diff options
| author | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:33:48 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:33:48 +0100 |
| commit | d701fda8601fe267fbd3648f108f0e751305101b (patch) | |
| tree | ed4e32e3ff33eb9e01a4c8321776b82b834c6fce /include/asm-x86 | |
| parent | d690b2afd5a7a02816386aa704c8c0b1aca8d2de (diff) | |
x86: fix early_ioremap()/btmap
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>
Diffstat (limited to 'include/asm-x86')
| -rw-r--r-- | include/asm-x86/fixmap_32.h | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/include/asm-x86/fixmap_32.h b/include/asm-x86/fixmap_32.h index 46bedb7b542..fde140fd6d9 100644 --- a/include/asm-x86/fixmap_32.h +++ b/include/asm-x86/fixmap_32.h @@ -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 |