ref: e2795e9978580a21e7399d3ccf919dc2f06f97ca
parent: dbd57c2663ce62a74c5f303ac906bddcc03628b5
author: Timothy B. Terriberry <tterribe@xiph.org>
date: Fri Sep 24 10:30:13 EDT 2010
Fix valgrind errors in vp8_sixtap_predict8x4_armv6(). This function was accessing values below the stack pointer, which can be corrupted by signal delivery at any time. Change-Id: I92945b30817562eb0340f289e74c108da72aeaca
--- a/vp8/common/arm/armv6/sixtappredict8x4_v6.asm
+++ b/vp8/common/arm/armv6/sixtappredict8x4_v6.asm
@@ -25,10 +25,10 @@
;and the result is stored in transpose.
|vp8_sixtap_predict8x4_armv6| PROC
stmdb sp!, {r4 - r11, lr}
- sub sp, sp, #184 ;reserve space on stack for temporary storage: 20x(8+1) +4
+ str r3, [sp, #-184]! ;reserve space on stack for temporary storage, store yoffset
cmp r2, #0 ;skip first_pass filter if xoffset=0
- str r3, [sp], #4 ;store yoffset
+ add lr, sp, #4 ;point to temporary buffer
beq skip_firstpass_filter
;first-pass filter
@@ -45,7 +45,6 @@
mov r2, #0x90000 ; height=9 is top part of counter
sub r1, r1, #8
- mov lr, #20
|first_pass_hloop_v6|
ldrb r6, [r0, #-5] ; load source data
@@ -83,10 +82,10 @@
tst r2, #0xff ; test loop counter
usat r11, #8, r11, asr #7
add r12, r12, #0x40
- strh r11, [sp], lr ; result is transposed and stored, which
+ strh r11, [lr], #20 ; result is transposed and stored, which
usat r12, #8, r12, asr #7
- strh r12, [sp], lr
+ strh r12, [lr], #20
movne r11, r6
movne r12, r7
@@ -107,8 +106,7 @@
subs r2, r2, #0x10000
- mov r6, #158
- sub sp, sp, r6
+ sub lr, lr, #158
add r0, r0, r1 ; move to next input line
@@ -116,10 +114,7 @@
;second pass filter
secondpass_filter
- mov r1, #18
- sub sp, sp, r1 ; 18+4
-
- ldr r3, [sp, #-4] ; load back yoffset
+ ldr r3, [sp], #4 ; load back yoffset
ldr r0, [sp, #216] ; load dst address from stack 180+36
ldr r1, [sp, #220] ; load dst stride from stack 180+40
@@ -192,30 +187,28 @@
sub r0, r0, r1, lsl #1
sub r1, r1, #8
mov r2, #9
- mov r3, #20
skip_firstpass_hloop
ldrb r4, [r0], #1 ; load data
subs r2, r2, #1
ldrb r5, [r0], #1
- strh r4, [sp], r3 ; store it to immediate buffer
+ strh r4, [lr], #20 ; store it to immediate buffer
ldrb r6, [r0], #1 ; load data
- strh r5, [sp], r3
+ strh r5, [lr], #20
ldrb r7, [r0], #1
- strh r6, [sp], r3
+ strh r6, [lr], #20
ldrb r8, [r0], #1
- strh r7, [sp], r3
+ strh r7, [lr], #20
ldrb r9, [r0], #1
- strh r8, [sp], r3
+ strh r8, [lr], #20
ldrb r10, [r0], #1
- strh r9, [sp], r3
+ strh r9, [lr], #20
ldrb r11, [r0], #1
- strh r10, [sp], r3
+ strh r10, [lr], #20
add r0, r0, r1 ; move to next input line
- strh r11, [sp], r3
+ strh r11, [lr], #20
- mov r4, #158
- sub sp, sp, r4 ; move over to next column
+ sub lr, lr, #158 ; move over to next column
bne skip_firstpass_hloop
b secondpass_filter