Re: [PATCH] powerpc/32: Stop printing the virtual memory layout

Christophe Leroy
2022-03-09T19:35:58Z

Le 05/03/2020 à 16:08, Arvind Sankar a écrit :
> For security, don't display the kernel's virtual memory layout.
>
> Kees Cook points out:
> "These have been entirely removed on other architectures, so let's
> just do the same for ia32 and remove it unconditionally."
>
> 071929dbdd86 ("arm64: Stop printing the virtual memory layout")
> 1c31d4e96b8c ("ARM: 8820/1: mm: Stop printing the virtual memory layout")
> 31833332f798 ("m68k/mm: Stop printing the virtual memory layout")
> fd8d0ca25631 ("parisc: Hide virtual kernel memory layout")
> adb1fe9ae2ee ("mm/page_alloc: Remove kernel address exposure in free_reserved_area()")
>
> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>

This patch doesn't apply anymore.

This patch is referenced in https://github.com/linuxppc/issues/issues/390

> ---
> arch/powerpc/mm/mem.c | 17 -----------------
> 1 file changed, 17 deletions(-)
>
> diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
> index ef7b1119b2e2..df2c143b6bf7 100644
> --- a/arch/powerpc/mm/mem.c
> +++ b/arch/powerpc/mm/mem.c
> @@ -331,23 +331,6 @@ void __init mem_init(void)
> #endif
>
> mem_init_print_info(NULL);
> -#ifdef CONFIG_PPC32
> - pr_info("Kernel virtual memory layout:\n");
> -#ifdef CONFIG_KASAN
> - pr_info(" * 0x%08lx..0x%08lx : kasan shadow mem\n",
> - KASAN_SHADOW_START, KASAN_SHADOW_END);
> -#endif
> - pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP);
> -#ifdef CONFIG_HIGHMEM
> - pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n",
> - PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
> -#endif /* CONFIG_HIGHMEM */
> - if (ioremap_bot != IOREMAP_TOP)
> - pr_info(" * 0x%08lx..0x%08lx : early ioremap\n",
> - ioremap_bot, IOREMAP_TOP);
> - pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n",
> - VMALLOC_START, VMALLOC_END);
> -#endif /* CONFIG_PPC32 */
> }
>
> void free_initmem(void)