAP) & HWCAP_SSBS)
+			td->feats_supported |= FEAT_SSBS;
+		if (getauxval(AT_HWCAP) & HWCAP_SVE)
+			td->feats_supported |= FEAT_SVE;
+		if (getauxval(AT_HWCAP2) & HWCAP2_SME)
+			td->feats_supported |= FEAT_SME;
+		if (getauxval(AT_HWCAP2) & HWCAP2_SME_FA64)
+			td->feats_supported |= FEAT_SME_FA64;
+		if (getauxval(AT_HWCAP2) & HWCAP2_SME2)
+			td->feats_supported |= FEAT_SME2;
+		if (getauxval(AT_HWCAP) & HWCAP_GCS)
+			td->feats_supported |= FEAT_GCS;
+		if (getauxval(AT_HWCAP2) & HWCAP2_POE)
+			td->feats_supported |= FEAT_POE;
+		if (feats_ok(td)) {
+			if (td->feats_required & td->feats_supported)
+				fprintf(stderr,
+					"Required Features: [%s] supported\n",
+					feats_to_string(td->feats_required &
+							td->feats_supported));
+			if (!(td->feats_incompatible & td->feats_supported))
+				fprintf(stderr,
+					"Incompatible Features: [%s] absent\n",
+					feats_to_string(td->feats_incompatible));
+		} else {
+			if ((td->feats_required & td->feats_supported) !=
+			    td->feats_supported)
+				fprintf(stderr,
+					"Required Features: [%s] NOT supported\n",
+					feats_to_string(td->feats_required &
+							~td->feats_supported));
+			if (td->feats_incompatible & td->feats_supported)
+				fprintf(stderr,
+					"Incompatible Features: [%s] supported\n",
+					feats_to_string(td->feats_incompatible &
+							~td->feats_supported));
+
+
+			td->result = KSFT_SKIP;
+			return 0;
+		}
+	}
+
+	/* Perform test specific additional initialization */
+	if (td->init && !td->init(td)) {
+		fprintf(stderr, "FAILED Testcase initialization.\n");
+		return 0;
+	}
+	td->initialized = 1;
+	fprintf(stderr, "Testcase initialized.\n");
+
+	return 1;
+}
+
+int test_setup(struct tdescr *td)
+{
+	/* assert core invariants symptom of a rotten testcase */
+	assert(current);
+	assert(td);
+	assert(td->name);
+	assert(td->run);
+
+	/* Default result is FAIL if test setup fails */
+	td->result = KSFT_FAIL;
+	if (td->setup)
+		return td->setup(td);
+	else
+		return default_setup(td);
+}
+
+int test_run(struct tdescr *td)
+{
+	if (td->trigger)
+		return td->trigger(td);
+	else if (td->sig_trig)
+		return default_trigger(td);
+	else
+		return td->run(td, NULL, NULL);
+}
+
+void test_result(struct tdescr *td)
+{
+	if (td->initialized && td->result != KSFT_SKIP && td->check_result)
+		td->check_result(td);
+	default_result(td, 0);
+}
+
+void test_cleanup(struct tdescr *td)
+{
+	if (td->cleanup)
+		td->cleanup(td);
+}

linux-7.2.3/tools/testing/selftests/arm64/signal/test_signals_utils.h

@@ -0,0 +1,203 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2019 ARM Limited */
+
+#ifndef __TEST_SIGNALS_UTILS_H__
+#define __TEST_SIGNALS_UTILS_H__
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <linux/compiler.h>
+
+#include "test_signals.h"
+
+int test_init(struct tdescr *td);
+int test_setup(struct tdescr *td);
+void test_cleanup(struct tdescr *td);
+int test_run(struct tdescr *td);
+void test_result(struct tdescr *td);
+
+#ifndef __NR_prctl
+#define __NR_prctl 167
+#endif
+
+/*
+ * The prctl takes 1 argument but we need to ensure that the other
+ * values passed in registers to the syscall are zero since the kernel
+ * validates them.
+ */
+#define gcs_set_state(state)					\
+	({								\
+		register long _num  __asm__ ("x8") = __NR_prctl;	\
+		register long _arg1 __asm__ ("x0") =  PR_SET_SHADOW_STACK_STATUS; \
+		register long _arg2 __asm__ ("x1") = (long)(state);	\
+		register long _arg3 __asm__ ("x2") = 0;			\
+		register long _arg4 __asm__ ("x3") = 0;			\
+		register long _arg5 __asm__ ("x4") = 0;			\
+	                                                                      \
+		__asm__  volatile (					\
+			"svc #0\n"					\
+			: "=r"(_arg1)					\
+			: "r"(_arg1), "r"(_arg2),			\
+			  "r"(_arg3), "r"(_arg4),			\
+			  "r"(_arg5), "r"(_num)				\
+			: "memory", "cc"				\
+			);						\
+		_arg1;							\
+	})
+
+static inline __attribute__((always_inline)) uint64_t get_gcspr_el0(void)
+{
+	uint64_t val;
+
+	asm volatile("mrs %0, S3_3_C2_C5_1" : "=r" (val));
+
+	return val;
+}
+
+#define SYS_POR_EL0 "S3_3_C10_C2_4"
+
+static inline uint64_t get_por_el0(void)
+{
+	uint64_t val;
+
+	asm volatile("mrs %0, " SYS_POR_EL0 "\n" : "=r"(val));
+
+	return val;
+}
+
+static inline void set_por_el0(uint64_t val)
+{
+	asm volatile("msr " SYS_POR_EL0 ", %0\n" :: "r"(val));
+}
+
+static inline bool feats_ok(struct tdescr *td)
+{
+	if (td->feats_incompatible & td->feats_supported)
+		return false;
+	return (td->feats_required & td->feats_supported) == td->feats_required;
+}
+
+/*
+ * Obtaining a valid and full-blown ucontext_t from userspace is tricky:
+ * libc getcontext does() not save all the regs and messes with some of
+ * them (pstate value in particular is not reliable).
+ *
+ * Here we use a service signal to grab the ucontext_t from inside a
+ * dedicated signal handler, since there, it is populated by Kernel
+ * itself in setup_sigframe(). The grabbed context is then stored and
+ * made available in td->live_uc.
+ *
+ * As service-signal is used a SIGTRAP induced by a 'brk' instruction,
+ * because here we have to avoid syscalls to trigger the signal since
+ * they would cause any SVE sigframe content (if any) to be removed.
+ *
+ * Anyway this function really serves a dual purpose:
+ *
+ * 1. grab a valid sigcontext into td->live_uc for result analysis: in
+ * such case it returns 1.
+ *
+ * 2. detect if, somehow, a previously grabbed live_uc context has been
+ * used actively with a sigreturn: in such a case the execution would have
+ * magically resumed in the middle of this function itself (seen_already==1):
+ * in such a case return 0, since in fact we have not just simply grabbed
+ * the context.
+ *
+ * This latter case is useful to detect when a fake_sigreturn test-case has
+ * unexpectedly survived without hitting a SEGV.
+ *
+ * Note that the case of runtime dynamically sized sigframes (like in SVE
+ * context) is still NOT addressed: sigframe size is supposed to be fixed
+ * at sizeof(ucontext_t).
+ */
+static __always_inline bool get_current_context(struct tdescr *td,
+						ucontext_t *dest_uc,
+						size_t dest_sz)
+{
+	static volatile bool seen_already;
+	int i;
+	char *uc = (char *)dest_uc;
+
+	assert(td && dest_uc);
+	/* it's a genuine invocation..reinit */
+	seen_already = 0;
+	td->live_uc_valid = 0;
+	td->live_sz = dest_sz;
+
+	/*
+	 * This is a memset() but we don't want the compiler to
+	 * optimise it into either instructions or a library call
+	 * which might be incompatible with streaming mode.
+	 */
+	for (i = 0; i < td->live_sz; i++) {
+		uc[i] = 0;
+		OPTIMIZER_HIDE_VAR(uc[0]);
+	}
+
+	td->live_uc = dest_uc;
+	/*
+	 * Grab ucontext_t triggering a SIGTRAP.
+	 *
+	 * Note that:
+	 * - live_uc_valid is declared volatile sig_atomic_t in
+	 *   struct tdescr since it will be changed inside the
+	 *   sig_copyctx handler
+	 * - the additional 'memory' clobber is there to avoid possible
+	 *   compiler's assumption on live_uc_valid and the content
+	 *   pointed by dest_uc, which are all changed inside the signal
+	 *   handler
+	 * - BRK causes a debug exception which is handled by the Kernel
+	 *   and finally causes the SIGTRAP signal to be delivered to this
+	 *   test thread. Since such delivery happens on the ret_to_user()
+	 *   /do_notify_resume() debug exception return-path, we are sure
+	 *   that the registered SIGTRAP handler has been run to completion
+	 *   before the execution path is restored here: as a consequence
+	 *   we can be sure that the volatile sig_atomic_t live_uc_valid
+	 *   carries a meaningful result. Being in a single thread context
+	 *   we'll also be sure that any access to memory modified by the
+	 *   handler (namely ucontext_t) will be visible once returned.
+	 * - note that since we are using a breakpoint instruction here
+	 *   to cause a SIGTRAP, the ucontext_t grabbed from the signal
+	 *   handler would naturally contain a PC pointing exactly to this
+	 *   BRK line, which means that, on return from the signal handler,
+	 *   or if we place the ucontext_t on the stack to fake a sigreturn,
+	 *   we'll end up in an infinite loop of BRK-SIGTRAP-handler.
+	 *   For this reason we take care to artificially move forward the
+	 *   PC to the next instruction while inside the signal handler.
+	 */
+	asm volatile ("brk #666"
+		      : "+m" (*dest_uc)
+		      :
+		      : "memory");
+
+	/*
+	 * If we were grabbing a streaming mode context then we may
+	 * have entered streaming mode behind the system's back and
+	 * libc or compiler generated code might decide to do
+	 * something invalid in streaming mode, or potentially even
+	 * the state of ZA.  Issue a SMSTOP to exit both now we have
+	 * grabbed the state.
+	 */
+	if (td->feats_supported & FEAT_SME)
+		asm volatile("msr S0_3_C4_C6_3, xzr");
+
+	/*
+	 * If we get here with seen_already==1 it implies the td->live_uc
+	 * context has been used to get back here....this probably means
+	 * a test has failed to cause a SEGV...anyway live_uc does not
+	 * point to a just acquired copy of ucontext_t...so return 0
+	 */
+	if (seen_already) {
+		fprintf(stdout,
+			"Unexpected successful sigreturn detected: live_uc is stale !\n");
+		return 0;
+	}
+	seen_already = 1;
+
+	return td->live_uc_valid;
+}
+
+int fake_sigreturn(void *sigframe, size_t sz, int misalign_bytes);
+#endif

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/TODO

@@ -0,0 +1 @@
+- Validate that register contents are saved and restored as expected.

