Merge branch 'for-next/late-arrivals' into for-next/core

Late patches for 5.10: MTE selftests, minor KCSAN preparation and removal
of some unused prototypes.

(Amit Daniel Kachhap and others)
* for-next/late-arrivals:
  arm64: random: Remove no longer needed prototypes
  arm64: initialize per-cpu offsets earlier
  kselftest/arm64: Check mte tagged user address in kernel
  kselftest/arm64: Verify KSM page merge for MTE pages
  kselftest/arm64: Verify all different mmap MTE options
  kselftest/arm64: Check forked child mte memory accessibility
  kselftest/arm64: Verify mte tag inclusion via prctl
  kselftest/arm64: Add utilities and a test to validate mte memory

arch/arm64/include/asm/archrandom.h

@@ -79,10 +79,5 @@ arch_get_random_seed_long_early(unsigned long *v)
 }
 #define arch_get_random_seed_long_early arch_get_random_seed_long_early
 
-#else
-
-static inline bool __arm64_rndr(unsigned long *v) { return false; }
-static inline bool __init __early_cpu_has_rndr(void) { return false; }
-
 #endif /* CONFIG_ARCH_RANDOM */
 #endif /* _ASM_ARCHRANDOM_H */

arch/arm64/include/asm/cpu.h

@@ -68,4 +68,6 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info);
 void update_cpu_features(int cpu, struct cpuinfo_arm64 *info,
 				 struct cpuinfo_arm64 *boot);
 
+void init_this_cpu_offset(void);
+
 #endif /* __ASM_CPU_H */

arch/arm64/kernel/head.S

@@ -448,6 +448,8 @@ SYM_FUNC_START_LOCAL(__primary_switched)
 	bl	__pi_memset
 	dsb	ishst				// Make zero page visible to PTW
 
+	bl	init_this_cpu_offset
+
 #ifdef CONFIG_KASAN
 	bl	kasan_early_init
 #endif
@@ -754,6 +756,7 @@ SYM_FUNC_START_LOCAL(__secondary_switched)
 	ptrauth_keys_init_cpu x2, x3, x4, x5
 #endif
 
+	bl	init_this_cpu_offset
 	b	secondary_start_kernel
 SYM_FUNC_END(__secondary_switched)
 

arch/arm64/kernel/setup.c

@@ -87,12 +87,6 @@ void __init smp_setup_processor_id(void)
 	u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
 	set_cpu_logical_map(0, mpidr);
 
-	/*
-	 * clear __my_cpu_offset on boot CPU to avoid hang caused by
-	 * using percpu variable early, for example, lockdep will
-	 * access percpu variable inside lock_release
-	 */
-	set_my_cpu_offset(0);
 	pr_info("Booting Linux on physical CPU 0x%010lx [0x%08x]\n",
 		(unsigned long)mpidr, read_cpuid_id());
 }
@@ -282,6 +276,12 @@ u64 cpu_logical_map(int cpu)
 }
 EXPORT_SYMBOL_GPL(cpu_logical_map);
 
+void noinstr init_this_cpu_offset(void)
+{
+	unsigned int cpu = task_cpu(current);
+	set_my_cpu_offset(per_cpu_offset(cpu));
+}
+
 void __init __no_sanitize_address setup_arch(char **cmdline_p)
 {
 	init_mm.start_code = (unsigned long) _text;

arch/arm64/kernel/smp.c

@@ -192,10 +192,7 @@ asmlinkage notrace void secondary_start_kernel(void)
 	u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
 	struct mm_struct *mm = &init_mm;
 	const struct cpu_operations *ops;
-	unsigned int cpu;
-
-	cpu = task_cpu(current);
-	set_my_cpu_offset(per_cpu_offset(cpu));
+	unsigned int cpu = smp_processor_id();
 
 	/*
 	 * All kernel threads share the same mm context; grab a
@@ -435,7 +432,13 @@ void __init smp_cpus_done(unsigned int max_cpus)
 
 void __init smp_prepare_boot_cpu(void)
 {
-	set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
+	/*
+	 * Now that setup_per_cpu_areas() has allocated the runtime per-cpu
+	 * areas it is only safe to read the CPU0 boot-time area, and we must
+	 * reinitialize the offset to point to the runtime area.
+	 */
+	init_this_cpu_offset();
+
 	cpuinfo_store_boot_cpu();
 
 	/*

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
+ARM64_SUBTARGETS ?= tags signal pauth fp mte
 else
 ARM64_SUBTARGETS :=
 endif

tools/testing/selftests/arm64/mte/.gitignore

+check_buffer_fill
+check_tags_inclusion
+check_child_memory
+check_mmap_options
+check_ksm_options
+check_user_mem

tools/testing/selftests/arm64/mte/Makefile

+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2020 ARM Limited
+
+CFLAGS += -std=gnu99 -I.
+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) $(CFLAGS) -E -x c /dev/null -o /dev/null 2>&1) then echo "1"; fi)
+
+ifeq ($(mte_cc_support),1)
+# Generated binaries to be installed by top KSFT script
+TEST_GEN_PROGS := $(PROGS)
+
+# Get Kernel headers installed and use them.
+KSFT_KHDR_INSTALL := 1
+endif
+
+# Include KSFT lib.mk.
+include ../../lib.mk
+
+ifeq ($(mte_cc_support),1)
+$(TEST_GEN_PROGS): mte_common_util.c mte_common_util.h mte_helper.S
+endif

