Commit 280abe14 authored by Adrian-Ken Rueegsegger's avatar Adrian-Ken Rueegsegger Committed by Thomas Gleixner
Browse files

x86/mm: Fix marking of unused sub-pmd ranges 



The unused part precedes the new range spanned by the start, end parameters
of vmemmap_use_new_sub_pmd(). This means it actually goes from
ALIGN_DOWN(start, PMD_SIZE) up to start.

Use the correct address when applying the mark using memset.

Fixes: 8d400913 ("x86/vmemmap: handle unpopulated sub-pmd ranges")
Signed-off-by: default avatarAdrian-Ken Rueegsegger <ken@codelabs.ch>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220509090637.24152-2-ken@codelabs.ch
parent c5eb0a61

arch/x86/mm/init_64.c

+3 −2
Original line number Diff line number Diff line
@@ -902,6 +902,8 @@ static void __meminit vmemmap_use_sub_pmd(unsigned long start, unsigned long end 


static void __meminit vmemmap_use_new_sub_pmd(unsigned long start, unsigned long end)

{

	const unsigned long page = ALIGN_DOWN(start, PMD_SIZE);



	vmemmap_flush_unused_pmd();



	/*
@@ -914,8 +916,7 @@ static void __meminit vmemmap_use_new_sub_pmd(unsigned long start, unsigned long 
	 * Mark with PAGE_UNUSED the unused parts of the new memmap range

	 */

	if (!IS_ALIGNED(start, PMD_SIZE))

		memset((void *)start, PAGE_UNUSED,

			start - ALIGN_DOWN(start, PMD_SIZE));

		memset((void *)page, PAGE_UNUSED, start - page);



	/*

	 * We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of