Re: patch series moving compat syscalls from fs/compat.c

From: Al Viro
Date: Sun Apr 23 2017 - 20:56:04 EST


On Mon, Apr 24, 2017 at 10:31:34AM +1000, Stephen Rothwell wrote:
> Hi Al,
>
> I couldn't easily find this patch series posted anywhere (I didn't try
> too hard) so I sill just comment here. I first noticed them in the vfs
> tree in linux-next today.
>
> Overall, I like what they day, but when I first created kernel/compat.c
> (in 2002), Linus did not want the compat code sprinkled all over the
> other files (due to the uglifiying effect of #ifdefs in the C code, and
> because the compat layer was only secondary). He may have changed his
> mind since then, but it is worth asking. The cleanups (including more
> static functions) make it worth while for me, at least.
>
> It also might have been worth asking the original (and subsequent)
> authors of the code for review and/or comments.

FWIW, the same kind of stuff had been done before (e.g. compat
variants of readv/writev moved to fs/read_write.c, compat aio syscalls
to fs/aio.c, etc.) with no objections from anybody.

The situation with kernel/compat.c is slightly different, but fs/compat.c
contains very little shared infrastructure - almost all of it is straight
"here's compat variant of this syscall, making use of the guts of the
native one".