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| author | Vegard Nossum <vegard.nossum@gmail.com> | 2009-02-27 13:35:55 +0300 |
|---|---|---|
| committer | Vegard Nossum <vegard.nossum@gmail.com> | 2009-06-15 17:49:22 +0400 |
| commit | ac61a7579625ddfca3b2e0aa298879a94d15884d (patch) | |
| tree | adb11c2513bfdb4825e1ac213f8116d7280ac4a9 /arch/x86/mm/kmemcheck/kmemcheck.c | |
| parent | eb63657e1314ae4af5e19a61db8dc1b6e935775a (diff) | |
| download | linux-ac61a7579625ddfca3b2e0aa298879a94d15884d.tar.xz | |
kmemcheck: add opcode self-testing at boot
We've had some troubles in the past with weird instructions. This
patch adds a self-test framework which can be used to verify that
a certain set of opcodes are decoded correctly. Of course, the
opcodes which are not tested can still give the wrong results.
In short, this is just a safeguard to catch unintentional changes
in the opcode decoder. It does not mean that errors can't still
occur!
[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Diffstat (limited to 'arch/x86/mm/kmemcheck/kmemcheck.c')
| -rw-r--r-- | arch/x86/mm/kmemcheck/kmemcheck.c | 25 |
1 files changed, 9 insertions, 16 deletions
diff --git a/arch/x86/mm/kmemcheck/kmemcheck.c b/arch/x86/mm/kmemcheck/kmemcheck.c index 6931e5115bcd..2c55ed098654 100644 --- a/arch/x86/mm/kmemcheck/kmemcheck.c +++ b/arch/x86/mm/kmemcheck/kmemcheck.c @@ -29,8 +29,10 @@ #include "error.h" #include "opcode.h" #include "pte.h" +#include "selftest.h" #include "shadow.h" + #ifdef CONFIG_KMEMCHECK_DISABLED_BY_DEFAULT # define KMEMCHECK_ENABLED 0 #endif @@ -47,8 +49,6 @@ int kmemcheck_enabled = KMEMCHECK_ENABLED; int __init kmemcheck_init(void) { - printk(KERN_INFO "kmemcheck: Initialized\n"); - #ifdef CONFIG_SMP /* * Limit SMP to use a single CPU. We rely on the fact that this code @@ -61,25 +61,18 @@ int __init kmemcheck_init(void) } #endif + if (!kmemcheck_selftest()) { + printk(KERN_INFO "kmemcheck: self-tests failed; disabling\n"); + kmemcheck_enabled = 0; + return -EINVAL; + } + + printk(KERN_INFO "kmemcheck: Initialized\n"); return 0; } early_initcall(kmemcheck_init); -#ifdef CONFIG_KMEMCHECK_DISABLED_BY_DEFAULT -# define KMEMCHECK_ENABLED 0 -#endif - -#ifdef CONFIG_KMEMCHECK_ENABLED_BY_DEFAULT -# define KMEMCHECK_ENABLED 1 -#endif - -#ifdef CONFIG_KMEMCHECK_ONESHOT_BY_DEFAULT -# define KMEMCHECK_ENABLED 2 -#endif - -int kmemcheck_enabled = KMEMCHECK_ENABLED; - /* * We need to parse the kmemcheck= option before any memory is allocated. */ |