tools/testing/selftests/arm64/mte/check_child_memory.c

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2020 ARM Limited
+
+#define _GNU_SOURCE
+
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ucontext.h>
+#include <sys/wait.h>
+
+#include "kselftest.h"
+#include "mte_common_util.h"
+#include "mte_def.h"
+
+#define BUFFER_SIZE		(5 * MT_GRANULE_SIZE)
+#define RUNS			(MT_TAG_COUNT)
+#define UNDERFLOW		MT_GRANULE_SIZE
+#define OVERFLOW		MT_GRANULE_SIZE
+
+static size_t page_size;
+static int sizes[] = {
+	1, 537, 989, 1269, MT_GRANULE_SIZE - 1, MT_GRANULE_SIZE,
+	/* page size - 1*/ 0, /* page_size */ 0, /* page size + 1 */ 0
+};
+
+static int check_child_tag_inheritance(char *ptr, int size, int mode)
+{
+	int i, parent_tag, child_tag, fault, child_status;
+	pid_t child;
+
+	parent_tag = MT_FETCH_TAG((uintptr_t)ptr);
+	fault = 0;
+
+	child = fork();
+	if (child == -1) {
+		ksft_print_msg("FAIL: child process creation\n");
+		return KSFT_FAIL;
+	} else if (child == 0) {
+		mte_initialize_current_context(mode, (uintptr_t)ptr, size);
+		/* Do copy on write */
+		memset(ptr, '1', size);
+		mte_wait_after_trig();
+		if (cur_mte_cxt.fault_valid == true) {
+			fault = 1;
+			goto check_child_tag_inheritance_err;
+		}
+		for (i = 0 ; i < size ; i += MT_GRANULE_SIZE) {
+			child_tag = MT_FETCH_TAG((uintptr_t)(mte_get_tag_address(ptr + i)));
+			if (parent_tag != child_tag) {
+				ksft_print_msg("FAIL: child mte tag mismatch\n");
+				fault = 1;
+				goto check_child_tag_inheritance_err;
+			}
+		}
+		mte_initialize_current_context(mode, (uintptr_t)ptr, -UNDERFLOW);
+		memset(ptr - UNDERFLOW, '2', UNDERFLOW);
+		mte_wait_after_trig();
+		if (cur_mte_cxt.fault_valid == false) {
+			fault = 1;
+			goto check_child_tag_inheritance_err;
+		}
+		mte_initialize_current_context(mode, (uintptr_t)ptr, size + OVERFLOW);
+		memset(ptr + size, '3', OVERFLOW);
+		mte_wait_after_trig();
+		if (cur_mte_cxt.fault_valid == false) {
+			fault = 1;
+			goto check_child_tag_inheritance_err;
+		}
+check_child_tag_inheritance_err:
+		_exit(fault);
+	}
+	/* Wait for child process to terminate */
+	wait(&child_status);
+	if (WIFEXITED(child_status))
+		fault = WEXITSTATUS(child_status);
+	else
+		fault = 1;
+	return (fault) ? KSFT_FAIL : KSFT_PASS;
+}
+
+static int check_child_memory_mapping(int mem_type, int mode, int mapping)
+{
+	char *ptr;
+	int run, result;
+	int item = sizeof(sizes)/sizeof(int);
+
+	item = sizeof(sizes)/sizeof(int);
+	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
+	for (run = 0; run < item; run++) {
+		ptr = (char *)mte_allocate_memory_tag_range(sizes[run], mem_type, mapping,
+							    UNDERFLOW, OVERFLOW);
+		if (check_allocated_memory_range(ptr, sizes[run], mem_type,
+						 UNDERFLOW, OVERFLOW) != KSFT_PASS)
+			return KSFT_FAIL;
+		result = check_child_tag_inheritance(ptr, sizes[run], mode);
+		mte_free_memory_tag_range((void *)ptr, sizes[run], mem_type, UNDERFLOW, OVERFLOW);
+		if (result == KSFT_FAIL)
+			return result;
+	}
+	return KSFT_PASS;
+}
+
+static int check_child_file_mapping(int mem_type, int mode, int mapping)
+{
+	char *ptr, *map_ptr;
+	int run, fd, map_size, result = KSFT_PASS;
+	int total = sizeof(sizes)/sizeof(int);
+
+	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
+	for (run = 0; run < total; run++) {
+		fd = create_temp_file();
+		if (fd == -1)
+			return KSFT_FAIL;
+
+		map_size = sizes[run] + OVERFLOW + UNDERFLOW;
+		map_ptr = (char *)mte_allocate_file_memory(map_size, mem_type, mapping, false, fd);
+		if (check_allocated_memory(map_ptr, map_size, mem_type, false) != KSFT_PASS) {
+			close(fd);
+			return KSFT_FAIL;
+		}
+		ptr = map_ptr + UNDERFLOW;
+		mte_initialize_current_context(mode, (uintptr_t)ptr, sizes[run]);
+		/* Only mte enabled memory will allow tag insertion */
+		ptr = mte_insert_tags((void *)ptr, sizes[run]);
+		if (!ptr || cur_mte_cxt.fault_valid == true) {
+			ksft_print_msg("FAIL: Insert tags on file based memory\n");
+			munmap((void *)map_ptr, map_size);
+			close(fd);
+			return KSFT_FAIL;
+		}
+		result = check_child_tag_inheritance(ptr, sizes[run], mode);
+		mte_clear_tags((void *)ptr, sizes[run]);
+		munmap((void *)map_ptr, map_size);
+		close(fd);
+		if (result != KSFT_PASS)
+			return KSFT_FAIL;
+	}
+	return KSFT_PASS;
+}
+
+int main(int argc, char *argv[])
+{
+	int err;
+	int item = sizeof(sizes)/sizeof(int);
+
+	page_size = getpagesize();
+	if (!page_size) {
+		ksft_print_msg("ERR: Unable to get page size\n");
+		return KSFT_FAIL;
+	}
+	sizes[item - 3] = page_size - 1;
+	sizes[item - 2] = page_size;
+	sizes[item - 1] = page_size + 1;
+
+	err = mte_default_setup();
+	if (err)
+		return err;
+
+	/* Register SIGSEGV handler */
+	mte_register_signal(SIGSEGV, mte_default_handler);
+	mte_register_signal(SIGBUS, mte_default_handler);
+
+	evaluate_test(check_child_memory_mapping(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE),
+		"Check child anonymous memory with private mapping, precise mode and mmap memory\n");
+	evaluate_test(check_child_memory_mapping(USE_MMAP, MTE_SYNC_ERR, MAP_SHARED),
+		"Check child anonymous memory with shared mapping, precise mode and mmap memory\n");
+	evaluate_test(check_child_memory_mapping(USE_MMAP, MTE_ASYNC_ERR, MAP_PRIVATE),
+		"Check child anonymous memory with private mapping, imprecise mode and mmap memory\n");
+	evaluate_test(check_child_memory_mapping(USE_MMAP, MTE_ASYNC_ERR, MAP_SHARED),
+		"Check child anonymous memory with shared mapping, imprecise mode and mmap memory\n");
+	evaluate_test(check_child_memory_mapping(USE_MPROTECT, MTE_SYNC_ERR, MAP_PRIVATE),
+		"Check child anonymous memory with private mapping, precise mode and mmap/mprotect memory\n");
+	evaluate_test(check_child_memory_mapping(USE_MPROTECT, MTE_SYNC_ERR, MAP_SHARED),
+		"Check child anonymous memory with shared mapping, precise mode and mmap/mprotect memory\n");
+
+	evaluate_test(check_child_file_mapping(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE),
+		"Check child file memory with private mapping, precise mode and mmap memory\n");
+	evaluate_test(check_child_file_mapping(USE_MMAP, MTE_SYNC_ERR, MAP_SHARED),
+		"Check child file memory with shared mapping, precise mode and mmap memory\n");
+	evaluate_test(check_child_memory_mapping(USE_MMAP, MTE_ASYNC_ERR, MAP_PRIVATE),
+		"Check child file memory with private mapping, imprecise mode and mmap memory\n");
+	evaluate_test(check_child_memory_mapping(USE_MMAP, MTE_ASYNC_ERR, MAP_SHARED),
+		"Check child file memory with shared mapping, imprecise mode and mmap memory\n");
+	evaluate_test(check_child_memory_mapping(USE_MPROTECT, MTE_SYNC_ERR, MAP_PRIVATE),
+		"Check child file memory with private mapping, precise mode and mmap/mprotect memory\n");
+	evaluate_test(check_child_memory_mapping(USE_MPROTECT, MTE_SYNC_ERR, MAP_SHARED),
+		"Check child file memory with shared mapping, precise mode and mmap/mprotect memory\n");
+
+	mte_restore_setup();
+	ksft_print_cnts();
+	return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL;
+}

