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

2022-03-09 Thread Christophe Leroy




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")
3182f798 ("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 


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)


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

2020-03-05 Thread Tycho Andersen
On Thu, Mar 05, 2020 at 10:08:37AM -0500, Arvind Sankar wrote:
> 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")
> 3182f798 ("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 

Acked-by: Tycho Andersen