From: Adrian-Ken Rueegsegger ken@codelabs.ch
commit 280abe14b6e0a38de9cc86fe6a019523aadd8f70 upstream.
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: 8d400913c231 ("x86/vmemmap: handle unpopulated sub-pmd ranges") Signed-off-by: Adrian-Ken Rueegsegger ken@codelabs.ch Signed-off-by: Thomas Gleixner tglx@linutronix.de Reviewed-by: Oscar Salvador osalvador@suse.de Reviewed-by: David Hildenbrand david@redhat.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220509090637.24152-2-ken@codelabs.ch Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/mm/init_64.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -902,6 +902,8 @@ static void __meminit vmemmap_use_sub_pm
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_su * 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