Re: [PATCH][RFC] global errno considered harmful

Jeff Dike
2001-12-30T18:36:18Z

buytenh@gnu.org said:
> Is there any particular reason we need a global errno in the kernel at
> all? (which, by the way, doesn't seem to be subject to any kind of
> locking)

As far as I've been able to tell, no.

> It makes life for User Mode Linux somewhat more complicated
> than it could be, and it generally just seems a bad idea.

Yeah. In order for -fno-common to not blow up the UML build (because of the
clash between libc errno and kernel errno), I had to add -Derrno=kernel_errno
to all the kernel file compiles. It would be nice to get rid of that wart.

> Referenced patch deletes all mention of a global errno from the
> kernel

Awesome. This definitely needs to happen. If no one spots any breakage,
send it in...

> and fixes up callers where necessary.

I did some grepping and the only problem I noticed was UML's execve (heh)
converting a -errno return to a -1.

Jeff