Re: [PATCH 16/28] nios2: System calls handling

[Pavel Machek]

On Fri 2014-04-18 20:26:59, Ley Foon Tan wrote:
> This patch adds support for system calls from userspaces. It uses the
> asm-generic/unistd.h definitions with architecture spcific syscall. The sys_call_table
> is just an array defined in a C file and it contains pointers to the syscall functions.
> 
> Signed-off-by: Ley Foon Tan <lftan@xxxxxxxxxx>


> +/* Additional Nios II specific syscalls. */
> +#define __NR_cacheflush (__NR_arch_specific_syscall)
> +__SYSCALL(__NR_cacheflush, sys_cacheflush)

I guess you should Cc: Michael Kerrisk on this one.

Also... explanation why you need this syscall while other
architectures live happily without it would be nice.

> +/* sys_cacheflush -- flush the processor cache. */
> +asmlinkage int sys_cacheflush(unsigned long addr, unsigned long len,
> +				unsigned int op)
> +{
> +	struct vm_area_struct *vma;
> +
> +	if (len == 0)
> +		return 0;

op is being ignored? You should remove it... or if (op) return -EINVAL
if you want future extensions.

-- 
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(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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