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ARM: 6482/2: Fix find_next_zero_bit and related assembly

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The find_next_bit, find_first_bit, find_next_zero_bit
and find_first_zero_bit functions were not properly
clamping to the maxbit argument at the bit level. They
were instead only checking maxbit at the byte level.
To fix this, add a compare and a conditional move
instruction to the end of the common bit-within-the-
byte code used by all the functions and be sure not to
clobber the maxbit argument before it is used.

Cc: <stable@kernel.org>
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: James Jones <jajones@nvidia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
James Jones
2010-11-24 00:21:37 +01:00
committed by Russell King
parent 28c22d7dc9
commit 0e91ec0c06
1 changed files with 4 additions and 2 deletions
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6
arch/arm/lib/findbit.S
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@@ -174,8 +174,8 @@ ENDPROC(_find_next_bit_be)
*/ */
.L_found: .L_found:
#if __LINUX_ARM_ARCH__ >= 5 #if __LINUX_ARM_ARCH__ >= 5
rsb r1, r3, #0 rsb r0, r3, #0
and r3, r3, r1 and r3, r3, r0
clz r3, r3 clz r3, r3
rsb r3, r3, #31 rsb r3, r3, #31
add r0, r2, r3 add r0, r2, r3
@@ -190,5 +190,7 @@ ENDPROC(_find_next_bit_be)
addeq r2, r2, #1 addeq r2, r2, #1
mov r0, r2 mov r0, r2
#endif #endif
cmp r1, r0 @ Clamp to maxbit
movlo r0, r1
mov pc, lr mov pc, lr