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authorThomas Gleixner <tglx@linutronix.de>2008-01-30 13:34:06 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-30 13:34:06 +0100
commit950f9d95bed1a366434d3597ea75f5b9d772d74f (patch)
tree900c548d99c14aacc31888a3483545f8352aea22
parent5f5192b9feeff6a96c97c143c3ca558fdbe2dc8e (diff)
x86: fix the missing BIOS area check in page_is_ram
page_is_ram has a FIXME since ages, which reminds to sanity check the BIOS area between 640k and 1M, which is sometimes falsely reported as RAM in the e820 tables. Implement the sanity check. Move the BIOS range defines from pageattr.c into e820.h to avoid duplicate defines. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--arch/x86/mm/ioremap.c15
-rw-r--r--arch/x86/mm/pageattr.c7
-rw-r--r--include/asm-x86/e820.h3
3 files changed, 14 insertions, 11 deletions
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index d3026e1906f..24e42cab8d5 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -42,13 +42,18 @@ int page_is_ram(unsigned long pagenr)
*/
if (e820.map[i].type != E820_RAM)
continue;
- /*
- * !!!FIXME!!! Some BIOSen report areas as RAM that
- * are not. Notably the 640->1Mb area. We need a sanity
- * check here.
- */
addr = (e820.map[i].addr + PAGE_SIZE-1) >> PAGE_SHIFT;
end = (e820.map[i].addr + e820.map[i].size) >> PAGE_SHIFT;
+
+ /*
+ * Sanity check: Some BIOSen report areas as RAM that
+ * are not. Notably the 640->1Mb area, which is the
+ * PCI BIOS area.
+ */
+ if (addr >= (BIOS_BEGIN >> PAGE_SHIFT) &&
+ end < (BIOS_END >> PAGE_SHIFT))
+ continue;
+
if ((pagenr >= addr) && (pagenr < end))
return 1;
}
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 19f7f7a0b36..fcd96125c5a 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -9,18 +9,13 @@
#include <linux/slab.h>
#include <linux/mm.h>
+#include <asm/e820.h>
#include <asm/processor.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
#include <asm/uaccess.h>
#include <asm/pgalloc.h>
-/*
- * We must allow the BIOS range to be executable:
- */
-#define BIOS_BEGIN 0x000a0000
-#define BIOS_END 0x00100000
-
static inline int
within(unsigned long addr, unsigned long start, unsigned long end)
{
diff --git a/include/asm-x86/e820.h b/include/asm-x86/e820.h
index f96f1853bc4..7004251fc66 100644
--- a/include/asm-x86/e820.h
+++ b/include/asm-x86/e820.h
@@ -25,6 +25,9 @@ struct e820map {
#define ISA_START_ADDRESS 0xa0000
#define ISA_END_ADDRESS 0x100000
+#define BIOS_BEGIN 0x000a0000
+#define BIOS_END 0x00100000
+
#ifdef __KERNEL__
#ifdef CONFIG_X86_32
# include "e820_32.h"