[28/44] ARM: 6482/2: Fix find_next_zero_bit and related assembly

[Greg KH]

2.6.27-stable review patch.  If anyone has any objections, please let us know.

------------------

From: James Jones <jajones@xxxxxxxxxx>

commit 0e91ec0c06d2cd15071a6021c94840a50e6671aa upstream.

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.

Reviewed-by: Nicolas Pitre <nicolas.pitre@xxxxxxxxxx>
Tested-by: Stephen Warren <swarren@xxxxxxxxxx>
Signed-off-by: James Jones <jajones@xxxxxxxxxx>
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 arch/arm/lib/findbit.S |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/arch/arm/lib/findbit.S
+++ b/arch/arm/lib/findbit.S
@@ -148,8 +148,8 @@ ENTRY(_find_next_bit_be)
  */
 .L_found:
 #if __LINUX_ARM_ARCH__ >= 5
-		rsb	r1, r3, #0
-		and	r3, r3, r1
+		rsb	r0, r3, #0
+		and	r3, r3, r0
 		clz	r3, r3
 		rsb	r3, r3, #31
 		add	r0, r2, r3
@@ -164,5 +164,7 @@ ENTRY(_find_next_bit_be)
 		addeq	r2, r2, #1
 		mov	r0, r2
 #endif
+		cmp	r1, r0			@ Clamp to maxbit
+		movlo	r0, r1
 		mov	pc, lr
 


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