Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:

 - MTE asynchronous support for KASan. Previously only synchronous
   (slower) mode was supported. Asynchronous is faster but does not
   allow precise identification of the illegal access.

 - Run kernel mode SIMD with softirqs disabled. This allows using NEON
   in softirq context for crypto performance improvements. The
   conditional yield support is modified to take softirqs into account
   and reduce the latency.

 - Preparatory patches for Apple M1: handle CPUs that only have the VHE
   mode available (host kernel running at EL2), add FIQ support.

 - arm64 perf updates: support for HiSilicon PA and SLLC PMU drivers,
   new functions for the HiSilicon HHA and L3C PMU, cleanups.

 - Re-introduce support for execute-only user permissions but only when
   the EPAN (Enhanced Privileged Access Never) architecture feature is
   available.

 - Disable fine-grained traps at boot and improve the documented boot
   requirements.

 - Support CONFIG_KASAN_VMALLOC on arm64 (only with KASAN_GENERIC).

 - Add hierarchical eXecute Never permissions for all page tables.

 - Add arm64 prctl(PR_PAC_{SET,GET}_ENABLED_KEYS) allowing user programs
   to control which PAC keys are enabled in a particular task.

 - arm64 kselftests for BTI and some improvements to the MTE tests.

 - Minor improvements to the compat vdso and sigpage.

 - Miscellaneous cleanups.

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (86 commits)
  arm64/sve: Add compile time checks for SVE hooks in generic functions
  arm64/kernel/probes: Use BUG_ON instead of if condition followed by BUG.
  arm64: pac: Optimize kernel entry/exit key installation code paths
  arm64: Introduce prctl(PR_PAC_{SET,GET}_ENABLED_KEYS)
  arm64: mte: make the per-task SCTLR_EL1 field usable elsewhere
  arm64/sve: Remove redundant system_supports_sve() tests
  arm64: fpsimd: run kernel mode NEON with softirqs disabled
  arm64: assembler: introduce wxN aliases for wN registers
  arm64: assembler: remove conditional NEON yield macros
  kasan, arm64: tests supports for HW_TAGS async mode
  arm64: mte: Report async tag faults before suspend
  arm64: mte: Enable async tag check fault
  arm64: mte: Conditionally compile mte_enable_kernel_*()
  arm64: mte: Enable TCO in functions that can read beyond buffer limits
  kasan: Add report for async mode
  arm64: mte: Drop arch_enable_tagging()
  kasan: Add KASAN mode kernel parameter
  arm64: mte: Add asynchronous mode support
  arm64: Get rid of CONFIG_ARM64_VHE
  arm64: Cope with CPUs stuck in VHE mode
  ...

20 files changed, 676 insertions, 24 deletions

diff --git a/tools/testing/selftests/arm64/Makefile b/tools/testing/selftests/arm64/Makefile
index 2c9d012797a7..ced910fb4019 100644
--- a/tools/testing/selftests/arm64/Makefile
+++ b/tools/testing/selftests/arm64/Makefile
@@ -4,7 +4,7 @@
 ARCH ?= $(shell uname -m 2>/dev/null || echo not)
 
