Re: [Qemu-devel] [PULL v3 47/55] linux headers: update against Linux 5.2-rc1

["Alex Bennée" <alex.bennee@linaro.org>]

Laurent Vivier <laurent@vivier.eu> writes:

> On 23/05/2019 13:56, Cornelia Huck wrote:
>> On Wed, 22 May 2019 15:22:23 +0200
>> Aleksandar Markovic <aleksandar.m.mail@gmail.com> wrote:
>>
>>> The alternative way of invoking via IPCV6 (else part of “ifdef
>>> __NR_MSGSND”) should work for MIPS in the present stage of headers and
>>> kernel.
>>
>> I tried to do that so that we have at least a workaround for now; but
>> this fails building on my x86 laptop (the safe_syscall6 for ipc
>> complains about missing __NR_ipc). Maybe I'm holding it wrong (should
>> that be conditional on the host?), but I think that really needs to be
>> done by the mips maintainers...
>>
>
> Perhaps a simple workaround could be:
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index e311fcda0517..5b431736032c 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -761,14 +761,8 @@ safe_syscall2(int, nanosleep, const struct timespec *, req,
>  safe_syscall4(int, clock_nanosleep, const clockid_t, clock, int, flags,
>                const struct timespec *, req, struct timespec *, rem)
>  #endif
> -#ifdef __NR_msgsnd
> -safe_syscall4(int, msgsnd, int, msgid, const void *, msgp, size_t, sz,
> -              int, flags)
> -safe_syscall5(int, msgrcv, int, msgid, void *, msgp, size_t, sz,
> -              long, msgtype, int, flags)
> -safe_syscall4(int, semtimedop, int, semid, struct sembuf *, tsops,
> -              unsigned, nsops, const struct timespec *, timeout)
> -#else
> +
> +#ifdef __NR_ipc
>  /* This host kernel architecture uses a single ipc syscall; fake up
>   * wrappers for the sub-operations to hide this implementation detail.
>   * Annoyingly we can't include linux/ipc.h to get the constant definitions
> @@ -783,14 +777,30 @@ safe_syscall4(int, semtimedop, int, semid, struct sembuf *, tsops,
>
>  safe_syscall6(int, ipc, int, call, long, first, long, second, long, third,
>                void *, ptr, long, fifth)
> +#endif

*sigh* almost but for arches we get complaints when the ipc syscall is
 defined but not used....

  https://app.shippable.com/github/stsquad/qemu/runs/835/summary/console

> +
> +#ifdef __NR_msgsnd
> +safe_syscall4(int, msgsnd, int, msgid, const void *, msgp, size_t, sz,
> +              int, flags)
> +#else
>  static int safe_msgsnd(int msgid, const void *msgp, size_t sz, int flags)
>  {
>      return safe_ipc(Q_IPCCALL(0, Q_MSGSND), msgid, sz, flags, (void *)msgp, 0);
>  }
> +#endif
> +#ifdef __NR_msgrcv
> +safe_syscall5(int, msgrcv, int, msgid, void *, msgp, size_t, sz,
> +              long, msgtype, int, flags)
> +#else
>  static int safe_msgrcv(int msgid, void *msgp, size_t sz, long type, int flags)
>  {
>      return safe_ipc(Q_IPCCALL(1, Q_MSGRCV), msgid, sz, flags, msgp, type);
>  }
> +#endif
> +#ifdef __NR_semtimedop
> +safe_syscall4(int, semtimedop, int, semid, struct sembuf *, tsops,
> +              unsigned, nsops, const struct timespec *, timeout)
> +#else
>  static int safe_semtimedop(int semid, struct sembuf *tsops, unsigned nsops,
>                             const struct timespec *timeout)
>  {


--
Alex Bennée