tools/testing/selftests/arm64/mte/check_ksm_options.c

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2020 ARM Limited
+
+#define _GNU_SOURCE
+
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ucontext.h>
+#include <sys/mman.h>
+
+#include "kselftest.h"
+#include "mte_common_util.h"
+#include "mte_def.h"
+
+#define TEST_UNIT	10
+#define PATH_KSM	"/sys/kernel/mm/ksm/"
+#define MAX_LOOP	4
+
+static size_t page_sz;
+static unsigned long ksm_sysfs[5];
+
+static unsigned long read_sysfs(char *str)
+{
+	FILE *f;
+	unsigned long val = 0;
+
+	f = fopen(str, "r");
+	if (!f) {
+		ksft_print_msg("ERR: missing %s\n", str);
+		return 0;
+	}
+	fscanf(f, "%lu", &val);
+	fclose(f);
+	return val;
+}
+
+static void write_sysfs(char *str, unsigned long val)
+{
+	FILE *f;
+
+	f = fopen(str, "w");
+	if (!f) {
+		ksft_print_msg("ERR: missing %s\n", str);
+		return;
+	}
+	fprintf(f, "%lu", val);
+	fclose(f);
+}
+
+static void mte_ksm_setup(void)
+{
+	ksm_sysfs[0] = read_sysfs(PATH_KSM "merge_across_nodes");
+	write_sysfs(PATH_KSM "merge_across_nodes", 1);
+	ksm_sysfs[1] = read_sysfs(PATH_KSM "sleep_millisecs");
+	write_sysfs(PATH_KSM "sleep_millisecs", 0);
+	ksm_sysfs[2] = read_sysfs(PATH_KSM "run");
+	write_sysfs(PATH_KSM "run", 1);
+	ksm_sysfs[3] = read_sysfs(PATH_KSM "max_page_sharing");
+	write_sysfs(PATH_KSM "max_page_sharing", ksm_sysfs[3] + TEST_UNIT);
+	ksm_sysfs[4] = read_sysfs(PATH_KSM "pages_to_scan");
+	write_sysfs(PATH_KSM "pages_to_scan", ksm_sysfs[4] + TEST_UNIT);
+}
+
+static void mte_ksm_restore(void)
+{
+	write_sysfs(PATH_KSM "merge_across_nodes", ksm_sysfs[0]);
+	write_sysfs(PATH_KSM "sleep_millisecs", ksm_sysfs[1]);
+	write_sysfs(PATH_KSM "run", ksm_sysfs[2]);
+	write_sysfs(PATH_KSM "max_page_sharing", ksm_sysfs[3]);
+	write_sysfs(PATH_KSM "pages_to_scan", ksm_sysfs[4]);
+}
+
+static void mte_ksm_scan(void)
+{
+	int cur_count = read_sysfs(PATH_KSM "full_scans");
+	int scan_count = cur_count + 1;
+	int max_loop_count = MAX_LOOP;
+
+	while ((cur_count < scan_count) && max_loop_count) {
+		sleep(1);
+		cur_count = read_sysfs(PATH_KSM "full_scans");
+		max_loop_count--;
+	}
+#ifdef DEBUG
+	ksft_print_msg("INFO: pages_shared=%lu pages_sharing=%lu\n",
+			read_sysfs(PATH_KSM "pages_shared"),
+			read_sysfs(PATH_KSM "pages_sharing"));
+#endif
+}
+
+static int check_madvise_options(int mem_type, int mode, int mapping)
+{
+	char *ptr;
+	int err, ret;
+
+	err = KSFT_FAIL;
+	if (access(PATH_KSM, F_OK) == -1) {
+		ksft_print_msg("ERR: Kernel KSM config not enabled\n");
+		return err;
+	}
+
+	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
+	ptr = mte_allocate_memory(TEST_UNIT * page_sz, mem_type, mapping, true);
+	if (check_allocated_memory(ptr, TEST_UNIT * page_sz, mem_type, false) != KSFT_PASS)
+		return KSFT_FAIL;
+
+	/* Insert same data in all the pages */
+	memset(ptr, 'A', TEST_UNIT * page_sz);
+	ret = madvise(ptr, TEST_UNIT * page_sz, MADV_MERGEABLE);
+	if (ret) {
+		ksft_print_msg("ERR: madvise failed to set MADV_UNMERGEABLE\n");
+		goto madvise_err;
+	}
+	mte_ksm_scan();
+	/* Tagged pages should not merge */
+	if ((read_sysfs(PATH_KSM "pages_shared") < 1) ||
+	    (read_sysfs(PATH_KSM "pages_sharing") < (TEST_UNIT - 1)))
+		err = KSFT_PASS;
+madvise_err:
+	mte_free_memory(ptr, TEST_UNIT * page_sz, mem_type, true);
+	return err;
+}
+
+int main(int argc, char *argv[])
+{
+	int err;
+
+	err = mte_default_setup();
+	if (err)
+		return err;
+	page_sz = getpagesize();
+	if (!page_sz) {
+		ksft_print_msg("ERR: Unable to get page size\n");
+		return KSFT_FAIL;
+	}
+	/* Register signal handlers */
+	mte_register_signal(SIGBUS, mte_default_handler);
+	mte_register_signal(SIGSEGV, mte_default_handler);
+	/* Enable KSM */
+	mte_ksm_setup();
+
+	evaluate_test(check_madvise_options(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE),
+		"Check KSM mte page merge for private mapping, sync mode and mmap memory\n");
+	evaluate_test(check_madvise_options(USE_MMAP, MTE_ASYNC_ERR, MAP_PRIVATE),
+		"Check KSM mte page merge for private mapping, async mode and mmap memory\n");
+	evaluate_test(check_madvise_options(USE_MMAP, MTE_SYNC_ERR, MAP_SHARED),
+		"Check KSM mte page merge for shared mapping, sync mode and mmap memory\n");
+	evaluate_test(check_madvise_options(USE_MMAP, MTE_ASYNC_ERR, MAP_SHARED),
+		"Check KSM mte page merge for shared mapping, async mode and mmap memory\n");
+
+	mte_ksm_restore();
+	mte_restore_setup();
+	ksft_print_cnts();
+	return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL;
+}

