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>

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>
Andi Kleen · Andi Kleen
1 parent 9893e49d64
Showing 3 changed files with 46 additions and 0 deletions Side-by-side Diff
mm/Kconfig
mm/Makefile
mm/hwpoison-inject.c
@@ -243,6 +243,10 @@
 	  even when some of its memory has uncorrected errors. This requires
 	  special hardware support and typically ECC memory.
  
+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
@@ -41,6 +41,7 @@
 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
 obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o
 obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o
+/* 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);
+	return __memory_failure(val, 18, 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);
+MODULE_LICENSE("GPL");
...	...	@@ -243,6 +243,10 @@
243	243	even when some of its memory has uncorrected errors. This requires
244	244	special hardware support and typically ECC memory.
245	245
	246	+config HWPOISON_INJECT
	247	+ tristate "Poison pages injector"
	248	+ depends on MEMORY_FAILURE && DEBUG_KERNEL
	249	+
246	250	config NOMMU_INITIAL_TRIM_EXCESS
247	251	int "Turn on mmap() excess space trimming before booting"
248	252	depends on !MMU
...	...	@@ -41,6 +41,7 @@
41	41	obj-$(CONFIG_QUICKLIST) += quicklist.o
42	42	obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o page_cgroup.o
43	43	obj-$(CONFIG_MEMORY_FAILURE) += memory-failure.o
	44	+obj-$(CONFIG_HWPOISON_INJECT) += hwpoison-inject.o
44	45	obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o
45	46	obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o
	1	+/* Inject a hwpoison memory failure on a arbitary pfn */
	2	+#include <linux/module.h>
	3	+#include <linux/debugfs.h>
	4	+#include <linux/kernel.h>
	5	+#include <linux/mm.h>
	6	+
	7	+static struct dentry hwpoison_dir, corrupt_pfn;
	8	+
	9	+static int hwpoison_inject(void *data, u64 val)
	10	+{
	11	+ if (!capable(CAP_SYS_ADMIN))
	12	+ return -EPERM;
	13	+ printk(KERN_INFO "Injecting memory failure at pfn %Lx\n", val);
	14	+ return __memory_failure(val, 18, 0);
	15	+}
	16	+
	17	+DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
	18	+
	19	+static void pfn_inject_exit(void)
	20	+{
	21	+ if (hwpoison_dir)
	22	+ debugfs_remove_recursive(hwpoison_dir);
	23	+}
	24	+
	25	+static int pfn_inject_init(void)
	26	+{
	27	+ hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
	28	+ if (hwpoison_dir == NULL)
	29	+ return -ENOMEM;
	30	+ corrupt_pfn = debugfs_create_file("corrupt-pfn", 0600, hwpoison_dir,
	31	+ NULL, &hwpoison_fops);
	32	+ if (corrupt_pfn == NULL) {
	33	+ pfn_inject_exit();
	34	+ return -ENOMEM;
	35	+ }
	36	+ return 0;
	37	+}
	38	+
	39	+module_init(pfn_inject_init);
	40	+module_exit(pfn_inject_exit);
	41	+MODULE_LICENSE("GPL");