From: "Alex Bennée" <alex.bennee@linaro.org>
To: Richard Henderson <richard.henderson@linaro.org>
Cc: qemu-devel@nongnu.org, pbonzini@redhat.com, riku.voipio@iki.fi,
laurent@vivier.eu, peter.maydell@linaro.org
Subject: Re: [PATCH 3/3] linux-user/i386: Emulate x86_64 vsyscalls
Date: Thu, 16 Jan 2020 20:15:04 +0000 [thread overview]
Message-ID: <87d0bjkvjr.fsf@linaro.org> (raw)
In-Reply-To: <3733f2cd-9262-d7f9-ab9c-c8a3032732df@linaro.org>
Richard Henderson <richard.henderson@linaro.org> writes:
> On 1/16/20 6:26 AM, Alex Bennée wrote:
>>> + /*
>>> + * Perform the syscall. None of the vsyscalls should need restarting,
>>> + * and all faults should have been caught above.
>>> + */
>>> + ret = do_syscall(env, syscall, env->regs[R_EDI], env->regs[R_ESI],
>>> + env->regs[R_EDX], env->regs[10], env->regs[8],
>>> + env->regs[9], 0, 0);
>>
>> How come the register ABI to the syscall is different to the others. I
>> can see why syscall doesn't come from EAX but the others are a different
>> set to normal syscalls which might be why:
>
> Cut and paste error, I assume.
>
> That said, the three syscalls have a maximum of 2 arguments,
> so I could really just pass EDI and ESI and 0 for the rest...
>
>> I'm seeing a EFAULT on the gettimeofday failure:
>
> What getttimeofday failure? Is this related to the mention of /sbin/ldconfig
> in your previous message?
No - the buster x86064 ldconfig seg is unrelated to this series. It has
however spawned an additional bug in gdbstub while it was at it ;-)
>
>> #0 do_syscall (cpu_env=cpu_env@entry=0x5555577d2b10, num=num@entry=96, arg1=0, arg2=0, arg3=4211016, arg4=8, arg5=274888677184, arg6=274886295415, arg7=0, arg8=0) at /home/alex/lsrc/qemu.git/linux-user/syscall.c:12076
>> #1 0x0000555555609b6e in emulate_vsyscall (env=0x5555577d2b10) at /home/alex/lsrc/qemu.git/linux-user/x86_64/../i386/cpu_loop.c:180
>> #2 cpu_loop (env=0x5555577d2b10) at /home/alex/lsrc/qemu.git/linux-user/x86_64/../i386/cpu_loop.c:246
>> #3 0x000055555559640e in main (argc=<optimized out>, argv=<optimized
>> #out>, envp=<optimized out>) at
>> #/home/alex/lsrc/qemu.git/linux-user/main.c:865
>>
>> arg1/arg2 don't seem right here.
>
> Why? NULL value for arg1 is legal, though semi-useless.
>
> Ah, I see that our implementation of gettimeofday doesn't honor NULL.
>
>
> r~
--
Alex Bennée
next prev parent reply other threads:[~2020-01-16 20:15 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-14 21:09 [PATCH 0/3] linux-user: Implement x86_64 vsyscalls Richard Henderson
2020-01-14 21:09 ` [PATCH 1/3] target/i386: Renumber EXCP_SYSCALL Richard Henderson
2020-01-15 7:22 ` Philippe Mathieu-Daudé
2020-01-15 9:55 ` Alex Bennée
2020-01-14 21:09 ` [PATCH 2/3] linux-user/i386: Split out gen_signal Richard Henderson
2020-01-15 7:22 ` Philippe Mathieu-Daudé
2020-01-15 9:58 ` Alex Bennée
2020-01-14 21:09 ` [PATCH 3/3] linux-user/i386: Emulate x86_64 vsyscalls Richard Henderson
2020-01-16 10:51 ` Alex Bennée
2020-01-16 16:26 ` Alex Bennée
2020-01-16 18:19 ` Richard Henderson
2020-01-16 18:22 ` Richard Henderson
2020-01-16 20:15 ` Alex Bennée [this message]
2020-01-14 23:35 ` [PATCH 0/3] linux-user: Implement " Paolo Bonzini
2020-01-15 7:01 ` Laurent Desnogues
2020-01-15 10:14 ` Laurent Vivier
2020-01-15 17:28 ` Richard Henderson
2020-01-16 14:05 ` Alex Bennée
2020-01-16 19:37 ` Richard Henderson
2020-01-16 14:30 ` Alex Bennée
2020-01-16 18:31 ` Richard Henderson
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