diff options
| author | Andreas Mohr <andi@rhlx01.fht-esslingen.de> | 2006-12-07 02:14:00 +0100 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2006-12-07 02:14:00 +0100 |
| commit | 9b483417527f2e47985856867c5716df013227c7 (patch) | |
| tree | 35c6e2b73ebbb9c4a97ad5d9a6f7520fab1796ef /arch/i386/kernel/cpu/mtrr/generic.c | |
| parent | dc3d1742543fffc79dc4d680ab64d2059e97d809 (diff) | |
[PATCH] i386: fix buggy MTRR address checks
Fix checks that failed to realize that values are 4-kB-unit-sized (note the
format strings in this same diff context which *do* realize the unit size,
via appended "000"!). Also fix an incorrect below-1MB area check (as
gathered from Jan Beulich's unapplied patch at
http://www.ussg.iu.edu/hypermail/linux/kernel/0411.1/1378.html ) Update
mtrr_add_page() docu to make 4-kB-sized calculation more obvious.
Given several further items mentioned in Jan's patch mail, all in all MTRR
code seems surprisingly buggy, for a surprisingly long period of time (many
years). Further work/investigation would be useful.
TBD Note that my patch is pretty much UNTESTED, since I can only verify that it
TBD successfully boots my machine, but I cannot test against actual buggy
TBD hardware which would require these (formerly broken) checks. Long -mm
TBD simmering would make sense, especially since these now-working checks might
TBD turn out to have adverse effects on unaffected hardware.
Signed-off-by: Andreas Mohr <andi@lisas.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Diffstat (limited to 'arch/i386/kernel/cpu/mtrr/generic.c')
| -rw-r--r-- | arch/i386/kernel/cpu/mtrr/generic.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/i386/kernel/cpu/mtrr/generic.c b/arch/i386/kernel/cpu/mtrr/generic.c index 0b61eed8bbd..ee8dc675395 100644 --- a/arch/i386/kernel/cpu/mtrr/generic.c +++ b/arch/i386/kernel/cpu/mtrr/generic.c @@ -366,7 +366,7 @@ int generic_validate_add_page(unsigned long base, unsigned long size, unsigned i printk(KERN_WARNING "mtrr: base(0x%lx000) is not 4 MiB aligned\n", base); return -EINVAL; } - if (!(base + size < 0x70000000 || base > 0x7003FFFF) && + if (!(base + size < 0x70000 || base > 0x7003F) && (type == MTRR_TYPE_WRCOMB || type == MTRR_TYPE_WRBACK)) { printk(KERN_WARNING "mtrr: writable mtrr between 0x70000000 and 0x7003FFFF may hang the CPU.\n"); @@ -374,7 +374,7 @@ int generic_validate_add_page(unsigned long base, unsigned long size, unsigned i } } - if (base + size < 0x100) { + if (base < 0x100) { printk(KERN_WARNING "mtrr: cannot set region below 1 MiB (0x%lx000,0x%lx000)\n", base, size); return -EINVAL; |