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mm: make __get_user_pages return -EHWPOISON for HWPOISON page optionally

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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>
This commit is contained in:
Huang Ying 2011-01-30 11:15:48 +08:00 committed by Marcelo Tosatti
parent 0014bd990e
commit 69ebb83e13
7 changed files with 21 additions and 3 deletions
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2
arch/alpha/include/asm/errno.h
View file

@ -122,4 +122,6 @@
#define ERFKILL 138 /* Operation not possible due to RF-kill */
#define EHWPOISON 139 /* Memory page has hardware error */
#endif

2
arch/mips/include/asm/errno.h
View file

@ -121,6 +121,8 @@
#define ERFKILL 167 /* Operation not possible due to RF-kill */
#define EHWPOISON 168 /* Memory page has hardware error */
#define EDQUOT 1133 /* Quota exceeded */
#ifdef __KERNEL__

2
arch/parisc/include/asm/errno.h
View file

@ -122,4 +122,6 @@
#define ERFKILL 256 /* Operation not possible due to RF-kill */
#define EHWPOISON 257 /* Memory page has hardware error */
#endif

2
arch/sparc/include/asm/errno.h
View file

@ -112,4 +112,6 @@
#define ERFKILL 134 /* Operation not possible due to RF-kill */
#define EHWPOISON 135 /* Memory page has hardware error */
#endif

2
include/asm-generic/errno.h
View file

@ -108,4 +108,6 @@
#define ERFKILL 132 /* Operation not possible due to RF-kill */
#define EHWPOISON 133 /* Memory page has hardware error */
#endif

1
include/linux/mm.h
View file

@ -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);

13
mm/memory.c
View file

@ -1576,9 +1576,16 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
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();
}