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authorHuang Ying <ying.huang@intel.com>2011-01-30 11:15:48 +0800
committerMarcelo Tosatti <mtosatti@redhat.com>2011-03-17 13:08:27 -0300
commit69ebb83e13e514222b0ae4f8bd813a17679ed876 (patch)
tree62ccc7ee1e840d0a6cc01a9fc1c44a5f4e6f1edd /include
parent0014bd990e69063b0fb78940b35439d7980ce3ee (diff)
downloadlinux-69ebb83e13e514222b0ae4f8bd813a17679ed876.tar.gz
mm: make __get_user_pages return -EHWPOISON for HWPOISON page optionally
Make __get_user_pages return -EHWPOISON for HWPOISON page only if
FOLL_HWPOISON is specified.  With this patch, the interested callers
can distinguish HWPOISON pages from general FAULT pages, while other
callers will still get -EFAULT for all these pages, so the user space
interface need not to be changed.

This feature is needed by KVM, where UCR MCE should be relayed to
guest for HWPOISON page, while instruction emulation and MMIO will be
tried for general FAULT page.

The idea comes from Andrew Morton.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'include')
-rw-r--r--include/asm-generic/errno.h2
-rw-r--r--include/linux/mm.h1
2 files changed, 3 insertions, 0 deletions
diff --git a/include/asm-generic/errno.h b/include/asm-generic/errno.h
index 28cc03bf19e6..a1331ce50445 100644
--- 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
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 46150c66318e..a77c82c56e05 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1532,6 +1532,7 @@ struct page *follow_page(struct vm_area_struct *, unsigned long address,
 #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);