The patch titled
fix buggy MTRR address checks
has been added to the -mm tree. Its filename is
fix-buggy-mtrr-address-checks.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: fix buggy MTRR address checks
From: Andreas Mohr <andi@xxxxxxxxxxxxxxxxxxxxxxx>
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.
Note that my patch is pretty much UNTESTED, since I can only verify that it
successfully boots my machine, but I cannot test against actual buggy
hardware which would require these (formerly broken) checks. Long -mm
simmering would make sense, especially since these now-working checks might
turn out to have adverse effects on unaffected hardware.
Signed-off-by: Andreas Mohr <andi@xxxxxxxx>
Cc: Jan Beulich <jbeulich@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
arch/i386/kernel/cpu/mtrr/generic.c | 4 ++--
arch/i386/kernel/cpu/mtrr/main.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff -puN arch/i386/kernel/cpu/mtrr/generic.c~fix-buggy-mtrr-address-checks arch/i386/kernel/cpu/mtrr/generic.c
--- a/arch/i386/kernel/cpu/mtrr/generic.c~fix-buggy-mtrr-address-checks
+++ a/arch/i386/kernel/cpu/mtrr/generic.c
@@ -366,7 +366,7 @@ int generic_validate_add_page(unsigned l
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 l
}
}
- 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;
diff -puN arch/i386/kernel/cpu/mtrr/main.c~fix-buggy-mtrr-address-checks arch/i386/kernel/cpu/mtrr/main.c
--- a/arch/i386/kernel/cpu/mtrr/main.c~fix-buggy-mtrr-address-checks
+++ a/arch/i386/kernel/cpu/mtrr/main.c
@@ -263,8 +263,8 @@ static void set_mtrr(unsigned int reg, u
/**
* mtrr_add_page - Add a memory type region
- * @base: Physical base address of region in pages (4 KB)
- * @size: Physical size of region in pages (4 KB)
+ * @base: Physical base address of region in pages (in units of 4 kB!)
+ * @size: Physical size of region in pages (4 kB)
* @type: Type of MTRR desired
* @increment: If this is true do usage counting on the region
*
_
Patches currently in -mm which might be from andi@xxxxxxxxxxxxxxxxxxxxxxx are
origin.patch
fs-bioc-tweaks.patch
fix-buggy-mtrr-address-checks.patch
acx1xx-wireless-driver.patch
-
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