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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2013-07-04 14:32:04 +0400 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2013-08-01 00:31:09 +0400 |
| commit | 5b43e7a383d69381ffe53423e46dd0fafae07da3 (patch) | |
| tree | dc963749afd1416d8737cf273385819896a33ba0 /arch | |
| parent | f928d4f2a86f46b030fa0850385b4391fc2b5918 (diff) | |
| download | linux-5b43e7a383d69381ffe53423e46dd0fafae07da3.tar.xz | |
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')
| -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 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 |