 ifneq (,$(filter $(ARCH),aarch64 arm64))
-ARM64_SUBTARGETS ?= tags signal pauth fp mte
+ARM64_SUBTARGETS ?= tags signal pauth fp mte bti
 else
 ARM64_SUBTARGETS :=
 endif
diff --git a/tools/testing/selftests/arm64/bti/.gitignore b/tools/testing/selftests/arm64/bti/.gitignore
new file mode 100644
index 000000000000..73869fabada4
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/.gitignore
@@ -0,0 +1,2 @@
+btitest
+nobtitest
diff --git a/tools/testing/selftests/arm64/bti/Makefile b/tools/testing/selftests/arm64/bti/Makefile
new file mode 100644
index 000000000000..73e013c082a6
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/Makefile
@@ -0,0 +1,61 @@
+# SPDX-License-Identifier: GPL-2.0
+
+TEST_GEN_PROGS := btitest nobtitest
+
+PROGS := $(patsubst %,gen/%,$(TEST_GEN_PROGS))
+
+# These tests are built as freestanding binaries since otherwise BTI
+# support in ld.so is required which is not currently widespread; when
+# it is available it will still be useful to test this separately as the
+# cases for statically linked and dynamically lined binaries are
+# slightly different.
+
+CFLAGS_NOBTI = -DBTI=0
+CFLAGS_BTI = -mbranch-protection=standard -DBTI=1
+
+CFLAGS_COMMON = -ffreestanding -Wall -Wextra $(CFLAGS)
+
+BTI_CC_COMMAND = $(CC) $(CFLAGS_BTI) $(CFLAGS_COMMON) -c -o $@ $<
+NOBTI_CC_COMMAND = $(CC) $(CFLAGS_NOBTI) $(CFLAGS_COMMON) -c -o $@ $<
+
+%-bti.o: %.c
+	$(BTI_CC_COMMAND)
+
+%-bti.o: %.S
+	$(BTI_CC_COMMAND)
+
+%-nobti.o: %.c
+	$(NOBTI_CC_COMMAND)
+
+%-nobti.o: %.S
+	$(NOBTI_CC_COMMAND)
+
+BTI_OBJS =                                      \
+	test-bti.o                           \
+	signal-bti.o                            \
+	start-bti.o                             \
+	syscall-bti.o                           \
+	system-bti.o                            \
+	teststubs-bti.o                         \
+	trampoline-bti.o
+gen/btitest: $(BTI_OBJS)
+	$(CC) $(CFLAGS_BTI) $(CFLAGS_COMMON) -nostdlib -o $@ $^
+
+NOBTI_OBJS =                                    \
+	test-nobti.o                         \
+	signal-nobti.o                          \
+	start-nobti.o                           \
+	syscall-nobti.o                         \
+	system-nobti.o                          \
+	teststubs-nobti.o                       \
+	trampoline-nobti.o
+gen/nobtitest: $(NOBTI_OBJS)
+	$(CC) $(CFLAGS_BTI) $(CFLAGS_COMMON) -nostdlib -o $@ $^
+
+# Including KSFT lib.mk here will also mangle the TEST_GEN_PROGS list
+# to account for any OUTPUT target-dirs optionally provided by
+# the toplevel makefile
+include ../../lib.mk
+
+$(TEST_GEN_PROGS): $(PROGS)
+	cp $(PROGS) $(OUTPUT)/
diff --git a/tools/testing/selftests/arm64/bti/assembler.h b/tools/testing/selftests/arm64/bti/assembler.h
new file mode 100644
index 000000000000..04e7b72880ef
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/assembler.h
@@ -0,0 +1,80 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019  Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#ifndef ASSEMBLER_H
+#define ASSEMBLER_H
+
+#define NT_GNU_PROPERTY_TYPE_0	5
+#define GNU_PROPERTY_AARCH64_FEATURE_1_AND	0xc0000000
+
+/* Bits for GNU_PROPERTY_AARCH64_FEATURE_1_BTI */
+#define GNU_PROPERTY_AARCH64_FEATURE_1_BTI	(1U << 0)
+#define GNU_PROPERTY_AARCH64_FEATURE_1_PAC	(1U << 1)
+
+
+.macro startfn name:req
+	.globl \name
+\name:
+	.macro endfn
+		.size \name, . - \name
+		.type \name, @function