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_magic.c

@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 ARM Limited
+ *
+ * Place a fake sigframe on the stack including a BAD Unknown magic
+ * record: on sigreturn Kernel must spot this attempt and the test
+ * case is expected to be terminated via SEGV.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+struct fake_sigframe sf;
+
+static int fake_sigreturn_bad_magic_run(struct tdescr *td,
+					siginfo_t *si, ucontext_t *uc)
+{
+	struct _aarch64_ctx *shead = GET_SF_RESV_HEAD(sf), *head;
+
+	/* just to fill the ucontext_t with something real */
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
+		return 1;
+
+	/* need at least 2*HDR_SZ space: KSFT_BAD_MAGIC + terminator. */
+	head = get_starting_head(shead, HDR_SZ * 2, GET_SF_RESV_SIZE(sf), NULL);
+	if (!head)
+		return 0;
+
+	/*
+	 * use a well known NON existent bad magic...something
+	 * we should pretty sure won't be ever defined in Kernel
+	 */
+	head->magic = KSFT_BAD_MAGIC;
+	head->size = HDR_SZ;
+	write_terminator_record(GET_RESV_NEXT_HEAD(head));
+
+	ASSERT_BAD_CONTEXT(&sf.uc);
+	fake_sigreturn(&sf, sizeof(sf), 0);
+
+	return 1;
+}
+
+struct tdescr tde = {
+		.name = "FAKE_SIGRETURN_BAD_MAGIC",
+		.descr = "Trigger a sigreturn with a sigframe with a bad magic",
+		.sig_ok = SIGSEGV,
+		.timeout = 3,
+		.run = fake_sigreturn_bad_magic_run,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size.c

@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 ARM Limited
+ *
+ * Place a fake sigframe on the stack including a bad record overflowing
+ * the __reserved space: on sigreturn Kernel must spot this attempt and
+ * the test case is expected to be terminated via SEGV.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+struct fake_sigframe sf;
+
+#define MIN_SZ_ALIGN	16
+
+static int fake_sigreturn_bad_size_run(struct tdescr *td,
+				       siginfo_t *si, ucontext_t *uc)
+{
+	size_t resv_sz, need_sz, offset;
+	struct _aarch64_ctx *shead = GET_SF_RESV_HEAD(sf), *head;
+
+	/* just to fill the ucontext_t with something real */
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
+		return 1;
+
+	resv_sz = GET_SF_RESV_SIZE(sf);
+	/* at least HDR_SZ + bad sized esr_context needed */
+	need_sz = sizeof(struct esr_context) + HDR_SZ;
+	head = get_starting_head(shead, need_sz, resv_sz, &offset);
+	if (!head)
+		return 0;
+
+	/*
+	 * Use an esr_context to build a fake header with a
+	 * size greater then the free __reserved area minus HDR_SZ;
+	 * using ESR_MAGIC here since it is not checked for size nor
+	 * is limited to one instance.
+	 *
+	 * At first inject an additional normal esr_context
+	 */
+	head->magic = ESR_MAGIC;
+	head->size = sizeof(struct esr_context);
+	/* and terminate properly */
+	write_terminator_record(GET_RESV_NEXT_HEAD(head));
+	ASSERT_GOOD_CONTEXT(&sf.uc);
+
+	/*
+	 * now mess with fake esr_context size: leaving less space than
+	 * needed while keeping size value 16-aligned
+	 *
+	 * It must trigger a SEGV from Kernel on:
+	 *
+	 *	resv_sz - offset < sizeof(*head)
+	 */
+	/* at first set the maximum good 16-aligned size */
+	head->size = (resv_sz - offset - need_sz + MIN_SZ_ALIGN) & ~0xfUL;
+	/* plus a bit more of 16-aligned sized stuff */
+	head->size += MIN_SZ_ALIGN;
+	/* and terminate properly */
+	write_terminator_record(GET_RESV_NEXT_HEAD(head));
+	ASSERT_BAD_CONTEXT(&sf.uc);
+	fake_sigreturn(&sf, sizeof(sf), 0);
+
+	return 1;
+}
+
+struct tdescr tde = {
+		.name = "FAKE_SIGRETURN_BAD_SIZE",
+		.descr = "Triggers a sigreturn with a overrun __reserved area",
+		.sig_ok = SIGSEGV,
+		.timeout = 3,
+		.run = fake_sigreturn_bad_size_run,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c

@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 ARM Limited
+ *
+ * Place a fake sigframe on the stack including a badly sized terminator
+ * record: on sigreturn Kernel must spot this attempt and the test case
+ * is expected to be terminated via SEGV.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+struct fake_sigframe sf;
+
+static int fake_sigreturn_bad_size_for_magic0_run(struct tdescr *td,
+						  siginfo_t *si, ucontext_t *uc)
+{
+	struct _aarch64_ctx *shead = GET_SF_RESV_HEAD(sf), *head;
+
+	/* just to fill the ucontext_t with something real */
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
+		return 1;
+
+	/* at least HDR_SZ for the badly sized terminator. */
+	head = get_starting_head(shead, HDR_SZ, GET_SF_RESV_SIZE(sf), NULL);
+	if (!head)
+		return 0;
+
+	head->magic = 0;
+	head->size = HDR_SZ;
+	ASSERT_BAD_CONTEXT(&sf.uc);
+	fake_sigreturn(&sf, sizeof(sf), 0);
+
+	return 1;
+}
+
+struct tdescr tde = {
+		.name = "FAKE_SIGRETURN_BAD_SIZE_FOR_TERMINATOR",
+		.descr = "Trigger a sigreturn using non-zero size terminator",
+		.sig_ok = SIGSEGV,
+		.timeout = 3,
+		.run = fake_sigreturn_bad_size_for_magic0_run,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_duplicated_fpsimd.c

@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 ARM Limited
+ *
+ * Place a fake sigframe on the stack including an additional FPSIMD
+ * record: on sigreturn Kernel must spot this attempt and the test
+ * case is expected to be terminated via SEGV.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+struct fake_sigframe sf;
+
+static int fake_sigreturn_duplicated_fpsimd_run(struct tdescr *td,
+						siginfo_t *si, ucontext_t *uc)
+{
+	struct _aarch64_ctx *shead = GET_SF_RESV_HEAD(sf), *head;
+
+	/* just to fill the ucontext_t with something real */
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
+		return 1;
+
+	head = get_starting_head(shead, sizeof(struct fpsimd_context) + HDR_SZ,
+				 GET_SF_RESV_SIZE(sf), NULL);
+	if (!head)
+		return 0;
+
+	/* Add a spurious fpsimd_context */
+	head->magic = FPSIMD_MAGIC;
+	head->size = sizeof(struct fpsimd_context);
+	/* and terminate */
+	write_terminator_record(GET_RESV_NEXT_HEAD(head));
+
+	ASSERT_BAD_CONTEXT(&sf.uc);
+	fake_sigreturn(&sf, sizeof(sf), 0);
+
+	return 1;
+}
+
+struct tdescr tde = {
+		.name = "FAKE_SIGRETURN_DUPLICATED_FPSIMD",
+		.descr = "Triggers a sigreturn including two fpsimd_context",
+		.sig_ok = SIGSEGV,
+		.timeout = 3,
+		.run = fake_sigreturn_duplicated_fpsimd_run,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_misaligned_sp.c

@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 ARM Limited
+ *
+ * Place a fake sigframe on the stack at a misaligned SP: on sigreturn
+ * Kernel must spot this attempt and the test case is expected to be
+ * terminated via SEGV.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+struct fake_sigframe sf;
+
+static int fake_sigreturn_misaligned_run(struct tdescr *td,
+					 siginfo_t *si, ucontext_t *uc)
+{
+	/* just to fill the ucontext_t with something real */
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
+		return 1;
+
+	/* Forcing sigframe on misaligned SP (16 + 3) */
+	fake_sigreturn(&sf, sizeof(sf), 3);
+
+	return 1;
+}
+
+struct tdescr tde = {
+		.name = "FAKE_SIGRETURN_MISALIGNED_SP",
+		.descr = "Triggers a sigreturn with a misaligned sigframe",
+		.sig_ok = SIGSEGV,
+		.timeout = 3,
+		.run = fake_sigreturn_misaligned_run,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_missing_fpsimd.c

@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 ARM Limited
+ *
+ * Place a fake sigframe on the stack missing the mandatory FPSIMD
+ * record: on sigreturn Kernel must spot this attempt and the test
+ * case is expected to be terminated via SEGV.
+ */
+
+#include <stdio.h>
+#include <signal.h>
+#include <ucontext.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+struct fake_sigframe sf;
+
+static int fake_sigreturn_missing_fpsimd_run(struct tdescr *td,
+					     siginfo_t *si, ucontext_t *uc)
+{
+	size_t resv_sz, offset;
+	struct _aarch64_ctx *head = GET_SF_RESV_HEAD(sf);
+
+	/* just to fill the ucontext_t with something real */
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
+		return 1;
+
+	resv_sz = GET_SF_RESV_SIZE(sf);
+	head = get_header(head, FPSIMD_MAGIC, resv_sz, &offset);
+	if (head && resv_sz - offset >= HDR_SZ) {
+		fprintf(stderr, "Mangling template header. Spare space:%zd\n",
+			resv_sz - offset);
+		/* Just overwrite fpsmid_context */
+		write_terminator_record(head);
+
+		ASSERT_BAD_CONTEXT(&sf.uc);
+		fake_sigreturn(&sf, sizeof(sf), 0);
+	}
+
+	return 1;
+}
+
+struct tdescr tde = {
+		.name = "FAKE_SIGRETURN_MISSING_FPSIMD",
+		.descr = "Triggers a sigreturn with a missing fpsimd_context",
+		.sig_ok = SIGSEGV,
+		.timeout = 3,
+		.run = fake_sigreturn_missing_fpsimd_run,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_sme_change_vl.c

@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 ARM Limited
+ *
+ * Attempt to change the streaming SVE vector length in a signal
+ * 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 bool sme_get_vls(struct tdescr *td)
+{
+	int res = sve_fill_vls(VLS_USE_SME, 2);
+
+	if (!res)
+		return true;
+
+	if (res == KSFT_SKIP)
+		td->result = KSFT_SKIP;
+
+	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 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, ZA_MAGIC, resv_sz, &offset);
+	if (!head) {
+		fprintf(stderr, "No ZA context\n");
+		return 1;
+	}
+
+	if (head->size != sizeof(struct za_context)) {
+		fprintf(stderr, "Register data present, aborting\n");
+		return 1;
+	}
+
+	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",
+		za->vl, vls[0]);
+	za->vl = vls[0];
+
+	fake_sigreturn(&sf, sizeof(sf), 0);
+
+	return 1;
+}
+
+struct tdescr tde = {
+	.name = "FAKE_SIGRETURN_SSVE_CHANGE",
+	.descr = "Attempt to change Streaming SVE VL",
+	.feats_required = FEAT_SME,
+	.sig_ok = SIGSEGV,
+	.timeout = 3,
+	.init = sme_get_vls,
+	.run = fake_sigreturn_ssve_change_vl,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_sve_change_vl.c

