[PATCH v2 0/6] kselftest: arm64/mte: Tests for user-space MTE

[PATCH v2 0/6] kselftest: arm64/mte: Tests for user-space MTE

[Amit Daniel Kachhap]

These patch series adds below kselftests to test the user-space support for the
ARMv8.5 Memory Tagging Extension present in arm64 tree [1]. This patch
series is based on Linux v5.9-rc3.

1) This test-case verifies that the memory allocated by kernel mmap interface
can support tagged memory access. It first checks the presence of tags at
address[56:59] and then proceeds with read and write. The pass criteria for
this test is that tag fault exception should not happen.

2) This test-case crosses the valid memory to the invalid memory. In this
memory area valid tags are not inserted so read and write should not pass. The
pass criteria for this test is that tag fault exception should happen for all
the illegal addresses. This test also verfies that PSTATE.TCO works properly.

3) This test-case verifies that the memory inherited by child process from
parent process should have same tags copied. The pass criteria for this test is
that tag fault exception should not happen.

4) This test checks different mmap flags with PROT_MTE memory protection.

5) This testcase checks that KSM should not merge pages containing different
MTE tag values. However, if the tags are same then the pages may merge. This
testcase uses the generic ksm sysfs interfaces to verify the MTE behaviour, so
this testcase is not fullproof and may be impacted due to other load in the system.

6) Fifth test verifies that syscalls read/write etc works by considering that
user pointer has valid/invalid allocation tags.

Changes since v1 [2]:
* Redefined MTE kernel header definitions to decouple kselftest compilations.
* Removed gmi masking instructions in mte_insert_random_tag assembly
  function. This simplifies the tag inclusion mask test with only GCR
  mask register used.
* Created a new mte_insert_random_tag function with gmi instruction.
  This is useful for the 6th test which reuses the original tag.
* Now use /dev/shm/* to hold temporary files.
* Updated the 6th test to handle the error properly in case of failure
  in accessing memory with invalid tag in kernel.
* Code and comment clean-ups.

Thanks,
Amit Daniel

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/mte
[2]: https://patchwork.kernel.org/patch/11747791/

Amit Daniel Kachhap (6):
  kselftest/arm64: Add utilities and a test to validate mte memory
  kselftest/arm64: Verify mte tag inclusion via prctl
  kselftest/arm64: Check forked child mte memory accessibility
  kselftest/arm64: Verify all different mmap MTE options
  kselftest/arm64: Verify KSM page merge for MTE pages
  kselftest/arm64: Check mte tagged user address in kernel

 tools/testing/selftests/arm64/Makefile        |   2 +-
 tools/testing/selftests/arm64/mte/.gitignore  |   6 +
 tools/testing/selftests/arm64/mte/Makefile    |  29 ++
 .../selftests/arm64/mte/check_buffer_fill.c   | 475 ++++++++++++++++++
 .../selftests/arm64/mte/check_child_memory.c  | 195 +++++++
 .../selftests/arm64/mte/check_ksm_options.c   | 159 ++++++
 .../selftests/arm64/mte/check_mmap_options.c  | 262 ++++++++++
 .../arm64/mte/check_tags_inclusion.c          | 185 +++++++
 .../selftests/arm64/mte/check_user_mem.c      | 111 ++++
 .../selftests/arm64/mte/mte_common_util.c     | 341 +++++++++++++
 .../selftests/arm64/mte/mte_common_util.h     | 118 +++++
 tools/testing/selftests/arm64/mte/mte_def.h   |  60 +++
 .../testing/selftests/arm64/mte/mte_helper.S  | 128 +++++
 13 files changed, 2070 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/arm64/mte/.gitignore
 create mode 100644 tools/testing/selftests/arm64/mte/Makefile
 create mode 100644 tools/testing/selftests/arm64/mte/check_buffer_fill.c
 create mode 100644 tools/testing/selftests/arm64/mte/check_child_memory.c
 create mode 100644 tools/testing/selftests/arm64/mte/check_ksm_options.c
 create mode 100644 tools/testing/selftests/arm64/mte/check_mmap_options.c
 create mode 100644 tools/testing/selftests/arm64/mte/check_tags_inclusion.c
 create mode 100644 tools/testing/selftests/arm64/mte/check_user_mem.c
 create mode 100644 tools/testing/selftests/arm64/mte/mte_common_util.c
 create mode 100644 tools/testing/selftests/arm64/mte/mte_common_util.h
 create mode 100644 tools/testing/selftests/arm64/mte/mte_def.h
 create mode 100644 tools/testing/selftests/arm64/mte/mte_helper.S

-- 
2.17.1

[PATCH v2 1/6] kselftest/arm64: Add utilities and a test to validate mte memory

[Amit Daniel Kachhap]

This test checks that the memory tag is present after mte allocation and
the memory is accessible with those tags. This testcase verifies all
sync, async and none mte error reporting mode. The allocated mte buffers
are verified for Allocated range (no error expected while accessing
buffer), Underflow range, and Overflow range.

Different test scenarios covered here are,
* Verify that mte memory are accessible at byte/block level.
* Force underflow and overflow to occur and check the data consistency.
* Check to/from between tagged and untagged memory.
* Check that initial allocated memory to have 0 tag.

This change also creates the necessary infrastructure to add mte test
cases. MTE kselftests can use the several utility functions provided here
to add wide variety of mte test scenarios.

GCC compiler need flag '-march=armv8.5-a+memtag' so those flags are
verified before compilation.

The mte testcases can be launched with kselftest framework as,

make TARGETS=arm64 ARM64_SUBTARGETS=mte kselftest

or compiled as,

make -C tools/testing/selftests TARGETS=arm64 ARM64_SUBTARGETS=mte CC='compiler'

Cc: Shuah Khan <shuah@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Co-developed-by: Gabor Kertesz <gabor.kertesz@arm.com>
Signed-off-by: Gabor Kertesz <gabor.kertesz@arm.com>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
---
Changes in v2:
* Redefined MTE kernel header definitions to decouple kselftest compilations.
* Removed gmi masking instructions in mte_insert_random_tag assembly
  function. This simplifies the tag inclusion mask test with only GCR
  mask register used.
* Now use /dev/shm/* to hold temporary tmpfs files.
* Few Code and comment clean-ups.

