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linux_old1/mm/hwpoison-inject.c

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HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs Useful for some testing scenarios, although specific testing is often done better through MADV_POISON This can be done with the x86 level MCE injector too, but this interface allows it to do independently from low level x86 changes. v2: Add module license (Haicheng Li) Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 17:50:17 +08:00
/* Inject a hwpoison memory failure on a arbitary pfn */
#include <linux/module.h>
#include <linux/debugfs.h>
#include <linux/kernel.h>
#include <linux/mm.h>
HWPOISON: Add unpoisoning support The unpoisoning interface is useful for stress testing tools to reclaim poisoned pages (to prevent OOM) There is no hardware level unpoisioning, so this cannot be used for real memory errors, only for software injected errors. Note that it may leak pages silently - those who have been removed from LRU cache, but not isolated from page cache/swap cache at hwpoison time. Especially the stress test of dirty swap cache pages shall reboot system before exhausting memory. AK: Fix comments, add documentation, add printks, rename symbol Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 19:19:58 +08:00
static struct dentry *hwpoison_dir;
HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs Useful for some testing scenarios, although specific testing is often done better through MADV_POISON This can be done with the x86 level MCE injector too, but this interface allows it to do independently from low level x86 changes. v2: Add module license (Haicheng Li) Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 17:50:17 +08:00
static int hwpoison_inject(void *data, u64 val)
{
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
printk(KERN_INFO "Injecting memory failure at pfn %Lx\n", val);
return __memory_failure(val, 18, 0);
}
HWPOISON: Add unpoisoning support The unpoisoning interface is useful for stress testing tools to reclaim poisoned pages (to prevent OOM) There is no hardware level unpoisioning, so this cannot be used for real memory errors, only for software injected errors. Note that it may leak pages silently - those who have been removed from LRU cache, but not isolated from page cache/swap cache at hwpoison time. Especially the stress test of dirty swap cache pages shall reboot system before exhausting memory. AK: Fix comments, add documentation, add printks, rename symbol Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 19:19:58 +08:00
static int hwpoison_unpoison(void *data, u64 val)
{
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
return unpoison_memory(val);
}
HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs Useful for some testing scenarios, although specific testing is often done better through MADV_POISON This can be done with the x86 level MCE injector too, but this interface allows it to do independently from low level x86 changes. v2: Add module license (Haicheng Li) Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 17:50:17 +08:00
DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
HWPOISON: Add unpoisoning support The unpoisoning interface is useful for stress testing tools to reclaim poisoned pages (to prevent OOM) There is no hardware level unpoisioning, so this cannot be used for real memory errors, only for software injected errors. Note that it may leak pages silently - those who have been removed from LRU cache, but not isolated from page cache/swap cache at hwpoison time. Especially the stress test of dirty swap cache pages shall reboot system before exhausting memory. AK: Fix comments, add documentation, add printks, rename symbol Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 19:19:58 +08:00
DEFINE_SIMPLE_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs Useful for some testing scenarios, although specific testing is often done better through MADV_POISON This can be done with the x86 level MCE injector too, but this interface allows it to do independently from low level x86 changes. v2: Add module license (Haicheng Li) Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 17:50:17 +08:00
static void pfn_inject_exit(void)
{
if (hwpoison_dir)
debugfs_remove_recursive(hwpoison_dir);
}
static int pfn_inject_init(void)
{
HWPOISON: Add unpoisoning support The unpoisoning interface is useful for stress testing tools to reclaim poisoned pages (to prevent OOM) There is no hardware level unpoisioning, so this cannot be used for real memory errors, only for software injected errors. Note that it may leak pages silently - those who have been removed from LRU cache, but not isolated from page cache/swap cache at hwpoison time. Especially the stress test of dirty swap cache pages shall reboot system before exhausting memory. AK: Fix comments, add documentation, add printks, rename symbol Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 19:19:58 +08:00
struct dentry *dentry;
HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs Useful for some testing scenarios, although specific testing is often done better through MADV_POISON This can be done with the x86 level MCE injector too, but this interface allows it to do independently from low level x86 changes. v2: Add module license (Haicheng Li) Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 17:50:17 +08:00
hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
if (hwpoison_dir == NULL)
return -ENOMEM;
HWPOISON: Add unpoisoning support The unpoisoning interface is useful for stress testing tools to reclaim poisoned pages (to prevent OOM) There is no hardware level unpoisioning, so this cannot be used for real memory errors, only for software injected errors. Note that it may leak pages silently - those who have been removed from LRU cache, but not isolated from page cache/swap cache at hwpoison time. Especially the stress test of dirty swap cache pages shall reboot system before exhausting memory. AK: Fix comments, add documentation, add printks, rename symbol Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 19:19:58 +08:00
/*
* Note that the below poison/unpoison interfaces do not involve
* hardware status change, hence do not require hardware support.
* They are mainly for testing hwpoison in software level.
*/
dentry = debugfs_create_file("corrupt-pfn", 0600, hwpoison_dir,
HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs Useful for some testing scenarios, although specific testing is often done better through MADV_POISON This can be done with the x86 level MCE injector too, but this interface allows it to do independently from low level x86 changes. v2: Add module license (Haicheng Li) Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 17:50:17 +08:00
NULL, &hwpoison_fops);
HWPOISON: Add unpoisoning support The unpoisoning interface is useful for stress testing tools to reclaim poisoned pages (to prevent OOM) There is no hardware level unpoisioning, so this cannot be used for real memory errors, only for software injected errors. Note that it may leak pages silently - those who have been removed from LRU cache, but not isolated from page cache/swap cache at hwpoison time. Especially the stress test of dirty swap cache pages shall reboot system before exhausting memory. AK: Fix comments, add documentation, add printks, rename symbol Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 19:19:58 +08:00
if (!dentry)
goto fail;
dentry = debugfs_create_file("unpoison-pfn", 0600, hwpoison_dir,
NULL, &unpoison_fops);
if (!dentry)
goto fail;
HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs Useful for some testing scenarios, although specific testing is often done better through MADV_POISON This can be done with the x86 level MCE injector too, but this interface allows it to do independently from low level x86 changes. v2: Add module license (Haicheng Li) Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 17:50:17 +08:00
return 0;
HWPOISON: Add unpoisoning support The unpoisoning interface is useful for stress testing tools to reclaim poisoned pages (to prevent OOM) There is no hardware level unpoisioning, so this cannot be used for real memory errors, only for software injected errors. Note that it may leak pages silently - those who have been removed from LRU cache, but not isolated from page cache/swap cache at hwpoison time. Especially the stress test of dirty swap cache pages shall reboot system before exhausting memory. AK: Fix comments, add documentation, add printks, rename symbol Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 19:19:58 +08:00
fail:
pfn_inject_exit();
return -ENOMEM;
HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs Useful for some testing scenarios, although specific testing is often done better through MADV_POISON This can be done with the x86 level MCE injector too, but this interface allows it to do independently from low level x86 changes. v2: Add module license (Haicheng Li) Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 17:50:17 +08:00
}
module_init(pfn_inject_init);
module_exit(pfn_inject_exit);
MODULE_LICENSE("GPL");