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author | Catalin Marinas <catalin.marinas@arm.com> | 2010-09-13 15:03:21 (GMT) |
---|---|---|
committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-11-04 15:44:31 (GMT) |
commit | 247055aa21ffef1c49dd64710d5e94c2aee19b58 (patch) | |
tree | e9e026b96597d080de4c16bb88c17b0495c61904 /arch/arm/lib/uaccess.S | |
parent | ff8b16d7e15a8ba2a6086645614a483e048e3fbf (diff) | |
download | linux-247055aa21ffef1c49dd64710d5e94c2aee19b58.tar.xz |
ARM: 6384/1: Remove the domain switching on ARMv6k/v7 CPUs
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>
Diffstat (limited to 'arch/arm/lib/uaccess.S')
-rw-r--r-- | arch/arm/lib/uaccess.S | 83 |
1 files changed, 42 insertions, 41 deletions
diff --git a/arch/arm/lib/uaccess.S b/arch/arm/lib/uaccess.S index fee9f6f..d0ece2a 100644 --- a/arch/arm/lib/uaccess.S +++ b/arch/arm/lib/uaccess.S @@ -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) |