 tools/testing/selftests/arm64/Makefile        |   2 +-
 tools/testing/selftests/arm64/mte/.gitignore  |   1 +
 tools/testing/selftests/arm64/mte/Makefile    |  29 ++
 .../selftests/arm64/mte/check_buffer_fill.c   | 475 ++++++++++++++++++
 .../selftests/arm64/mte/mte_common_util.c     | 341 +++++++++++++
 .../selftests/arm64/mte/mte_common_util.h     | 117 +++++
 tools/testing/selftests/arm64/mte/mte_def.h   |  60 +++
 .../testing/selftests/arm64/mte/mte_helper.S  | 114 +++++
 8 files changed, 1138 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/arm64/mte/.gitignore
 create mode 100644 tools/testing/selftests/arm64/mte/Makefile
 create mode 100644 tools/testing/selftests/arm64/mte/check_buffer_fill.c
 create mode 100644 tools/testing/selftests/arm64/mte/mte_common_util.c
 create mode 100644 tools/testing/selftests/arm64/mte/mte_common_util.h
 create mode 100644 tools/testing/selftests/arm64/mte/mte_def.h
 create mode 100644 tools/testing/selftests/arm64/mte/mte_helper.S

diff --git a/tools/testing/selftests/arm64/Makefile b/tools/testing/selftests/arm64/Makefile
index 93b567d23c8b..3723d9dea11a 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
+ARM64_SUBTARGETS ?= tags signal mte
 else
 ARM64_SUBTARGETS :=
 endif
diff --git a/tools/testing/selftests/arm64/mte/.gitignore b/tools/testing/selftests/arm64/mte/.gitignore
new file mode 100644
index 000000000000..3f8c1f6c82b9
--- /dev/null
+++ b/tools/testing/selftests/arm64/mte/.gitignore
@@ -0,0 +1 @@
+check_buffer_fill
diff --git a/tools/testing/selftests/arm64/mte/Makefile b/tools/testing/selftests/arm64/mte/Makefile
new file mode 100644
index 000000000000..2480226dfe57
--- /dev/null
+++ b/tools/testing/selftests/arm64/mte/Makefile
@@ -0,0 +1,29 @@
+# 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
diff --git a/tools/testing/selftests/arm64/mte/check_buffer_fill.c b/tools/testing/selftests/arm64/mte/check_buffer_fill.c
new file mode 100644
index 000000000000..242635d79035
--- /dev/null
+++ b/tools/testing/selftests/arm64/mte/check_buffer_fill.c
@@ -0,0 +1,475 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2020 ARM Limited
+
+#define _GNU_SOURCE
+
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "kselftest.h"
+#include "mte_common_util.h"
+#include "mte_def.h"
+
+#define OVERFLOW_RANGE MT_GRANULE_SIZE
+
+static int sizes[] = {
+	1, 555, 1033, MT_GRANULE_SIZE - 1, MT_GRANULE_SIZE,
+	/* page size - 1*/ 0, /* page_size */ 0, /* page size + 1 */ 0
+};
+
+enum mte_block_test_alloc {
+	UNTAGGED_TAGGED,
+	TAGGED_UNTAGGED,
+	TAGGED_TAGGED,
+	BLOCK_ALLOC_MAX,
+};
+
+static int check_buffer_by_byte(int mem_type, int mode)
+{
+	char *ptr;
+	int i, j, item;
+	bool err;
+
+	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
+	item = sizeof(sizes)/sizeof(int);
+
+	for (i = 0; i < item; i++) {
+		ptr = (char *)mte_allocate_memory(sizes[i], mem_type, 0, true);
+		if (check_allocated_memory(ptr, sizes[i], mem_type, true) != KSFT_PASS)
+			return KSFT_FAIL;
+		mte_initialize_current_context(mode, (uintptr_t)ptr, sizes[i]);
+		/* Set some value in tagged memory */
+		for (j = 0; j < sizes[i]; j++)
+			ptr[j] = '1';
+		mte_wait_after_trig();
+		err = cur_mte_cxt.fault_valid;
+		/* Check the buffer whether it is filled. */
+		for (j = 0; j < sizes[i] && !err; j++) {
+			if (ptr[j] != '1')
+				err = true;
+		}
+		mte_free_memory((void *)ptr, sizes[i], mem_type, true);
+
+		if (err)
+			break;
+	}
+	if (!err)
+		return KSFT_PASS;
+	else
+		return KSFT_FAIL;
+}
+
+static int check_buffer_underflow_by_byte(int mem_type, int mode,
+					  int underflow_range)
+{
+	char *ptr;
+	int i, j, item, last_index;
+	bool err;
+	char *und_ptr = NULL;
+
+	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
+	item = sizeof(sizes)/sizeof(int);
+	for (i = 0; i < item; i++) {
+		ptr = (char *)mte_allocate_memory_tag_range(sizes[i], mem_type, 0,
+							    underflow_range, 0);
+		if (check_allocated_memory_range(ptr, sizes[i], mem_type,
+					       underflow_range, 0) != KSFT_PASS)
+			return KSFT_FAIL;
+
+		mte_initialize_current_context(mode, (uintptr_t)ptr, -underflow_range);
+		last_index = 0;
+		/* Set some value in tagged memory and make the buffer underflow */
+		for (j = sizes[i] - 1; (j >= -underflow_range) &&
+				       (cur_mte_cxt.fault_valid == false); j--) {
+			ptr[j] = '1';
+			last_index = j;
+		}
+		mte_wait_after_trig();
+		err = false;
+		/* Check whether the buffer is filled */
+		for (j = 0; j < sizes[i]; j++) {
+			if (ptr[j] != '1') {
+				err = true;
+				ksft_print_msg("Buffer is not filled at index:%d of ptr:0x%lx\n",
+						j, ptr);
+				break;
+			}
+		}
+		if (err)
+			goto check_buffer_underflow_by_byte_err;
+
+		switch (mode) {
+		case MTE_NONE_ERR:
+			if (cur_mte_cxt.fault_valid == true || last_index != -underflow_range) {
+				err = true;
+				break;
+			}
+			/* There were no fault so the underflow area should be filled */
+			und_ptr = (char *) MT_CLEAR_TAG((size_t) ptr - underflow_range);
+			for (j = 0 ; j < underflow_range; j++) {
+				if (und_ptr[j] != '1') {
+					err = true;
+					break;
+				}
+			}
+			break;
+		case MTE_ASYNC_ERR:
+			/* Imprecise fault should occur otherwise return error */
+			if (cur_mte_cxt.fault_valid == false) {
+				err = true;
+				break;
+			}
+			/*
+			 * The imprecise fault is checked after the write to the buffer,
+			 * so the underflow area before the fault should be filled.
+			 */
+			und_ptr = (char *) MT_CLEAR_TAG((size_t) ptr);
+			for (j = last_index ; j < 0 ; j++) {
+				if (und_ptr[j] != '1') {
+					err = true;
+					break;
+				}
+			}
+			break;
+		case MTE_SYNC_ERR:
+			/* Precise fault should occur otherwise return error */
+			if (!cur_mte_cxt.fault_valid || (last_index != (-1))) {
+				err = true;
+				break;
+			}
+			/* Underflow area should not be filled */
+			und_ptr = (char *) MT_CLEAR_TAG((size_t) ptr);
+			if (und_ptr[-1] == '1')
+				err = true;
+			break;
+		default:
+			err = true;
+		break;
+		}
+check_buffer_underflow_by_byte_err:
+		mte_free_memory_tag_range((void *)ptr, sizes[i], mem_type, underflow_range, 0);
+		if (err)
+			break;
+	}
+	return (err ? KSFT_FAIL : KSFT_PASS);
+}
+
+static int check_buffer_overflow_by_byte(int mem_type, int mode,
+					  int overflow_range)
