Re: [RFC] unexport linux/elfcore.h

[Al Viro <viro@zeniv.linux.org.uk>]

On Thu, Jun 11, 2020 at 01:01:40PM -0700, Linus Torvalds wrote:
> On Thu, Jun 11, 2020 at 8:23 AM Al Viro <viro@zeniv.linux.org.uk> wrote:
> >
> > I mean something like this.  Objections?
> 
> I'm not seeing that alot of people would care.
> 
> That said, is there any reason not to try to fix it instead and expose
> elf_gregset_t some way?
> 
> But I do suspect it all really boils down to "nobody cares". If you
> can't find somebody to speak up for it, might as well remove it.

Anyone who wants to use that stuff includes sys/procfs.h anyway (since
1996).  As for the reasons...  I would love to kill off these gems, for
example:
#define PRSTATUS_SIZE(S, R) (R != sizeof(S.pr_reg) ? 144 : 296)
#define SET_PR_FPVALID(S, V, R) \
  do { *(int *) (((void *) &((S)->pr_reg)) + R) = (V); } \
  while (0)
(x86 asm/compat.h)  And being able to massage the definition of
elf_prstatus (while keeping the size and layout - it describes
a part of file format, after all) would simplify the life alot.

struct __kernel_elf_prstatus would be an obvious solution, but...
nobody in userland pulls the definition in linux/elfcore.h and
hadn't been able to do that for at least a decade (if not more than
that).  So I'd rather get rid of exporting it.