[PATCH] [16/16] HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs

Andi Kleen
2009-05-27T20:18:04Z

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.

Open issues:

Should be disabled for cgroups.

Signed-off-by: Andi Kleen <ak@linux.intel.com>

---
mm/Kconfig | 4 ++++
mm/Makefile | 1 +
mm/hwpoison-inject.c | 41 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 46 insertions(+)

Index: linux/mm/hwpoison-inject.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux/mm/hwpoison-inject.c 2009-05-27 21:14:21.000000000 +0200
@@ -0,0 +1,41 @@
+/* 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>
+
+static struct dentry *hwpoison_dir, *corrupt_pfn;
+
+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);
+ memory_failure(val, 18);
+ return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
+
+static void pfn_inject_exit(void)
+{
+ if (hwpoison_dir)
+ debugfs_remove_recursive(hwpoison_dir);
+}
+
+static int pfn_inject_init(void)
+{
+ hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
+ if (hwpoison_dir == NULL)
+ return -ENOMEM;
+ corrupt_pfn = debugfs_create_file("corrupt-pfn", 0600, hwpoison_dir, NULL,
+ &hwpoison_fops);
+ if (corrupt_pfn == NULL) {
+ pfn_inject_exit();
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+module_init(pfn_inject_init);
+module_exit(pfn_inject_exit);
Index: linux/mm/Kconfig
===================================================================
--- linux.orig/mm/Kconfig 2009-05-27 21:14:21.000000000 +0200
+++ linux/mm/Kconfig 2009-05-27 21:14:21.000000000 +0200
@@ -231,6 +231,10 @@
default y
depends on MMU

+config HWPOISON_INJECT
+ tristate "Poison pages injector"
+ depends on MEMORY_FAILURE && DEBUG_KERNEL
+
config NOMMU_INITIAL_TRIM_EXCESS
int "Turn on mmap() excess space trimming before booting"
depends on !MMU
Index: linux/mm/Makefile
===================================================================
--- linux.orig/mm/Makefile 2009-05-27 21:14:21.000000000 +0200
+++ linux/mm/Makefile 2009-05-27 21:14:21.000000000 +0200
@@ -39,3 +39,4 @@
obj-$(CONFIG_QUICKLIST) += quicklist.o
obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o page_cgroup.o
obj-$(CONFIG_MEMORY_FAILURE) += memory-failure.o
+obj-$(CONFIG_HWPOISON_INJECT) += hwpoison-inject.o