Re: [PATCH] unicore32: Stop printing the virtual memory layout

From: Kees Cook
Date: Tue Aug 28 2018 - 10:30:39 EST


On Tue, Aug 28, 2018 at 7:23 AM, Geert Uytterhoeven
<geert+renesas@xxxxxxxxx> wrote:
> Since commit ad67b74d2469d9b8 ("printk: hash addresses printed with
> %p"), the virtual memory layout printed during boot up contains "ptrval"
> instead of actual addresses.
>
> Instead of changing the printing to "%px", and leaking virtual memory
> layout information again, just remove the printing completely, cfr. e.g.
> commits 071929dbdd865f77 ("arm64: Stop printing the virtual memory
> layout") and 31833332f7987636 ("m68k/mm: Stop printing the virtual
> memory layout").
>
> All interesting information (actual section sizes) is already printed by
> mem_init_print_info() just above anyway.
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

Nice!

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

-Kees

> ---
> arch/unicore32/mm/init.c | 24 ------------------------
> 1 file changed, 24 deletions(-)
>
> diff --git a/arch/unicore32/mm/init.c b/arch/unicore32/mm/init.c
> index f4950fbfe57493c7..1662058c272a5917 100644
> --- a/arch/unicore32/mm/init.c
> +++ b/arch/unicore32/mm/init.c
> @@ -344,30 +344,6 @@ void __init mem_init(void)
> free_all_bootmem();
>
> mem_init_print_info(NULL);
> - printk(KERN_NOTICE "Virtual kernel memory layout:\n"
> - " vector : 0x%08lx - 0x%08lx (%4ld kB)\n"
> - " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
> - " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n"
> - " modules : 0x%08lx - 0x%08lx (%4ld MB)\n"
> - " .init : 0x%p" " - 0x%p" " (%4d kB)\n"
> - " .text : 0x%p" " - 0x%p" " (%4d kB)\n"
> - " .data : 0x%p" " - 0x%p" " (%4d kB)\n",
> -
> - VECTORS_BASE, VECTORS_BASE + PAGE_SIZE,
> - DIV_ROUND_UP(PAGE_SIZE, SZ_1K),
> - VMALLOC_START, VMALLOC_END,
> - DIV_ROUND_UP((VMALLOC_END - VMALLOC_START), SZ_1M),
> - PAGE_OFFSET, (unsigned long)high_memory,
> - DIV_ROUND_UP(((unsigned long)high_memory - PAGE_OFFSET), SZ_1M),
> - MODULES_VADDR, MODULES_END,
> - DIV_ROUND_UP((MODULES_END - MODULES_VADDR), SZ_1M),
> -
> - __init_begin, __init_end,
> - DIV_ROUND_UP((__init_end - __init_begin), SZ_1K),
> - _stext, _etext,
> - DIV_ROUND_UP((_etext - _stext), SZ_1K),
> - _sdata, _edata,
> - DIV_ROUND_UP((_edata - _sdata), SZ_1K));
>
> BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
> BUG_ON(TASK_SIZE > MODULES_VADDR);
> --
> 2.17.1
>



--
Kees Cook
Pixel Security