Re: [PATCH 17/21] powerpc: Add missing prototype for sys_debug_setcontext

[Mathieu Malaterre]

On Sun, Mar 4, 2018 at 11:54 AM, Michael Ellerman <mpe@xxxxxxxxxxxxxx> wrote:
> Mathieu Malaterre <malat@xxxxxxxxxx> writes:
>
>> In commit 81e7009ea46c ("powerpc: merge ppc signal.c and ppc64 signal32.c")
>> the function sys_debug_setcontext was added without a prototype.
>>
>> Fix compilation warning (treated as error in W=1):
>>
>>   CC      arch/powerpc/kernel/signal_32.o
>> arch/powerpc/kernel/signal_32.c:1227:5: error: no previous prototype for âsys_debug_setcontextâ [-Werror=missing-prototypes]
>>  int sys_debug_setcontext(struct ucontext __user *ctx,
>>      ^~~~~~~~~~~~~~~~~~~~
>> cc1: all warnings being treated as errors
>
> This one should actually be using the SYSCALL_DEFINE syntax, so that it
> can be used with CONFIG_FTRACE_SYSCALLS.
>
> See eg. our mmap:
>
>   SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len,
>                 unsigned long, prot, unsigned long, flags,
>                 unsigned long, fd, off_t, offset)
>   {
>         return do_mmap2(addr, len, prot, flags, fd, offset, PAGE_SHIFT);
>   }
>
>
> We probably still need this patch, but I'm not entirely sure because the
> SYSCALL_DEFINE macro does all sorts of shenanigans.

I see. Could you please drop this patch then. The patch does not look
that trivial anymore. I'll need to dig a bit more on how to do the
syscall stuff with a 7 params function.

Thanks