Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 156fbc3f authored by Arjan van de Ven's avatar Arjan van de Ven Committed by Ingo Molnar
Browse files

x86: fix page_is_ram() thinko 



page_is_ram() has a special case for the 640k-1M bios area, however
due to a thinko the special case checks the e820 table entry and
not the memory the user has asked for. This patch fixes the bug.

[ mingo@elte.hu: this too is better solved in the e820 space, but those
  fixes are too intrusive for v2.6.25. ]

Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent d8a9e6a5

arch/x86/mm/ioremap.c

+7 −8
Original line number Diff line number Diff line
@@ -50,6 +50,13 @@ int page_is_ram(unsigned long pagenr) 
	if (pagenr == 0)

		return 0;



	/*

	 * Second special case: Some BIOSen report the PC BIOS

	 * area (640->1Mb) as ram even though it is not.

	 */

	if (pagenr >= (BIOS_BEGIN >> PAGE_SHIFT) &&

		    pagenr < (BIOS_END >> PAGE_SHIFT))

		return 0;



	for (i = 0; i < e820.nr_map; i++) {

		/*
@@ -60,14 +67,6 @@ int page_is_ram(unsigned long pagenr) 
		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;