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authorRussell King <rmk+kernel@arm.linux.org.uk>2013-07-04 11:32:04 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2013-07-31 21:31:09 +0100
commit5b43e7a383d69381ffe53423e46dd0fafae07da3 (patch)
treedc963749afd1416d8737cf273385819896a33ba0 /arch/arm/kernel/entry-armv.S
parentf928d4f2a86f46b030fa0850385b4391fc2b5918 (diff)
downloadlinux-linaro-stable-5b43e7a383d69381ffe53423e46dd0fafae07da3.tar.gz
ARM: poison memory between kuser helpers
Poison the memory between each kuser helper. This ensures that any branch between the kuser helpers will be appropriately trapped. Cc: <stable@vger.kernel.org> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/entry-armv.S')
-rw-r--r--arch/arm/kernel/entry-armv.S25
1 files changed, 16 insertions, 9 deletions
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index a39cfc2a1f90..02437345289a 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -742,6 +742,17 @@ ENDPROC(__switch_to)
#endif
.endm
+ .macro kuser_pad, sym, size
+ .if (. - \sym) & 3
+ .rept 4 - (. - \sym) & 3
+ .byte 0
+ .endr
+ .endif
+ .rept (\size - (. - \sym)) / 4
+ .word 0xe7fddef1
+ .endr
+ .endm
+
.align 5
.globl __kuser_helper_start
__kuser_helper_start:
@@ -832,18 +843,13 @@ kuser_cmpxchg64_fixup:
#error "incoherent kernel configuration"
#endif
- /* pad to next slot */
- .rept (16 - (. - __kuser_cmpxchg64)/4)
- .word 0
- .endr
-
- .align 5
+ kuser_pad __kuser_cmpxchg64, 64
__kuser_memory_barrier: @ 0xffff0fa0
smp_dmb arm
usr_ret lr
- .align 5
+ kuser_pad __kuser_memory_barrier, 32
__kuser_cmpxchg: @ 0xffff0fc0
@@ -916,13 +922,14 @@ kuser_cmpxchg32_fixup:
#endif
- .align 5
+ kuser_pad __kuser_cmpxchg, 32
__kuser_get_tls: @ 0xffff0fe0
ldr r0, [pc, #(16 - 8)] @ read TLS, set in kuser_get_tls_init
usr_ret lr
mrc p15, 0, r0, c13, c0, 3 @ 0xffff0fe8 hardware TLS code
- .rep 4
+ kuser_pad __kuser_get_tls, 16
+ .rep 3
.word 0 @ 0xffff0ff0 software TLS value, then
.endr @ pad up to __kuser_helper_version