tools/testing/selftests/arm64/mte/check_tags_inclusion.c

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2020 ARM Limited
+
+#define _GNU_SOURCE
+
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ucontext.h>
+#include <sys/wait.h>
+
+#include "kselftest.h"
+#include "mte_common_util.h"
+#include "mte_def.h"
+
+#define BUFFER_SIZE		(5 * MT_GRANULE_SIZE)
+#define RUNS			(MT_TAG_COUNT * 2)
+#define MTE_LAST_TAG_MASK	(0x7FFF)
+
+static int verify_mte_pointer_validity(char *ptr, int mode)
+{
+	mte_initialize_current_context(mode, (uintptr_t)ptr, BUFFER_SIZE);
+	/* Check the validity of the tagged pointer */
+	memset((void *)ptr, '1', BUFFER_SIZE);
+	mte_wait_after_trig();
+	if (cur_mte_cxt.fault_valid)
+		return KSFT_FAIL;
+	/* Proceed further for nonzero tags */
+	if (!MT_FETCH_TAG((uintptr_t)ptr))
+		return KSFT_PASS;
+	mte_initialize_current_context(mode, (uintptr_t)ptr, BUFFER_SIZE + 1);
+	/* Check the validity outside the range */
+	ptr[BUFFER_SIZE] = '2';
+	mte_wait_after_trig();
+	if (!cur_mte_cxt.fault_valid)
+		return KSFT_FAIL;
+	else
+		return KSFT_PASS;
+}
+
+static int check_single_included_tags(int mem_type, int mode)
+{
+	char *ptr;
+	int tag, run, result = KSFT_PASS;
+
+	ptr = (char *)mte_allocate_memory(BUFFER_SIZE + MT_GRANULE_SIZE, mem_type, 0, false);
+	if (check_allocated_memory(ptr, BUFFER_SIZE + MT_GRANULE_SIZE,
+				   mem_type, false) != KSFT_PASS)
+		return KSFT_FAIL;
+
+	for (tag = 0; (tag < MT_TAG_COUNT) && (result == KSFT_PASS); tag++) {
+		mte_switch_mode(mode, MT_INCLUDE_VALID_TAG(tag));
+		/* Try to catch a excluded tag by a number of tries. */
+		for (run = 0; (run < RUNS) && (result == KSFT_PASS); run++) {
+			ptr = (char *)mte_insert_tags(ptr, BUFFER_SIZE);
+			/* Check tag value */
+			if (MT_FETCH_TAG((uintptr_t)ptr) == tag) {
+				ksft_print_msg("FAIL: wrong tag = 0x%x with include mask=0x%x\n",
+					       MT_FETCH_TAG((uintptr_t)ptr),
+					       MT_INCLUDE_VALID_TAG(tag));
+				result = KSFT_FAIL;
+				break;
+			}
+			result = verify_mte_pointer_validity(ptr, mode);
+		}
+	}
+	mte_free_memory_tag_range((void *)ptr, BUFFER_SIZE, mem_type, 0, MT_GRANULE_SIZE);
+	return result;
+}
+
+static int check_multiple_included_tags(int mem_type, int mode)
+{
+	char *ptr;
+	int tag, run, result = KSFT_PASS;
+	unsigned long excl_mask = 0;
+
+	ptr = (char *)mte_allocate_memory(BUFFER_SIZE + MT_GRANULE_SIZE, mem_type, 0, false);
+	if (check_allocated_memory(ptr, BUFFER_SIZE + MT_GRANULE_SIZE,
+				   mem_type, false) != KSFT_PASS)
+		return KSFT_FAIL;
+
+	for (tag = 0; (tag < MT_TAG_COUNT - 1) && (result == KSFT_PASS); tag++) {
+		excl_mask |= 1 << tag;
+		mte_switch_mode(mode, MT_INCLUDE_VALID_TAGS(excl_mask));
+		/* Try to catch a excluded tag by a number of tries. */
+		for (run = 0; (run < RUNS) && (result == KSFT_PASS); run++) {
+			ptr = (char *)mte_insert_tags(ptr, BUFFER_SIZE);
+			/* Check tag value */
+			if (MT_FETCH_TAG((uintptr_t)ptr) < tag) {
+				ksft_print_msg("FAIL: wrong tag = 0x%x with include mask=0x%x\n",
+					       MT_FETCH_TAG((uintptr_t)ptr),
+					       MT_INCLUDE_VALID_TAGS(excl_mask));
+				result = KSFT_FAIL;
+				break;
+			}
+			result = verify_mte_pointer_validity(ptr, mode);
+		}
+	}
+	mte_free_memory_tag_range((void *)ptr, BUFFER_SIZE, mem_type, 0, MT_GRANULE_SIZE);
+	return result;
+}
+
+static int check_all_included_tags(int mem_type, int mode)
+{
+	char *ptr;
+	int run, result = KSFT_PASS;
+
+	ptr = (char *)mte_allocate_memory(BUFFER_SIZE + MT_GRANULE_SIZE, mem_type, 0, false);
+	if (check_allocated_memory(ptr, BUFFER_SIZE + MT_GRANULE_SIZE,
+				   mem_type, false) != KSFT_PASS)
+		return KSFT_FAIL;
+
+	mte_switch_mode(mode, MT_INCLUDE_TAG_MASK);
+	/* Try to catch a excluded tag by a number of tries. */
+	for (run = 0; (run < RUNS) && (result == KSFT_PASS); run++) {
+		ptr = (char *)mte_insert_tags(ptr, BUFFER_SIZE);
+		/*
+		 * Here tag byte can be between 0x0 to 0xF (full allowed range)
+		 * so no need to match so just verify if it is writable.
+		 */
+		result = verify_mte_pointer_validity(ptr, mode);
+	}
+	mte_free_memory_tag_range((void *)ptr, BUFFER_SIZE, mem_type, 0, MT_GRANULE_SIZE);
+	return result;
+}
+
+static int check_none_included_tags(int mem_type, int mode)
+{
+	char *ptr;
+	int run;
+
+	ptr = (char *)mte_allocate_memory(BUFFER_SIZE, mem_type, 0, false);
+	if (check_allocated_memory(ptr, BUFFER_SIZE, mem_type, false) != KSFT_PASS)
+		return KSFT_FAIL;
+
+	mte_switch_mode(mode, MT_EXCLUDE_TAG_MASK);
+	/* Try to catch a excluded tag by a number of tries. */
+	for (run = 0; run < RUNS; run++) {
+		ptr = (char *)mte_insert_tags(ptr, BUFFER_SIZE);
+		/* Here all tags exluded so tag value generated should be 0 */
+		if (MT_FETCH_TAG((uintptr_t)ptr)) {
+			ksft_print_msg("FAIL: included tag value found\n");
+			mte_free_memory((void *)ptr, BUFFER_SIZE, mem_type, true);
+			return KSFT_FAIL;
+		}
+		mte_initialize_current_context(mode, (uintptr_t)ptr, BUFFER_SIZE);
+		/* Check the write validity of the untagged pointer */
+		memset((void *)ptr, '1', BUFFER_SIZE);
+		mte_wait_after_trig();
+		if (cur_mte_cxt.fault_valid)
+			break;
+	}
+	mte_free_memory((void *)ptr, BUFFER_SIZE, mem_type, false);
+	if (cur_mte_cxt.fault_valid)
+		return KSFT_FAIL;
+	else
+		return KSFT_PASS;
+}
+
+int main(int argc, char *argv[])
+{
+	int err;
+
+	err = mte_default_setup();
+	if (err)
+		return err;
+
+	/* Register SIGSEGV handler */
+	mte_register_signal(SIGSEGV, mte_default_handler);
+
+	evaluate_test(check_single_included_tags(USE_MMAP, MTE_SYNC_ERR),
+		      "Check an included tag value with sync mode\n");
+	evaluate_test(check_multiple_included_tags(USE_MMAP, MTE_SYNC_ERR),
+		      "Check different included tags value with sync mode\n");
+	evaluate_test(check_none_included_tags(USE_MMAP, MTE_SYNC_ERR),
+		      "Check none included tags value with sync mode\n");
+	evaluate_test(check_all_included_tags(USE_MMAP, MTE_SYNC_ERR),
+		      "Check all included tags value with sync mode\n");
+
+	mte_restore_setup();
+	ksft_print_cnts();
+	return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL;
+}

