Re: [PATCH v4 16/36] nds32: System calls handling

[Arnd Bergmann]

On Mon, Dec 18, 2017 at 7:46 AM, Greentime Hu <green.hu@xxxxxxxxx> wrote:


> new file mode 100644
> index 0000000..90da745
> --- /dev/null
> +++ b/arch/nds32/include/uapi/asm/unistd.h
> @@ -0,0 +1,12 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (C) 2005-2017 Andes Technology Corporation
> +
> +#define __ARCH_WANT_SYNC_FILE_RANGE2
> +
> +/* Use the standard ABI for syscalls */
> +#include <asm-generic/unistd.h>
> +
> +/* Additional NDS32 specific syscalls. */
> +#define __NR_cacheflush                (__NR_arch_specific_syscall)
> +#define __NR__llseek             __NR_llseek
> +__SYSCALL(__NR_cacheflush, sys_cacheflush)

I'm still confused by __NR__llseek here, why do you need that one?

> +SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
> +              unsigned long, prot, unsigned long, flags,
> +              unsigned long, fd, unsigned long, pgoff)
> +{
> +       if (pgoff & (~PAGE_MASK >> 12))
> +               return -EINVAL;
> +
> +       return sys_mmap_pgoff(addr, len, prot, flags, fd,
> +                             pgoff >> (PAGE_SHIFT - 12));
> +}
> +
> +SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
> +              unsigned long, prot, unsigned long, flags,
> +              unsigned long, fd, unsigned long, pgoff)
> +{
> +       if (unlikely(pgoff & ~PAGE_MASK))
> +               return -EINVAL;
> +
> +       return sys_mmap_pgoff(addr, len, prot, flags, fd,
> +                             pgoff >> PAGE_SHIFT);
> +}

And I don't see why you define sys_mmap() in addition to sys_mmap2().

The rest of the syscall handling looks good now.

         Arnd