Re: [Qemu-devel] [PATCH] seccomp: add timerfd_create and timerfd_settime to the whitelist

[Eduardo Otubo]

On 01/26/2014 10:21 AM, Felix Geyer wrote:
> libusb calls timerfd_create() and timerfd_settime() when it's built with
> timerfd support.
>
> Command to reproduce:
>
> qemu -sandbox on -monitor stdio -device piix3-usb-uhci,id=usb
>       -device usb-host,hostbus=1,hostaddr=3,id=hostdev0
>
> Log messages:
>
> audit(1390730418.924:135): auid=4294967295 uid=121 gid=103 ses=4294967295
>                             pid=5232 comm="qemu-system-x86" sig=31 syscall=283
>                             compat=0 ip=0x7f2b0f4e96a7 code=0x0
> audit(1390733100.580:142): auid=4294967295 uid=121 gid=103 ses=4294967295
>                             pid=16909 comm="qemu-system-x86" sig=31 syscall=286
>                             compat=0 ip=0x7f03513a06da code=0x0
>
> Signed-off-by: Felix Geyer <address@hidden>
> ---
>   qemu-seccomp.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/qemu-seccomp.c b/qemu-seccomp.c
> index caa926e..2705468 100644
> --- a/qemu-seccomp.c
> +++ b/qemu-seccomp.c
> @@ -225,7 +225,9 @@ static const struct QemuSeccompSyscall seccomp_whitelist[] 
> = {
>       { SCMP_SYS(fchmod), 240 },
>       { SCMP_SYS(shmget), 240 },
>       { SCMP_SYS(shmat), 240 },
> -    { SCMP_SYS(shmdt), 240 }
> +    { SCMP_SYS(shmdt), 240 },
> +    { SCMP_SYS(timerfd_create), 240 },
> +    { SCMP_SYS(timerfd_settime), 240 }

Did you deliberately set the priority to 240? Or did you run any sort of 
benchmark (strace) to find this value?

Regards,

--
Eduardo Otubo
IBM Linux Technology Center