@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 ARM Limited
+ *
+ * Attempt to change the SVE vector length in a signal hander, 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 bool sve_get_vls(struct tdescr *td)
+{
+	int res = sve_fill_vls(VLS_USE_SVE, 2);
+
+	if (!res)
+		return true;
+
+	if (res == KSFT_SKIP)
+		td->result = KSFT_SKIP;
+
+	return false;
+}
+
+static int fake_sigreturn_sve_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;
+
+	/* Get a signal context with a SVE 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);
+	if (!head) {
+		fprintf(stderr, "No SVE context\n");
+		return 1;
+	}
+
+	if (head->size != sizeof(struct sve_context)) {
+		fprintf(stderr, "SVE register state active, skipping\n");
+		return 1;
+	}
+
+	sve = (struct sve_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];
+
+	fake_sigreturn(&sf, sizeof(sf), 0);
+
+	return 1;
+}
+
+struct tdescr tde = {
+	.name = "FAKE_SIGRETURN_SVE_CHANGE",
+	.descr = "Attempt to change SVE VL",
+	.feats_required = FEAT_SVE,
+	.sig_ok = SIGSEGV,
+	.timeout = 3,
+	.init = sve_get_vls,
+	.run = fake_sigreturn_sve_change_vl,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/fpmr_siginfo.c

@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023 ARM Limited
+ *
+ * Verify that the FPMR register context in signal frames is set up as
+ * expected.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+#include <sys/auxv.h>
+#include <sys/prctl.h>
+#include <unistd.h>
+#include <asm/sigcontext.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+static union {
+	ucontext_t uc;
+	char buf[1024 * 128];
+} context;
+
+#define SYS_FPMR "S3_3_C4_C4_2"
+
+static uint64_t get_fpmr(void)
+{
+	uint64_t val;
+
+	asm volatile (
+		"mrs	%0, " SYS_FPMR "\n"
+		: "=r"(val)
+		:
+		: "cc");
+
+	return val;
+}
+
+int fpmr_present(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
+	struct fpmr_context *fpmr_ctx;
+	size_t offset;
+	bool in_sigframe;
+	bool have_fpmr;
+	__u64 orig_fpmr;
+
+	have_fpmr = getauxval(AT_HWCAP2) & HWCAP2_FPMR;
+	if (have_fpmr)
+		orig_fpmr = get_fpmr();
+
+	if (!get_current_context(td, &context.uc, sizeof(context)))
+		return 1;
+
+	fpmr_ctx = (struct fpmr_context *)
+		get_header(head, FPMR_MAGIC, td->live_sz, &offset);
+
+	in_sigframe = fpmr_ctx != NULL;
+
+	fprintf(stderr, "FPMR sigframe %s on system %s FPMR\n",
+		in_sigframe ? "present" : "absent",
+		have_fpmr ? "with" : "without");
+
+	td->pass = (in_sigframe == have_fpmr);
+
+	if (have_fpmr && fpmr_ctx) {
+		if (fpmr_ctx->fpmr != orig_fpmr) {
+			fprintf(stderr, "FPMR in frame is %llx, was %llx\n",
+				fpmr_ctx->fpmr, orig_fpmr);
+			td->pass = false;
+		}
+	}
+
+	return 0;
+}
+
+struct tdescr tde = {
+	.name = "FPMR",
+	.descr = "Validate that FPMR is present as expected",
+	.timeout = 3,
+	.run = fpmr_present,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/gcs_exception_fault.c

@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023 ARM Limited
+ */
+
+#include <errno.h>
+#include <signal.h>
+#include <unistd.h>
+
+#include <sys/mman.h>
+#include <sys/prctl.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+/*
+ * We should get this from asm/siginfo.h but the testsuite is being
+ * clever with redefining siginfo_t.
+ */
+#ifndef SEGV_CPERR
+#define SEGV_CPERR 10
+#endif
+
+static inline void gcsss1(uint64_t Xt)
+{
+	asm volatile (
+		"sys #3, C7, C7, #2, %0\n"
+		:
+		: "rZ" (Xt)
+		: "memory");
+}
+
+static int gcs_op_fault_trigger(struct tdescr *td)
+{
+	/*
+	 * The slot below our current GCS should be in a valid GCS but
+	 * must not have a valid cap in it.
+	 */
+	gcsss1(get_gcspr_el0() - 8);
+
+	return 0;
+}
+
+static int gcs_op_fault_signal(struct tdescr *td, siginfo_t *si,
+				  ucontext_t *uc)
+{
+	ASSERT_GOOD_CONTEXT(uc);
+
+	return 1;
+}
+
+struct tdescr tde = {
+	.name = "Invalid GCS operation",
+	.descr = "An invalid GCS operation generates the expected signal",
+	.feats_required = FEAT_GCS,
+	.timeout = 3,
+	.sig_ok = SIGSEGV,
+	.sig_ok_code = SEGV_CPERR,
+	.sanity_disabled = true,
+	.trigger = gcs_op_fault_trigger,
+	.run = gcs_op_fault_signal,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/gcs_frame.c

@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023 ARM Limited
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+#include <sys/prctl.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+static union {
+	ucontext_t uc;
+	char buf[1024 * 64];
+} context;
+
+static int gcs_regs(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+	size_t offset;
+	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
+	struct gcs_context *gcs;
+	unsigned long expected, gcspr;
+	uint64_t *u64_val;
+	int ret;
+
+	ret = prctl(PR_GET_SHADOW_STACK_STATUS, &expected, 0, 0, 0);
+	if (ret != 0) {
+		fprintf(stderr, "Unable to query GCS status\n");
+		return 1;
+	}
+
+	/* We expect a cap to be added to the GCS in the signal frame */
+	gcspr = get_gcspr_el0();
+	gcspr -= 8;
+	fprintf(stderr, "Expecting GCSPR_EL0 %lx\n", gcspr);
+
+	if (!get_current_context(td, &context.uc, sizeof(context))) {
+		fprintf(stderr, "Failed getting context\n");
+		return 1;
+	}
+
+	/* Ensure that the signal restore token was consumed */
+	u64_val = (uint64_t *)get_gcspr_el0() + 1;
+	if (*u64_val) {
+		fprintf(stderr, "GCS value at %p is %lx not 0\n",
+			u64_val, *u64_val);
+		return 1;
+	}
+
+	fprintf(stderr, "Got context\n");
+
+	head = get_header(head, GCS_MAGIC, GET_BUF_RESV_SIZE(context),
+			  &offset);
+	if (!head) {
+		fprintf(stderr, "No GCS context\n");
+		return 1;
+	}
+
+	gcs = (struct gcs_context *)head;
+
+	/* Basic size validation is done in get_current_context() */
+
+	if (gcs->features_enabled != expected) {
+		fprintf(stderr, "Features enabled %llx but expected %lx\n",
+			gcs->features_enabled, expected);
+		return 1;
+	}
+
+	if (gcs->gcspr != gcspr) {
+		fprintf(stderr, "Got GCSPR %llx but expected %lx\n",
+			gcs->gcspr, gcspr);
+		return 1;
+	}
+
+	fprintf(stderr, "GCS context validated\n");
+	td->pass = 1;
+
+	return 0;
+}
+
+struct tdescr tde = {
+	.name = "GCS basics",
+	.descr = "Validate a GCS signal context",
+	.feats_required = FEAT_GCS,
+	.timeout = 3,
+	.run = gcs_regs,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/gcs_prot_none_fault.c

@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2026 ARM Limited
+ */
+
+#include <errno.h>
+#include <signal.h>
+#include <unistd.h>
+
+#include <sys/mman.h>
+#include <sys/prctl.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+static uint64_t *gcs_page;
+static bool post_mprotect;
+
+#ifndef __NR_map_shadow_stack
+#define __NR_map_shadow_stack 453
+#endif
+
+static bool alloc_gcs(struct tdescr *td)
+{
+	long page_size = sysconf(_SC_PAGE_SIZE);
+
+	gcs_page = (void *)syscall(__NR_map_shadow_stack, 0,
+				   page_size, 0);
+	if (gcs_page == MAP_FAILED) {
+		fprintf(stderr, "Failed to map %ld byte GCS: %d\n",
+			page_size, errno);
+		return false;
+	}
+
+	return true;
+}
+
+static int gcs_prot_none_fault_trigger(struct tdescr *td)
+{
+	/* Verify that the page is readable (ie, not completely unmapped) */
+	fprintf(stderr, "Read value 0x%lx\n", gcs_page[0]);
+
+	if (mprotect(gcs_page, sysconf(_SC_PAGE_SIZE), PROT_NONE) != 0) {
+		fprintf(stderr, "mprotect(PROT_NONE) failed: %d\n", errno);
+		return 0;
+	}
+	post_mprotect = true;
+
+	/* This should trigger a fault if PROT_NONE is honoured for the GCS page */
+	fprintf(stderr, "Read value after mprotect(PROT_NONE) 0x%lx\n", gcs_page[0]);
+	return 0;
+}
+
+static int gcs_prot_none_fault_signal(struct tdescr *td, siginfo_t *si,
+				      ucontext_t *uc)
+{
+	ASSERT_GOOD_CONTEXT(uc);
+
+	/* A fault before mprotect(PROT_NONE) is unexpected. */
+	if (!post_mprotect)
+		return 0;
+
+	return 1;
+}
+
+struct tdescr tde = {
+	.name = "GCS PROT_NONE fault",
+	.descr = "Read from GCS after mprotect(PROT_NONE) segfaults",
+	.feats_required = FEAT_GCS,
+	.timeout = 3,
+	.sig_ok = SIGSEGV,
+	.sanity_disabled = true,
+	.init = alloc_gcs,
+	.trigger = gcs_prot_none_fault_trigger,
+	.run = gcs_prot_none_fault_signal,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/gcs_write_fault.c

@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023 ARM Limited
+ */
+
+#include <errno.h>
+#include <signal.h>
+#include <unistd.h>
+
+#include <sys/mman.h>
+#include <sys/prctl.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+static uint64_t *gcs_page;
+
+#ifndef __NR_map_shadow_stack
+#define __NR_map_shadow_stack 453
+#endif
+
+static bool alloc_gcs(struct tdescr *td)
+{
+	long page_size = sysconf(_SC_PAGE_SIZE);
+
+	gcs_page = (void *)syscall(__NR_map_shadow_stack, 0,
+				   page_size, 0);
+	if (gcs_page == MAP_FAILED) {
+		fprintf(stderr, "Failed to map %ld byte GCS: %d\n",
+			page_size, errno);
+		return false;
+	}
+
+	return true;
+}
+
+static int gcs_write_fault_trigger(struct tdescr *td)
+{
+	/* Verify that the page is readable (ie, not completely unmapped) */
+	fprintf(stderr, "Read value 0x%lx\n", gcs_page[0]);
+
+	/* A regular write should trigger a fault */
+	gcs_page[0] = EINVAL;
+
+	return 0;
+}
+
+static int gcs_write_fault_signal(struct tdescr *td, siginfo_t *si,
+				  ucontext_t *uc)
+{
+	ASSERT_GOOD_CONTEXT(uc);
+
+	return 1;
+}
+
+
+struct tdescr tde = {
+	.name = "GCS write fault",
+	.descr = "Normal writes to a GCS segfault",
+	.feats_required = FEAT_GCS,
+	.timeout = 3,
+	.sig_ok = SIGSEGV,
+	.sanity_disabled = true,
+	.init = alloc_gcs,
+	.trigger = gcs_write_fault_trigger,
+	.run = gcs_write_fault_signal,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_compat_toggle.c