+{
+	char *ptr;
+	int i, j, item, last_index;
+	bool err;
+	size_t tagged_size, overflow_size;
+	char *over_ptr = NULL;
+
+	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
+	item = sizeof(sizes)/sizeof(int);
+	for (i = 0; i < item; i++) {
+		ptr = (char *)mte_allocate_memory_tag_range(sizes[i], mem_type, 0,
+							    0, overflow_range);
+		if (check_allocated_memory_range(ptr, sizes[i], mem_type,
+						 0, overflow_range) != KSFT_PASS)
+			return KSFT_FAIL;
+
+		tagged_size = MT_ALIGN_UP(sizes[i]);
+
+		mte_initialize_current_context(mode, (uintptr_t)ptr, sizes[i] + overflow_range);
+
+		/* Set some value in tagged memory and make the buffer underflow */
+		for (j = 0, last_index = 0 ; (j < (sizes[i] + overflow_range)) &&
+					     (cur_mte_cxt.fault_valid == false); j++) {
+			ptr[j] = '1';
+			last_index = j;
+		}
+		mte_wait_after_trig();
+		err = false;
+		/* Check whether the buffer is filled */
+		for (j = 0; j < sizes[i]; j++) {
+			if (ptr[j] != '1') {
+				err = true;
+				ksft_print_msg("Buffer is not filled at index:%d of ptr:0x%lx\n",
+						j, ptr);
+				break;
+			}
+		}
+		if (err)
+			goto check_buffer_overflow_by_byte_err;
+
+		overflow_size = overflow_range - (tagged_size - sizes[i]);
+
+		switch (mode) {
+		case MTE_NONE_ERR:
+			if ((cur_mte_cxt.fault_valid == true) ||
+			    (last_index != (sizes[i] + overflow_range - 1))) {
+				err = true;
+				break;
+			}
+			/* There were no fault so the overflow area should be filled */
+			over_ptr = (char *) MT_CLEAR_TAG((size_t) ptr + tagged_size);
+			for (j = 0 ; j < overflow_size; j++) {
+				if (over_ptr[j] != '1') {
+					err = true;
+					break;
+				}
+			}
+			break;
+		case MTE_ASYNC_ERR:
+			/* Imprecise fault should occur otherwise return error */
+			if (cur_mte_cxt.fault_valid == false) {
+				err = true;
+				break;
+			}
+			/*
+			 * The imprecise fault is checked after the write to the buffer,
+			 * so the overflow area should be filled before the fault.
+			 */
+			over_ptr = (char *) MT_CLEAR_TAG((size_t) ptr);
+			for (j = tagged_size ; j < last_index; j++) {
+				if (over_ptr[j] != '1') {
+					err = true;
+					break;
+				}
+			}
+			break;
+		case MTE_SYNC_ERR:
+			/* Precise fault should occur otherwise return error */
+			if (!cur_mte_cxt.fault_valid || (last_index != tagged_size)) {
+				err = true;
+				break;
+			}
+			/* Underflow area should not be filled */
+			over_ptr = (char *) MT_CLEAR_TAG((size_t) ptr + tagged_size);
+			for (j = 0 ; j < overflow_size; j++) {
+				if (over_ptr[j] == '1')
+					err = true;
+			}
+			break;
+		default:
+			err = true;
+		break;
+		}
+check_buffer_overflow_by_byte_err:
+		mte_free_memory_tag_range((void *)ptr, sizes[i], mem_type, 0, overflow_range);
+		if (err)
+			break;
+	}
+	return (err ? KSFT_FAIL : KSFT_PASS);
+}
+
+static int check_buffer_by_block_iterate(int mem_type, int mode, size_t size)
+{
+	char *src, *dst;
+	int j, result = KSFT_PASS;
+	enum mte_block_test_alloc alloc_type = UNTAGGED_TAGGED;
+
+	for (alloc_type = UNTAGGED_TAGGED; alloc_type < (int) BLOCK_ALLOC_MAX; alloc_type++) {
+		switch (alloc_type) {
+		case UNTAGGED_TAGGED:
+			src = (char *)mte_allocate_memory(size, mem_type, 0, false);
+			if (check_allocated_memory(src, size, mem_type, false) != KSFT_PASS)
+				return KSFT_FAIL;
+
+			dst = (char *)mte_allocate_memory(size, mem_type, 0, true);
+			if (check_allocated_memory(dst, size, mem_type, true) != KSFT_PASS) {
+				mte_free_memory((void *)src, size, mem_type, false);
+				return KSFT_FAIL;
+			}
+
+			break;
+		case TAGGED_UNTAGGED:
+			dst = (char *)mte_allocate_memory(size, mem_type, 0, false);
+			if (check_allocated_memory(dst, size, mem_type, false) != KSFT_PASS)
+				return KSFT_FAIL;
+
+			src = (char *)mte_allocate_memory(size, mem_type, 0, true);
+			if (check_allocated_memory(src, size, mem_type, true) != KSFT_PASS) {
+				mte_free_memory((void *)dst, size, mem_type, false);
+				return KSFT_FAIL;
+			}
+			break;
+		case TAGGED_TAGGED:
+			src = (char *)mte_allocate_memory(size, mem_type, 0, true);
+			if (check_allocated_memory(src, size, mem_type, true) != KSFT_PASS)
+				return KSFT_FAIL;
+
+			dst = (char *)mte_allocate_memory(size, mem_type, 0, true);
+			if (check_allocated_memory(dst, size, mem_type, true) != KSFT_PASS) {
+				mte_free_memory((void *)src, size, mem_type, true);
+				return KSFT_FAIL;
+			}
+			break;
+		default:
+			return KSFT_FAIL;
+		}
+
+		cur_mte_cxt.fault_valid = false;
+		result = KSFT_PASS;
+		mte_initialize_current_context(mode, (uintptr_t)dst, size);
+		/* Set some value in memory and copy*/
+		memset((void *)src, (int)'1', size);
+		memcpy((void *)dst, (void *)src, size);
+		mte_wait_after_trig();
+		if (cur_mte_cxt.fault_valid) {
+			result = KSFT_FAIL;
+			goto check_buffer_by_block_err;
+		}
+		/* Check the buffer whether it is filled. */
+		for (j = 0; j < size; j++) {
+			if (src[j] != dst[j] || src[j] != '1') {
+				result = KSFT_FAIL;
+				break;
+			}
+		}
+check_buffer_by_block_err:
+		mte_free_memory((void *)src, size, mem_type,
+				MT_FETCH_TAG((uintptr_t)src) ? true : false);
+		mte_free_memory((void *)dst, size, mem_type,
+				MT_FETCH_TAG((uintptr_t)dst) ? true : false);
+		if (result != KSFT_PASS)
+			return result;
+	}
+	return result;
+}
+
+static int check_buffer_by_block(int mem_type, int mode)
+{
+	int i, item, result = KSFT_PASS;
+
+	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
+	item = sizeof(sizes)/sizeof(int);
+	cur_mte_cxt.fault_valid = false;
+	for (i = 0; i < item; i++) {
+		result = check_buffer_by_block_iterate(mem_type, mode, sizes[i]);
+		if (result != KSFT_PASS)
+			break;
+	}
+	return result;
+}
+
+static int compare_memory_tags(char *ptr, size_t size, int tag)
+{
+	int i, new_tag;
+
+	for (i = 0 ; i < size ; i += MT_GRANULE_SIZE) {
+		new_tag = MT_FETCH_TAG((uintptr_t)(mte_get_tag_address(ptr + i)));
+		if (tag != new_tag) {
+			ksft_print_msg("FAIL: child mte tag mismatch\n");
+			return KSFT_FAIL;
+		}
+	}
+	return KSFT_PASS;
+}
+
+static int check_memory_initial_tags(int mem_type, int mode, int mapping)
+{
+	char *ptr;
+	int run, fd;
+	int total = sizeof(sizes)/sizeof(int);
+
+	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