+		.purgem endfn
+	.endm
+.endm
+
+.macro emit_aarch64_feature_1_and
+	.pushsection .note.gnu.property, "a"
+	.align	3
+	.long	2f - 1f
+	.long	6f - 3f
+	.long	NT_GNU_PROPERTY_TYPE_0
+1:	.string	"GNU"
+2:
+	.align	3
+3:	.long	GNU_PROPERTY_AARCH64_FEATURE_1_AND
+	.long	5f - 4f
+4:
+#if BTI
+	.long	GNU_PROPERTY_AARCH64_FEATURE_1_PAC | \
+		GNU_PROPERTY_AARCH64_FEATURE_1_BTI
+#else
+	.long	0
+#endif
+5:
+	.align	3
+6:
+	.popsection
+.endm
+
+.macro paciasp
+	hint	0x19
+.endm
+
+.macro autiasp
+	hint	0x1d
+.endm
+
+.macro __bti_
+	hint	0x20
+.endm
+
+.macro __bti_c
+	hint	0x22
+.endm
+
+.macro __bti_j
+	hint	0x24
+.endm
+
+.macro __bti_jc
+	hint	0x26
+.endm
+
+.macro bti what=
+	__bti_\what
+.endm
+
+#endif /* ! ASSEMBLER_H */
diff --git a/tools/testing/selftests/arm64/bti/btitest.h b/tools/testing/selftests/arm64/bti/btitest.h
new file mode 100644
index 000000000000..2aff9b10336e
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/btitest.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019  Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#ifndef BTITEST_H
+#define BTITEST_H
+
+/* Trampolines for calling the test stubs: */
+void call_using_br_x0(void (*)(void));
+void call_using_br_x16(void (*)(void));
+void call_using_blr(void (*)(void));
+
+/* Test stubs: */
+void nohint_func(void);
+void bti_none_func(void);
+void bti_c_func(void);
+void bti_j_func(void);
+void bti_jc_func(void);
+void paciasp_func(void);
+
+#endif /* !BTITEST_H */
diff --git a/tools/testing/selftests/arm64/bti/compiler.h b/tools/testing/selftests/arm64/bti/compiler.h
new file mode 100644
index 000000000000..ebb6204f447a
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/compiler.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019  Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#ifndef COMPILER_H
+#define COMPILER_H
+
+#define __always_unused __attribute__((__unused__))
+#define __noreturn __attribute__((__noreturn__))
+#define __unreachable() __builtin_unreachable()
+
+/* curse(e) has value e, but the compiler cannot assume so */
+#define curse(e) ({				\
+	__typeof__(e) __curse_e = (e);		\
+	asm ("" : "+r" (__curse_e));		\
+	__curse_e;				\
+})
+
+#endif /* ! COMPILER_H */
diff --git a/tools/testing/selftests/arm64/bti/gen/.gitignore b/tools/testing/selftests/arm64/bti/gen/.gitignore
new file mode 100644
index 000000000000..73869fabada4
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/gen/.gitignore
@@ -0,0 +1,2 @@
+btitest
+nobtitest
diff --git a/tools/testing/selftests/arm64/bti/signal.c b/tools/testing/selftests/arm64/bti/signal.c
new file mode 100644
index 000000000000..f3fd29b91141
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/signal.c
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019  Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#include "system.h"
+#include "signal.h"
+
+int sigemptyset(sigset_t *s)
+{
+	unsigned int i;
+
+	for (i = 0; i < _NSIG_WORDS; ++i)
+		s->sig[i] = 0;
+
+	return 0;
+}
+
+int sigaddset(sigset_t *s, int n)
+{
+	if (n < 1 || n > _NSIG)
+		return -EINVAL;
+
+	s->sig[(n - 1) / _NSIG_BPW] |= 1UL << (n - 1) % _NSIG_BPW;
+	return 0;
+}
+
+int sigaction(int n, struct sigaction *sa, const struct sigaction *old)
+{
+	return syscall(__NR_rt_sigaction, n, sa, old, sizeof(sa->sa_mask));
+}
+
+int sigprocmask(int how, const sigset_t *mask, sigset_t *old)
+{