@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 ARM Limited
+ *
+ * Try to mangle the ucontext from inside a signal handler, toggling
+ * the execution state bit: this attempt must be spotted by Kernel and
+ * the test case is expected to be terminated via SEGV.
+ */
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+static int mangle_invalid_pstate_run(struct tdescr *td, siginfo_t *si,
+				     ucontext_t *uc)
+{
+	ASSERT_GOOD_CONTEXT(uc);
+
+	/* This config should trigger a SIGSEGV by Kernel */
+	uc->uc_mcontext.pstate ^= PSR_MODE32_BIT;
+
+	return 1;
+}
+
+struct tdescr tde = {
+		.sanity_disabled = true,
+		.name = "MANGLE_PSTATE_INVALID_STATE_TOGGLE",
+		.descr = "Mangling uc_mcontext with INVALID STATE_TOGGLE",
+		.sig_trig = SIGUSR1,
+		.sig_ok = SIGSEGV,
+		.run = mangle_invalid_pstate_run,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_daif_bits.c

@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 ARM Limited
+ *
+ * Try to mangle the ucontext from inside a signal handler, mangling the
+ * DAIF bits in an illegal manner: this attempt must be spotted by Kernel
+ * and the test case is expected to be terminated via SEGV.
+ *
+ */
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+static int mangle_invalid_pstate_run(struct tdescr *td, siginfo_t *si,
+				     ucontext_t *uc)
+{
+	ASSERT_GOOD_CONTEXT(uc);
+
+	/*
+	 * This config should trigger a SIGSEGV by Kernel when it checks
+	 * the sigframe consistency in valid_user_regs() routine.
+	 */
+	uc->uc_mcontext.pstate |= PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT;
+
+	return 1;
+}
+
+struct tdescr tde = {
+		.sanity_disabled = true,
+		.name = "MANGLE_PSTATE_INVALID_DAIF_BITS",
+		.descr = "Mangling uc_mcontext with INVALID DAIF_BITS",
+		.sig_trig = SIGUSR1,
+		.sig_ok = SIGSEGV,
+		.run = mangle_invalid_pstate_run,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_mode_el1h.c

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 ARM Limited
+ *
+ * Try to mangle the ucontext from inside a signal handler, toggling
+ * the mode bit to escalate exception level: this attempt must be spotted
+ * by Kernel and the test case is expected to be termninated via SEGV.
+ */
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+#include "mangle_pstate_invalid_mode_template.h"
+
+DEFINE_TESTCASE_MANGLE_PSTATE_INVALID_MODE(1h);

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_mode_el1t.c

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 ARM Limited
+ *
+ * Try to mangle the ucontext from inside a signal handler, toggling
+ * the mode bit to escalate exception level: this attempt must be spotted
+ * by Kernel and the test case is expected to be termninated via SEGV.
+ */
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+#include "mangle_pstate_invalid_mode_template.h"
+
+DEFINE_TESTCASE_MANGLE_PSTATE_INVALID_MODE(1t);

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_mode_el2h.c

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 ARM Limited
+ *
+ * Try to mangle the ucontext from inside a signal handler, toggling
+ * the mode bit to escalate exception level: this attempt must be spotted
+ * by Kernel and the test case is expected to be termninated via SEGV.
+ */
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+#include "mangle_pstate_invalid_mode_template.h"
+
+DEFINE_TESTCASE_MANGLE_PSTATE_INVALID_MODE(2h);

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_mode_el2t.c

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 ARM Limited
+ *
+ * Try to mangle the ucontext from inside a signal handler, toggling
+ * the mode bit to escalate exception level: this attempt must be spotted
+ * by Kernel and the test case is expected to be termninated via SEGV.
+ */
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+#include "mangle_pstate_invalid_mode_template.h"
+
+DEFINE_TESTCASE_MANGLE_PSTATE_INVALID_MODE(2t);

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_mode_el3h.c

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 ARM Limited
+ *
+ * Try to mangle the ucontext from inside a signal handler, toggling
+ * the mode bit to escalate exception level: this attempt must be spotted
+ * by Kernel and the test case is expected to be termninated via SEGV.
+ */
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+#include "mangle_pstate_invalid_mode_template.h"
+
+DEFINE_TESTCASE_MANGLE_PSTATE_INVALID_MODE(3h);

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_mode_el3t.c

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 ARM Limited
+ *
+ * Try to mangle the ucontext from inside a signal handler, toggling
+ * the mode bit to escalate exception level: this attempt must be spotted
+ * by Kernel and the test case is expected to be termninated via SEGV.
+ */
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+#include "mangle_pstate_invalid_mode_template.h"
+
+DEFINE_TESTCASE_MANGLE_PSTATE_INVALID_MODE(3t);

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_mode_template.h

@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 ARM Limited
+ *
+ * Utility macro to ease definition of testcases toggling mode EL
+ */
+
+#define DEFINE_TESTCASE_MANGLE_PSTATE_INVALID_MODE(_mode)		\
+									\
+static int mangle_invalid_pstate_run(struct tdescr *td, siginfo_t *si,	\
+				     ucontext_t *uc)			\
+{									\
+	ASSERT_GOOD_CONTEXT(uc);					\
+									\
+	uc->uc_mcontext.pstate &= ~PSR_MODE_MASK;			\
+	uc->uc_mcontext.pstate |= PSR_MODE_EL ## _mode;			\
+									\
+	return 1;							\
+}									\
+									\
+struct tdescr tde = {							\
+		.sanity_disabled = true,				\
+		.name = "MANGLE_PSTATE_INVALID_MODE_EL"#_mode,		\
+		.descr = "Mangling uc_mcontext INVALID MODE EL"#_mode,	\
+		.sig_trig = SIGUSR1,					\
+		.sig_ok = SIGSEGV,					\
+		.run = mangle_invalid_pstate_run,			\
+}

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/poe_missing_poe_context.c

@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2026 Arm Ltd
+ *
+ * Verify that the POR_EL0 register is left untouched on sigreturn if the
+ * POE frame record is missing.
+ */
+
+#include <asm/sigcontext.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+#define POR_EL0_INIT	0x07ul
+#define POR_EL0_CUSTOM	0x77ul
+
+static bool failed_check;
+
+static bool modify_por_el0(struct tdescr *td)
+{
+	set_por_el0(POR_EL0_CUSTOM);
+
+	return true;
+}
+
+static int signal_remove_poe_context(struct tdescr *td, siginfo_t *si,
+				      ucontext_t *uc)
+{
+	struct _aarch64_ctx *ctx = GET_UC_RESV_HEAD(uc);
+	size_t resv_size = GET_UCP_RESV_SIZE(uc);
+	struct _aarch64_ctx *poe_ctx_head;
+
+	poe_ctx_head = get_header(ctx, POE_MAGIC, resv_size, NULL);
+	if (!poe_ctx_head) {
+		fprintf(stderr, "Missing poe_context record\n");
+		failed_check = true;
+		return 0;
+	}
+
+	/*
+	 * Actually removing the record would require moving down the next
+	 * records. An easier option is to turn it into an ESR record, which is
+	 * ignored by sigreturn().
+	 */
+	poe_ctx_head->magic = ESR_MAGIC;
+
+	return 0;
+}
+
+static void check_por_el0_preserved(struct tdescr *td)
+{
+	uint64_t por_el0 = get_por_el0();
+
+	if (por_el0 == POR_EL0_INIT) {
+		fprintf(stderr, "POR_EL0 preserved\n");
+	} else {
+		fprintf(stderr, "POR_EL0 unexpectedly set to %lx\n", por_el0);
+		failed_check = true;
+	}
+
+	td->pass = !failed_check;
+}
+
+struct tdescr tde = {
+	.name = "POR_EL0 missing poe_context",
+	.descr = "Remove poe_context record and check POR_EL0 is preserved",
+	.feats_required = FEAT_POE,
+	.timeout = 3,
+	.sig_trig = SIGUSR1,
+	.init = modify_por_el0,
+	.run = signal_remove_poe_context,
+	.check_result = check_por_el0_preserved,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/poe_restore.c

@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2026 Arm Ltd
+ *
+ * Verify that the POR_EL0 register is saved and restored as expected on signal
+ * entry/return.
+ */
+
+#include <asm/sigcontext.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+#define POR_EL0_INIT	0x07ul
+#define POR_EL0_CUSTOM	0x77ul
+
+static bool failed_check;
+
+static bool modify_por_el0(struct tdescr *td)
+{
+	set_por_el0(POR_EL0_CUSTOM);
+
+	return true;
+}
+
+static int signal_check_por_el0_reset(struct tdescr *td, siginfo_t *si,
+				      ucontext_t *uc)
+{
+	uint64_t signal_por_el0 = get_por_el0();
+
+	if (signal_por_el0 != POR_EL0_INIT) {
+		fprintf(stderr, "POR_EL0 is %lx in signal handler (expected %lx)\n",
+			signal_por_el0, POR_EL0_INIT);
+		failed_check = true;
+	}
+
+	return 0;
+}
+
+static void check_por_el0_restored(struct tdescr *td)
+{
+	uint64_t por_el0 = get_por_el0();
+
+	if (por_el0 == POR_EL0_CUSTOM) {
+		fprintf(stderr, "POR_EL0 restored\n");
+	} else {
+		fprintf(stderr, "POR_EL0 was %lx but is now %lx\n",
+			POR_EL0_CUSTOM, por_el0);
+		failed_check = true;
+	}
+
+	td->pass = !failed_check;
+}
+
+struct tdescr tde = {
+	.name = "POR_EL0 restore",
+	.descr = "Validate that POR_EL0 is saved/restored on signal entry/return",
+	.feats_required = FEAT_POE,
+	.timeout = 3,
+	.sig_trig = SIGUSR1,
+	.init = modify_por_el0,
+	.run = signal_check_por_el0_reset,
+	.check_result = check_por_el0_restored,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/poe_siginfo.c