+	for (run = 0; run < total; run++) {
+		/* check initial tags for anonymous mmap */
+		ptr = (char *)mte_allocate_memory(sizes[run], mem_type, mapping, false);
+		if (check_allocated_memory(ptr, sizes[run], mem_type, false) != KSFT_PASS)
+			return KSFT_FAIL;
+		if (compare_memory_tags(ptr, sizes[run], 0) != KSFT_PASS) {
+			mte_free_memory((void *)ptr, sizes[run], mem_type, false);
+			return KSFT_FAIL;
+		}
+		mte_free_memory((void *)ptr, sizes[run], mem_type, false);
+
+		/* check initial tags for file mmap */
+		fd = create_temp_file();
+		if (fd == -1)
+			return KSFT_FAIL;
+		ptr = (char *)mte_allocate_file_memory(sizes[run], mem_type, mapping, false, fd);
+		if (check_allocated_memory(ptr, sizes[run], mem_type, false) != KSFT_PASS) {
+			close(fd);
+			return KSFT_FAIL;
+		}
+		if (compare_memory_tags(ptr, sizes[run], 0) != KSFT_PASS) {
+			mte_free_memory((void *)ptr, sizes[run], mem_type, false);
+			close(fd);
+			return KSFT_FAIL;
+		}
+		mte_free_memory((void *)ptr, sizes[run], mem_type, false);
+		close(fd);
+	}
+	return KSFT_PASS;
+}
+
+int main(int argc, char *argv[])
+{
+	int err;
+	size_t page_size = getpagesize();
+	int item = sizeof(sizes)/sizeof(int);
+
+	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);
+
+	/* Buffer by byte tests */
+	evaluate_test(check_buffer_by_byte(USE_MMAP, MTE_SYNC_ERR),
+	"Check buffer correctness by byte with sync err mode and mmap memory\n");
+	evaluate_test(check_buffer_by_byte(USE_MMAP, MTE_ASYNC_ERR),
+	"Check buffer correctness by byte with async err mode and mmap memory\n");
+	evaluate_test(check_buffer_by_byte(USE_MPROTECT, MTE_SYNC_ERR),
+	"Check buffer correctness by byte with sync err mode and mmap/mprotect memory\n");
+	evaluate_test(check_buffer_by_byte(USE_MPROTECT, MTE_ASYNC_ERR),
+	"Check buffer correctness by byte with async err mode and mmap/mprotect memory\n");
+
+	/* Check buffer underflow with underflow size as 16 */
+	evaluate_test(check_buffer_underflow_by_byte(USE_MMAP, MTE_SYNC_ERR, MT_GRANULE_SIZE),
+	"Check buffer write underflow by byte with sync mode and mmap memory\n");
+	evaluate_test(check_buffer_underflow_by_byte(USE_MMAP, MTE_ASYNC_ERR, MT_GRANULE_SIZE),
+	"Check buffer write underflow by byte with async mode and mmap memory\n");
+	evaluate_test(check_buffer_underflow_by_byte(USE_MMAP, MTE_NONE_ERR, MT_GRANULE_SIZE),
+	"Check buffer write underflow by byte with tag check fault ignore and mmap memory\n");
+
+	/* Check buffer underflow with underflow size as page size */
+	evaluate_test(check_buffer_underflow_by_byte(USE_MMAP, MTE_SYNC_ERR, page_size),
+	"Check buffer write underflow by byte with sync mode and mmap memory\n");
+	evaluate_test(check_buffer_underflow_by_byte(USE_MMAP, MTE_ASYNC_ERR, page_size),
+	"Check buffer write underflow by byte with async mode and mmap memory\n");
+	evaluate_test(check_buffer_underflow_by_byte(USE_MMAP, MTE_NONE_ERR, page_size),
+	"Check buffer write underflow by byte with tag check fault ignore and mmap memory\n");
+
+	/* Check buffer overflow with overflow size as 16 */
+	evaluate_test(check_buffer_overflow_by_byte(USE_MMAP, MTE_SYNC_ERR, MT_GRANULE_SIZE),
+	"Check buffer write overflow by byte with sync mode and mmap memory\n");
+	evaluate_test(check_buffer_overflow_by_byte(USE_MMAP, MTE_ASYNC_ERR, MT_GRANULE_SIZE),
+	"Check buffer write overflow by byte with async mode and mmap memory\n");
+	evaluate_test(check_buffer_overflow_by_byte(USE_MMAP, MTE_NONE_ERR, MT_GRANULE_SIZE),
+	"Check buffer write overflow by byte with tag fault ignore mode and mmap memory\n");
+
+	/* Buffer by block tests */
+	evaluate_test(check_buffer_by_block(USE_MMAP, MTE_SYNC_ERR),
+	"Check buffer write correctness by block with sync mode and mmap memory\n");
+	evaluate_test(check_buffer_by_block(USE_MMAP, MTE_ASYNC_ERR),
+	"Check buffer write correctness by block with async mode and mmap memory\n");
+	evaluate_test(check_buffer_by_block(USE_MMAP, MTE_NONE_ERR),
+	"Check buffer write correctness by block with tag fault ignore and mmap memory\n");
+
+	/* Initial tags are supposed to be 0 */
+	evaluate_test(check_memory_initial_tags(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE),
+	"Check initial tags with private mapping, sync error mode and mmap memory\n");
+	evaluate_test(check_memory_initial_tags(USE_MPROTECT, MTE_SYNC_ERR, MAP_PRIVATE),
+	"Check initial tags with private mapping, sync error mode and mmap/mprotect memory\n");
+	evaluate_test(check_memory_initial_tags(USE_MMAP, MTE_SYNC_ERR, MAP_SHARED),
+	"Check initial tags with shared mapping, sync error mode and mmap memory\n");
+	evaluate_test(check_memory_initial_tags(USE_MPROTECT, MTE_SYNC_ERR, MAP_SHARED),
+	"Check initial tags with shared mapping, sync error mode and mmap/mprotect memory\n");
+
+	mte_restore_setup();
+	ksft_print_cnts();
+	return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL;
+}
diff --git a/tools/testing/selftests/arm64/mte/mte_common_util.c b/tools/testing/selftests/arm64/mte/mte_common_util.c
new file mode 100644
index 000000000000..39f8908988ea
--- /dev/null
+++ b/tools/testing/selftests/arm64/mte/mte_common_util.c
@@ -0,0 +1,341 @@
+// 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;
+}
diff --git a/tools/testing/selftests/arm64/mte/mte_common_util.h b/tools/testing/selftests/arm64/mte/mte_common_util.h
new file mode 100644
index 000000000000..45160e061a0e
--- /dev/null
+++ b/tools/testing/selftests/arm64/mte/mte_common_util.h
@@ -0,0 +1,117 @@
+/* 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_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 */
diff --git a/tools/testing/selftests/arm64/mte/mte_def.h b/tools/testing/selftests/arm64/mte/mte_def.h
new file mode 100644
index 000000000000..9b188254b61a
--- /dev/null
+++ b/tools/testing/selftests/arm64/mte/mte_def.h
@@ -0,0 +1,60 @@
+/* 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)
diff --git a/tools/testing/selftests/arm64/mte/mte_helper.S b/tools/testing/selftests/arm64/mte/mte_helper.S
new file mode 100644
index 000000000000..48e049fbad9a
--- /dev/null
+++ b/tools/testing/selftests/arm64/mte/mte_helper.S
@@ -0,0 +1,114 @@
+/* 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_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)
-- 
2.17.1