+	return syscall(__NR_rt_sigprocmask, how, mask, old, sizeof(*mask));
+}
diff --git a/tools/testing/selftests/arm64/bti/signal.h b/tools/testing/selftests/arm64/bti/signal.h
new file mode 100644
index 000000000000..103457dc880e
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/signal.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019  Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#ifndef SIGNAL_H
+#define SIGNAL_H
+
+#include <linux/signal.h>
+
+#include "system.h"
+
+typedef __sighandler_t sighandler_t;
+
+int sigemptyset(sigset_t *s);
+int sigaddset(sigset_t *s, int n);
+int sigaction(int n, struct sigaction *sa, const struct sigaction *old);
+int sigprocmask(int how, const sigset_t *mask, sigset_t *old);
+
+#endif /* ! SIGNAL_H */
diff --git a/tools/testing/selftests/arm64/bti/start.S b/tools/testing/selftests/arm64/bti/start.S
new file mode 100644
index 000000000000..831f952e0572
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/start.S
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019  Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#include "assembler.h"
+
+startfn _start
+	mov	x0, sp
+	b	start
+endfn
+
+emit_aarch64_feature_1_and
diff --git a/tools/testing/selftests/arm64/bti/syscall.S b/tools/testing/selftests/arm64/bti/syscall.S
new file mode 100644
index 000000000000..8dde8b6f3db1
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/syscall.S
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019  Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#include "assembler.h"
+
+startfn syscall
+	bti	c
+	mov	w8, w0
+	mov	x0, x1
+	mov	x1, x2
+	mov	x2, x3
+	mov	x3, x4
+	mov	x4, x5
+	mov	x5, x6
+	mov	x6, x7
+	svc	#0
+	ret
+endfn
+
+emit_aarch64_feature_1_and
diff --git a/tools/testing/selftests/arm64/bti/system.c b/tools/testing/selftests/arm64/bti/system.c
new file mode 100644
index 000000000000..6385d8d4973b
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/system.c
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019  Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#include "system.h"
+
+#include <asm/unistd.h>
+
+#include "compiler.h"
+
+void __noreturn exit(int n)
+{
+	syscall(__NR_exit, n);
+	__unreachable();
+}
+
+ssize_t write(int fd, const void *buf, size_t size)
+{
+	return syscall(__NR_write, fd, buf, size);
+}
diff --git a/tools/testing/selftests/arm64/bti/system.h b/tools/testing/selftests/arm64/bti/system.h
new file mode 100644
index 000000000000..aca118589705
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/system.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019  Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#ifndef SYSTEM_H
+#define SYSTEM_H
+
+#include <linux/types.h>
+#include <linux/stddef.h>
+
+typedef __kernel_size_t size_t;
+typedef __kernel_ssize_t ssize_t;
+
+#include <linux/errno.h>
+#include <asm/hwcap.h>
+#include <asm/ptrace.h>
+#include <asm/unistd.h>
+
+#include "compiler.h"
+
+long syscall(int nr, ...);
+
+void __noreturn exit(int n);
+ssize_t write(int fd, const void *buf, size_t size);
+
+#endif /* ! SYSTEM_H */
diff --git a/tools/testing/selftests/arm64/bti/test.c b/tools/testing/selftests/arm64/bti/test.c
new file mode 100644
index 000000000000..656b04976ccc
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/test.c
@@ -0,0 +1,234 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019,2021  Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#include "system.h"
+
+#include <linux/errno.h>
+#include <linux/auxvec.h>
+#include <linux/signal.h>
+#include <asm/sigcontext.h>
+#include <asm/ucontext.h>
+
+typedef struct ucontext ucontext_t;
+
+#include "btitest.h"
+#include "compiler.h"
+#include "signal.h"
+
+#define EXPECTED_TESTS 18
+
+static volatile unsigned int test_num = 1;
+static unsigned int test_passed;
+static unsigned int test_failed;
+static unsigned int test_skipped;
+
+static void fdputs(int fd, const char *str)
+{
+	size_t len = 0;
+	const char *p = str;
+
+	while (*p++)
+		++len;
+
+	write(fd, str, len);
+}
+
+static void putstr(const char *str)
+{
+	fdputs(1, str);
+}
+
+static void putnum(unsigned int num)
+{
+	char c;
+
+	if (num / 10)
+		putnum(num / 10);
+
+	c = '0' + (num % 10);
+	write(1, &c, 1);
+}
+
+#define puttestname(test_name, trampoline_name) do {	\
+	putstr(test_name);				\
+	putstr("/");					\
+	putstr(trampoline_name);			\
+} while (0)
+
+void print_summary(void)
+{
+	putstr("# Totals: pass:");
+	putnum(test_passed);
+	putstr(" fail:");
+	putnum(test_failed);
+	putstr(" xfail:0 xpass:0 skip:");
+	putnum(test_skipped);
+	putstr(" error:0\n");
+}
+
+static const char *volatile current_test_name;
+static const char *volatile current_trampoline_name;
+static volatile int sigill_expected, sigill_received;
+
+static void handler(int n, siginfo_t *si __always_unused,
+		    void *uc_ __always_unused)
+{
+	ucontext_t *uc = uc_;
+
+	putstr("# \t[SIGILL in ");
+	puttestname(current_test_name, current_trampoline_name);
+	putstr(", BTYPE=");
+	write(1, &"00011011"[((uc->uc_mcontext.pstate & PSR_BTYPE_MASK)
+			      >> PSR_BTYPE_SHIFT) * 2], 2);
+	if (!sigill_expected) {
+		putstr("]\n");
+		putstr("not ok ");
+		putnum(test_num);
+		putstr(" ");
+		puttestname(current_test_name, current_trampoline_name);
+		putstr("(unexpected SIGILL)\n");
+		print_summary();
+		exit(128 + n);
+	}
+
+	putstr(" (expected)]\n");
+	sigill_received = 1;
+	/* zap BTYPE so that resuming the faulting code will work */
+	uc->uc_mcontext.pstate &= ~PSR_BTYPE_MASK;
+}
+
+static int skip_all;
+
+static void __do_test(void (*trampoline)(void (*)(void)),
+		      void (*fn)(void),
+		      const char *trampoline_name,
+		      const char *name,
+		      int expect_sigill)
+{
+	if (skip_all) {
+		test_skipped++;
+		putstr("ok ");
+		putnum(test_num);
+		putstr(" ");
+		puttestname(name, trampoline_name);
+		putstr(" # SKIP\n");
+
+		return;
+	}
+
+	/* Branch Target exceptions should only happen in BTI binaries: */
+	if (!BTI)
+		expect_sigill = 0;
+
+	sigill_expected = expect_sigill;
+	sigill_received = 0;
+	current_test_name = name;
+	current_trampoline_name = trampoline_name;
+
+	trampoline(fn);
+
+	if (expect_sigill && !sigill_received) {
+		putstr("not ok ");
+		test_failed++;
+	} else {
+		putstr("ok ");
+		test_passed++;
+	}
+	putnum(test_num++);
+	putstr(" ");
+	puttestname(name, trampoline_name);
+	putstr("\n");
+}
+
+#define do_test(expect_sigill_br_x0,					\
+		expect_sigill_br_x16,					\
+		expect_sigill_blr,					\
+		name)							\
+do {									\
+	__do_test(call_using_br_x0, name, "call_using_br_x0", #name,	\
+		  expect_sigill_br_x0);					\
+	__do_test(call_using_br_x16, name, "call_using_br_x16", #name,	\
+		  expect_sigill_br_x16);				\
+	__do_test(call_using_blr, name, "call_using_blr", #name,	\
+		  expect_sigill_blr);					\
