Re: [Qemu-devel] [PATCH] seccomp: change configure to avoid arm 32 to break

[Peter Maydell]

On 6 November 2014 14:49, Eduardo Otubo <address@hidden> wrote:
> Right now seccomp is breaking the compilation of Qemu on armv7l due
> to libsecomp current lack of support for this arch. This problem is
> already fixed on libseccomp upstream but no release date for that is
> scheduled to far. This patch disables support for seccomp on armv7l
> temporarily until libseccomp does a new release. Then I'll remove the
> hack and update libseccomp dependency on configure script.
>
> Related bug: https://bugs.launchpad.net/qemu/+bug/1363641
>
> Signed-off-by: Eduardo Otubo <address@hidden>
> ---
>  configure | 20 +++++++++++---------
>  1 file changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/configure b/configure
> index 2f17bf3..16fd7f5 100755
> --- a/configure
> +++ b/configure
> @@ -1823,15 +1823,17 @@ fi
>  # libseccomp check
>
>  if test "$seccomp" != "no" ; then
> -    if $pkg_config --atleast-version=2.1.0 libseccomp; then
> -        libs_softmmu="$libs_softmmu `$pkg_config --libs libseccomp`"
> -        QEMU_CFLAGS="$QEMU_CFLAGS `$pkg_config --cflags libseccomp`"
> -       seccomp="yes"
> -    else
> -       if test "$seccomp" = "yes"; then
> -            feature_not_found "libseccomp" "Install libseccomp devel >= 
> 2.1.0"
> -       fi
> -       seccomp="no"
> +    if test "$cpu" = "i386" || test "$cpu" = "x86_64"; then
> +        if $pkg_config --atleast-version=2.1.0 libseccomp; then
> +            libs_softmmu="$libs_softmmu `$pkg_config --libs libseccomp`"
> +            QEMU_CFLAGS="$QEMU_CFLAGS `$pkg_config --cflags libseccomp`"
> +            seccomp="yes"
> +        else
> +            if test "$seccomp" = "yes"; then
> +                feature_not_found "libseccomp" "Install libseccomp devel >= 
> 2.1.0"
> +            fi
> +            seccomp="no"
> +        fi
>      fi

This is missing the logic for turning "" into "no" or printing the
feature_not_found message if the probe failed because of the CPU
being wrong. The easiest fix for that is just to roll the whole check
into one if:
    if { test "$cpu" = "i386" || test "$cpu" = "x86_64"; } &&
        $pkg_config --atleast-version=2.1.0 libseccomp; then

(the { ... ; } are not strictly necessary since the shell's
precedence rules mean we'll evaluate the || before the && but
I think they make the intent clearer.)

thanks
-- PMM