diff options
| author | James Morse <james.morse@arm.com> | 2016-02-05 14:58:48 +0000 |
|---|---|---|
| committer | Alex Shi <alex.shi@linaro.org> | 2016-05-11 22:19:23 +0800 |
| commit | 13e05550e107e46ef982e5c4347e4986aeeee7ec (patch) | |
| tree | 6e1f5c028f590ded69239fffe1285e2d93b1f3f1 /arch/arm64/include/asm/processor.h | |
| parent | f6c5d808273093c8220da4163c548932d18e8e36 (diff) | |
arm64: kernel: Add support for User Access Override
'User Access Override' is a new ARMv8.2 feature which allows the
unprivileged load and store instructions to be overridden to behave in
the normal way.
This patch converts {get,put}_user() and friends to use ldtr*/sttr*
instructions - so that they can only access EL0 memory, then enables
UAO when fs==KERNEL_DS so that these functions can access kernel memory.
This allows user space's read/write permissions to be checked against the
page tables, instead of testing addr<USER_DS, then using the kernel's
read/write permissions.
Signed-off-by: James Morse <james.morse@arm.com>
[catalin.marinas@arm.com: move uao_thread_switch() above dsb()]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 57f4959bad0a154aeca125b7d38d1d9471a12422)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Diffstat (limited to 'arch/arm64/include/asm/processor.h')
| -rw-r--r-- | arch/arm64/include/asm/processor.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index 5bb1d763d17a..cef1cf398356 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -191,5 +191,6 @@ static inline void spin_lock_prefetch(const void *ptr) #endif void cpu_enable_pan(void *__unused); +void cpu_enable_uao(void *__unused); #endif /* __ASM_PROCESSOR_H */ |