[PATCH v2 2/6] kselftest/arm64: Verify mte tag inclusion via prctl

[Amit Daniel Kachhap]

This testcase verifies that the tag generated with "irg" instruction
contains only included tags. This is done via prtcl call.

This test covers 4 scenarios,
* At least one included tag.
* More than one included tags.
* All included.
* None included.

Cc: Shuah Khan <shuah@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Co-developed-by: Gabor Kertesz <gabor.kertesz@arm.com>
Signed-off-by: Gabor Kertesz <gabor.kertesz@arm.com>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
---
Changes in v2:
* Small fix to check all tags in check_multiple_included_tags function.

 tools/testing/selftests/arm64/mte/.gitignore  |   1 +
 .../arm64/mte/check_tags_inclusion.c          | 185 ++++++++++++++++++
 2 files changed, 186 insertions(+)
 create mode 100644 tools/testing/selftests/arm64/mte/check_tags_inclusion.c

diff --git a/tools/testing/selftests/arm64/mte/.gitignore b/tools/testing/selftests/arm64/mte/.gitignore
index 3f8c1f6c82b9..c3fca255d3d6 100644
--- a/tools/testing/selftests/arm64/mte/.gitignore
+++ b/tools/testing/selftests/arm64/mte/.gitignore
@@ -1 +1,2 @@
 check_buffer_fill
+check_tags_inclusion
diff --git a/tools/testing/selftests/arm64/mte/check_tags_inclusion.c b/tools/testing/selftests/arm64/mte/check_tags_inclusion.c
new file mode 100644
index 000000000000..94d245a0ed56
--- /dev/null
+++ b/tools/testing/selftests/arm64/mte/check_tags_inclusion.c
@@ -0,0 +1,185 @@
+// 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;
+}
-- 
2.17.1

[PATCH v2 3/6] kselftest/arm64: Check forked child mte memory accessibility

[Amit Daniel Kachhap]

This test covers the mte memory behaviour of the forked process with
different mapping properties and flags. It checks that all bytes of
forked child memory are accessible with the same tag as that of the
parent and memory accessed outside the tag range causes fault to
occur.

Cc: Shuah Khan <shuah@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Co-developed-by: Gabor Kertesz <gabor.kertesz@arm.com>
Signed-off-by: Gabor Kertesz <gabor.kertesz@arm.com>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
---
 tools/testing/selftests/arm64/mte/.gitignore  |   1 +
 .../selftests/arm64/mte/check_child_memory.c  | 195 ++++++++++++++++++
 2 files changed, 196 insertions(+)
 create mode 100644 tools/testing/selftests/arm64/mte/check_child_memory.c

diff --git a/tools/testing/selftests/arm64/mte/.gitignore b/tools/testing/selftests/arm64/mte/.gitignore
index c3fca255d3d6..b5fcc0fb4d97 100644
--- a/tools/testing/selftests/arm64/mte/.gitignore
+++ b/tools/testing/selftests/arm64/mte/.gitignore
@@ -1,2 +1,3 @@
 check_buffer_fill
 check_tags_inclusion
+check_child_memory
diff --git a/tools/testing/selftests/arm64/mte/check_child_memory.c b/tools/testing/selftests/arm64/mte/check_child_memory.c
new file mode 100644
index 000000000000..97bebdecd29e
--- /dev/null
+++ b/tools/testing/selftests/arm64/mte/check_child_memory.c
@@ -0,0 +1,195 @@
+// 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;
+}
-- 
2.17.1

[PATCH v2 4/6] kselftest/arm64: Verify all different mmap MTE options

[Amit Daniel Kachhap]

This testcase checks the different unsupported/supported options for mmap
if used with PROT_MTE memory protection flag. These checks are,

* Either pstate.tco enable or prctl PR_MTE_TCF_NONE option should not cause
  any tag mismatch faults.
* Different combinations of anonymous/file memory mmap, mprotect,
  sync/async error mode and private/shared mappings should work.
* mprotect should not be able to clear the PROT_MTE page property.

