[PATCH] xtensa/mm: Stop printing the virtual memory layout

Arvind Sankar
2020-03-05T15:12:05Z

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>
---
arch/xtensa/mm/init.c | 46 -------------------------------------------
1 file changed, 46 deletions(-)

diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c
index 19c625e6d81f..7ba3f1fce8ec 100644
--- a/arch/xtensa/mm/init.c
+++ b/arch/xtensa/mm/init.c
@@ -155,52 +155,6 @@ void __init mem_init(void)
memblock_free_all();

mem_init_print_info(NULL);
- pr_info("virtual kernel memory layout:\n"
-#ifdef CONFIG_KASAN
- " kasan : 0x%08lx - 0x%08lx (%5lu MB)\n"
-#endif
-#ifdef CONFIG_MMU
- " vmalloc : 0x%08lx - 0x%08lx (%5lu MB)\n"
-#endif
-#ifdef CONFIG_HIGHMEM
- " pkmap : 0x%08lx - 0x%08lx (%5lu kB)\n"
- " fixmap : 0x%08lx - 0x%08lx (%5lu kB)\n"
-#endif
- " lowmem : 0x%08lx - 0x%08lx (%5lu MB)\n"
- " .text : 0x%08lx - 0x%08lx (%5lu kB)\n"
- " .rodata : 0x%08lx - 0x%08lx (%5lu kB)\n"
- " .data : 0x%08lx - 0x%08lx (%5lu kB)\n"
- " .init : 0x%08lx - 0x%08lx (%5lu kB)\n"
- " .bss : 0x%08lx - 0x%08lx (%5lu kB)\n",
-#ifdef CONFIG_KASAN
- KASAN_SHADOW_START, KASAN_SHADOW_START + KASAN_SHADOW_SIZE,
- KASAN_SHADOW_SIZE >> 20,
-#endif
-#ifdef CONFIG_MMU
- VMALLOC_START, VMALLOC_END,
- (VMALLOC_END - VMALLOC_START) >> 20,
-#ifdef CONFIG_HIGHMEM
- PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
- (LAST_PKMAP*PAGE_SIZE) >> 10,
- FIXADDR_START, FIXADDR_TOP,
- (FIXADDR_TOP - FIXADDR_START) >> 10,
-#endif
- PAGE_OFFSET, PAGE_OFFSET +
- (max_low_pfn - min_low_pfn) * PAGE_SIZE,
-#else
- min_low_pfn * PAGE_SIZE, max_low_pfn * PAGE_SIZE,
-#endif
- ((max_low_pfn - min_low_pfn) * PAGE_SIZE) >> 20,
- (unsigned long)_text, (unsigned long)_etext,
- (unsigned long)(_etext - _text) >> 10,
- (unsigned long)__start_rodata, (unsigned long)__end_rodata,
- (unsigned long)(__end_rodata - __start_rodata) >> 10,
- (unsigned long)_sdata, (unsigned long)_edata,
- (unsigned long)(_edata - _sdata) >> 10,
- (unsigned long)__init_begin, (unsigned long)__init_end,
- (unsigned long)(__init_end - __init_begin) >> 10,
- (unsigned long)__bss_start, (unsigned long)__bss_stop,
- (unsigned long)(__bss_stop - __bss_start) >> 10);
}

static void __init parse_memmap_one(char *p)
--
2.24.1