path: root/arch/arm64/include/uapi/asm/ptrace.h
diff options
authorJames Morse <james.morse@arm.com>2016-02-05 14:58:48 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2016-02-18 17:27:04 +0000
commit57f4959bad0a154aeca125b7d38d1d9471a12422 (patch)
tree6d75f86840bb0bd2d3f4928993f696c44e2033c0 /arch/arm64/include/uapi/asm/ptrace.h
parentarm64: add ARMv8.2 id_aa64mmfr2 boiler plate (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>
Diffstat (limited to '')
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm64/include/uapi/asm/ptrace.h b/arch/arm64/include/uapi/asm/ptrace.h
index 208db3df135a..b5c3933ed441 100644
--- a/arch/arm64/include/uapi/asm/ptrace.h
+++ b/arch/arm64/include/uapi/asm/ptrace.h
@@ -45,6 +45,7 @@
#define PSR_A_BIT 0x00000100
#define PSR_D_BIT 0x00000200
#define PSR_PAN_BIT 0x00400000
+#define PSR_UAO_BIT 0x00800000
#define PSR_Q_BIT 0x08000000
#define PSR_V_BIT 0x10000000
#define PSR_C_BIT 0x20000000