kselftest/arm64: Check mte tagged user address in kernel

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.

Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201002115630.24683-7-amit.kachhap@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 1 insertions, 0 deletions

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);