diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2013-07-04 11:32:04 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-08-11 18:35:20 -0700 |
| commit | ddc8d5e58a818e543ac658a572b3155c8ea3e45d (patch) | |
| tree | 32ded1c46f9f13709266ab720b395b29082e3471 /arch | |
| parent | bde516f7a535b9bafa00e54a06c6538b9eb830e5 (diff) | |
ARM: poison memory between kuser helpers
commit 5b43e7a383d69381ffe53423e46dd0fafae07da3 upstream.
Poison the memory between each kuser helper. This ensures that any
branch between the kuser helpers will be appropriately trapped.
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/kernel/entry-armv.S | 25 |
1 files changed, 16 insertions, 9 deletions
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 582b405befc..f864f7e3a67 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -741,6 +741,17 @@ 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: @@ -831,18 +842,13 @@ 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 @@ -915,13 +921,14 @@ 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 |