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ARM: 6384/1: Remove the domain switching on ARMv6k/v7 CPUs

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This patch removes the domain switching functionality via the set_fs and
__switch_to functions on cores that have a TLS register.

Currently, the ioremap and vmalloc areas share the same level 1 page
tables and therefore have the same domain (DOMAIN_KERNEL). When the
kernel domain is modified from Client to Manager (via the __set_fs or in
the __switch_to function), the XN (eXecute Never) bit is overridden and
newer CPUs can speculatively prefetch the ioremap'ed memory.

Linux performs the kernel domain switching to allow user-specific
functions (copy_to/from_user, get/put_user etc.) to access kernel
memory. In order for these functions to work with the kernel domain set
to Client, the patch modifies the LDRT/STRT and related instructions to
the LDR/STR ones.

The user pages access rights are also modified for kernel read-only
access rather than read/write so that the copy-on-write mechanism still
works. CPU_USE_DOMAINS gets disabled only if the hardware has a TLS register
(CPU_32v6K is defined) since writing the TLS value to the high vectors page
isn't possible.

The user addresses passed to the kernel are checked by the access_ok()
function so that they do not point to the kernel space.

Tested-by: Anton Vorontsov <cbouatmailru@gmail.com>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Catalin Marinas
2010-09-13 16:03:21 +01:00
committed by Russell King
parent ff8b16d7e1
commit 247055aa21
15 changed files with 153 additions and 92 deletions
Download Patch File Download Diff File Expand all files Collapse all files

