On Tue, Sep 25, 2018 at 11:42:26PM +0800, Michael Mikonos wrote:
> On Tue, Sep 25, 2018 at 05:25:54PM +0200, Sebastien Marie wrote:
> > On Tue, Sep 25, 2018 at 11:15:43PM +0800, Michael Mikonos wrote:
> > > On Tue, Sep 25, 2018 at 03:22:38PM +0100, Ricardo Mestre wrote:
> > > > This is an example of better to start at just hoisting the code that
> > > > opens the many fds and put them all inside open_files(). After that it's
> > > > just a matter of calling pledge("stdio") and we are done.
> > > >
> > > > Of course that after this is done we can still make a list of all the
> > > > files
> > > > we need to open and unveil them, but not the way it's done here.
> > > >
> > > > Once I get back home from $DAYJOB I'll try to have a look at this.
> > >
> > > After open_files() the wpath pledge can be dropped. rpath is still
> > > needed because /tmp files are reopened for read in output(). cpath
> > > is needed because /tmp files are unlinked at the end. This patch
> > > adds a pledge call, but is it better to just move the first pledge()
> > > down?
> > >
> >
> > you could try with the "tmppath" promise. I will allow opening/creating
> > files on /tmp and unlinking them (but not sure it will cover all yacc
> > need as it is designed for mkstemp(3) family). Unveil for such
> > operations are fine too, without explicit unveil(2) call.
> >
>
> Ah, I see what you mean. pledging "tmppath" is kind of like unveil
> because the allowed operations only work under /tmp.
> It's possible to do this after calling open_files() because the only
> files (re)opened later are in /tmp.
My description was wrong. tmppath allows unlink of /tmp files at the
end. rpath is still needed to reopen the /tmp files.
>
> Index: main.c
> ===================================================================
> RCS file: /cvs/src/usr.bin/yacc/main.c,v
> retrieving revision 1.29
> diff -u -p -u -r1.29 main.c
> --- main.c 25 May 2017 20:11:03 -0000 1.29
> +++ main.c 25 Sep 2018 15:38:18 -0000
> @@ -346,12 +346,16 @@ open_files(void)
> int
> main(int argc, char *argv[])
> {
> - if (pledge("stdio rpath wpath cpath", NULL) == -1)
> + if (pledge("stdio rpath wpath cpath tmppath", NULL) == -1)
> fatal("pledge: invalid arguments");
>
> set_signals();
> getargs(argc, argv);
> open_files();
> +
> + if (pledge("stdio rpath tmppath", NULL) == -1)
> + fatal("pledge: invalid arguments");
> +
> reader();
> lr0();
> lalr();
