[-v2,2/3] mm, Make __get_user_pages return -EHWPOISON for HWPOISON page optionally

Commit Message

Huang, Ying Jan. 30, 2011, 3:15 a.m. UTC

None

Patch

--- a/include/asm-generic/errno.h
+++ b/include/asm-generic/errno.h
@@ -108,4 +108,6 @@ 
 
 #define ERFKILL		132	/* Operation not possible due to RF-kill */
 
+#define EHWPOISON	133	/* Memory page has hardware error */
+
 #endif
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1534,6 +1534,7 @@  struct page *follow_page(struct vm_area_
 #define FOLL_FORCE	0x10	/* get_user_pages read/write w/o permission */
 #define FOLL_MLOCK	0x40	/* mark page as mlocked */
 #define FOLL_SPLIT	0x80	/* don't return transhuge pages, split them */
+#define FOLL_HWPOISON	0x100	/* check page is hwpoisoned */
 
 typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
 			void *data);
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1576,9 +1576,16 @@  int __get_user_pages(struct task_struct
 				if (ret & VM_FAULT_ERROR) {
 					if (ret & VM_FAULT_OOM)
 						return i ? i : -ENOMEM;
-					if (ret &
-					    (VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE|
-					     VM_FAULT_SIGBUS))
+					if (ret & (VM_FAULT_HWPOISON |
+						   VM_FAULT_HWPOISON_LARGE)) {
+						if (i)
+							return i;
+						else if (gup_flags & FOLL_HWPOISON)
+							return -EHWPOISON;
+						else
+							return -EFAULT;
+					}
+					if (ret & VM_FAULT_SIGBUS)
 						return i ? i : -EFAULT;
 					BUG();
 				}