Re: [PATCH 4/4] openrisc: use mmgrab

[Stafford Horne]

On Mon, Dec 30, 2019 at 12:49:19PM +0800, kbuild test robot wrote:
> Hi Julia,
> 
> I love your patch! Yet something to improve:
> 
> [auto build test ERROR on vfio/next]
> [also build test ERROR on char-misc/char-misc-testing v5.5-rc3 next-20191220]
> [if your patch is applied to the wrong git tree, please drop us a note to help
> improve the system. BTW, we also suggest to use '--base' option to specify the
> base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
> 
> url:    https://github.com/0day-ci/linux/commits/Julia-Lawall/use-mmgrab/20191230-011611
> base:   https://github.com/awilliam/linux-vfio.git next
> config: openrisc-simple_smp_defconfig (attached as .config)
> compiler: or1k-linux-gcc (GCC) 9.2.0
> reproduce:
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # save the attached .config to linux build tree
>         GCC_VERSION=9.2.0 make.cross ARCH=openrisc 
> 
> If you fix the issue, kindly add following tag
> Reported-by: kbuild test robot <lkp@xxxxxxxxx>
> 
> All errors (new ones prefixed by >>):
> 
>    arch/openrisc/kernel/smp.c: In function 'secondary_start_kernel':
> >> arch/openrisc/kernel/smp.c:116:2: error: implicit declaration of function 'mmgrab'; did you mean 'igrab'? [-Werror=implicit-function-declaration]
>      116 |  mmgrab(mm);
>          |  ^~~~~~
>          |  igrab
>    cc1: some warnings being treated as errors
> 
> vim +116 arch/openrisc/kernel/smp.c
> 
>    107	
>    108	asmlinkage __init void secondary_start_kernel(void)
>    109	{
>    110		struct mm_struct *mm = &init_mm;
>    111		unsigned int cpu = smp_processor_id();
>    112		/*
>    113		 * All kernel threads share the same mm context; grab a
>    114		 * reference and switch to it.
>    115		 */
>  > 116		mmgrab(mm);
>    117		current->active_mm = mm;
>    118		cpumask_set_cpu(cpu, mm_cpumask(mm));
>    119	
>    120		pr_info("CPU%u: Booted secondary processor\n", cpu);
>    121	
>    122		setup_cpuinfo();
>    123		openrisc_clockevent_init();
>    124	
>    125		notify_cpu_starting(cpu);
>    126	
>    127		/*
>    128		 * OK, now it's safe to let the boot CPU continue
>    129		 */
>    130		complete(&cpu_running);
>    131	
>    132		synchronise_count_slave(cpu);
>    133		set_cpu_online(cpu, true);
>    134	
>    135		local_irq_enable();
>    136	
>    137		preempt_disable();
>    138		/*
>    139		 * OK, it's off to the idle thread for us
>    140		 */
>    141		cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
>    142	}
>    143	
> 

Hello,  FYI I have fixed this commit and queued it on my 5.7 branch.

-Stafford