83
arch/arm/lib/uaccess.S
View File

@@ -14,6 +14,7 @@
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/errno.h>
#include <asm/domain.h>
.text
@@ -31,11 +32,11 @@
rsb ip, ip, #4
cmp ip, #2
ldrb r3, [r1], #1
USER( strbt r3, [r0], #1) @ May fault
USER( T(strb) r3, [r0], #1) @ May fault
ldrgeb r3, [r1], #1
USER( strgebt r3, [r0], #1) @ May fault
USER( T(strgeb) r3, [r0], #1) @ May fault
ldrgtb r3, [r1], #1
USER( strgtbt r3, [r0], #1) @ May fault
USER( T(strgtb) r3, [r0], #1) @ May fault
sub r2, r2, ip
b .Lc2u_dest_aligned
@@ -58,7 +59,7 @@ ENTRY(__copy_to_user)
addmi ip, r2, #4
bmi .Lc2u_0nowords
ldr r3, [r1], #4
USER( strt r3, [r0], #4) @ May fault
USER( T(str) r3, [r0], #4) @ May fault
mov ip, r0, lsl #32 - PAGE_SHIFT @ On each page, use a ld/st??t instruction
rsb ip, ip, #0
movs ip, ip, lsr #32 - PAGE_SHIFT
@@ -87,18 +88,18 @@ USER( strt r3, [r0], #4) @ May fault
stmneia r0!, {r3 - r4} @ Shouldnt fault
tst ip, #4
ldrne r3, [r1], #4
strnet r3, [r0], #4 @ Shouldnt fault
T(strne) r3, [r0], #4 @ Shouldnt fault
ands ip, ip, #3
beq .Lc2u_0fupi
.Lc2u_0nowords: teq ip, #0
beq .Lc2u_finished
.Lc2u_nowords: cmp ip, #2
ldrb r3, [r1], #1
USER( strbt r3, [r0], #1) @ May fault
USER( T(strb) r3, [r0], #1) @ May fault
ldrgeb r3, [r1], #1
USER( strgebt r3, [r0], #1) @ May fault
USER( T(strgeb) r3, [r0], #1) @ May fault
ldrgtb r3, [r1], #1
USER( strgtbt r3, [r0], #1) @ May fault
USER( T(strgtb) r3, [r0], #1) @ May fault
b .Lc2u_finished
.Lc2u_not_enough:
@@ -119,7 +120,7 @@ USER( strgtbt r3, [r0], #1) @ May fault
mov r3, r7, pull #8
ldr r7, [r1], #4
orr r3, r3, r7, push #24
USER( strt r3, [r0], #4) @ May fault
USER( T(str) r3, [r0], #4) @ May fault
mov ip, r0, lsl #32 - PAGE_SHIFT
rsb ip, ip, #0
movs ip, ip, lsr #32 - PAGE_SHIFT
@@ -154,18 +155,18 @@ USER( strt r3, [r0], #4) @ May fault
movne r3, r7, pull #8
ldrne r7, [r1], #4
orrne r3, r3, r7, push #24
strnet r3, [r0], #4 @ Shouldnt fault
T(strne) r3, [r0], #4 @ Shouldnt fault
ands ip, ip, #3
beq .Lc2u_1fupi
.Lc2u_1nowords: mov r3, r7, get_byte_1
teq ip, #0
beq .Lc2u_finished
cmp ip, #2
USER( strbt r3, [r0], #1) @ May fault
USER( T(strb) r3, [r0], #1) @ May fault
movge r3, r7, get_byte_2
USER( strgebt r3, [r0], #1) @ May fault
USER( T(strgeb) r3, [r0], #1) @ May fault
movgt r3, r7, get_byte_3
USER( strgtbt r3, [r0], #1) @ May fault
USER( T(strgtb) r3, [r0], #1) @ May fault
b .Lc2u_finished
.Lc2u_2fupi: subs r2, r2, #4
@@ -174,7 +175,7 @@ USER( strgtbt r3, [r0], #1) @ May fault
mov r3, r7, pull #16
ldr r7, [r1], #4
orr r3, r3, r7, push #16
USER( strt r3, [r0], #4) @ May fault
USER( T(str) r3, [r0], #4) @ May fault
mov ip, r0, lsl #32 - PAGE_SHIFT
rsb ip, ip, #0
movs ip, ip, lsr #32 - PAGE_SHIFT
@@ -209,18 +210,18 @@ USER( strt r3, [r0], #4) @ May fault
movne r3, r7, pull #16
ldrne r7, [r1], #4
orrne r3, r3, r7, push #16
strnet r3, [r0], #4 @ Shouldnt fault
T(strne) r3, [r0], #4 @ Shouldnt fault
ands ip, ip, #3
beq .Lc2u_2fupi
.Lc2u_2nowords: mov r3, r7, get_byte_2
teq ip, #0
beq .Lc2u_finished
cmp ip, #2
USER( strbt r3, [r0], #1) @ May fault
USER( T(strb) r3, [r0], #1) @ May fault
movge r3, r7, get_byte_3
USER( strgebt r3, [r0], #1) @ May fault
USER( T(strgeb) r3, [r0], #1) @ May fault
ldrgtb r3, [r1], #0
USER( strgtbt r3, [r0], #1) @ May fault
USER( T(strgtb) r3, [r0], #1) @ May fault
b .Lc2u_finished
.Lc2u_3fupi: subs r2, r2, #4
@@ -229,7 +230,7 @@ USER( strgtbt r3, [r0], #1) @ May fault
mov r3, r7, pull #24
ldr r7, [r1], #4
orr r3, r3, r7, push #8
USER( strt r3, [r0], #4) @ May fault
USER( T(str) r3, [r0], #4) @ May fault
mov ip, r0, lsl #32 - PAGE_SHIFT
rsb ip, ip, #0
movs ip, ip, lsr #32 - PAGE_SHIFT
@@ -264,18 +265,18 @@ USER( strt r3, [r0], #4) @ May fault
movne r3, r7, pull #24
ldrne r7, [r1], #4
orrne r3, r3, r7, push #8
strnet r3, [r0], #4 @ Shouldnt fault
T(strne) r3, [r0], #4 @ Shouldnt fault
ands ip, ip, #3
beq .Lc2u_3fupi
.Lc2u_3nowords: mov r3, r7, get_byte_3
teq ip, #0
beq .Lc2u_finished
cmp ip, #2
USER( strbt r3, [r0], #1) @ May fault