+} while (0)
+
+void start(int *argcp)
+{
+	struct sigaction sa;
+	void *const *p;
+	const struct auxv_entry {
+		unsigned long type;
+		unsigned long val;
+	} *auxv;
+	unsigned long hwcap = 0, hwcap2 = 0;
+
+	putstr("TAP version 13\n");
+	putstr("1..");
+	putnum(EXPECTED_TESTS);
+	putstr("\n");
+
+	/* Gross hack for finding AT_HWCAP2 from the initial process stack: */
+	p = (void *const *)argcp + 1 + *argcp + 1; /* start of environment */
+	/* step over environment */
+	while (*p++)
+		;
+	for (auxv = (const struct auxv_entry *)p; auxv->type != AT_NULL; ++auxv) {
+		switch (auxv->type) {
+		case AT_HWCAP:
+			hwcap = auxv->val;
+			break;
+		case AT_HWCAP2:
+			hwcap2 = auxv->val;
+			break;
+		default:
+			break;
+		}
+	}
+
+	if (hwcap & HWCAP_PACA)
+		putstr("# HWCAP_PACA present\n");
+	else
+		putstr("# HWCAP_PACA not present\n");
+
+	if (hwcap2 & HWCAP2_BTI) {
+		putstr("# HWCAP2_BTI present\n");
+		if (!(hwcap & HWCAP_PACA))
+			putstr("# Bad hardware?  Expect problems.\n");
+	} else {
+		putstr("# HWCAP2_BTI not present\n");
+		skip_all = 1;
+	}
+
+	putstr("# Test binary");
+	if (!BTI)
+		putstr(" not");
+	putstr(" built for BTI\n");
+
+	sa.sa_handler = (sighandler_t)(void *)handler;
+	sa.sa_flags = SA_SIGINFO;
+	sigemptyset(&sa.sa_mask);
+	sigaction(SIGILL, &sa, NULL);
+	sigaddset(&sa.sa_mask, SIGILL);
+	sigprocmask(SIG_UNBLOCK, &sa.sa_mask, NULL);
+
+	do_test(1, 1, 1, nohint_func);
+	do_test(1, 1, 1, bti_none_func);
+	do_test(1, 0, 0, bti_c_func);
+	do_test(0, 0, 1, bti_j_func);
+	do_test(0, 0, 0, bti_jc_func);
+	do_test(1, 0, 0, paciasp_func);
+
+	print_summary();
+
+	if (test_num - 1 != EXPECTED_TESTS)
+		putstr("# WARNING - EXPECTED TEST COUNT WRONG\n");
+
+	if (test_failed)
+		exit(1);
+	else
+		exit(0);
+}
diff --git a/tools/testing/selftests/arm64/bti/teststubs.S b/tools/testing/selftests/arm64/bti/teststubs.S
new file mode 100644
index 000000000000..b62c8c35f67e
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/teststubs.S
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019  Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#include "assembler.h"
+
+startfn bti_none_func
+	bti
+	ret
+endfn
+
+startfn bti_c_func
+	bti	c
+	ret
+endfn
+
+startfn bti_j_func
+	bti	j
+	ret
+endfn
+
+startfn bti_jc_func
+	bti	jc
+	ret
+endfn
+
+startfn paciasp_func
+	paciasp
+	autiasp
+	ret
+endfn
+
+startfn nohint_func
+	ret
+endfn
+
+emit_aarch64_feature_1_and
diff --git a/tools/testing/selftests/arm64/bti/trampoline.S b/tools/testing/selftests/arm64/bti/trampoline.S
new file mode 100644
index 000000000000..09beb3f361f1
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/trampoline.S
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019  Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#include "assembler.h"
+
+startfn call_using_br_x0
+	bti	c
+	br	x0
+endfn
+
+startfn call_using_br_x16
+	bti	c
+	mov	x16, x0
+	br	x16
+endfn
+
+startfn call_using_blr
+	paciasp
+	stp	x29, x30, [sp, #-16]!
+	blr	x0
+	ldp	x29, x30, [sp], #16
+	autiasp
+	ret
+endfn
+
+emit_aarch64_feature_1_and
diff --git a/tools/testing/selftests/arm64/mte/Makefile b/tools/testing/selftests/arm64/mte/Makefile
index 0b3af552632a..409e3e53d00a 100644
--- a/tools/testing/selftests/arm64/mte/Makefile
+++ b/tools/testing/selftests/arm64/mte/Makefile
@@ -1,14 +1,18 @@
 # SPDX-License-Identifier: GPL-2.0
 # Copyright (C) 2020 ARM Limited
 
-CFLAGS += -std=gnu99 -I. -lpthread
+# preserve CC value from top level Makefile
+ifeq ($(CC),cc)
+CC := $(CROSS_COMPILE)gcc
+endif
+
+CFLAGS += -std=gnu99 -I. -pthread
+LDFLAGS += -pthread
 SRCS := $(filter-out mte_common_util.c,$(wildcard *.c))
 PROGS := $(patsubst %.c,%,$(SRCS))
 
 #Add mte compiler option
-ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep gcc),)
 CFLAGS += -march=armv8.5-a+memtag
-endif
 
 #check if the compiler works well
 mte_cc_support := $(shell if ($(CC) $(CFLAGS) -E -x c /dev/null -o /dev/null 2>&1) then echo "1"; fi)
@@ -19,11 +23,14 @@ TEST_GEN_PROGS := $(PROGS)
 
 # Get Kernel headers installed and use them.
 KSFT_KHDR_INSTALL := 1
+else
+    $(warning compiler "$(CC)" does not support the ARMv8.5 MTE extension.)
+    $(warning test program "mte" will not be created.)
 endif
 
 # Include KSFT lib.mk.
 include ../../lib.mk
 
 ifeq ($(mte_cc_support),1)
-$(TEST_GEN_PROGS): mte_common_util.c mte_common_util.h mte_helper.S
+$(TEST_GEN_PROGS): mte_common_util.c mte_helper.S
 endif
diff --git a/tools/testing/selftests/arm64/mte/check_ksm_options.c b/tools/testing/selftests/arm64/mte/check_ksm_options.c
index 3b23c4d61d38..88c74bc46d4f 100644
--- a/tools/testing/selftests/arm64/mte/check_ksm_options.c
+++ b/tools/testing/selftests/arm64/mte/check_ksm_options.c
@@ -33,7 +33,10 @@ static unsigned long read_sysfs(char *str)
 		ksft_print_msg("ERR: missing %s\n", str);
 		return 0;
 	}
-	fscanf(f, "%lu", &val);
+	if (fscanf(f, "%lu", &val) != 1) {
+		ksft_print_msg("ERR: parsing %s\n", str);
+		val = 0;
+	}
 	fclose(f);
 	return val;
 }
diff --git a/tools/testing/selftests/arm64/mte/check_user_mem.c b/tools/testing/selftests/arm64/mte/check_user_mem.c
index 4bfa80f2a8c3..1de7a0abd0ae 100644
--- a/tools/testing/selftests/arm64/mte/check_user_mem.c
+++ b/tools/testing/selftests/arm64/mte/check_user_mem.c
@@ -33,7 +33,8 @@ static int check_usermem_access_fault(int mem_type, int mode, int mapping)
 	if (fd == -1)
 		return KSFT_FAIL;
 	for (i = 0; i < len; i++)
-		write(fd, &val, sizeof(val));
+		if (write(fd, &val, sizeof(val)) != sizeof(val))
+			return KSFT_FAIL;
 	lseek(fd, 0, 0);
 	ptr = mte_allocate_memory(len, mem_type, mapping, true);
 	if (check_allocated_memory(ptr, len, mem_type, true) != KSFT_PASS) {
diff --git a/tools/testing/selftests/arm64/mte/mte_common_util.c b/tools/testing/selftests/arm64/mte/mte_common_util.c
index 39f8908988ea..f50ac31920d1 100644
--- a/tools/testing/selftests/arm64/mte/mte_common_util.c
+++ b/tools/testing/selftests/arm64/mte/mte_common_util.c
@@ -181,10 +181,17 @@ void *mte_allocate_file_memory(size_t size, int mem_type, int mapping, bool tags
 	}
 	/* Initialize the file for mappable size */
 	lseek(fd, 0, SEEK_SET);
-	for (index = INIT_BUFFER_SIZE; index < size; index += INIT_BUFFER_SIZE)
-		write(fd, buffer, INIT_BUFFER_SIZE);
+	for (index = INIT_BUFFER_SIZE; index < size; index += INIT_BUFFER_SIZE) {
+		if (write(fd, buffer, INIT_BUFFER_SIZE) != INIT_BUFFER_SIZE) {
+			perror("initialising buffer");
+			return NULL;
+		}
+	}
 	index -= INIT_BUFFER_SIZE;
-	write(fd, buffer, size - index);
+	if (write(fd, buffer, size - index) != size - index) {
+		perror("initialising buffer");
+		return NULL;
+	}
 	return __mte_allocate_memory_range(size, mem_type, mapping, 0, 0, tags, fd);
 }
 
@@ -202,9 +209,15 @@ void *mte_allocate_file_memory_tag_range(size_t size, int mem_type, int mapping,
 	/* Initialize the file for mappable size */
 	lseek(fd, 0, SEEK_SET);
 	for (index = INIT_BUFFER_SIZE; index < map_size; index += INIT_BUFFER_SIZE)
-		write(fd, buffer, INIT_BUFFER_SIZE);
+		if (write(fd, buffer, INIT_BUFFER_SIZE) != INIT_BUFFER_SIZE) {
+			perror("initialising buffer");
+			return NULL;
+		}
 	index -= INIT_BUFFER_SIZE;
-	write(fd, buffer, map_size - index);
+	if (write(fd, buffer, map_size - index) != map_size - index) {
+		perror("initialising buffer");
+		return NULL;
+	}
 	return __mte_allocate_memory_range(size, mem_type, mapping, range_before,
 					   range_after, true, fd);
 }
@@ -271,29 +284,20 @@ int mte_switch_mode(int mte_option, unsigned long incl_mask)
 
 	en |= (incl_mask << PR_MTE_TAG_SHIFT);
 	/* Enable address tagging ABI, mte error reporting mode and tag inclusion mask. */
-	if (!prctl(PR_SET_TAGGED_ADDR_CTRL, en, 0, 0, 0) == 0) {
+	if (prctl(PR_SET_TAGGED_ADDR_CTRL, en, 0, 0, 0) != 0) {
 		ksft_print_msg("FAIL:prctl PR_SET_TAGGED_ADDR_CTRL for mte mode\n");
 		return -EINVAL;
 	}
 	return 0;
 }
 
-#define ID_AA64PFR1_MTE_SHIFT		8
-#define ID_AA64PFR1_MTE			2
-
 int mte_default_setup(void)
 {
-	unsigned long hwcaps = getauxval(AT_HWCAP);
+	unsigned long hwcaps2 = getauxval(AT_HWCAP2);
 	unsigned long en = 0;
 	int ret;
 
-	if (!(hwcaps & HWCAP_CPUID)) {
-		ksft_print_msg("FAIL: CPUID registers unavailable\n");
-		return KSFT_FAIL;
-	}
-	/* Read ID_AA64PFR1_EL1 register */
-	asm volatile("mrs %0, id_aa64pfr1_el1" : "=r"(hwcaps) : : "memory");
-	if (((hwcaps >> ID_AA64PFR1_MTE_SHIFT) & MT_TAG_MASK) != ID_AA64PFR1_MTE) {
+	if (!(hwcaps2 & HWCAP2_MTE)) {
 		ksft_print_msg("FAIL: MTE features unavailable\n");
 		return KSFT_SKIP;
 	}
@@ -333,6 +337,7 @@ int create_temp_file(void)
 	/* Create a file in the tmpfs filesystem */
 	fd = mkstemp(&filename[0]);
 	if (fd == -1) {
+		perror(filename);
 		ksft_print_msg("FAIL: Unable to open temporary file\n");
 		return 0;
 	}