Re: [Qemu-devel] [PATCH] linux-user: fix __NR_semtimedop undeclared error

[Philippe Mathieu-Daudé]

On 5/23/19 7:54 PM, Laurent Vivier wrote:
> In current code, __NR_msgrcv and__NR_semtimedop are supposed to be
> defined if __NR_msgsnd is defined.
> 
> But linux headers 5.2-rc1 for MIPS define __NR_msgsnd without defining
> __NR_semtimedop and it breaks the QEMU build.
> 
> __NR_semtimedop is defined in asm-mips/unistd_n64.h and asm-mips/unistd_n32.h
> but not in asm-mips/unistd_o32.h.
> 
> Commit d9cb4336159a ("linux headers: update against Linux 5.2-rc1") has
> updated asm-mips/unistd_o32.h and added __NR_msgsnd but not __NR_semtimedop.
> It introduces __NR_semtimedop_time64 instead.
> 
> This patch fixes the problem by checking for each __NR_XXX symbol
> before defining the corresponding syscall.

Thanks for the quick fix Laurent.

> 
> Fixes: d9cb4336159a ("linux headers: update against Linux 5.2-rc1")
> Reported-by: Philippe Mathieu-Daudé <address@hidden>
> Signed-off-by: Laurent Vivier <address@hidden>

Tested-by: Philippe Mathieu-Daudé <address@hidden>

> ---
>  linux-user/syscall.c | 24 ++++++++++++++++--------
>  1 file changed, 16 insertions(+), 8 deletions(-)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index e311fcda0517..d316de25c9f2 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -761,14 +761,7 @@ 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
> +#if !defined(__NR_msgsnd) || !defined(__NR_msgrcv) || 
> !defined(__NR_semtimedop)
>  /* 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 +776,29 @@ 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
> +#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)
>  {
>