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authorAndi Kleen <andi@firstfloor.org>2009-09-16 11:50:17 +0200
committerAndi Kleen <ak@linux.intel.com>2009-09-16 11:50:17 +0200
commit9893e49d64a4874ea67849ee2cfbf3f3d6817573 (patch)
tree2bf3c7950cdae1c1ed03a513a6690d95f0c02d5c
parentf590f333fb15444d2971f979d434ecad56c09698 (diff)
downloadop-kernel-dev-9893e49d64a4874ea67849ee2cfbf3f3d6817573.zip
op-kernel-dev-9893e49d64a4874ea67849ee2cfbf3f3d6817573.tar.gz
HWPOISON: Add madvise() based injector for hardware poisoned pages v4
Impact: optional, useful for debugging Add a new madvice sub command to inject poison for some pages in a process' address space. This is useful for testing the poison page handling. This patch can allow root to tie up large amounts of memory. I got feedback from container developers and they didn't see any problem. v2: Use write flag for get_user_pages to make sure to always get a fresh page v3: Don't request write mapping (Fengguang Wu) v4: Move MADV_* number to avoid conflict with KSM (Hugh Dickins) Signed-off-by: Andi Kleen <ak@linux.intel.com>
-rw-r--r--include/asm-generic/mman-common.h1
-rw-r--r--mm/madvise.c30
2 files changed, 31 insertions, 0 deletions
diff --git a/include/asm-generic/mman-common.h b/include/asm-generic/mman-common.h
index 3b69ad3..c325d1e 100644
--- a/include/asm-generic/mman-common.h
+++ b/include/asm-generic/mman-common.h
@@ -34,6 +34,7 @@
#define MADV_REMOVE 9 /* remove these pages & resources */
#define MADV_DONTFORK 10 /* don't inherit across fork */
#define MADV_DOFORK 11 /* do inherit across fork */
+#define MADV_HWPOISON 100 /* poison a page for testing */
/* compatibility flags */
#define MAP_FILE 0
diff --git a/mm/madvise.c b/mm/madvise.c
index 76eb419..8dbd38b 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -207,6 +207,32 @@ static long madvise_remove(struct vm_area_struct *vma,
return error;
}
+#ifdef CONFIG_MEMORY_FAILURE
+/*
+ * Error injection support for memory error handling.
+ */
+static int madvise_hwpoison(unsigned long start, unsigned long end)
+{
+ int ret = 0;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ for (; start < end; start += PAGE_SIZE) {
+ struct page *p;
+ int ret = get_user_pages(current, current->mm, start, 1,
+ 0, 0, &p, NULL);
+ if (ret != 1)
+ return ret;
+ printk(KERN_INFO "Injecting memory failure for page %lx at %lx\n",
+ page_to_pfn(p), start);
+ /* Ignore return value for now */
+ __memory_failure(page_to_pfn(p), 0, 1);
+ put_page(p);
+ }
+ return ret;
+}
+#endif
+
static long
madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
unsigned long start, unsigned long end, int behavior)
@@ -307,6 +333,10 @@ SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
int write;
size_t len;
+#ifdef CONFIG_MEMORY_FAILURE
+ if (behavior == MADV_HWPOISON)
+ return madvise_hwpoison(start, start+len_in);
+#endif
if (!madvise_behavior_valid(behavior))
return error;
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