[Qemu-devel] forking with x86_64

[Qemu-devel] forking with x86_64

[maheen butt]

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hiwhy qemu does not provide NPTL support for x86 in user mode? is there any big hindrance behind it? I did a small experimentI make a program with fork system call and give its executable to qemu-x86_64
out put shows it does not create child. the I commented out this if block of linux-user/syscall.cif ((flags & ~(CSIGNAL | CLONE_NPTL_FLAGS2)) != 0)            return -EINVAL;so that it can fork now as next line of code is thisfork_start(); ret = fork();now it started working, the child has created.if it is so simple then wat is the hurdle that original qemu code can not run fork'ed program?REGARDS


      

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Re: [Qemu-devel] forking with x86_64

[Mulyadi Santosa]

On Wed, Jan 12, 2011 at 17:17, maheen butt <maheen_butt26@yahoo.com> wrote:
>
> hi
> why qemu does not provide NPTL support for x86 in user mode? is there any big hindrance behind it?

IMHO, your experiment works since it simply fork(). What qemu wanna do
here is complete NPTL handling...and afaik that means clone(),
pthread_ family function and so on. Yes, fork() is based on clone(),
but it really create wholly new task, while NPTL as we speak here
means thread....

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regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
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