tools/testing/selftests/arm64/mte/check_user_mem.c

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2020 ARM Limited
+
+#define _GNU_SOURCE
+
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <ucontext.h>
+#include <unistd.h>
+#include <sys/mman.h>
+
+#include "kselftest.h"
+#include "mte_common_util.h"
+#include "mte_def.h"
+
+static size_t page_sz;
+
+static int check_usermem_access_fault(int mem_type, int mode, int mapping)
+{
+	int fd, i, err;
+	char val = 'A';
+	size_t len, read_len;
+	void *ptr, *ptr_next;
+
+	err = KSFT_FAIL;
+	len = 2 * page_sz;
+	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
+	fd = create_temp_file();
+	if (fd == -1)
+		return KSFT_FAIL;
+	for (i = 0; i < len; i++)
+		write(fd, &val, sizeof(val));
+	lseek(fd, 0, 0);
+	ptr = mte_allocate_memory(len, mem_type, mapping, true);
+	if (check_allocated_memory(ptr, len, mem_type, true) != KSFT_PASS) {
+		close(fd);
+		return KSFT_FAIL;
+	}
+	mte_initialize_current_context(mode, (uintptr_t)ptr, len);
+	/* Copy from file into buffer with valid tag */
+	read_len = read(fd, ptr, len);
+	mte_wait_after_trig();
+	if (cur_mte_cxt.fault_valid || read_len < len)
+		goto usermem_acc_err;
+	/* Verify same pattern is read */
+	for (i = 0; i < len; i++)
+		if (*(char *)(ptr + i) != val)
+			break;
+	if (i < len)
+		goto usermem_acc_err;
+
+	/* Tag the next half of memory with different value */
+	ptr_next = (void *)((unsigned long)ptr + page_sz);
+	ptr_next = mte_insert_new_tag(ptr_next);
+	mte_set_tag_address_range(ptr_next, page_sz);
+
+	lseek(fd, 0, 0);
+	/* Copy from file into buffer with invalid tag */
+	read_len = read(fd, ptr, len);
+	mte_wait_after_trig();
+	/*
+	 * Accessing user memory in kernel with invalid tag should fail in sync
+	 * mode without fault but may not fail in async mode as per the
+	 * implemented MTE userspace support in Arm64 kernel.
+	 */
+	if (mode == MTE_SYNC_ERR &&
+	    !cur_mte_cxt.fault_valid && read_len < len) {
+		err = KSFT_PASS;
+	} else if (mode == MTE_ASYNC_ERR &&
+		   !cur_mte_cxt.fault_valid && read_len == len) {
+		err = KSFT_PASS;
+	}
+usermem_acc_err:
+	mte_free_memory((void *)ptr, len, mem_type, true);
+	close(fd);
+	return err;
+}
+
+int main(int argc, char *argv[])
+{
+	int err;
+
+	page_sz = getpagesize();
+	if (!page_sz) {
+		ksft_print_msg("ERR: Unable to get page size\n");
+		return KSFT_FAIL;
+	}
+	err = mte_default_setup();
+	if (err)
+		return err;
+	/* Register signal handlers */
+	mte_register_signal(SIGSEGV, mte_default_handler);
+
+	evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE),
+		"Check memory access from kernel in sync mode, private mapping and mmap memory\n");
+	evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_SYNC_ERR, MAP_SHARED),
+		"Check memory access from kernel in sync mode, shared mapping and mmap memory\n");
+
+	evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_ASYNC_ERR, MAP_PRIVATE),
+		"Check memory access from kernel in async mode, private mapping and mmap memory\n");
+	evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_ASYNC_ERR, MAP_SHARED),
+		"Check memory access from kernel in async mode, shared mapping and mmap memory\n");
+
+	mte_restore_setup();
+	ksft_print_cnts();
+	return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL;
+}

