korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-12-23 19:14:30 +08:00
Code Issues Packages Projects Releases Wiki Activity

x86: fix early_ioremap()/btmap

Browse Source 
fix a long-standing weakness of the early-ioremap allocator: it
uses a single pgd entry for the boot mappings, and was not properly
protecting itself against crossing a 2MB (4MB) boundary.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Ingo Molnar 2008-01-30 13:33:48 +01:00
parent d690b2afd5
commit d701fda860
1 changed files with 10 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
include/asm-x86/fixmap_32.h
View File

@ -90,10 +90,18 @@ enum fixed_addresses {
FIX_PARAVIRT_BOOTMAP,
#endif
__end_of_permanent_fixed_addresses,
/* temporary boot-time mappings, used before ioremap() is functional */
/*
* 256 temporary boot-time mappings, used by early_ioremap(),
* before ioremap() is functional.
*
* We round it up to the next 512 pages boundary so that we
* can have a single pgd entry and a single pte table:
*/
#define NR_FIX_BTMAPS 64
#define FIX_BTMAPS_NESTING 4
FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
FIX_BTMAP_END =
__end_of_permanent_fixed_addresses + 512 -
(__end_of_permanent_fixed_addresses & 511),
FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS*FIX_BTMAPS_NESTING - 1,
FIX_WP_TEST,
__end_of_fixed_addresses