@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023 Arm Limited
+ *
+ * Verify that the POR_EL0 register context in signal frames is set up as
+ * expected.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+#include <sys/auxv.h>
+#include <sys/prctl.h>
+#include <unistd.h>
+#include <asm/sigcontext.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+static union {
+	ucontext_t uc;
+	char buf[1024 * 128];
+} context;
+
+int poe_present(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
+	struct poe_context *poe_ctx;
+	size_t offset;
+	bool in_sigframe;
+	bool have_poe;
+	__u64 orig_poe;
+
+	have_poe = getauxval(AT_HWCAP2) & HWCAP2_POE;
+	if (have_poe)
+		orig_poe = get_por_el0();
+
+	if (!get_current_context(td, &context.uc, sizeof(context)))
+		return 1;
+
+	poe_ctx = (struct poe_context *)
+		get_header(head, POE_MAGIC, td->live_sz, &offset);
+
+	in_sigframe = poe_ctx != NULL;
+
+	fprintf(stderr, "POR_EL0 sigframe %s on system %s POE\n",
+		in_sigframe ? "present" : "absent",
+		have_poe ? "with" : "without");
+
+	td->pass = (in_sigframe == have_poe);
+
+	/*
+	 * Check that the value we read back was the one present at
+	 * the time that the signal was triggered.
+	 */
+	if (have_poe && poe_ctx) {
+		if (poe_ctx->por_el0 != orig_poe) {
+			fprintf(stderr, "POR_EL0 in frame is %llx, was %llx\n",
+				poe_ctx->por_el0, orig_poe);
+			td->pass = false;
+		}
+	}
+
+	return 0;
+}
+
+struct tdescr tde = {
+	.name = "POR_EL0",
+	.descr = "Validate that POR_EL0 is present as expected",
+	.timeout = 3,
+	.run = poe_present,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/sme_trap_no_sm.c

@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 ARM Limited
+ *
+ * Verify that using a streaming mode instruction without enabling it
+ * generates a SIGILL.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+#include <sys/prctl.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+int sme_trap_no_sm_trigger(struct tdescr *td)
+{
+	/* SMSTART ZA ; ADDHA ZA0.S, P0/M, P0/M, Z0.S */
+	asm volatile(".inst 0xd503457f ; .inst 0xc0900000");
+
+	return 0;
+}
+
+int sme_trap_no_sm_run(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+	return 1;
+}
+
+struct tdescr tde = {
+	.name = "SME trap without SM",
+	.descr = "Check that we get a SIGILL if we use streaming mode without enabling it",
+	.timeout = 3,
+	.feats_required = FEAT_SME,   /* We need a SMSTART ZA */
+	.sanity_disabled = true,
+	.trigger = sme_trap_no_sm_trigger,
+	.run = sme_trap_no_sm_run,
+	.sig_ok = SIGILL,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/sme_trap_non_streaming.c

@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 ARM Limited
+ *
+ * Verify that using an instruction not supported in streaming mode
+ * traps when in streaming mode.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+#include <sys/prctl.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+int sme_trap_non_streaming_trigger(struct tdescr *td)
+{
+	/*
+	 * The framework will handle SIGILL so we need to exit SM to
+	 * stop any other code triggering a further SIGILL down the
+	 * line from using a streaming-illegal instruction.
+	 */
+	asm volatile(".inst 0xd503437f; /* SMSTART ZA */ \
+		      cnt v0.16b, v0.16b; \
+                      .inst 0xd503447f  /* SMSTOP ZA */");
+
+	return 0;
+}
+
+int sme_trap_non_streaming_run(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+	return 1;
+}
+
+struct tdescr tde = {
+	.name = "SME SM trap unsupported instruction",
+	.descr = "Check that we get a SIGILL if we use an unsupported instruction in streaming mode",
+	.feats_required = FEAT_SME,
+	.feats_incompatible = FEAT_SME_FA64,
+	.timeout = 3,
+	.sanity_disabled = true,
+	.trigger = sme_trap_non_streaming_trigger,
+	.run = sme_trap_non_streaming_run,
+	.sig_ok = SIGILL,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/sme_trap_za.c

@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 ARM Limited
+ *
+ * Verify that accessing ZA without enabling it generates a SIGILL.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+#include <sys/prctl.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+int sme_trap_za_trigger(struct tdescr *td)
+{
+	/* ZERO ZA */
+	asm volatile(".inst 0xc00800ff");
+
+	return 0;
+}
+
+int sme_trap_za_run(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+	return 1;
+}
+
+struct tdescr tde = {
+	.name = "SME ZA trap",
+	.descr = "Check that we get a SIGILL if we access ZA without enabling",
+	.timeout = 3,
+	.sanity_disabled = true,
+	.trigger = sme_trap_za_trigger,
+	.run = sme_trap_za_run,
+	.sig_ok = SIGILL,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/sme_vl.c

@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 ARM Limited
+ *
+ * Check that the SME vector length reported in signal contexts is the
+ * expected one.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+#include <sys/prctl.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+struct fake_sigframe sf;
+unsigned int vl;
+
+static bool get_sme_vl(struct tdescr *td)
+{
+	int ret = prctl(PR_SME_GET_VL);
+	if (ret == -1)
+		return false;
+
+	vl = ret;
+
+	return true;
+}
+
+static int sme_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 za_context *za;
+
+	/* Get a signal context which should have a 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, ZA_MAGIC, resv_sz, &offset);
+	if (!head) {
+		fprintf(stderr, "No ZA context\n");
+		return 1;
+	}
+	za = (struct za_context *)head;
+
+	if (za->vl != vl) {
+		fprintf(stderr, "ZA sigframe VL %u, expected %u\n",
+			za->vl, vl);
+		return 1;
+	} else {
+		fprintf(stderr, "got expected VL %u\n", vl);
+	}
+
+	td->pass = 1;
+
+	return 0;
+}
+
+struct tdescr tde = {
+	.name = "SME VL",
+	.descr = "Check that we get the right SME VL reported",
+	.feats_required = FEAT_SME,
+	.timeout = 3,
+	.init = get_sme_vl,
+	.run = sme_vl,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c

@@ -0,0 +1,117 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 ARM Limited
+ *
+ * Verify that the streaming SVE register context in signal frames is
+ * 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 bool sme_get_vls(struct tdescr *td)
+{
+	int res = sve_fill_vls(VLS_USE_SME, 1);
+
+	if (!res)
+		return true;
+
+	if (res == KSFT_SKIP)
+		td->result = KSFT_SKIP;
+
+	return false;
+}
+
+static void setup_ssve_regs(void)
+{
+	/* smstart sm; real data is TODO */
+	asm volatile(".inst 0xd503437f" : : : );
+}
+
+static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
+			 unsigned int vl)
+{
+	size_t offset;
+	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
+	struct sve_context *ssve;
+	int ret;
+
+	fprintf(stderr, "Testing VL %d\n", vl);
+
+	ret = prctl(PR_SME_SET_VL, vl);
+	if (ret != vl) {
+		fprintf(stderr, "Failed to set VL, got %d\n", ret);
+		return 1;
+	}
+
+	/*
+	 * Get a signal context which should have a SVE frame and registers
+	 * in it.
+	 */
+	setup_ssve_regs();
+	if (!get_current_context(td, &context.uc, sizeof(context)))
+		return 1;
+
+	head = get_header(head, SVE_MAGIC, GET_BUF_RESV_SIZE(context),
+			  &offset);
+	if (!head) {
+		fprintf(stderr, "No SVE context\n");
+		return 1;
+	}
+
+	ssve = (struct sve_context *)head;
+	if (ssve->vl != vl) {
+		fprintf(stderr, "Got VL %d, expected %d\n", ssve->vl, vl);
+		return 1;
+	}
+
+	if (!(ssve->flags & SVE_SIG_FLAG_SM)) {
+		fprintf(stderr, "SVE_SIG_FLAG_SM not set in SVE record\n");
+		return 1;
+	}
+
+	/* The actual size validation is done in get_current_context() */
+	fprintf(stderr, "Got expected size %u and VL %d\n",
+		head->size, ssve->vl);
+
+	if (get_svcr() != 0) {
+		fprintf(stderr, "Unexpected SVCR %lx\n", get_svcr());
+		return 1;
+	}
+
+	return 0;
+}
+
+static int sme_regs(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+	int i;
+
+	for (i = 0; i < nvls; i++) {
+		if (do_one_sme_vl(td, si, uc, vls[i]))
+			return 1;
+	}
+
+	td->pass = 1;
+
+	return 0;
+}
+
+struct tdescr tde = {
+	.name = "Streaming SVE registers",
+	.descr = "Check that we get the right Streaming SVE registers reported",
+	.feats_required = FEAT_SME,
+	.timeout = 3,
+	.init = sme_get_vls,
+	.run = sme_regs,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/ssve_za_regs.c

@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 ARM Limited
+ *
+ * Verify that both the streaming SVE and ZA register context in
+ * 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 bool sme_get_vls(struct tdescr *td)
+{
+	int res = sve_fill_vls(VLS_USE_SME, 1);
+
+	if (!res)
+		return true;
+
+	if (res == KSFT_SKIP)
+		td->result = KSFT_SKIP;
+
+	return false;
+}
+
+static void setup_regs(void)
+{
+	/* smstart sm; real data is TODO */
+	asm volatile(".inst 0xd503437f" : : : );
+
+	/* smstart za; real data is TODO */
+	asm volatile(".inst 0xd503457f" : : : );
+}
+
+static char zeros[ZA_SIG_REGS_SIZE(SVE_VQ_MAX)];
+
+static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
+			 unsigned int vl)
+{
+	size_t offset;
+	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
+	struct _aarch64_ctx *regs;
+	struct sve_context *ssve;
+	struct za_context *za;
+	int ret;
+
+	fprintf(stderr, "Testing VL %d\n", vl);
+
+	ret = prctl(PR_SME_SET_VL, vl);
+	if (ret != vl) {
+		fprintf(stderr, "Failed to set VL, got %d\n", ret);
+		return 1;
+	}
+
+	/*
+	 * Get a signal context which should have the SVE and ZA
+	 * frames in it.
+	 */
+	setup_regs();
+	if (!get_current_context(td, &context.uc, sizeof(context)))
+		return 1;
+
+	regs = get_header(head, SVE_MAGIC, GET_BUF_RESV_SIZE(context),
+			  &offset);
+	if (!regs) {
+		fprintf(stderr, "No SVE context\n");
+		return 1;
+	}
+
+	ssve = (struct sve_context *)regs;
+	if (ssve->vl != vl) {
+		fprintf(stderr, "Got SSVE VL %d, expected %d\n", ssve->vl, vl);
+		return 1;
+	}
+
+	if (!(ssve->flags & SVE_SIG_FLAG_SM)) {
+		fprintf(stderr, "SVE_SIG_FLAG_SM not set in SVE record\n");
+		return 1;
+	}
+
+	fprintf(stderr, "Got expected SSVE size %u and VL %d\n",
+		regs->size, ssve->vl);
+
+	regs = get_header(head, ZA_MAGIC, GET_BUF_RESV_SIZE(context),
+			  &offset);
+	if (!regs) {
+		fprintf(stderr, "No ZA context\n");
+		return 1;
+	}
+
+	za = (struct za_context *)regs;
+	if (za->vl != vl) {
+		fprintf(stderr, "Got ZA VL %d, expected %d\n", za->vl, vl);
+		return 1;
+	}
+
+	fprintf(stderr, "Got expected ZA size %u and VL %d\n",
+		regs->size, za->vl);
+
+	/* We didn't load any data into ZA so it should be all zeros */
+	if (memcmp(zeros, (char *)za + ZA_SIG_REGS_OFFSET,
+		   ZA_SIG_REGS_SIZE(sve_vq_from_vl(za->vl))) != 0) {
+		fprintf(stderr, "ZA data invalid\n");
+		return 1;
+	}
+
+	return 0;
+}
+
+static int sme_regs(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+	int i;
+
+	for (i = 0; i < nvls; i++) {
+		if (do_one_sme_vl(td, si, uc, vls[i]))
+			return 1;
+	}
+
+	td->pass = 1;
+
+	return 0;
+}
+
+struct tdescr tde = {
+	.name = "Streaming SVE registers",
+	.descr = "Check that we get the right Streaming SVE registers reported",
+	.feats_required = FEAT_SME,
+	.timeout = 3,
+	.init = sme_get_vls,
+	.run = sme_regs,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/sve_regs.c

