On 15.09.2014 17:32, Martin Kletzander wrote:
On Mon, Sep 15, 2014 at 04:22:18PM +0100, Daniel P. Berrange wrote:
On Mon, Sep 15, 2014 at 05:20:46PM +0200, Michal Privoznik wrote:
On 15.09.2014 17:15, Martin Kletzander wrote:
On Mon, Sep 15, 2014 at 03:43:55PM +0200, Michal Privoznik wrote:
Currently, the setns() wrapper is supported only for x86_64 and i686 which leaves us failing to build on other platforms like arm, aarch64 and so on. This means, that the wrapper needs to be extended to those platforms and make to fail on runtime not compile time.
The syscall numbers for other platforms was fetched using this command:
kernel.git $ git grep "define.*__NR_setns" | grep -e arm -e powerpc -e s390 arch/arm/include/uapi/asm/unistd.h:#define __NR_setns (__NR_SYSCALL_BASE+375) arch/arm64/include/asm/unistd32.h:#define __NR_setns 375 arch/powerpc/include/uapi/asm/unistd.h:#define __NR_setns 350 arch/s390/include/uapi/asm/unistd.h:#define __NR_setns 339
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- src/util/virprocess.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-)
NACK, we shouldn't be duplicating syscall definitions. There should be AC_CHECK_FUNCS([setns]) (instead of AC_CHECK_FUNCS_ONCE() for the syscall) and having with_lxc = "yes" and ac_cv_func_setns != "yes" should result in an error.
The only problem with this might be that on systems with older glibc (and there is plenty of them) libvirt will fail to build / miss this feature. And it's not that the kernel doesn't support the namesapces. But let me see if I can get some ACKs on that approach you're suggesting.
That's basically what the code did before we added the #define or NR_setns. We took the patch specifically to help Debian where the kernel has it but glibc is outdated.
Either Debian should patch their glibc or we should at lease use SYS_setns IMHO.
That's not gonna fly either. On my system, the SYS_setns is declared in: # grep -r SYS_setns /usr/include/ /usr/include/bits/syscall.h:#define SYS_setns __NR_setns And the syscall.h belongs to glibc, not kernel headers. So we are back at the start. Michal