Cc: Shuah Khan <shuah@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Co-developed-by: Gabor Kertesz <gabor.kertesz@arm.com>
Signed-off-by: Gabor Kertesz <gabor.kertesz@arm.com>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
---
 tools/testing/selftests/arm64/mte/.gitignore  |   1 +
 .../selftests/arm64/mte/check_mmap_options.c  | 262 ++++++++++++++++++
 2 files changed, 263 insertions(+)
 create mode 100644 tools/testing/selftests/arm64/mte/check_mmap_options.c

diff --git a/tools/testing/selftests/arm64/mte/.gitignore b/tools/testing/selftests/arm64/mte/.gitignore
index b5fcc0fb4d97..79a215d3bbd0 100644
--- a/tools/testing/selftests/arm64/mte/.gitignore
+++ b/tools/testing/selftests/arm64/mte/.gitignore
@@ -1,3 +1,4 @@
 check_buffer_fill
 check_tags_inclusion
 check_child_memory
+check_mmap_options
diff --git a/tools/testing/selftests/arm64/mte/check_mmap_options.c b/tools/testing/selftests/arm64/mte/check_mmap_options.c
new file mode 100644
index 000000000000..33b13b86199b
--- /dev/null
+++ b/tools/testing/selftests/arm64/mte/check_mmap_options.c
@@ -0,0 +1,262 @@
+// 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 <sys/stat.h>
+#include <sys/types.h>
+
+#include "kselftest.h"
+#include "mte_common_util.h"
+#include "mte_def.h"
+
+#define RUNS			(MT_TAG_COUNT)
+#define UNDERFLOW		MT_GRANULE_SIZE
+#define OVERFLOW		MT_GRANULE_SIZE
+#define TAG_CHECK_ON		0
+#define TAG_CHECK_OFF		1
+
+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_mte_memory(char *ptr, int size, int mode, int tag_check)
+{
+	mte_initialize_current_context(mode, (uintptr_t)ptr, size);
+	memset(ptr, '1', size);
+	mte_wait_after_trig();
+	if (cur_mte_cxt.fault_valid == true)
+		return KSFT_FAIL;
+
+	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 && tag_check == TAG_CHECK_ON)
+		return KSFT_FAIL;
+	if (cur_mte_cxt.fault_valid == true && tag_check == TAG_CHECK_OFF)
+		return KSFT_FAIL;
+
+	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 && tag_check == TAG_CHECK_ON)
+		return KSFT_FAIL;
+	if (cur_mte_cxt.fault_valid == true && tag_check == TAG_CHECK_OFF)
+		return KSFT_FAIL;
+
+	return KSFT_PASS;
+}
+
+static int check_anonymous_memory_mapping(int mem_type, int mode, int mapping, int tag_check)
+{
+	char *ptr, *map_ptr;
+	int run, result, map_size;
+	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++) {
+		map_size = sizes[run] + OVERFLOW + UNDERFLOW;
+		map_ptr = (char *)mte_allocate_memory(map_size, mem_type, mapping, false);
+		if (check_allocated_memory(map_ptr, map_size, mem_type, false) != KSFT_PASS)
+			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 anonymous mmap memory\n");
+			munmap((void *)map_ptr, map_size);
+			return KSFT_FAIL;
+		}
+		result = check_mte_memory(ptr, sizes[run], mode, tag_check);
+		mte_clear_tags((void *)ptr, sizes[run]);
+		mte_free_memory((void *)map_ptr, map_size, mem_type, false);
+		if (result == KSFT_FAIL)
+			return KSFT_FAIL;
+	}
+	return KSFT_PASS;
+}
+
+static int check_file_memory_mapping(int mem_type, int mode, int mapping, int tag_check)
+{
+	char *ptr, *map_ptr;
+	int run, fd, map_size;
+	int total = sizeof(sizes)/sizeof(int);
+	int result = KSFT_PASS;
+
+	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] + UNDERFLOW + OVERFLOW;
+		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_mte_memory(ptr, sizes[run], mode, tag_check);
+		mte_clear_tags((void *)ptr, sizes[run]);
+		munmap((void *)map_ptr, map_size);
+		close(fd);
+		if (result == KSFT_FAIL)
+			break;
+	}
+	return result;
+}
+
+static int check_clear_prot_mte_flag(int mem_type, int mode, int mapping)
+{
+	char *ptr, *map_ptr;
+	int run, prot_flag, result, fd, map_size;
+	int total = sizeof(sizes)/sizeof(int);
+
+	prot_flag = PROT_READ | PROT_WRITE;
+	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
+	for (run = 0; run < total; run++) {
+		map_size = sizes[run] + OVERFLOW + UNDERFLOW;
+		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;
+		map_ptr = ptr - UNDERFLOW;
+		/* Try to clear PROT_MTE property and verify it by tag checking */
+		if (mprotect(map_ptr, map_size, prot_flag)) {
+			mte_free_memory_tag_range((void *)ptr, sizes[run], mem_type,
+						  UNDERFLOW, OVERFLOW);
+			ksft_print_msg("FAIL: mprotect not ignoring clear PROT_MTE property\n");
+			return KSFT_FAIL;
+		}
+		result = check_mte_memory(ptr, sizes[run], mode, TAG_CHECK_ON);
+		mte_free_memory_tag_range((void *)ptr, sizes[run], mem_type, UNDERFLOW, OVERFLOW);
+		if (result != KSFT_PASS)
+			return KSFT_FAIL;
+
+		fd = create_temp_file();
+		if (fd == -1)
+			return KSFT_FAIL;
+		ptr = (char *)mte_allocate_file_memory_tag_range(sizes[run], mem_type, mapping,
+								 UNDERFLOW, OVERFLOW, fd);
+		if (check_allocated_memory_range(ptr, sizes[run], mem_type,
+						 UNDERFLOW, OVERFLOW) != KSFT_PASS) {
+			close(fd);
+			return KSFT_FAIL;
+		}
+		map_ptr = ptr - UNDERFLOW;
+		/* Try to clear PROT_MTE property and verify it by tag checking */
+		if (mprotect(map_ptr, map_size, prot_flag)) {
+			ksft_print_msg("FAIL: mprotect not ignoring clear PROT_MTE property\n");
+			mte_free_memory_tag_range((void *)ptr, sizes[run], mem_type,
+						  UNDERFLOW, OVERFLOW);
+			close(fd);
+			return KSFT_FAIL;
+		}
+		result = check_mte_memory(ptr, sizes[run], mode, TAG_CHECK_ON);
