From 57f4959bad0a154aeca125b7d38d1d9471a12422 Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 5 Feb 2016 14:58:48 +0000 Subject: 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 [catalin.marinas@arm.com: move uao_thread_switch() above dsb()] Signed-off-by: Catalin Marinas --- arch/arm64/lib/copy_in_user.S | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'arch/arm64/lib/copy_in_user.S') diff --git a/arch/arm64/lib/copy_in_user.S b/arch/arm64/lib/copy_in_user.S index 81c8fc93c100..feaad1520dc1 100644 --- a/arch/arm64/lib/copy_in_user.S +++ b/arch/arm64/lib/copy_in_user.S @@ -35,35 +35,35 @@ * x0 - bytes not copied */ .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 - USER(9998f, strb \ptr, [\regB], \val) + uao_user_alternative 9998f, strb, sttrb, \ptr, \regB, \val .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 - USER(9998f, strh \ptr, [\regB], \val) + uao_user_alternative 9998f, strh, sttrh, \ptr, \regB, \val .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 - USER(9998f, str \ptr, [\regB], \val) + uao_user_alternative 9998f, str, sttr, \ptr, \regB, \val .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 - USER(9998f, stp \ptr, \regB, [\regC], \val) + uao_stp 9998f, \ptr, \regB, \regC, \val .endm end .req x5 -- cgit v1.2.3