Re: [PATCH v2 14/35] nds32: System calls handling

[Vincent Chen]

2017-11-27 22:46 GMT+08:00 Arnd Bergmann <arnd@xxxxxxxx>:
> On Mon, Nov 27, 2017 at 1:28 PM, Greentime Hu <green.hu@xxxxxxxxx> wrote:
>
>> diff --git a/arch/nds32/include/asm/syscalls.h b/arch/nds32/include/asm/syscalls.h
>> new file mode 100644
>> index 0000000..741ccdc
>> --- /dev/null
>> +++ b/arch/nds32/include/asm/syscalls.h
>> @@ -0,0 +1,27 @@
>> +/*
>> + * Copyright (C) 2005-2017 Andes Technology Corporation
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
>> + */
>> +
>> +#ifndef __ASM_NDS32_SYSCALLS_H
>> +#define __ASM_NDS32_SYSCALLS_H
>> +
>> +int sys_cacheflush(unsigned long addr, unsigned long len, unsigned int op);
>> +long sys_fadvise64_64_wrapper(int fd, int advice, loff_t offset, loff_t len);
>> +asmlinkage int sys_syscall(void);
>> +asmlinkage int sys_rt_sigreturn_wrapper(void);
>
> You mentioned that sys_syscall() should be removed in this version.
>

Sorry, I will remove it in next version patch.

> By convention, all syscall declarations should start with 'asmlinkage long',
> even though this has no effect in your architecture.
>

Thanks.
I will modify it  in next version patch.

>> diff --git a/arch/nds32/include/uapi/asm/unistd.h b/arch/nds32/include/uapi/asm/unistd.h
>> new file mode 100644
>> index 0000000..2bad1e7
>> --- /dev/null
>> +++ b/arch/nds32/include/uapi/asm/unistd.h
>
>> +
>> +#define __ARCH_WANT_RENAMEAT
>> +#define __ARCH_WANT_SYSCALL_OFF_T
>
> These two should not be here.
>

Thanks.
But, I don't know I should move these two macro to which file.
In asm-generic/unistd.h, these two are used to decide whether relative
syscall number is defined or not.
Therefore,  I put these two macros here in order that these two
definitions are available in user space.


>> +#define __ARCH_WANT_SYNC_FILE_RANGE2
>
> This one is fine though
>
>> +/* Use the standard ABI for syscalls */
>> +#include <asm-generic/unistd.h>
>> +
>> +__SYSCALL(__NR_fadvise64_64, sys_fadvise64_64_wrapper)
>> +__SYSCALL(__NR_rt_sigreturn, sys_rt_sigreturn_wrapper)
>
> I think you are overriding the array assignment here, this may cause a
> compiler warning when building with "make C=1 V=1" since you have
> the same index assigned to two pointers. A better way to do this
> is to override the name:
>
> #define sys_rt_sigreturn sys_rt_sigreturn_wrapper
> #define sys_fadvise64_64 sys_fadvise64_64_wrapper
> #include <asm-generic/unistd.h>
>
Thanks,
I will follow your suggestion to modify it in the next version patch.

>
>       Arnd


Vincent