+		mte_free_memory_tag_range((void *)ptr, sizes[run], mem_type, UNDERFLOW, OVERFLOW);
+		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);
+
+	err = mte_default_setup();
+	if (err)
+		return err;
+	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;
+
+	/* Register signal handlers */
+	mte_register_signal(SIGBUS, mte_default_handler);
+	mte_register_signal(SIGSEGV, mte_default_handler);
+
+	mte_enable_pstate_tco();
+	evaluate_test(check_anonymous_memory_mapping(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE, TAG_CHECK_OFF),
+	"Check anonymous memory with private mapping, sync error mode, mmap memory and tag check off\n");
+	evaluate_test(check_file_memory_mapping(USE_MPROTECT, MTE_SYNC_ERR, MAP_PRIVATE, TAG_CHECK_OFF),
+	"Check file memory with private mapping, sync error mode, mmap/mprotect memory and tag check off\n");
+
+	mte_disable_pstate_tco();
+	evaluate_test(check_anonymous_memory_mapping(USE_MMAP, MTE_NONE_ERR, MAP_PRIVATE, TAG_CHECK_OFF),
+	"Check anonymous memory with private mapping, no error mode, mmap memory and tag check off\n");
+	evaluate_test(check_file_memory_mapping(USE_MPROTECT, MTE_NONE_ERR, MAP_PRIVATE, TAG_CHECK_OFF),
+	"Check file memory with private mapping, no error mode, mmap/mprotect memory and tag check off\n");
+
+	evaluate_test(check_anonymous_memory_mapping(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE, TAG_CHECK_ON),
+	"Check anonymous memory with private mapping, sync error mode, mmap memory and tag check on\n");
+	evaluate_test(check_anonymous_memory_mapping(USE_MPROTECT, MTE_SYNC_ERR, MAP_PRIVATE, TAG_CHECK_ON),
+	"Check anonymous memory with private mapping, sync error mode, mmap/mprotect memory and tag check on\n");
+	evaluate_test(check_anonymous_memory_mapping(USE_MMAP, MTE_SYNC_ERR, MAP_SHARED, TAG_CHECK_ON),
+	"Check anonymous memory with shared mapping, sync error mode, mmap memory and tag check on\n");
+	evaluate_test(check_anonymous_memory_mapping(USE_MPROTECT, MTE_SYNC_ERR, MAP_SHARED, TAG_CHECK_ON),
+	"Check anonymous memory with shared mapping, sync error mode, mmap/mprotect memory and tag check on\n");
+	evaluate_test(check_anonymous_memory_mapping(USE_MMAP, MTE_ASYNC_ERR, MAP_PRIVATE, TAG_CHECK_ON),
+	"Check anonymous memory with private mapping, async error mode, mmap memory and tag check on\n");
+	evaluate_test(check_anonymous_memory_mapping(USE_MPROTECT, MTE_ASYNC_ERR, MAP_PRIVATE, TAG_CHECK_ON),
+	"Check anonymous memory with private mapping, async error mode, mmap/mprotect memory and tag check on\n");
+	evaluate_test(check_anonymous_memory_mapping(USE_MMAP, MTE_ASYNC_ERR, MAP_SHARED, TAG_CHECK_ON),
+	"Check anonymous memory with shared mapping, async error mode, mmap memory and tag check on\n");
+	evaluate_test(check_anonymous_memory_mapping(USE_MPROTECT, MTE_ASYNC_ERR, MAP_SHARED, TAG_CHECK_ON),
+	"Check anonymous memory with shared mapping, async error mode, mmap/mprotect memory and tag check on\n");
+
+	evaluate_test(check_file_memory_mapping(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE, TAG_CHECK_ON),
+	"Check file memory with private mapping, sync error mode, mmap memory and tag check on\n");
+	evaluate_test(check_file_memory_mapping(USE_MPROTECT, MTE_SYNC_ERR, MAP_PRIVATE, TAG_CHECK_ON),
+	"Check file memory with private mapping, sync error mode, mmap/mprotect memory and tag check on\n");
+	evaluate_test(check_file_memory_mapping(USE_MMAP, MTE_SYNC_ERR, MAP_SHARED, TAG_CHECK_ON),
+	"Check file memory with shared mapping, sync error mode, mmap memory and tag check on\n");
+	evaluate_test(check_file_memory_mapping(USE_MPROTECT, MTE_SYNC_ERR, MAP_SHARED, TAG_CHECK_ON),
+	"Check file memory with shared mapping, sync error mode, mmap/mprotect memory and tag check on\n");
+	evaluate_test(check_file_memory_mapping(USE_MMAP, MTE_ASYNC_ERR, MAP_PRIVATE, TAG_CHECK_ON),
+	"Check file memory with private mapping, async error mode, mmap memory and tag check on\n");
+	evaluate_test(check_file_memory_mapping(USE_MPROTECT, MTE_ASYNC_ERR, MAP_PRIVATE, TAG_CHECK_ON),
+	"Check file memory with private mapping, async error mode, mmap/mprotect memory and tag check on\n");
+	evaluate_test(check_file_memory_mapping(USE_MMAP, MTE_ASYNC_ERR, MAP_SHARED, TAG_CHECK_ON),
+	"Check file memory with shared mapping, async error mode, mmap memory and tag check on\n");
+	evaluate_test(check_file_memory_mapping(USE_MPROTECT, MTE_ASYNC_ERR, MAP_SHARED, TAG_CHECK_ON),
+	"Check file memory with shared mapping, async error mode, mmap/mprotect memory and tag check on\n");
+
+	evaluate_test(check_clear_prot_mte_flag(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE),
+	"Check clear PROT_MTE flags with private mapping, sync error mode and mmap memory\n");
+	evaluate_test(check_clear_prot_mte_flag(USE_MPROTECT, MTE_SYNC_ERR, MAP_PRIVATE),
+	"Check clear PROT_MTE flags with private mapping and sync error mode and mmap/mprotect memory\n");
+
+	mte_restore_setup();
+	ksft_print_cnts();
+	return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL;
+}
-- 
2.17.1

[PATCH v2 5/6] kselftest/arm64: Verify KSM page merge for MTE pages

[Amit Daniel Kachhap]

Add a testcase to check that KSM should not merge pages containing
same data with same/different MTE tag values.