@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 ARM Limited
+ *
+ * Verify that the SVE register context in signal frames is 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 bool sve_get_vls(struct tdescr *td)
+{
+	int res = sve_fill_vls(VLS_USE_SVE, 1);
+
+	if (!res)
+		return true;
+
+	if (res == KSFT_SKIP)
+		td->result = KSFT_SKIP;
+
+	return false;
+}
+
+static void setup_sve_regs(void)
+{
+	/* RDVL x16, #1 so we should have SVE regs; real data is TODO */
+	asm volatile(".inst 0x04bf5030" : : : "x16" );
+}
+
+static int do_one_sve_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
+			 unsigned int vl)
+{
+	size_t offset;
+	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
+	struct sve_context *sve;
+
+	fprintf(stderr, "Testing VL %d\n", vl);
+
+	if (prctl(PR_SVE_SET_VL, vl) == -1) {
+		fprintf(stderr, "Failed to set VL\n");
+		return 1;
+	}
+
+	/*
+	 * Get a signal context which should have a SVE frame and registers
+	 * in it.
+	 */
+	setup_sve_regs();
+	if (!get_current_context(td, &context.uc, sizeof(context)))
+		return 1;
+
+	head = get_header(head, SVE_MAGIC, GET_BUF_RESV_SIZE(context),
+			  &offset);
+	if (!head) {
+		fprintf(stderr, "No SVE context\n");
+		return 1;
+	}
+
+	sve = (struct sve_context *)head;
+	if (sve->vl != vl) {
+		fprintf(stderr, "Got VL %d, expected %d\n", sve->vl, vl);
+		return 1;
+	}
+
+	/* The actual size validation is done in get_current_context() */
+	fprintf(stderr, "Got expected size %u and VL %d\n",
+		head->size, sve->vl);
+
+	return 0;
+}
+
+static int sve_regs(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+	int i;
+
+	for (i = 0; i < nvls; i++) {
+		if (do_one_sve_vl(td, si, uc, vls[i]))
+			return 1;
+	}
+
+	td->pass = 1;
+
+	return 0;
+}
+
+struct tdescr tde = {
+	.name = "SVE registers",
+	.descr = "Check that we get the right SVE registers reported",
+	.feats_required = FEAT_SVE,
+	.timeout = 3,
+	.init = sve_get_vls,
+	.run = sve_regs,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/sve_vl.c

@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 ARM Limited
+ *
+ * Check that the SVE vector length reported in signal contexts is the
+ * expected one.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+#include <sys/prctl.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+struct fake_sigframe sf;
+unsigned int vl;
+
+static bool get_sve_vl(struct tdescr *td)
+{
+	int ret = prctl(PR_SVE_GET_VL);
+	if (ret == -1)
+		return false;
+
+	vl = ret;
+
+	return true;
+}
+
+static int sve_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;
+
+	/* Get a signal context which should have a SVE 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);
+	if (!head) {
+		fprintf(stderr, "No SVE context\n");
+		return 1;
+	}
+	sve = (struct sve_context *)head;
+
+	if (sve->vl != vl) {
+		fprintf(stderr, "sigframe VL %u, expected %u\n",
+			sve->vl, vl);
+		return 1;
+	} else {
+		fprintf(stderr, "got expected VL %u\n", vl);
+	}
+
+	td->pass = 1;
+
+	return 0;
+}
+
+struct tdescr tde = {
+	.name = "SVE VL",
+	.descr = "Check that we get the right SVE VL reported",
+	.feats_required = FEAT_SVE,
+	.timeout = 3,
+	.init = get_sve_vl,
+	.run = sve_vl,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/testcases.c

@@ -0,0 +1,331 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2019 ARM Limited */
+
+#include <ctype.h>
+#include <string.h>
+
+#include "testcases.h"
+
+bool validate_extra_context(struct extra_context *extra, char **err,
+			    void **extra_data, size_t *extra_size)
+{
+	struct _aarch64_ctx *term;
+
+	if (!extra || !err)
+		return false;
+
+	fprintf(stderr, "Validating EXTRA...\n");
+	term = GET_RESV_NEXT_HEAD(&extra->head);
+	if (!term || term->magic || term->size) {
+		*err = "Missing terminator after EXTRA context";
+		return false;
+	}
+	if (extra->datap & 0x0fUL)
+		*err = "Extra DATAP misaligned";
+	else if (extra->size & 0x0fUL)
+		*err = "Extra SIZE misaligned";
+	else if (extra->datap != (uint64_t)term + 0x10UL)
+		*err = "Extra DATAP misplaced (not contiguous)";
+	if (*err)
+		return false;
+
+	*extra_data = (void *)extra->datap;
+	*extra_size = extra->size;
+
+	return true;
+}
+
+bool validate_sve_context(struct sve_context *sve, char **err)
+{
+	/* Size will be rounded up to a multiple of 16 bytes */
+	size_t regs_size
+		= ((SVE_SIG_CONTEXT_SIZE(sve_vq_from_vl(sve->vl)) + 15) / 16) * 16;
+
+	if (!sve || !err)
+		return false;
+
+	/* Either a bare sve_context or a sve_context followed by regs data */
+	if ((sve->head.size != sizeof(struct sve_context)) &&
+	    (sve->head.size != regs_size)) {
+		*err = "bad size for SVE context";
+		return false;
+	}
+
+	if (!sve_vl_valid(sve->vl)) {
+		*err = "SVE VL invalid";
+
+		return false;
+	}
+
+	return true;
+}
+
+bool validate_za_context(struct za_context *za, char **err)
+{
+	/* Size will be rounded up to a multiple of 16 bytes */
+	size_t regs_size
+		= ((ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(za->vl)) + 15) / 16) * 16;
+
+	if (!za || !err)
+		return false;
+
+	/* Either a bare za_context or a za_context followed by regs data */
+	if ((za->head.size != sizeof(struct za_context)) &&
+	    (za->head.size != regs_size)) {
+		*err = "bad size for ZA context";
+		return false;
+	}
+
+	if (!sve_vl_valid(za->vl)) {
+		*err = "SME VL in ZA context invalid";
+
+		return false;
+	}
+
+	return true;
+}
+
+bool validate_zt_context(struct zt_context *zt, char **err)
+{
+	if (!zt || !err)
+		return false;
+
+	/* If the context is present there should be at least one register */
+	if (zt->nregs == 0) {
+		*err = "no registers";
+		return false;
+	}
+
+	/* Size should agree with the number of registers */
+	if (zt->head.size != ZT_SIG_CONTEXT_SIZE(zt->nregs)) {
+		*err = "register count does not match size";
+		return false;
+	}
+
+	return true;
+}
+
+bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
+{
+	bool terminated = false;
+	size_t offs = 0;
+	int flags = 0;
+	int new_flags, i;
+	struct extra_context *extra = NULL;
+	struct sve_context *sve = NULL;
+	struct za_context *za = NULL;
+	struct zt_context *zt = NULL;
+	struct _aarch64_ctx *head =
+		(struct _aarch64_ctx *)uc->uc_mcontext.__reserved;
+	void *extra_data = NULL;
+	size_t extra_sz = 0;
+	char magic[4];
+
+	if (!err)
+		return false;
+	/* Walk till the end terminator verifying __reserved contents */
+	while (head && !terminated && offs < resv_sz) {
+		if ((uint64_t)head & 0x0fUL) {
+			*err = "Misaligned HEAD";
+			return false;
+		}
+
+		new_flags = 0;
+
+		switch (head->magic) {
+		case 0:
+			if (head->size) {
+				*err = "Bad size for terminator";
+			} else if (extra_data) {
+				/* End of main data, walking the extra data */
+				head = extra_data;
+				resv_sz = extra_sz;
+				offs = 0;
+
+				extra_data = NULL;
+				extra_sz = 0;
+				continue;
+			} else {
+				terminated = true;
+			}
+			break;
+		case FPSIMD_MAGIC:
+			if (flags & FPSIMD_CTX)
+				*err = "Multiple FPSIMD_MAGIC";
+			else if (head->size !=
+				 sizeof(struct fpsimd_context))
+				*err = "Bad size for fpsimd_context";
+			new_flags |= FPSIMD_CTX;
+			break;
+		case ESR_MAGIC:
+			if (head->size != sizeof(struct esr_context))
+				*err = "Bad size for esr_context";
+			break;
+		case POE_MAGIC:
+			if (head->size != sizeof(struct poe_context))
+				*err = "Bad size for poe_context";
+			break;
+		case TPIDR2_MAGIC:
+			if (head->size != sizeof(struct tpidr2_context))
+				*err = "Bad size for tpidr2_context";
+			break;
+		case SVE_MAGIC:
+			if (flags & SVE_CTX)
+				*err = "Multiple SVE_MAGIC";
+			/* Size is validated in validate_sve_context() */
+			sve = (struct sve_context *)head;
+			new_flags |= SVE_CTX;
+			break;
+		case ZA_MAGIC:
+			if (flags & ZA_CTX)
+				*err = "Multiple ZA_MAGIC";
+			/* Size is validated in validate_za_context() */
+			za = (struct za_context *)head;
+			new_flags |= ZA_CTX;
+			break;
+		case ZT_MAGIC:
+			if (flags & ZT_CTX)
+				*err = "Multiple ZT_MAGIC";
+			/* Size is validated in validate_za_context() */
+			zt = (struct zt_context *)head;
+			new_flags |= ZT_CTX;
+			break;
+		case FPMR_MAGIC:
+			if (flags & FPMR_CTX)
+				*err = "Multiple FPMR_MAGIC";
+			else if (head->size !=
+				 sizeof(struct fpmr_context))
+				*err = "Bad size for fpmr_context";
+			new_flags |= FPMR_CTX;
+			break;
+		case GCS_MAGIC:
+			if (flags & GCS_CTX)
+				*err = "Multiple GCS_MAGIC";
+			if (head->size != sizeof(struct gcs_context))
+				*err = "Bad size for gcs_context";
+			new_flags |= GCS_CTX;
+			break;
+		case EXTRA_MAGIC:
+			if (flags & EXTRA_CTX)
+				*err = "Multiple EXTRA_MAGIC";
+			else if (head->size !=
+				 sizeof(struct extra_context))
+				*err = "Bad size for extra_context";
+			new_flags |= EXTRA_CTX;
+			extra = (struct extra_context *)head;
+			break;
+		case KSFT_BAD_MAGIC:
+			/*
+			 * This is a BAD magic header defined
+			 * artificially by a testcase and surely
+			 * unknown to the Kernel parse_user_sigframe().
+			 * It MUST cause a Kernel induced SEGV
+			 */
+			*err = "BAD MAGIC !";
+			break;
+		default:
+			/*
+			 * A still unknown Magic: potentially freshly added
+			 * to the Kernel code and still unknown to the
+			 * tests.  Magic numbers are supposed to be allocated
+			 * as somewhat meaningful ASCII strings so try to
+			 * print as such as well as the raw number.
+			 */
+			memcpy(magic, &head->magic, sizeof(magic));
+			for (i = 0; i < sizeof(magic); i++)
+				if (!isalnum(magic[i]))
+					magic[i] = '?';
+
+			fprintf(stdout,
+				"SKIP Unknown MAGIC: 0x%X (%c%c%c%c) - Is KSFT arm64/signal up to date ?\n",
+				head->magic,
+				magic[3], magic[2], magic[1], magic[0]);
+			break;
+		}
+
+		if (*err)
+			return false;
+
+		offs += head->size;
+		if (resv_sz < offs + sizeof(*head)) {
+			*err = "HEAD Overrun";
+			return false;
+		}
+
+		if (new_flags & EXTRA_CTX)
+			if (!validate_extra_context(extra, err,
+						    &extra_data, &extra_sz))
+				return false;
+		if (new_flags & SVE_CTX)
+			if (!validate_sve_context(sve, err))
+				return false;
+		if (new_flags & ZA_CTX)
+			if (!validate_za_context(za, err))
+				return false;
+		if (new_flags & ZT_CTX)
+			if (!validate_zt_context(zt, err))
+				return false;
+
+		flags |= new_flags;
+
+		head = GET_RESV_NEXT_HEAD(head);
+	}
+
+	if (terminated && !(flags & FPSIMD_CTX)) {
+		*err = "Missing FPSIMD";
+		return false;
+	}
+
+	if (terminated && (flags & ZT_CTX) && !(flags & ZA_CTX)) {
+		*err = "ZT context but no ZA context";
+		return false;
+	}
+
+	return true;
+}
+
+/*
+ * This function walks through the records inside the provided reserved area
+ * trying to find enough space to fit @need_sz bytes: if not enough space is
+ * available and an extra_context record is present, it throws away the
+ * extra_context record.
+ *
+ * It returns a pointer to a new header where it is possible to start storing
+ * our need_sz bytes.
+ *
+ * @shead: points to the start of reserved area
+ * @need_sz: needed bytes
+ * @resv_sz: reserved area size in bytes
+ * @offset: if not null, this will be filled with the offset of the return
+ *	    head pointer from @shead
+ *
+ * @return: pointer to a new head where to start storing need_sz bytes, or
+ *	    NULL if space could not be made available.
+ */
+struct _aarch64_ctx *get_starting_head(struct _aarch64_ctx *shead,
+				       size_t need_sz, size_t resv_sz,
+				       size_t *offset)
+{
+	size_t offs = 0;
+	struct _aarch64_ctx *head;
+
+	head = get_terminator(shead, resv_sz, &offs);
+	/* not found a terminator...no need to update offset if any */
+	if (!head)
+		return head;
+	if (resv_sz - offs < need_sz) {
+		fprintf(stderr, "Low on space:%zd. Discarding extra_context.\n",
+			resv_sz - offs);
+		head = get_header(shead, EXTRA_MAGIC, resv_sz, &offs);
+		if (!head || resv_sz - offs < need_sz) {
+			fprintf(stderr,
+				"Failed to reclaim space on sigframe.\n");
+			return NULL;
+		}
+	}
+
+	fprintf(stderr, "Available space:%zd\n", resv_sz - offs);
+	if (offset)
+		*offset = offs;
+	return head;
+}

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/testcases.h

@@ -0,0 +1,137 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2019 ARM Limited */
+#ifndef __TESTCASES_H__
+#define __TESTCASES_H__
+
+#include <stddef.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <ucontext.h>
+#include <signal.h>
+
+/* Architecture specific sigframe definitions */
+#include <asm/sigcontext.h>
+
+#define FPSIMD_CTX	(1 << 0)
+#define SVE_CTX		(1 << 1)
+#define ZA_CTX		(1 << 2)
+#define EXTRA_CTX	(1 << 3)
+#define ZT_CTX		(1 << 4)
+#define FPMR_CTX	(1 << 5)
+#define GCS_CTX		(1 << 6)
+
+#define KSFT_BAD_MAGIC	0xdeadbeef
+
+#define HDR_SZ \
+	sizeof(struct _aarch64_ctx)
+
+#define GET_UC_RESV_HEAD(uc) \
+	(struct _aarch64_ctx *)(&(uc->uc_mcontext.__reserved))
+
+#define GET_SF_RESV_HEAD(sf) \
+	(struct _aarch64_ctx *)(&(sf).uc.uc_mcontext.__reserved)
+
+#define GET_SF_RESV_SIZE(sf) \
+	sizeof((sf).uc.uc_mcontext.__reserved)
+
+#define GET_BUF_RESV_HEAD(buf) \
+	(struct _aarch64_ctx *)(&(buf).uc.uc_mcontext.__reserved)
+
+#define GET_BUF_RESV_SIZE(buf) \
+	(sizeof(buf) - sizeof(buf.uc) +	\
+	 sizeof((buf).uc.uc_mcontext.__reserved))
+
+#define GET_UCP_RESV_SIZE(ucp) \
+	sizeof((ucp)->uc_mcontext.__reserved)
+
+#define ASSERT_BAD_CONTEXT(uc) do {					\
+	char *err = NULL;						\
+	if (!validate_reserved((uc), GET_UCP_RESV_SIZE((uc)), &err)) {	\
+		if (err)						\
+			fprintf(stderr,					\
+				"Using badly built context - ERR: %s\n",\
+				err);					\
+	} else {							\
+		abort();						\
+	}								\
+} while (0)
+
+#define ASSERT_GOOD_CONTEXT(uc) do {					 \
+	char *err = NULL;						 \
+	if (!validate_reserved((uc), GET_UCP_RESV_SIZE((uc)), &err)) {	 \
+		if (err)						 \
+			fprintf(stderr,					 \
+				"Detected BAD context - ERR: %s\n", err);\
+		abort();						 \
+	} else {							 \
+		fprintf(stderr, "uc context validated.\n");		 \
+	}								 \
+} while (0)
+
+/*
+ * A simple record-walker for __reserved area: it walks through assuming
+ * only to find a proper struct __aarch64_ctx header descriptor.
+ *
+ * Instead it makes no assumptions on the content and ordering of the
+ * records, any needed bounds checking must be enforced by the caller
+ * if wanted: this way can be used by caller on any maliciously built bad
+ * contexts.
+ *
+ * head->size accounts both for payload and header _aarch64_ctx size !
+ */
+#define GET_RESV_NEXT_HEAD(h) \
+	(struct _aarch64_ctx *)((char *)(h) + (h)->size)
+
+struct fake_sigframe {
+	siginfo_t	info;
+	ucontext_t	uc;
+};
+
+
+bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err);
+
+static inline struct _aarch64_ctx *get_header(struct _aarch64_ctx *head, uint32_t magic,
+				size_t resv_sz, size_t *offset)
+{
+	size_t offs = 0;
+	struct _aarch64_ctx *found = NULL;
+
+	if (!head || resv_sz < HDR_SZ)
+		return found;
+
+	while (offs <= resv_sz - HDR_SZ &&
+	       head->magic != magic && head->magic) {
+		offs += head->size;
+		head = GET_RESV_NEXT_HEAD(head);
+	}
+	if (head->magic == magic) {
+		found = head;
+		if (offset)
+			*offset = offs;
+	}
+
+	return found;
+}
+
+
+static inline struct _aarch64_ctx *get_terminator(struct _aarch64_ctx *head,
+						  size_t resv_sz,
+						  size_t *offset)
+{
+	return get_header(head, 0, resv_sz, offset);
+}
+
+static inline void write_terminator_record(struct _aarch64_ctx *tail)
+{
+	if (tail) {
+		tail->magic = 0;
+		tail->size = 0;
+	}
+}
+
+struct _aarch64_ctx *get_starting_head(struct _aarch64_ctx *shead,
+				       size_t need_sz, size_t resv_sz,
+				       size_t *offset);
+#endif

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/tpidr2_restore.c

@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023 ARM Limited
+ *
+ * Verify that the TPIDR2 register context in signal frames is restored.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+#include <sys/auxv.h>
+#include <sys/prctl.h>
+#include <unistd.h>
+#include <asm/sigcontext.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+#define SYS_TPIDR2 "S3_3_C13_C0_5"
+
+static uint64_t get_tpidr2(void)
+{
+	uint64_t val;
+
+	asm volatile (
+		"mrs	%0, " SYS_TPIDR2 "\n"
+		: "=r"(val)
+		:
+		: "cc");
+
+	return val;
+}
+
+static void set_tpidr2(uint64_t val)
+{
+	asm volatile (
+		"msr	" SYS_TPIDR2 ", %0\n"
+		:
+		: "r"(val)
+		: "cc");
+}
+
+
+static uint64_t initial_tpidr2;
+
+static bool save_tpidr2(struct tdescr *td)
+{
+	initial_tpidr2 = get_tpidr2();
+	fprintf(stderr, "Initial TPIDR2: %lx\n", initial_tpidr2);
+
+	return true;
+}
+
+static int modify_tpidr2(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+	uint64_t my_tpidr2 = get_tpidr2();
+
+	my_tpidr2++;
+	fprintf(stderr, "Setting TPIDR2 to %lx\n", my_tpidr2);
+	set_tpidr2(my_tpidr2);
+
+	return 0;
+}
+
+static void check_tpidr2(struct tdescr *td)
+{
+	uint64_t tpidr2 = get_tpidr2();
+
+	td->pass = tpidr2 == initial_tpidr2;
+
+	if (td->pass)
+		fprintf(stderr, "TPIDR2 restored\n");
+	else
+		fprintf(stderr, "TPIDR2 was %lx but is now %lx\n",
+			initial_tpidr2, tpidr2);
+}
+
+struct tdescr tde = {
+	.name = "TPIDR2 restore",
+	.descr = "Validate that TPIDR2 is restored from the sigframe",
+	.feats_required = FEAT_SME,
+	.timeout = 3,
+	.sig_trig = SIGUSR1,
+	.init = save_tpidr2,
+	.run = modify_tpidr2,
+	.check_result = check_tpidr2,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/tpidr2_siginfo.c

