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| author | Catalin Marinas <catalin.marinas@arm.com> | 2022-04-23 11:07:50 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2022-04-25 10:25:43 +0100 |
| commit | f3ba50a7a100e91b0b13ca43190a66c1bfdb9993 (patch) | |
| tree | 99884d8d9b030537a94d99d2646a8f5ec618864d /arch/arm64/Kconfig | |
| parent | da32b5817253697671af961715517bfbb308a592 (diff) | |
| download | linux-f3ba50a7a100e91b0b13ca43190a66c1bfdb9993.tar.gz | |
arm64: Add support for user sub-page fault probing
With MTE, even if the pte allows an access, a mismatched tag somewhere
within a page can still cause a fault. Select ARCH_HAS_SUBPAGE_FAULTS if
MTE is enabled and implement the probe_subpage_writeable() function.
Note that get_user() is sufficient for the writeable MTE check since the
same tag mismatch fault would be triggered by a read. The caller of
probe_subpage_writeable() will need to check the pte permissions
(put_user, GUP).
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220423100751.1870771-3-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/Kconfig')
| -rw-r--r-- | arch/arm64/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 57c4c995965f..290b88238103 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1871,6 +1871,7 @@ config ARM64_MTE depends on AS_HAS_LSE_ATOMICS # Required for tag checking in the uaccess routines depends on ARM64_PAN + select ARCH_HAS_SUBPAGE_FAULTS select ARCH_USES_HIGH_VMA_FLAGS help Memory Tagging (part of the ARMv8.5 Extensions) provides |