Re: [PATCH 3/3] [v4] lib/vsprintf: no_hash_pointers prints all addresses as unhashed

Marco Elver
2021-03-02T19:48:14Z

On Tue, 2 Mar 2021 at 15:35, Matthew Wilcox <willy@infradead.org> wrote:
>
> On Tue, Mar 02, 2021 at 03:26:50PM +0100, Marco Elver wrote:
> > +static const char no_hash_pointers_warning[9][55] __initconst = {
> > + "******************************************************",
> > + " NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE ",
> > + " ",
> > + " This system shows unhashed kernel memory addresses ",
> > + " via the console, logs, and other interfaces. This ",
> > + " might reduce the security of your system. ",
> > + " If you see this message and you are not debugging ",
> > + " the kernel, report this immediately to your system ",
> > + " administrator! ",
> > +};
> > +
> > static int __init no_hash_pointers_enable(char *str)
> > {
> > + const int lines[] = { 0, 1, 2, 3, 4, 5, 2, 6, 7, 8, 2, 1, 0 };
> > + int i;
> > +
> > no_hash_pointers = true;
> >
> > - pr_warn("**********************************************************\n");
> > - pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
> > - pr_warn("** **\n");
> > - pr_warn("** This system shows unhashed kernel memory addresses **\n");
> > - pr_warn("** via the console, logs, and other interfaces. This **\n");
> > - pr_warn("** might reduce the security of your system. **\n");
> > - pr_warn("** **\n");
> > - pr_warn("** If you see this message and you are not debugging **\n");
> > - pr_warn("** the kernel, report this immediately to your system **\n");
> > - pr_warn("** administrator! **\n");
> > - pr_warn("** **\n");
> > - pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
> > - pr_warn("**********************************************************\n");
> > + for (i = 0; i < ARRAY_SIZE(lines); i++)
> > + pr_warn("**%s**\n", no_hash_pointers_warning[lines[i]]);
>
> + for (i = 0; i < 3; i++)
> + pr_warn("**%s**\n", no_hash_pointers_warning[lines[2 - i]]);

Yeah, I had that before, but then wanted to deal with the blank line
in the middle of the thing. So I just went with the lines array above,
which seemed cleanest for dealing with the middle blank line and
footer. Or maybe there's something even nicer I missed? :-)

Thanks,
-- Marco