[Qemu-devel] why does qemu i386 userspace emulation crashes when pthread used?

[Qemu-devel] why does qemu i386 userspace emulation crashes when pthread used?

[Yale Zhang]

[-- Attachment #1: Type: text/plain, Size: 769 bytes --]

Hi. I'm want to run some pthread programs using qemu userspace emulation
(target=i386, host=x86_64,arm), but see NPTL support isn't supported for the
i386 target. I have applied a patch from here
http://patchwork.ozlabs.org/patch/45206/ and used it to run a simple pthread
fork, join program. The program is able to launch multiple threads, but the
1st thread that exits causes the program to crash inside the pthread
library.

What are the reasons NPTL isn't supported for i386 and was it ever supported
in the past? I even wrote another simple program that does the equivalent,
but with using fork(), waitpid() instead of pthread_create(),
pthread_join(), and it works correctly. This seems to suggest thread local
storage wasn't implemented correctly?

Thanks,
Yale

[-- Attachment #2: Type: text/html, Size: 946 bytes --]

Re: [Qemu-devel] why does qemu i386 userspace emulation crashes when pthread used?

[Yale Zhang]

[-- Attachment #1: Type: text/plain, Size: 1006 bytes --]

I have found the problem and fix. NEW_STACK_SIZE for clone()  should be
increased from the default 16384 (x86_64) to  256 KiB.

On Tue, Apr 19, 2011 at 6:33 PM, Yale Zhang <yzhang1985@gmail.com> wrote:

> Hi. I'm want to run some pthread programs using qemu userspace emulation
> (target=i386, host=x86_64,arm), but see NPTL support isn't supported for the
> i386 target. I have applied a patch from here
> http://patchwork.ozlabs.org/patch/45206/ and used it to run a simple
> pthread fork, join program. The program is able to launch multiple threads,
> but the 1st thread that exits causes the program to crash inside the pthread
> library.
>
> What are the reasons NPTL isn't supported for i386 and was it ever
> supported in the past? I even wrote another simple program that does the
> equivalent, but with using fork(), waitpid() instead of pthread_create(),
> pthread_join(), and it works correctly. This seems to suggest thread local
> storage wasn't implemented correctly?
>
> Thanks,
> Yale
>
>

[-- Attachment #2: Type: text/html, Size: 1432 bytes --]