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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/lib
parentarm64: add ARMv8.2 id_aa64mmfr2 boiler plate (diff)
downloadlinux-dev-57f4959bad0a154aeca125b7d38d1d9471a12422.tar.xz
linux-dev-57f4959bad0a154aeca125b7d38d1d9471a12422.zip
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 '')
-rw-r--r--arch/arm64/lib/clear_user.S8
-rw-r--r--arch/arm64/lib/copy_from_user.S8
-rw-r--r--arch/arm64/lib/copy_in_user.S16
-rw-r--r--arch/arm64/lib/copy_to_user.S8
4 files changed, 20 insertions, 20 deletions
diff --git a/arch/arm64/lib/clear_user.S b/arch/arm64/lib/clear_user.S
index a9723c71c52b..3f950b677c07 100644
--- a/arch/arm64/lib/clear_user.S
+++ b/arch/arm64/lib/clear_user.S
@@ -39,20 +39,20 @@ ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_HAS_PAN, \
subs x1, x1, #8
b.mi 2f
1:
-USER(9f, str xzr, [x0], #8 )
+uao_user_alternative 9f, str, sttr, xzr, x0, 8
subs x1, x1, #8
b.pl 1b
2: adds x1, x1, #4
b.mi 3f
-USER(9f, str wzr, [x0], #4 )
+uao_user_alternative 9f, str, sttr, wzr, x0, 4
sub x1, x1, #4
3: adds x1, x1, #2
b.mi 4f
-USER(9f, strh wzr, [x0], #2 )
+uao_user_alternative 9f, strh, sttrh, wzr, x0, 2
sub x1, x1, #2
4: adds x1, x1, #1
b.mi 5f
-USER(9f, strb wzr, [x0] )
+uao_user_alternative 9f, strb, sttrb, wzr, x0, 0
5: mov x0, #0
ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_HAS_PAN, \
CONFIG_ARM64_PAN)
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
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
diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S
index 7512bbbc07ac..2dae2cd2c481 100644
--- a/arch/arm64/lib/copy_to_user.S
+++ b/arch/arm64/lib/copy_to_user.S
@@ -37,7 +37,7 @@
.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
@@ -45,7 +45,7 @@
.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
@@ -53,7 +53,7 @@
.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
@@ -61,7 +61,7 @@
.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