Re: [PATCH v2 0/2] vfs: Define new syscall getumask.

From: H. Peter Anvin
Date: Sun Apr 17 2016 - 22:16:17 EST


On 04/17/16 19:12, Josh Triplett wrote:
>>
>> I really like the 'libinux' idea, did anyone every hack up a first-pass
>> at this? And I'm guessing we have more syscalls now that would need to
>> be added (like getrandom(), but that shouldn't be too difficult.
>
> Personally, I'd suggest that libinux should wire up *all* (non-obsolete)
> syscalls, not just those that haven't already been exposed via any
> particular libc implementation. Each such syscall function would have
> minimal overhead, since unlike libc these wrappers would not have any
> special handling (other than use of the vdso) and would directly map to
> the kernel syscall signature. Given a standard prefix like sys_ or
> linux_, that would provide a clear distinction between direct-syscall
> functions and libc functions, and avoid any future conflict if libc adds
> a function named the same as the syscall.
>
> As a random example, sys_getpid() would *always* call the getpid
> syscall, rather than reading a cache within the library. (And
> sys_gettid would call the gettid syscall, rather than failing to exist.)
>

I'm not so sure this is a good idea. It has definite pros and cons. In
some ways it pushes it more to be like syscall(3).

-hpa