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* [PATCH] fix a bug in emitting the 16-bit immediate operand of AND
@ 2012-03-29  9:27 zhuangfeiran
  2012-03-29 11:45 ` Eric Dumazet
  0 siblings, 1 reply; 3+ messages in thread
From: zhuangfeiran @ 2012-03-29  9:27 UTC (permalink / raw)
  To: davem; +Cc: netdev, linux-kernel, eric.dumazet

When K >= 0xFFFF0000, AND needs the two least significant bytes of K as
its operand, but EMIT2() gives it the least significant byte of K and
0x2. EMIT() should be used here to replace EMIT2().

Signed-off-by: Feiran Zhuang  <zhuangfeiran@ict.ac.cn>
---
 arch/x86/net/bpf_jit_comp.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 5671752..5a5b6e4 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -289,7 +289,7 @@ void bpf_jit_compile(struct sk_filter *fp)
 					EMIT2(0x24, K & 0xFF); /* and imm8,%al */
 				} else if (K >= 0xFFFF0000) {
 					EMIT2(0x66, 0x25);	/* and imm16,%ax */
-					EMIT2(K, 2);
+					EMIT(K, 2);
 				} else {
 					EMIT1_off32(0x25, K);	/* and imm32,%eax */
 				}
-- 
1.7.5.4



^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] fix a bug in emitting the 16-bit immediate operand of AND
  2012-03-29  9:27 [PATCH] fix a bug in emitting the 16-bit immediate operand of AND zhuangfeiran
@ 2012-03-29 11:45 ` Eric Dumazet
  2012-03-29 22:13   ` David Miller
  0 siblings, 1 reply; 3+ messages in thread
From: Eric Dumazet @ 2012-03-29 11:45 UTC (permalink / raw)
  To: zhuangfeiran; +Cc: davem, netdev, linux-kernel

Le jeudi 29 mars 2012 à 17:27 +0800, zhuangfeiran@ict.ac.cn a écrit :
> When K >= 0xFFFF0000, AND needs the two least significant bytes of K as
> its operand, but EMIT2() gives it the least significant byte of K and
> 0x2. EMIT() should be used here to replace EMIT2().
> 
> Signed-off-by: Feiran Zhuang  <zhuangfeiran@ict.ac.cn>
> ---
>  arch/x86/net/bpf_jit_comp.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
> index 5671752..5a5b6e4 100644
> --- a/arch/x86/net/bpf_jit_comp.c
> +++ b/arch/x86/net/bpf_jit_comp.c
> @@ -289,7 +289,7 @@ void bpf_jit_compile(struct sk_filter *fp)
>  					EMIT2(0x24, K & 0xFF); /* and imm8,%al */
>  				} else if (K >= 0xFFFF0000) {
>  					EMIT2(0x66, 0x25);	/* and imm16,%ax */
> -					EMIT2(K, 2);
> +					EMIT(K, 2);
>  				} else {
>  					EMIT1_off32(0x25, K);	/* and imm32,%eax */
>  				}

Good catch, thanks !

Acked-by: Eric Dumazet <eric.dumazet@gmail.com>




^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] fix a bug in emitting the 16-bit immediate operand of AND
  2012-03-29 11:45 ` Eric Dumazet
@ 2012-03-29 22:13   ` David Miller
  0 siblings, 0 replies; 3+ messages in thread
From: David Miller @ 2012-03-29 22:13 UTC (permalink / raw)
  To: eric.dumazet; +Cc: zhuangfeiran, netdev, linux-kernel

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 29 Mar 2012 13:45:25 +0200

> Le jeudi 29 mars 2012 à 17:27 +0800, zhuangfeiran@ict.ac.cn a écrit :
>> When K >= 0xFFFF0000, AND needs the two least significant bytes of K as
>> its operand, but EMIT2() gives it the least significant byte of K and
>> 0x2. EMIT() should be used here to replace EMIT2().
>> 
>> Signed-off-by: Feiran Zhuang  <zhuangfeiran@ict.ac.cn>
>> ---
>>  arch/x86/net/bpf_jit_comp.c |    2 +-
>>  1 files changed, 1 insertions(+), 1 deletions(-)
>> 
>> diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
>> index 5671752..5a5b6e4 100644
>> --- a/arch/x86/net/bpf_jit_comp.c
>> +++ b/arch/x86/net/bpf_jit_comp.c
>> @@ -289,7 +289,7 @@ void bpf_jit_compile(struct sk_filter *fp)
>>  					EMIT2(0x24, K & 0xFF); /* and imm8,%al */
>>  				} else if (K >= 0xFFFF0000) {
>>  					EMIT2(0x66, 0x25);	/* and imm16,%ax */
>> -					EMIT2(K, 2);
>> +					EMIT(K, 2);
>>  				} else {
>>  					EMIT1_off32(0x25, K);	/* and imm32,%eax */
>>  				}
> 
> Good catch, thanks !
> 
> Acked-by: Eric Dumazet <eric.dumazet@gmail.com>

Applied.

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2012-03-29 22:14 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2012-03-29  9:27 [PATCH] fix a bug in emitting the 16-bit immediate operand of AND zhuangfeiran
2012-03-29 11:45 ` Eric Dumazet
2012-03-29 22:13   ` David Miller

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