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| author | James Morse <james.morse@arm.com> | 2016-02-05 17:58:48 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2016-02-18 20:27:04 +0300 |
| commit | 57f4959bad0a154aeca125b7d38d1d9471a12422 (patch) | |
| tree | 6d75f86840bb0bd2d3f4928993f696c44e2033c0 /arch/arm64/lib/copy_from_user.S | |
| parent | 406e308770a92bd33995b2e5b681e86358328bb0 (diff) | |
| download | linux-57f4959bad0a154aeca125b7d38d1d9471a12422.tar.xz | |
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>
Diffstat (limited to 'arch/arm64/lib/copy_from_user.S')
| -rw-r--r-- | arch/arm64/lib/copy_from_user.S | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S index 4699cd74f87e..1d982d64f1a7 100644 --- a/arch/arm64/lib/copy_from_user.S +++ b/arch/arm64/lib/copy_from_user.S @@ -34,7 +34,7 @@ */ .macro ldrb1 ptr, regB, val - USER(9998f, ldrb \ptr, [\regB], \val) + uao_user_alternative 9998f, ldrb, ldtrb, \ptr, \regB, \val .endm .macro strb1 ptr, regB, val @@ -42,7 +42,7 @@ .endm .macro ldrh1 ptr, regB, val - USER(9998f, ldrh \ptr, [\regB], \val) + uao_user_alternative 9998f, ldrh, ldtrh, \ptr, \regB, \val .endm .macro strh1 ptr, regB, val @@ -50,7 +50,7 @@ .endm .macro ldr1 ptr, regB, val - USER(9998f, ldr \ptr, [\regB], \val) + uao_user_alternative 9998f, ldr, ldtr, \ptr, \regB, \val .endm .macro str1 ptr, regB, val @@ -58,7 +58,7 @@ .endm .macro ldp1 ptr, regB, regC, val - USER(9998f, ldp \ptr, \regB, [\regC], \val) + uao_ldp 9998f, \ptr, \regB, \regC, \val .endm .macro stp1 ptr, regB, regC, val |