From: Vitaly Chipounov <vitaly.chipounov@epfl.ch>
To: Max Filippov <jcmvbkbc@gmail.com>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH] x86: Fixed incorrect segment base address addition
Date: Tue, 03 Jul 2012 00:09:13 +0200 [thread overview]
Message-ID: <4FF21C09.5090005@epfl.ch> (raw)
In-Reply-To: <CAMo8BfL2d+eR4Sq0x76Dr9o_A-gNzrOt+FEj2mq+S3yz5bBxyQ@mail.gmail.com>
Max,
On 02.07.2012 17:18, Max Filippov wrote:
> On Mon, Jul 2, 2012 at 2:29 PM, Vitaly Chipounov
> <vitaly.chipounov@epfl.ch> wrote:
>> An instruction with address and segment size override triggers the bug.
>> inc dword ptr gs:260h[ebx*4] gets incorrectly translated to:
>> (uint32_t)(gs.base + ebx * 4 + 0x260)
>> instead of
>> gs.base + (uint32_t)(ebx * 4 + 0x260)
> Do I understand it right that this fixes address calculation for
> 64-bit mode but breaks it for compatibility mode?
You are right, it indeed breaks compatibility mode. Thanks for the
reference from the Intel manual.
I will send an updated patch.
Vitaly
>> Signed-off-by: Vitaly Chipounov <vitaly.chipounov@epfl.ch>
>> ---
>> target-i386/translate.c | 2 +-
>> 1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/target-i386/translate.c b/target-i386/translate.c
>> index a902f4a..9ca7375 100644
>> --- a/target-i386/translate.c
>> +++ b/target-i386/translate.c
>> @@ -459,10 +459,10 @@ static inline void gen_op_movl_A0_seg(int reg)
>> static inline void gen_op_addl_A0_seg(int reg)
>> {
>> tcg_gen_ld_tl(cpu_tmp0, cpu_env, offsetof(CPUX86State, segs[reg].base));
>> - tcg_gen_add_tl(cpu_A0, cpu_A0, cpu_tmp0);
>> #ifdef TARGET_X86_64
>> tcg_gen_andi_tl(cpu_A0, cpu_A0, 0xffffffff);
>> #endif
>> + tcg_gen_add_tl(cpu_A0, cpu_A0, cpu_tmp0);
>> }
>>
>> #ifdef TARGET_X86_64
>> --
>> 1.7.4.1
>>
>>
>
>
next prev parent reply other threads:[~2012-07-02 22:09 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-02 10:29 [Qemu-devel] [PATCH] x86: Fixed incorrect segment base address addition Vitaly Chipounov
2012-07-02 15:18 ` Max Filippov
2012-07-02 22:09 ` Vitaly Chipounov [this message]
2012-07-02 22:20 ` [Qemu-devel] [PATCH v2] x86: Fixed incorrect segment base address addition in 64-bits mode Vitaly Chipounov
2012-07-03 12:52 ` Max Filippov
2012-07-29 9:38 ` Blue Swirl
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