lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

x86: fix the missing BIOS area check in page_is_ram

Browse Source 
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>
This commit is contained in:
Thomas Gleixner
2008-01-30 13:34:06 +01:00
committed by Ingo Molnar
parent 5f5192b9fe
commit 950f9d95be
3 changed files with 14 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
arch/x86/mm/ioremap.c
View File

@@ -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;
}