kselftest/arm64: mte: user_mem: test a wider range of values

Instead of hard coding a small amount of tests, generate a wider
range of tests to try catch any corner cases that could show up.

These new tests test different MTE tag lengths and offsets, which
previously would have caused infinite loops in the kernel. This was
fixed by 295cf156231c ("arm64: Avoid premature usercopy failure"),
so these are regressions tests for that corner case.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220209152240.52788-7-joey.gouly@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

kselftest/arm64: mte: user_mem: add more test types

To expand the test coverage for MTE tags in userspace memory,
also perform the test with `write`, `readv` and `writev` syscalls.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220209152240.52788-6-joey.gouly@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

kselftest/arm64: mte: user_mem: add test type enum

The test is currently hardcoded to use the `read` syscall, this commit adds
a test_type enum to support expanding the test coverage to other syscalls.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220209152240.52788-5-joey.gouly@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

kselftest/arm64: mte: user_mem: check different offsets and sizes

To check there are no assumptions in the kernel about buffer sizes or alignments of
user space pointers, expand the test to cover different sizes and offsets.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220209152240.52788-4-joey.gouly@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

kselftest/arm64: mte: user_mem: rework error handling

Future commits will have multiple iterations of tests in this function,
so make the error handling assume it will pass and then bail out if there
is an error.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220209152240.52788-3-joey.gouly@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

kselftest/arm64: mte: user_mem: introduce tag_offset and tag_len

These can be used to place an MTE tag at an address that is not at a
page size boundary.

The kernel prior to 295cf156231c ("arm64: Avoid premature usercopy failure"),
would infinite loop if an MTE tag was placed not at a PAGE_SIZE boundary.
This is because the kernel checked if the pages were readable by checking the
first byte of each page, but would then fault in the middle of the page due
to the MTE tag.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220209152240.52788-2-joey.gouly@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

kselftest/arm64: mte: user_mem: Fix write() warning

Out of the box Ubuntu's 20.04 compiler warns about missing return value
checks for write() (sys)calls.

Make GCC happy by checking whether we actually managed to write "val".

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Mark Brown <broone@kernel.org>
Link: https://lore.kernel.org/r/20210319165334.29213-5-andre.przywara@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kselftest/arm64: Fix check_user_mem test

The check_user_mem test reports the error below because the test
plan is not declared correctly:

# Planned tests != run tests (0 != 4)

Fix the test adding the correct test plan declaration.

Fixes: 4dafc08d0ba4 ("kselftest/arm64: Check mte tagged user address in kernel")
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Gabor Kertesz <gabor.kertesz@arm.com>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Link: https://lore.kernel.org/r/20201026121248.2340-7-vincenzo.frascino@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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>