tools/testing/selftests/arm64/mte/mte_common_util.c

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2020 ARM Limited
+
+#include <fcntl.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <linux/auxvec.h>
+#include <sys/auxv.h>
+#include <sys/mman.h>
+#include <sys/prctl.h>
+
+#include <asm/hwcap.h>
+
+#include "kselftest.h"
+#include "mte_common_util.h"
+#include "mte_def.h"
+
+#define INIT_BUFFER_SIZE       256
+
+struct mte_fault_cxt cur_mte_cxt;
+static unsigned int mte_cur_mode;
+static unsigned int mte_cur_pstate_tco;
+
+void mte_default_handler(int signum, siginfo_t *si, void *uc)
+{
+	unsigned long addr = (unsigned long)si->si_addr;
+
+	if (signum == SIGSEGV) {
+#ifdef DEBUG
+		ksft_print_msg("INFO: SIGSEGV signal at pc=%lx, fault addr=%lx, si_code=%lx\n",
+				((ucontext_t *)uc)->uc_mcontext.pc, addr, si->si_code);
+#endif
+		if (si->si_code == SEGV_MTEAERR) {
+			if (cur_mte_cxt.trig_si_code == si->si_code)
+				cur_mte_cxt.fault_valid = true;
+			return;
+		}
+		/* Compare the context for precise error */
+		else if (si->si_code == SEGV_MTESERR) {
+			if (cur_mte_cxt.trig_si_code == si->si_code &&
+			    ((cur_mte_cxt.trig_range >= 0 &&
+			      addr >= MT_CLEAR_TAG(cur_mte_cxt.trig_addr) &&
+			      addr <= (MT_CLEAR_TAG(cur_mte_cxt.trig_addr) + cur_mte_cxt.trig_range)) ||
+			     (cur_mte_cxt.trig_range < 0 &&
+			      addr <= MT_CLEAR_TAG(cur_mte_cxt.trig_addr) &&
+			      addr >= (MT_CLEAR_TAG(cur_mte_cxt.trig_addr) + cur_mte_cxt.trig_range)))) {
+				cur_mte_cxt.fault_valid = true;
+				/* Adjust the pc by 4 */
+				((ucontext_t *)uc)->uc_mcontext.pc += 4;
+			} else {
+				ksft_print_msg("Invalid MTE synchronous exception caught!\n");
+				exit(1);
+			}
+		} else {
+			ksft_print_msg("Unknown SIGSEGV exception caught!\n");
+			exit(1);
+		}
+	} else if (signum == SIGBUS) {
+		ksft_print_msg("INFO: SIGBUS signal at pc=%lx, fault addr=%lx, si_code=%lx\n",
+				((ucontext_t *)uc)->uc_mcontext.pc, addr, si->si_code);
+		if ((cur_mte_cxt.trig_range >= 0 &&
+		     addr >= MT_CLEAR_TAG(cur_mte_cxt.trig_addr) &&
+		     addr <= (MT_CLEAR_TAG(cur_mte_cxt.trig_addr) + cur_mte_cxt.trig_range)) ||
+		    (cur_mte_cxt.trig_range < 0 &&
+		     addr <= MT_CLEAR_TAG(cur_mte_cxt.trig_addr) &&
+		     addr >= (MT_CLEAR_TAG(cur_mte_cxt.trig_addr) + cur_mte_cxt.trig_range))) {
+			cur_mte_cxt.fault_valid = true;
+			/* Adjust the pc by 4 */
+			((ucontext_t *)uc)->uc_mcontext.pc += 4;
+		}
+	}
+}
+
+void mte_register_signal(int signal, void (*handler)(int, siginfo_t *, void *))
+{
+	struct sigaction sa;
+
+	sa.sa_sigaction = handler;
+	sa.sa_flags = SA_SIGINFO;
+	sigemptyset(&sa.sa_mask);
+	sigaction(signal, &sa, NULL);
+}
+
+void mte_wait_after_trig(void)
+{
+	sched_yield();
+}
+
+void *mte_insert_tags(void *ptr, size_t size)
+{
+	void *tag_ptr;
+	int align_size;
+
+	if (!ptr || (unsigned long)(ptr) & MT_ALIGN_GRANULE) {
+		ksft_print_msg("FAIL: Addr=%lx: invalid\n", ptr);
+		return NULL;
+	}
+	align_size = MT_ALIGN_UP(size);
+	tag_ptr = mte_insert_random_tag(ptr);
+	mte_set_tag_address_range(tag_ptr, align_size);
+	return tag_ptr;
+}
+
+void mte_clear_tags(void *ptr, size_t size)
+{
+	if (!ptr || (unsigned long)(ptr) & MT_ALIGN_GRANULE) {
+		ksft_print_msg("FAIL: Addr=%lx: invalid\n", ptr);
+		return;
+	}
+	size = MT_ALIGN_UP(size);
+	ptr = (void *)MT_CLEAR_TAG((unsigned long)ptr);
+	mte_clear_tag_address_range(ptr, size);
+}
+
+static void *__mte_allocate_memory_range(size_t size, int mem_type, int mapping,
+					 size_t range_before, size_t range_after,
+					 bool tags, int fd)
+{
+	void *ptr;
+	int prot_flag, map_flag;
+	size_t entire_size = size + range_before + range_after;
+
+	if (mem_type != USE_MALLOC && mem_type != USE_MMAP &&
+	    mem_type != USE_MPROTECT) {
+		ksft_print_msg("FAIL: Invalid allocate request\n");
+		return NULL;
+	}
+	if (mem_type == USE_MALLOC)
+		return malloc(entire_size) + range_before;
+
+	prot_flag = PROT_READ | PROT_WRITE;
+	if (mem_type == USE_MMAP)
+		prot_flag |= PROT_MTE;
+
+	map_flag = mapping;
+	if (fd == -1)
+		map_flag = MAP_ANONYMOUS | map_flag;
+	if (!(mapping & MAP_SHARED))
+		map_flag |= MAP_PRIVATE;
+	ptr = mmap(NULL, entire_size, prot_flag, map_flag, fd, 0);
+	if (ptr == MAP_FAILED) {
+		ksft_print_msg("FAIL: mmap allocation\n");
+		return NULL;
+	}
+	if (mem_type == USE_MPROTECT) {
+		if (mprotect(ptr, entire_size, prot_flag | PROT_MTE)) {
+			munmap(ptr, size);
+			ksft_print_msg("FAIL: mprotect PROT_MTE property\n");
+			return NULL;
+		}
+	}
+	if (tags)
+		ptr = mte_insert_tags(ptr + range_before, size);
+	return ptr;
+}
+
+void *mte_allocate_memory_tag_range(size_t size, int mem_type, int mapping,
+				    size_t range_before, size_t range_after)
+{
+	return __mte_allocate_memory_range(size, mem_type, mapping, range_before,
+					   range_after, true, -1);
+}
+
+void *mte_allocate_memory(size_t size, int mem_type, int mapping, bool tags)
+{
+	return __mte_allocate_memory_range(size, mem_type, mapping, 0, 0, tags, -1);
+}
+
+void *mte_allocate_file_memory(size_t size, int mem_type, int mapping, bool tags, int fd)
+{
+	int index;
+	char buffer[INIT_BUFFER_SIZE];
+
+	if (mem_type != USE_MPROTECT && mem_type != USE_MMAP) {
+		ksft_print_msg("FAIL: Invalid mmap file request\n");
+		return NULL;
+	}
+	/* 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);
+	index -= INIT_BUFFER_SIZE;
+	write(fd, buffer, size - index);
+	return __mte_allocate_memory_range(size, mem_type, mapping, 0, 0, tags, fd);
+}
+
+void *mte_allocate_file_memory_tag_range(size_t size, int mem_type, int mapping,
+					 size_t range_before, size_t range_after, int fd)
+{
+	int index;
+	char buffer[INIT_BUFFER_SIZE];
+	int map_size = size + range_before + range_after;
+
+	if (mem_type != USE_MPROTECT && mem_type != USE_MMAP) {
+		ksft_print_msg("FAIL: Invalid mmap file request\n");
+		return NULL;
+	}
+	/* 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);
+	index -= INIT_BUFFER_SIZE;
+	write(fd, buffer, map_size - index);
+	return __mte_allocate_memory_range(size, mem_type, mapping, range_before,
+					   range_after, true, fd);
+}
+
+static void __mte_free_memory_range(void *ptr, size_t size, int mem_type,
+				    size_t range_before, size_t range_after, bool tags)
+{
+	switch (mem_type) {
+	case USE_MALLOC:
+		free(ptr - range_before);
+		break;
+	case USE_MMAP:
+	case USE_MPROTECT:
+		if (tags)
+			mte_clear_tags(ptr, size);
+		munmap(ptr - range_before, size + range_before + range_after);
+		break;
+	default:
+		ksft_print_msg("FAIL: Invalid free request\n");
+		break;
+	}
+}
+
+void mte_free_memory_tag_range(void *ptr, size_t size, int mem_type,
+			       size_t range_before, size_t range_after)
+{
+	__mte_free_memory_range(ptr, size, mem_type, range_before, range_after, true);
+}
+
+void mte_free_memory(void *ptr, size_t size, int mem_type, bool tags)
+{
+	__mte_free_memory_range(ptr, size, mem_type, 0, 0, tags);
+}
+
+void mte_initialize_current_context(int mode, uintptr_t ptr, ssize_t range)
+{
+	cur_mte_cxt.fault_valid = false;
+	cur_mte_cxt.trig_addr = ptr;
+	cur_mte_cxt.trig_range = range;
+	if (mode == MTE_SYNC_ERR)
+		cur_mte_cxt.trig_si_code = SEGV_MTESERR;
+	else if (mode == MTE_ASYNC_ERR)
+		cur_mte_cxt.trig_si_code = SEGV_MTEAERR;
+	else
+		cur_mte_cxt.trig_si_code = 0;
+}
+
+int mte_switch_mode(int mte_option, unsigned long incl_mask)
+{
+	unsigned long en = 0;
+
+	if (!(mte_option == MTE_SYNC_ERR || mte_option == MTE_ASYNC_ERR ||
+	      mte_option == MTE_NONE_ERR || incl_mask <= MTE_ALLOW_NON_ZERO_TAG)) {
+		ksft_print_msg("FAIL: Invalid mte config option\n");
+		return -EINVAL;
+	}
+	en = PR_TAGGED_ADDR_ENABLE;
+	if (mte_option == MTE_SYNC_ERR)
+		en |= PR_MTE_TCF_SYNC;
+	else if (mte_option == MTE_ASYNC_ERR)
+		en |= PR_MTE_TCF_ASYNC;
+	else if (mte_option == MTE_NONE_ERR)
+		en |= PR_MTE_TCF_NONE;
+
+	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) {
+		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 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) {
+		ksft_print_msg("FAIL: MTE features unavailable\n");
+		return KSFT_SKIP;
+	}
+	/* Get current mte mode */
+	ret = prctl(PR_GET_TAGGED_ADDR_CTRL, en, 0, 0, 0);
+	if (ret < 0) {
+		ksft_print_msg("FAIL:prctl PR_GET_TAGGED_ADDR_CTRL with error =%d\n", ret);
+		return KSFT_FAIL;
+	}
+	if (ret & PR_MTE_TCF_SYNC)
+		mte_cur_mode = MTE_SYNC_ERR;
+	else if (ret & PR_MTE_TCF_ASYNC)
+		mte_cur_mode = MTE_ASYNC_ERR;
+	else if (ret & PR_MTE_TCF_NONE)
+		mte_cur_mode = MTE_NONE_ERR;
+
+	mte_cur_pstate_tco = mte_get_pstate_tco();
+	/* Disable PSTATE.TCO */
+	mte_disable_pstate_tco();
+	return 0;
+}
+
+void mte_restore_setup(void)
+{
+	mte_switch_mode(mte_cur_mode, MTE_ALLOW_NON_ZERO_TAG);
+	if (mte_cur_pstate_tco == MT_PSTATE_TCO_EN)
+		mte_enable_pstate_tco();
+	else if (mte_cur_pstate_tco == MT_PSTATE_TCO_DIS)
+		mte_disable_pstate_tco();
+}
+
+int create_temp_file(void)
+{
+	int fd;
+	char filename[] = "/dev/shm/tmp_XXXXXX";
+
+	/* Create a file in the tmpfs filesystem */
+	fd = mkstemp(&filename[0]);
+	if (fd == -1) {
+		ksft_print_msg("FAIL: Unable to open temporary file\n");
+		return 0;
+	}
+	unlink(&filename[0]);
+	return fd;
+}