@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022 ARM Limited
+ *
+ * Verify that the TPIDR2 register context in signal frames is set up as
+ * expected.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+#include <sys/auxv.h>
+#include <sys/prctl.h>
+#include <unistd.h>
+#include <asm/sigcontext.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+static union {
+	ucontext_t uc;
+	char buf[1024 * 128];
+} context;
+
+#define SYS_TPIDR2 "S3_3_C13_C0_5"
+
+static uint64_t get_tpidr2(void)
+{
+	uint64_t val;
+
+	asm volatile (
+		"mrs	%0, " SYS_TPIDR2 "\n"
+		: "=r"(val)
+		:
+		: "cc");
+
+	return val;
+}
+
+int tpidr2_present(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
+	struct tpidr2_context *tpidr2_ctx;
+	size_t offset;
+	bool in_sigframe;
+	bool have_sme;
+	__u64 orig_tpidr2;
+
+	have_sme = getauxval(AT_HWCAP2) & HWCAP2_SME;
+	if (have_sme)
+		orig_tpidr2 = get_tpidr2();
+
+	if (!get_current_context(td, &context.uc, sizeof(context)))
+		return 1;
+
+	tpidr2_ctx = (struct tpidr2_context *)
+		get_header(head, TPIDR2_MAGIC, td->live_sz, &offset);
+
+	in_sigframe = tpidr2_ctx != NULL;
+
+	fprintf(stderr, "TPIDR2 sigframe %s on system %s SME\n",
+		in_sigframe ? "present" : "absent",
+		have_sme ? "with" : "without");
+
+	td->pass = (in_sigframe == have_sme);
+
+	/*
+	 * Check that the value we read back was the one present at
+	 * the time that the signal was triggered.  TPIDR2 is owned by
+	 * libc so we can't safely choose the value and it is possible
+	 * that we may need to revisit this in future if something
+	 * starts deciding to set a new TPIDR2 between us reading and
+	 * the signal.
+	 */
+	if (have_sme && tpidr2_ctx) {
+		if (tpidr2_ctx->tpidr2 != orig_tpidr2) {
+			fprintf(stderr, "TPIDR2 in frame is %llx, was %llx\n",
+				tpidr2_ctx->tpidr2, orig_tpidr2);
+			td->pass = false;
+		}
+	}
+
+	return 0;
+}
+
+struct tdescr tde = {
+	.name = "TPIDR2",
+	.descr = "Validate that TPIDR2 is present as expected",
+	.timeout = 3,
+	.run = tpidr2_present,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/za_no_regs.c

@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 ARM Limited
+ *
+ * Verify that the ZA register context in signal frames is 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 * 128];
+} context;
+
+static bool sme_get_vls(struct tdescr *td)
+{
+	int res = sve_fill_vls(VLS_USE_SME, 1);
+
+	if (!res)
+		return true;
+
+	if (res == KSFT_SKIP)
+		td->result = KSFT_SKIP;
+
+	return false;
+}
+
+static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
+			 unsigned int vl)
+{
+	size_t offset;
+	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
+	struct za_context *za;
+
+	fprintf(stderr, "Testing VL %d\n", vl);
+
+	if (prctl(PR_SME_SET_VL, vl) != vl) {
+		fprintf(stderr, "Failed to set VL\n");
+		return 1;
+	}
+
+	/*
+	 * Get a signal context which should have a SVE frame and registers
+	 * in it.
+	 */
+	if (!get_current_context(td, &context.uc, sizeof(context)))
+		return 1;
+
+	head = get_header(head, ZA_MAGIC, GET_BUF_RESV_SIZE(context), &offset);
+	if (!head) {
+		fprintf(stderr, "No ZA context\n");
+		return 1;
+	}
+
+	za = (struct za_context *)head;
+	if (za->vl != vl) {
+		fprintf(stderr, "Got VL %d, expected %d\n", za->vl, vl);
+		return 1;
+	}
+
+	if (head->size != ZA_SIG_REGS_OFFSET) {
+		fprintf(stderr, "Context size %u, expected %lu\n",
+			head->size, ZA_SIG_REGS_OFFSET);
+		return 1;
+	}
+
+	/* The actual size validation is done in get_current_context() */
+	fprintf(stderr, "Got expected size %u and VL %d\n",
+		head->size, za->vl);
+
+	return 0;
+}
+
+static int sme_regs(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+	int i;
+
+	for (i = 0; i < nvls; i++) {
+		if (do_one_sme_vl(td, si, uc, vls[i]))
+			return 1;
+	}
+
+	td->pass = 1;
+
+	return 0;
+}
+
+struct tdescr tde = {
+	.name = "ZA registers - ZA disabled",
+	.descr = "Check ZA context with ZA disabled",
+	.feats_required = FEAT_SME,
+	.timeout = 3,
+	.init = sme_get_vls,
+	.run = sme_regs,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/za_regs.c

@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 ARM Limited
+ *
+ * Verify that the ZA register context in signal frames is 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 * 128];
+} context;
+
+static bool sme_get_vls(struct tdescr *td)
+{
+	int res = sve_fill_vls(VLS_USE_SME, 1);
+
+	if (!res)
+		return true;
+
+	if (res == KSFT_SKIP)
+		td->result = KSFT_SKIP;
+
+	return false;
+}
+
+static void setup_za_regs(void)
+{
+	/* smstart za; real data is TODO */
+	asm volatile(".inst 0xd503457f" : : : );
+}
+
+static char zeros[ZA_SIG_REGS_SIZE(SVE_VQ_MAX)];
+
+static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
+			 unsigned int vl)
+{
+	size_t offset;
+	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
+	struct za_context *za;
+
+	fprintf(stderr, "Testing VL %d\n", vl);
+
+	if (prctl(PR_SME_SET_VL, vl) != vl) {
+		fprintf(stderr, "Failed to set VL\n");
+		return 1;
+	}
+
+	/*
+	 * Get a signal context which should have a SVE frame and registers
+	 * in it.
+	 */
+	setup_za_regs();
+	if (!get_current_context(td, &context.uc, sizeof(context)))
+		return 1;
+
+	head = get_header(head, ZA_MAGIC, GET_BUF_RESV_SIZE(context), &offset);
+	if (!head) {
+		fprintf(stderr, "No ZA context\n");
+		return 1;
+	}
+
+	za = (struct za_context *)head;
+	if (za->vl != vl) {
+		fprintf(stderr, "Got VL %d, expected %d\n", za->vl, vl);
+		return 1;
+	}
+
+	if (head->size != ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(vl))) {
+		fprintf(stderr, "ZA context size %u, expected %lu\n",
+			head->size, ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(vl)));
+		return 1;
+	}
+
+	fprintf(stderr, "Got expected size %u and VL %d\n",
+		head->size, za->vl);
+
+	/* We didn't load any data into ZA so it should be all zeros */
+	if (memcmp(zeros, (char *)za + ZA_SIG_REGS_OFFSET,
+		   ZA_SIG_REGS_SIZE(sve_vq_from_vl(za->vl))) != 0) {
+		fprintf(stderr, "ZA data invalid\n");
+		return 1;
+	}
+
+	if (get_svcr() != 0) {
+		fprintf(stderr, "Unexpected SVCR %lx\n", get_svcr());
+		return 1;
+	}
+
+	return 0;
+}
+
+static int sme_regs(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+	int i;
+
+	for (i = 0; i < nvls; i++) {
+		if (do_one_sme_vl(td, si, uc, vls[i]))
+			return 1;
+	}
+
+	td->pass = 1;
+
+	return 0;
+}
+
+struct tdescr tde = {
+	.name = "ZA register",
+	.descr = "Check that we get the right ZA registers reported",
+	.feats_required = FEAT_SME,
+	.timeout = 3,
+	.init = sme_get_vls,
+	.run = sme_regs,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/zt_no_regs.c

@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 ARM Limited
+ *
+ * Verify that using an instruction not supported in streaming mode
+ * traps when in streaming mode.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+#include <sys/prctl.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+static union {
+	ucontext_t uc;
+	char buf[1024 * 128];
+} context;
+
+int zt_no_regs_run(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+	size_t offset;
+	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
+
+	/*
+	 * Get a signal context which should not have a ZT frame and
+	 * registers in it.
+	 */
+	if (!get_current_context(td, &context.uc, sizeof(context)))
+		return 1;
+
+	head = get_header(head, ZT_MAGIC, GET_BUF_RESV_SIZE(context), &offset);
+	if (head) {
+		fprintf(stderr, "Got unexpected ZT context\n");
+		return 1;
+	}
+
+	td->pass = 1;
+
+	return 0;
+}
+
+struct tdescr tde = {
+	.name = "ZT register data not present",
+	.descr = "Validate that ZT is not present when ZA is disabled",
+	.feats_required = FEAT_SME2,
+	.timeout = 3,
+	.sanity_disabled = true,
+	.run = zt_no_regs_run,
+};

linux-7.2.3/tools/testing/selftests/arm64/signal/testcases/zt_regs.c

@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 ARM Limited
+ *
+ * Verify that using an instruction not supported in streaming mode
+ * traps when in streaming mode.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+#include <sys/prctl.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+static union {
+	ucontext_t uc;
+	char buf[1024 * 128];
+} context;
+
+static void enable_za(void)
+{
+	/* smstart za; real data is TODO */
+	asm volatile(".inst 0xd503457f" : : : );
+}
+
+int zt_regs_run(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+	size_t offset;
+	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
+	struct zt_context *zt;
+	char *zeros;
+
+	/*
+	 * Get a signal context which should have a ZT frame and registers
+	 * in it.
+	 */
+	enable_za();
+	if (!get_current_context(td, &context.uc, sizeof(context)))
+		return 1;
+
+	head = get_header(head, ZT_MAGIC, GET_BUF_RESV_SIZE(context), &offset);
+	if (!head) {
+		fprintf(stderr, "No ZT context\n");
+		return 1;
+	}
+
+	zt = (struct zt_context *)head;
+	if (zt->nregs == 0) {
+		fprintf(stderr, "Got context with no registers\n");
+		return 1;
+	}
+
+	fprintf(stderr, "Got expected size %u for %d registers\n",
+		head->size, zt->nregs);
+
+	/* We didn't load any data into ZT so it should be all zeros */
+	zeros = malloc(ZT_SIG_REGS_SIZE(zt->nregs));
+	if (!zeros) {
+		fprintf(stderr, "Out of memory, nregs=%u\n", zt->nregs);
+		return 1;
+	}
+	memset(zeros, 0, ZT_SIG_REGS_SIZE(zt->nregs));
+
+	if (memcmp(zeros, (char *)zt + ZT_SIG_REGS_OFFSET,
+		   ZT_SIG_REGS_SIZE(zt->nregs)) != 0) {
+		fprintf(stderr, "ZT data invalid\n");
+		free(zeros);
+		return 1;
+	}
+
+	free(zeros);
+
+	td->pass = 1;
+
+	return 0;
+}
+
+struct tdescr tde = {
+	.name = "ZT register data",
+	.descr = "Validate that ZT is present and has data when ZA is enabled",
+	.feats_required = FEAT_SME2,
+	.timeout = 3,
+	.sanity_disabled = true,
+	.run = zt_regs_run,
+};