[PATCH] powerpc: Wire up clone3 syscall

[Michael Ellerman]

Christian Brauner <christian at brauner.io> writes:
> On Mon, Jul 22, 2019 at 11:22:31PM +1000, Michael Ellerman wrote:
>> Wire up the new clone3 syscall added in commit 7f192e3cd316 ("fork:
>> add clone3").
>> 
>> This requires a ppc_clone3 wrapper, in order to save the non-volatile
>> GPRs before calling into the generic syscall code. Otherwise we hit
>> the BUG_ON in CHECK_FULL_REGS in copy_thread().
>> 
>> Lightly tested using Christian's test code on a Power8 LE VM.
>> 
>> Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
>
> Thank you, Michael!
>
> One comment below, otherwise:
>
> Acked-by: Christian Brauner <christian at brauner.io>

Thanks.

...
>> diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
>> index f2c3bda2d39f..6886ecb590d5 100644
>> --- a/arch/powerpc/kernel/syscalls/syscall.tbl
>> +++ b/arch/powerpc/kernel/syscalls/syscall.tbl
>> @@ -516,3 +516,4 @@
>>  432	common	fsmount				sys_fsmount
>>  433	common	fspick				sys_fspick
>>  434	common	pidfd_open			sys_pidfd_open
>> +435	common	clone3				ppc_clone3
>
> Note that in v5.3-rc1 there's now a comment that 435 is reserved in
> there. So this will likely cause a merge conflict. You might want to
> base your change off of v5.3-rc1 instead to avoid that. :)

Thanks for the heads-up.

My fixes branch is already based off pre-rc1, and in general Linus can
handle a trivial merge conflict like that.

But given I had to send a v2 to fix the 32-bit build (doh!), I'll move
my fixes up past rc1 once Linus has merged what's in there now, and then
do this patch based on top of rc1, so there'll be no conflict.

cheers