From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Baoquan He <bhe@redhat.com>
Date: Sat, 28 Oct 2017 09:30:38 +0800
Subject: [PATCH] x86/mm/64: Rename the register_page_bootmem_memmap() 'size'
 parameter to 'nr_pages'
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CVE-2017-5754

register_page_bootmem_memmap()'s 3rd 'size' parameter is named
in a somewhat misleading fashion - rename it to 'nr_pages' which
makes the units of it much clearer.

Meanwhile rename the existing local variable 'nr_pages' to
'nr_pmd_pages', a more expressive name, to avoid conflict with
new function parameter 'nr_pages'.

(Also clean up the unnecessary parentheses in which get_order() is called.)

Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: akpm@linux-foundation.org
Link: http://lkml.kernel.org/r/1509154238-23250-1-git-send-email-bhe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
(cherry picked from commit 15670bfe19905b1dcbb63137f40d718b59d84479)
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
(cherry picked from commit d73ad1d31ef8a44c6e5977c5123cbaa6d02e2035)
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
---
 include/linux/mm.h    |  2 +-
 arch/x86/mm/init_64.c | 10 +++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 07630442bbf2..97f6ca707010 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2475,7 +2475,7 @@ void vmemmap_populate_print_last(void);
 void vmemmap_free(unsigned long start, unsigned long end);
 #endif
 void register_page_bootmem_memmap(unsigned long section_nr, struct page *map,
-				  unsigned long size);
+				  unsigned long nr_pages);
 
 enum mf_flags {
 	MF_COUNT_INCREASED = 1 << 0,
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 136422d7d539..902983c8ea8c 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1418,16 +1418,16 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
 
 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HAVE_BOOTMEM_INFO_NODE)
 void register_page_bootmem_memmap(unsigned long section_nr,
-				  struct page *start_page, unsigned long size)
+				  struct page *start_page, unsigned long nr_pages)
 {
 	unsigned long addr = (unsigned long)start_page;
-	unsigned long end = (unsigned long)(start_page + size);
+	unsigned long end = (unsigned long)(start_page + nr_pages);
 	unsigned long next;
 	pgd_t *pgd;
 	p4d_t *p4d;
 	pud_t *pud;
 	pmd_t *pmd;
-	unsigned int nr_pages;
+	unsigned int nr_pmd_pages;
 	struct page *page;
 
 	for (; addr < end; addr = next) {
@@ -1474,9 +1474,9 @@ void register_page_bootmem_memmap(unsigned long section_nr,
 			if (pmd_none(*pmd))
 				continue;
 
-			nr_pages = 1 << (get_order(PMD_SIZE));
+			nr_pmd_pages = 1 << get_order(PMD_SIZE);
 			page = pmd_page(*pmd);
-			while (nr_pages--)
+			while (nr_pmd_pages--)
 				get_page_bootmem(section_nr, page++,
 						 SECTION_INFO);
 		}
-- 
2.14.2