USER( T(strb) r3, [r0], #1) @ May fault
ldrgeb r3, [r1], #1
USER( strgebt r3, [r0], #1) @ May fault
USER( T(strgeb) r3, [r0], #1) @ May fault
ldrgtb r3, [r1], #0
USER( strgtbt r3, [r0], #1) @ May fault
USER( T(strgtb) r3, [r0], #1) @ May fault
b .Lc2u_finished
ENDPROC(__copy_to_user)
@@ -294,11 +295,11 @@ ENDPROC(__copy_to_user)
.Lcfu_dest_not_aligned:
rsb ip, ip, #4
cmp ip, #2
USER( ldrbt r3, [r1], #1) @ May fault
USER( T(ldrb) r3, [r1], #1) @ May fault
strb r3, [r0], #1
USER( ldrgebt r3, [r1], #1) @ May fault
USER( T(ldrgeb) r3, [r1], #1) @ May fault
strgeb r3, [r0], #1
USER( ldrgtbt r3, [r1], #1) @ May fault
USER( T(ldrgtb) r3, [r1], #1) @ May fault
strgtb r3, [r0], #1
sub r2, r2, ip
b .Lcfu_dest_aligned
@@ -321,7 +322,7 @@ ENTRY(__copy_from_user)
.Lcfu_0fupi: subs r2, r2, #4
addmi ip, r2, #4
bmi .Lcfu_0nowords
USER( ldrt r3, [r1], #4)
USER( T(ldr) r3, [r1], #4)
str r3, [r0], #4
mov ip, r1, lsl #32 - PAGE_SHIFT @ On each page, use a ld/st??t instruction
rsb ip, ip, #0
@@ -350,18 +351,18 @@ USER( ldrt r3, [r1], #4)
ldmneia r1!, {r3 - r4} @ Shouldnt fault
stmneia r0!, {r3 - r4}
tst ip, #4
ldrnet r3, [r1], #4 @ Shouldnt fault
T(ldrne) r3, [r1], #4 @ Shouldnt fault
strne r3, [r0], #4
ands ip, ip, #3
beq .Lcfu_0fupi
.Lcfu_0nowords: teq ip, #0
beq .Lcfu_finished
.Lcfu_nowords: cmp ip, #2
USER( ldrbt r3, [r1], #1) @ May fault
USER( T(ldrb) r3, [r1], #1) @ May fault
strb r3, [r0], #1
USER( ldrgebt r3, [r1], #1) @ May fault
USER( T(ldrgeb) r3, [r1], #1) @ May fault
strgeb r3, [r0], #1
USER( ldrgtbt r3, [r1], #1) @ May fault
USER( T(ldrgtb) r3, [r1], #1) @ May fault
strgtb r3, [r0], #1
b .Lcfu_finished
@@ -374,7 +375,7 @@ USER( ldrgtbt r3, [r1], #1) @ May fault
.Lcfu_src_not_aligned:
bic r1, r1, #3
USER( ldrt r7, [r1], #4) @ May fault
USER( T(ldr) r7, [r1], #4) @ May fault
cmp ip, #2
bgt .Lcfu_3fupi
beq .Lcfu_2fupi
@@ -382,7 +383,7 @@ USER( ldrt r7, [r1], #4) @ May fault
addmi ip, r2, #4
bmi .Lcfu_1nowords
mov r3, r7, pull #8
USER( ldrt r7, [r1], #4) @ May fault
USER( T(ldr) r7, [r1], #4) @ May fault
orr r3, r3, r7, push #24
str r3, [r0], #4
mov ip, r1, lsl #32 - PAGE_SHIFT
@@ -417,7 +418,7 @@ USER( ldrt r7, [r1], #4) @ May fault
stmneia r0!, {r3 - r4}
tst ip, #4
movne r3, r7, pull #8
USER( ldrnet r7, [r1], #4) @ May fault
USER( T(ldrne) r7, [r1], #4) @ May fault
orrne r3, r3, r7, push #24
strne r3, [r0], #4
ands ip, ip, #3
@@ -437,7 +438,7 @@ USER( ldrnet r7, [r1], #4) @ May fault
addmi ip, r2, #4
bmi .Lcfu_2nowords
mov r3, r7, pull #16
USER( ldrt r7, [r1], #4) @ May fault
USER( T(ldr) r7, [r1], #4) @ May fault
orr r3, r3, r7, push #16
str r3, [r0], #4
mov ip, r1, lsl #32 - PAGE_SHIFT
@@ -473,7 +474,7 @@ USER( ldrt r7, [r1], #4) @ May fault
stmneia r0!, {r3 - r4}
tst ip, #4
movne r3, r7, pull #16
USER( ldrnet r7, [r1], #4) @ May fault
USER( T(ldrne) r7, [r1], #4) @ May fault
orrne r3, r3, r7, push #16
strne r3, [r0], #4
ands ip, ip, #3
@@ -485,7 +486,7 @@ USER( ldrnet r7, [r1], #4) @ May fault
strb r3, [r0], #1
movge r3, r7, get_byte_3
strgeb r3, [r0], #1
USER( ldrgtbt r3, [r1], #0) @ May fault
USER( T(ldrgtb) r3, [r1], #0) @ May fault
strgtb r3, [r0], #1
b .Lcfu_finished
@@ -493,7 +494,7 @@ USER( ldrgtbt r3, [r1], #0) @ May fault
addmi ip, r2, #4
bmi .Lcfu_3nowords
mov r3, r7, pull #24
USER( ldrt r7, [r1], #4) @ May fault
USER( T(ldr) r7, [r1], #4) @ May fault
orr r3, r3, r7, push #8
str r3, [r0], #4
mov ip, r1, lsl #32 - PAGE_SHIFT
@@ -528,7 +529,7 @@ USER( ldrt r7, [r1], #4) @ May fault
stmneia r0!, {r3 - r4}
tst ip, #4
movne r3, r7, pull #24
USER( ldrnet r7, [r1], #4) @ May fault
USER( T(ldrne) r7, [r1], #4) @ May fault
orrne r3, r3, r7, push #8
strne r3, [r0], #4
ands ip, ip, #3
@@ -538,9 +539,9 @@ USER( ldrnet r7, [r1], #4) @ May fault
beq .Lcfu_finished
cmp ip, #2
strb r3, [r0], #1
USER( ldrgebt r3, [r1], #1) @ May fault
USER( T(ldrgeb) r3, [r1], #1) @ May fault
strgeb r3, [r0], #1
USER( ldrgtbt r3, [r1], #1) @ May fault
USER( T(ldrgtb) r3, [r1], #1) @ May fault
strgtb r3, [r0], #1
b .Lcfu_finished
ENDPROC(__copy_from_user)