[PATCH v3 1/6] kselftest/arm64: mte: user_mem: introduce tag_offset and tag_len

[Catalin Marinas]

On Wed, Feb 09, 2022 at 03:22:35PM +0000, Joey Gouly wrote:
> 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 at arm.com>
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Will Deacon <will at kernel.org>
> Cc: Mark Brown <broonie at kernel.org>
> Cc: Shuah Khan <shuah at kernel.org>
> Reviewed-by: Mark Brown <broonie at kernel.org>
> Tested-by: Mark Brown <broonie at kernel.org>
> Reviewed-by: Shuah Khan <skhan at linuxfoundation.org>

Reviewed-by: Catalin Marinas <catalin.marinas at arm.com>