tools/testing/selftests/arm64/mte/mte_common_util.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2020 ARM Limited */
+
+#ifndef _MTE_COMMON_UTIL_H
+#define _MTE_COMMON_UTIL_H
+
+#include <signal.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <sys/auxv.h>
+#include <sys/mman.h>
+#include <sys/prctl.h>
+#include "mte_def.h"
+#include "kselftest.h"
+
+enum mte_mem_type {
+	USE_MALLOC,
+	USE_MMAP,
+	USE_MPROTECT,
+};
+
+enum mte_mode {
+	MTE_NONE_ERR,
+	MTE_SYNC_ERR,
+	MTE_ASYNC_ERR,
+};
+
+struct mte_fault_cxt {
+	/* Address start which triggers mte tag fault */
+	unsigned long trig_addr;
+	/* Address range for mte tag fault and negative value means underflow */
+	ssize_t trig_range;
+	/* siginfo si code */
+	unsigned long trig_si_code;
+	/* Flag to denote if correct fault caught */
+	bool fault_valid;
+};
+
+extern struct mte_fault_cxt cur_mte_cxt;
+
+/* MTE utility functions */
+void mte_default_handler(int signum, siginfo_t *si, void *uc);
+void mte_register_signal(int signal, void (*handler)(int, siginfo_t *, void *));
+void mte_wait_after_trig(void);
+void *mte_allocate_memory(size_t size, int mem_type, int mapping, bool tags);
+void *mte_allocate_memory_tag_range(size_t size, int mem_type, int mapping,
+				    size_t range_before, size_t range_after);
+void *mte_allocate_file_memory(size_t size, int mem_type, int mapping,
+			       bool tags, int fd);
+void *mte_allocate_file_memory_tag_range(size_t size, int mem_type, int mapping,
+					 size_t range_before, size_t range_after, int fd);
+void mte_free_memory(void *ptr, size_t size, int mem_type, bool tags);
+void mte_free_memory_tag_range(void *ptr, size_t size, int mem_type,
+			       size_t range_before, size_t range_after);
+void *mte_insert_tags(void *ptr, size_t size);
+void mte_clear_tags(void *ptr, size_t size);
+int mte_default_setup(void);
+void mte_restore_setup(void);
+int mte_switch_mode(int mte_option, unsigned long incl_mask);
+void mte_initialize_current_context(int mode, uintptr_t ptr, ssize_t range);
+
+/* Common utility functions */
+int create_temp_file(void);
+
+/* Assembly MTE utility functions */
+void *mte_insert_random_tag(void *ptr);
+void *mte_insert_new_tag(void *ptr);
+void *mte_get_tag_address(void *ptr);
+void mte_set_tag_address_range(void *ptr, int range);
+void mte_clear_tag_address_range(void *ptr, int range);
+void mte_disable_pstate_tco(void);
+void mte_enable_pstate_tco(void);
+unsigned int mte_get_pstate_tco(void);
+
+/* Test framework static inline functions/macros */
+static inline void evaluate_test(int err, const char *msg)
+{
+	if (err == KSFT_PASS)
+		ksft_test_result_pass(msg);
+	else if (err == KSFT_FAIL)
+		ksft_test_result_fail(msg);
+}
+
+static inline int check_allocated_memory(void *ptr, size_t size,
+					 int mem_type, bool tags)
+{
+	if (ptr == NULL) {
+		ksft_print_msg("FAIL: memory allocation\n");
+		return KSFT_FAIL;
+	}
+
+	if (tags && !MT_FETCH_TAG((uintptr_t)ptr)) {
+		ksft_print_msg("FAIL: tag not found at addr(%p)\n", ptr);
+		mte_free_memory((void *)ptr, size, mem_type, false);
+		return KSFT_FAIL;
+	}
+
+	return KSFT_PASS;
+}
+
+static inline int check_allocated_memory_range(void *ptr, size_t size, int mem_type,
+					       size_t range_before, size_t range_after)
+{
+	if (ptr == NULL) {
+		ksft_print_msg("FAIL: memory allocation\n");
+		return KSFT_FAIL;
+	}
+
+	if (!MT_FETCH_TAG((uintptr_t)ptr)) {
+		ksft_print_msg("FAIL: tag not found at addr(%p)\n", ptr);
+		mte_free_memory_tag_range((void *)ptr, size, mem_type, range_before,
+					  range_after);
+		return KSFT_FAIL;
+	}
+	return KSFT_PASS;
+}
+
+#endif /* _MTE_COMMON_UTIL_H */

