Re: [PATCH] ARC: uaccess: get_user to zero out dest in cause of fault

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

On Mon, Aug 22, 2016 at 04:48:00PM -0700, Linus Torvalds wrote:
> On Mon, Aug 22, 2016 at 4:12 PM, H. Peter Anvin <hpa@zytor.com> wrote:
> >
> > How about the gcc native __builtin_setjmp stuff which is supposedly better?
> 
> How new is it? The whole point was that we'd not have to worry and
> wait for gcc features..

Sat Jan 27 07:59:25 1996  Richard Kenner  (kenner@vlsi1.ultra.nyu.edu)

        * tree.h (enum built_in_function): Add BUILT_IN_{SET,LONG}JMP.
        * expr.c: Include hard-reg-set.h.
        (arg_pointer_save_area): New declaration.
        (expand_builtin, case BUILT_IN_{SET,LONG}JMP): New cases.
        * Makefile.in (expr.o): Includes hard-reg-set.h.
        * c-decl.c (init_decl_processing): Add definitions for
        __builtin_setjmp and __builtin_longjmp.
        * cccp.c (initialize_builtins): Add def of __HAVE_BUILTIN_SETJMP__.

        * expr.c (expand_expr, case COMPONENT_REF): Pass EXPAND_INITIALIZER
        to recursive call.

IOW - old; the last branch lacking it is 2.7.2.*  Both 2.8 and egcs (and thus
2.95 and everything subsequent) have it.