Re: [Qemu-devel] [PATCH 17/23] bsd-user: add shims for thread related system calls

[Peter Maydell]

On 24 June 2013 03:03, Stacey Son <address@hidden> wrote:
> diff --git a/configure b/configure
> index ba90975..812ea3f 100755
> --- a/configure
> +++ b/configure
> @@ -1438,6 +1438,15 @@ fi
>
>  if test "$nptl" != "no" ; then
>    cat > $TMPC <<EOF
> +#ifdef __FreeBSD__
> +#include <sys/thr.h>
> +int main(void) {
> +#if !defined(THR_SUSPENDED)
> +#error bork
> +#endif
> +  return 0;
> +}
> +#else
>  #include <sched.h>
>  #include <linux/futex.h>
>  int main(void) {
> @@ -1446,6 +1455,7 @@ int main(void) {
>  #endif
>    return 0;
>  }
> +#endif
>  EOF
>
>    if compile_object ; then
> @@ -4202,6 +4212,7 @@ case "$target_name" in
>      TARGET_ARCH=mips64
>      TARGET_BASE_ARCH=mips
>      echo "TARGET_ABI_MIPSN64=y" >> $config_target_mak
> +    target_nptl="yes"
>    ;;
>    moxie)
>    ;;

I think this is the wrong way to do this. target_nptl should
be a linux-user specific define (and we really ought to try
to get rid of it altogether there at some point).

For bsd-user, the ideal would be if you could just support
guest threads always, ie no #defines or configure checks needed.
If you do need a configure check, then it should be its own,
totally separate from CONFIG_NPTL. In any case, definitely
do not make the Linux mistake of having "do we support threads?"
be target specific if you can avoid it. (You might not be
able to avoid it, though -- not sure :-( )

(I suspect these other MIPS targets should actually have
target_nptl set as your patch fragment does, but that should
be done as a linux-user bugfix patch, not buried in the
bsd-user support patchset.)

> diff --git a/include/qemu/tls.h b/include/qemu/tls.h
> index b92ea9d..ae7d79d 100644
> --- a/include/qemu/tls.h
> +++ b/include/qemu/tls.h
> @@ -38,7 +38,7 @@
>   * TODO: proper implementations via Win32 .tls sections and
>   * POSIX pthread_getspecific.
>   */
> -#ifdef __linux__
> +#if defined(__linux__) || defined(__FreeBSD__)
>  #define DECLARE_TLS(type, x) extern DEFINE_TLS(type, x)
>  #define DEFINE_TLS(type, x)  __thread __typeof__(type) tls__##x
>  #define tls_var(x)           tls__##x

This should be its own patch (especially as it affects the
system emulation code on FreeBSD hosts).

thanks
-- PMM