From a0bdcb019e24f8a75ebef54289c4b8c015f77f41 Mon Sep 17 00:00:00 2001
From: "Ronald S. Bultje" <rsbultje@gmail.com>
Date: Sat, 17 Mar 2012 08:58:48 -0700
Subject: [PATCH] h264: add overread protection to get_cabac_bypass_sign_x86().
---
libavcodec/x86/cabac.h | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/libavcodec/x86/cabac.h b/libavcodec/x86/cabac.h
index b00652be943..adf4fc39b22 100644
--- a/libavcodec/x86/cabac.h
+++ b/libavcodec/x86/cabac.h
@@ -105,7 +105,7 @@ static av_always_inline int get_cabac_bypass_sign_x86(CABACContext *c, int val)
{
x86_reg tmp;
__asm__ volatile(
- "movl %a5(%2), %k1 \n\t"
+ "movl %a6(%2), %k1 \n\t"
"movl %a3(%2), %%eax \n\t"
"shl $17, %k1 \n\t"
"add %%eax, %%eax \n\t"
@@ -122,9 +122,10 @@ static av_always_inline int get_cabac_bypass_sign_x86(CABACContext *c, int val)
"movzwl (%1), %%edx \n\t"
"bswap %%edx \n\t"
"shrl $15, %%edx \n\t"
- "add $2, %1 \n\t"
"addl %%edx, %%eax \n\t"
- "mov %1, %a4(%2) \n\t"
+ "cmp %a5(%2), %1 \n\t"
+ "jge 1f \n\t"
+ "add"OPSIZE" $2, %a4(%2) \n\t"
"1: \n\t"
"movl %%eax, %a3(%2) \n\t"
@@ -132,6 +133,7 @@ static av_always_inline int get_cabac_bypass_sign_x86(CABACContext *c, int val)
: "r"(c),
"i"(offsetof(CABACContext, low)),
"i"(offsetof(CABACContext, bytestream)),
+ "i"(offsetof(CABACContext, bytestream_end)),
"i"(offsetof(CABACContext, range))
: "%eax", "%edx", "memory"
);
--
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