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

Matthew Wilcox
2021-03-02T17:22:23Z

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]]);