This testcase has one positive tests and passes if page merging
happens according to the above rule. It also saves and restores
any modified ksm sysfs entries.

Cc: Shuah Khan <shuah@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
---
Changes in v2:
* Moved read/write sysfs functions from global to local functions.

 tools/testing/selftests/arm64/mte/.gitignore  |   1 +
 .../selftests/arm64/mte/check_ksm_options.c   | 159 ++++++++++++++++++
 2 files changed, 160 insertions(+)
 create mode 100644 tools/testing/selftests/arm64/mte/check_ksm_options.c

diff --git a/tools/testing/selftests/arm64/mte/.gitignore b/tools/testing/selftests/arm64/mte/.gitignore
index 79a215d3bbd0..44e9bfdaeca6 100644
--- a/tools/testing/selftests/arm64/mte/.gitignore
+++ b/tools/testing/selftests/arm64/mte/.gitignore
@@ -2,3 +2,4 @@ check_buffer_fill
 check_tags_inclusion
 check_child_memory
 check_mmap_options
+check_ksm_options
diff --git a/tools/testing/selftests/arm64/mte/check_ksm_options.c b/tools/testing/selftests/arm64/mte/check_ksm_options.c
new file mode 100644
index 000000000000..bc41ae630c86
--- /dev/null
+++ b/tools/testing/selftests/arm64/mte/check_ksm_options.c
@@ -0,0 +1,159 @@
+// 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;
+}
-- 
2.17.1

[PATCH v2 6/6] kselftest/arm64: Check mte tagged user address in kernel

[Amit Daniel Kachhap]

Add a testcase to check that user address with valid/invalid
mte tag works in kernel mode. This test verifies that the kernel
API's __arch_copy_from_user/__arch_copy_to_user works by considering
if the user pointer has valid/invalid allocation tags.

In MTE sync mode, file memory read/write and other similar interfaces
fails if a user memory with invalid tag is accessed in kernel. In async
mode no such failure occurs.

Cc: Shuah Khan <shuah@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
---
Changes in v2:
* Updated the test to handle the error properly in case of failure
  in accessing memory with invalid tag in kernel. errno check is not
  done now and read length checks are sufficient.

 tools/testing/selftests/arm64/mte/.gitignore  |   1 +
 .../selftests/arm64/mte/check_user_mem.c      | 111 ++++++++++++++++++
 .../selftests/arm64/mte/mte_common_util.h     |   1 +
 .../testing/selftests/arm64/mte/mte_helper.S  |  14 +++
 4 files changed, 127 insertions(+)
 create mode 100644 tools/testing/selftests/arm64/mte/check_user_mem.c

diff --git a/tools/testing/selftests/arm64/mte/.gitignore b/tools/testing/selftests/arm64/mte/.gitignore
index 44e9bfdaeca6..bc3ac63f3314 100644
--- a/tools/testing/selftests/arm64/mte/.gitignore
+++ b/tools/testing/selftests/arm64/mte/.gitignore
@@ -3,3 +3,4 @@ check_tags_inclusion
 check_child_memory
 check_mmap_options
 check_ksm_options
+check_user_mem
diff --git a/tools/testing/selftests/arm64/mte/check_user_mem.c b/tools/testing/selftests/arm64/mte/check_user_mem.c
new file mode 100644
index 000000000000..594e98e76880
--- /dev/null
+++ b/tools/testing/selftests/arm64/mte/check_user_mem.c
@@ -0,0 +1,111 @@
+// 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;
+}
diff --git a/tools/testing/selftests/arm64/mte/mte_common_util.h b/tools/testing/selftests/arm64/mte/mte_common_util.h
index 45160e061a0e..195a7d1879e6 100644
--- a/tools/testing/selftests/arm64/mte/mte_common_util.h
+++ b/tools/testing/selftests/arm64/mte/mte_common_util.h
@@ -64,6 +64,7 @@ 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);
diff --git a/tools/testing/selftests/arm64/mte/mte_helper.S b/tools/testing/selftests/arm64/mte/mte_helper.S
index 48e049fbad9a..a02c04cd0aac 100644
--- a/tools/testing/selftests/arm64/mte/mte_helper.S
+++ b/tools/testing/selftests/arm64/mte/mte_helper.S
@@ -26,6 +26,20 @@ ENTRY(mte_insert_random_tag)
 	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:
-- 
2.17.1

Re: [PATCH v2 0/6] kselftest: arm64/mte: Tests for user-space MTE

[Catalin Marinas]

On Fri, Oct 02, 2020 at 05:26:24PM +0530, Amit Daniel Kachhap wrote:
> Amit Daniel Kachhap (6):
>   kselftest/arm64: Add utilities and a test to validate mte memory
>   kselftest/arm64: Verify mte tag inclusion via prctl
>   kselftest/arm64: Check forked child mte memory accessibility
>   kselftest/arm64: Verify all different mmap MTE options
>   kselftest/arm64: Verify KSM page merge for MTE pages
>   kselftest/arm64: Check mte tagged user address in kernel

Thanks Amit for respinning the series. Tested on FVP (some Qemu bugs get
in the way and they fail).

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>

Re: [PATCH v2 0/6] kselftest: arm64/mte: Tests for user-space MTE

[Will Deacon]

On Fri, 2 Oct 2020 17:26:24 +0530, Amit Daniel Kachhap wrote:
> These patch series adds below kselftests to test the user-space support for the
> ARMv8.5 Memory Tagging Extension present in arm64 tree [1]. This patch
> series is based on Linux v5.9-rc3.
> 
> 1) This test-case verifies that the memory allocated by kernel mmap interface
> can support tagged memory access. It first checks the presence of tags at
> address[56:59] and then proceeds with read and write. The pass criteria for
> this test is that tag fault exception should not happen.
> 
> [...]

Applied to arm64 (for-next/late-arrivals), thanks!

[1/6] kselftest/arm64: Add utilities and a test to validate mte memory
      https://git.kernel.org/arm64/c/e9b60476bea0
[2/6] kselftest/arm64: Verify mte tag inclusion via prctl
      https://git.kernel.org/arm64/c/f3b2a26ca78d
[3/6] kselftest/arm64: Check forked child mte memory accessibility
      https://git.kernel.org/arm64/c/dfe537cf4718
[4/6] kselftest/arm64: Verify all different mmap MTE options
      https://git.kernel.org/arm64/c/53ec81d23213
[5/6] kselftest/arm64: Verify KSM page merge for MTE pages
      https://git.kernel.org/arm64/c/f981d8fa2646
[6/6] kselftest/arm64: Check mte tagged user address in kernel
      https://git.kernel.org/arm64/c/4dafc08d0ba4

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev