Commit 681ff018 authored by Arvind Sankar's avatar Arvind Sankar Committed by Thomas Gleixner
Browse files

x86/mm/init/32: Stop printing the virtual memory layout 



For security reasons, 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."

071929db ("arm64: Stop printing the virtual memory layout")
1c31d4e9 ("ARM: 8820/1: mm: Stop printing the virtual memory layout")
31833332 ("m68k/mm: Stop printing the virtual memory layout")
fd8d0ca2 ("parisc: Hide virtual kernel memory layout")
adb1fe9a ("mm/page_alloc: Remove kernel address exposure in free_reserved_area()")

Signed-off-by: default avatarArvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarTycho Andersen <tycho@tycho.ws>
Acked-by: default avatarKees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20200305150152.831697-1-nivedita@alum.mit.edu
parent 98d54f81

arch/x86/mm/init_32.c

+0 −38
Original line number Diff line number Diff line
@@ -788,44 +788,6 @@ void __init mem_init(void) 
	x86_init.hyper.init_after_bootmem();



	mem_init_print_info(NULL);

	printk(KERN_INFO "virtual kernel memory layout:\n"

		"    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"

		"  cpu_entry : 0x%08lx - 0x%08lx   (%4ld kB)\n"

#ifdef CONFIG_HIGHMEM

		"    pkmap   : 0x%08lx - 0x%08lx   (%4ld kB)\n"

#endif

		"    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"

		"    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"

		"      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"

		"      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"

		"      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",

		FIXADDR_START, FIXADDR_TOP,

		(FIXADDR_TOP - FIXADDR_START) >> 10,



		CPU_ENTRY_AREA_BASE,

		CPU_ENTRY_AREA_BASE + CPU_ENTRY_AREA_MAP_SIZE,

		CPU_ENTRY_AREA_MAP_SIZE >> 10,



#ifdef CONFIG_HIGHMEM

		PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,

		(LAST_PKMAP*PAGE_SIZE) >> 10,

#endif



		VMALLOC_START, VMALLOC_END,

		(VMALLOC_END - VMALLOC_START) >> 20,



		(unsigned long)__va(0), (unsigned long)high_memory,

		((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,



		(unsigned long)&__init_begin, (unsigned long)&__init_end,

		((unsigned long)&__init_end -

		 (unsigned long)&__init_begin) >> 10,



		(unsigned long)&_etext, (unsigned long)&_edata,

		((unsigned long)&_edata - (unsigned long)&_etext) >> 10,



		(unsigned long)&_text, (unsigned long)&_etext,

		((unsigned long)&_etext - (unsigned long)&_text) >> 10);



	/*

	 * Check boundaries twice: Some fundamental inconsistencies can

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