tools/testing/selftests/arm64/mte/mte_def.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2020 ARM Limited */
+
+/*
+ * Below definitions may be found in kernel headers, However, they are
+ * redefined here to decouple the MTE selftests compilations from them.
+ */
+#ifndef SEGV_MTEAERR
+#define	SEGV_MTEAERR	8
+#endif
+#ifndef SEGV_MTESERR
+#define	SEGV_MTESERR	9
+#endif
+#ifndef PROT_MTE
+#define PROT_MTE	 0x20
+#endif
+#ifndef HWCAP2_MTE
+#define HWCAP2_MTE	(1 << 18)
+#endif
+
+#ifndef PR_MTE_TCF_SHIFT
+#define PR_MTE_TCF_SHIFT	1
+#endif
+#ifndef PR_MTE_TCF_NONE
+#define PR_MTE_TCF_NONE		(0UL << PR_MTE_TCF_SHIFT)
+#endif
+#ifndef PR_MTE_TCF_SYNC
+#define	PR_MTE_TCF_SYNC		(1UL << PR_MTE_TCF_SHIFT)
+#endif
+#ifndef PR_MTE_TCF_ASYNC
+#define PR_MTE_TCF_ASYNC	(2UL << PR_MTE_TCF_SHIFT)
+#endif
+#ifndef PR_MTE_TAG_SHIFT
+#define	PR_MTE_TAG_SHIFT	3
+#endif
+
+/* MTE Hardware feature definitions below. */
+#define MT_TAG_SHIFT		56
+#define MT_TAG_MASK		0xFUL
+#define MT_FREE_TAG		0x0UL
+#define MT_GRANULE_SIZE         16
+#define MT_TAG_COUNT		16
+#define MT_INCLUDE_TAG_MASK	0xFFFF
+#define MT_EXCLUDE_TAG_MASK	0x0
+
+#define MT_ALIGN_GRANULE	(MT_GRANULE_SIZE - 1)
+#define MT_CLEAR_TAG(x)		((x) & ~(MT_TAG_MASK << MT_TAG_SHIFT))
+#define MT_SET_TAG(x, y)	((x) | (y << MT_TAG_SHIFT))
+#define MT_FETCH_TAG(x)		((x >> MT_TAG_SHIFT) & (MT_TAG_MASK))
+#define MT_ALIGN_UP(x)		((x + MT_ALIGN_GRANULE) & ~(MT_ALIGN_GRANULE))
+
+#define MT_PSTATE_TCO_SHIFT	25
+#define MT_PSTATE_TCO_MASK	~(0x1 << MT_PSTATE_TCO_SHIFT)
+#define MT_PSTATE_TCO_EN	1
+#define MT_PSTATE_TCO_DIS	0
+
+#define MT_EXCLUDE_TAG(x)		(1 << (x))
+#define MT_INCLUDE_VALID_TAG(x)		(MT_INCLUDE_TAG_MASK ^ MT_EXCLUDE_TAG(x))
+#define MT_INCLUDE_VALID_TAGS(x)	(MT_INCLUDE_TAG_MASK ^ (x))
+#define MTE_ALLOW_NON_ZERO_TAG		MT_INCLUDE_VALID_TAG(0)

tools/testing/selftests/arm64/mte/mte_helper.S

+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2020 ARM Limited */
+
+#include "mte_def.h"
+
+#define ENTRY(name) \
+	.globl name ;\
+	.p2align 2;\
+	.type name, @function ;\
+name:
+
+#define ENDPROC(name) \
+	.size name, .-name ;
+
+	.text
+/*
+ * mte_insert_random_tag: Insert random tag and might be same as the source tag if
+ *			  the source pointer has it.
+ * Input:
+ *		x0 - source pointer with a tag/no-tag
+ * Return:
+ *		x0 - pointer with random tag
+ */
+ENTRY(mte_insert_random_tag)
+	irg	x0, x0, xzr
+	ret
+ENDPROC(mte_insert_random_tag)
+
+/*
+ * mte_insert_new_tag: Insert new tag and different from the source tag if
+ *		       source pointer has it.
+ * Input:
+ *		x0 - source pointer with a tag/no-tag
+ * Return:
+ *		x0 - pointer with random tag
+ */
+ENTRY(mte_insert_new_tag)
+	gmi	x1, x0, xzr
+	irg	x0, x0, x1
+	ret
+ENDPROC(mte_insert_new_tag)
+
+/*
+ * mte_get_tag_address: Get the tag from given address.
+ * Input:
+ *		x0 - source pointer
+ * Return:
+ *		x0 - pointer with appended tag
+ */
+ENTRY(mte_get_tag_address)
+	ldg	x0, [x0]
+	ret
+ENDPROC(mte_get_tag_address)
+
+/*
+ * mte_set_tag_address_range: Set the tag range from the given address
+ * Input:
+ *		x0 - source pointer with tag data
+ *		x1 - range
+ * Return:
+ *		none
+ */
+ENTRY(mte_set_tag_address_range)
+	cbz	x1, 2f
+1:
+	stg	x0, [x0, #0x0]
+	add	x0, x0, #MT_GRANULE_SIZE
+	sub	x1, x1, #MT_GRANULE_SIZE
+	cbnz	x1, 1b
+2:
+	ret
+ENDPROC(mte_set_tag_address_range)
+
+/*
+ * mt_clear_tag_address_range: Clear the tag range from the given address
+ * Input:
+ *		x0 - source pointer with tag data
+ *		x1 - range
+ * Return:
+ *		none
+ */
+ENTRY(mte_clear_tag_address_range)
+	cbz	x1, 2f
+1:
+	stzg	x0, [x0, #0x0]
+	add	x0, x0, #MT_GRANULE_SIZE
+	sub	x1, x1, #MT_GRANULE_SIZE
+	cbnz	x1, 1b
+2:
+	ret
+ENDPROC(mte_clear_tag_address_range)
+
+/*
+ * mte_enable_pstate_tco: Enable PSTATE.TCO (tag check override) field
+ * Input:
+ *		none
+ * Return:
+ *		none
+ */
+ENTRY(mte_enable_pstate_tco)
+	msr	tco, #MT_PSTATE_TCO_EN
+	ret
+ENDPROC(mte_enable_pstate_tco)
+
+/*
+ * mte_disable_pstate_tco: Disable PSTATE.TCO (tag check override) field
+ * Input:
+ *		none
+ * Return:
+ *		none
+ */
+ENTRY(mte_disable_pstate_tco)
+	msr	tco, #MT_PSTATE_TCO_DIS
+	ret
+ENDPROC(mte_disable_pstate_tco)
+
+/*
+ * mte_get_pstate_tco: Get PSTATE.TCO (tag check override) field
+ * Input:
+ *		none
+ * Return:
+ *		x0
+ */
+ENTRY(mte_get_pstate_tco)
+	mrs	x0, tco
+	ubfx	x0, x0, #MT_PSTATE_TCO_SHIFT, #1
+	ret
+ENDPROC(mte_get_pstate_tco)