Make __get_user_pages return -EHWPOISON for HWPOISON page only if
FOLL_HWPOISON is specified. With this patch, the interested callers
can distinguish HWPOISON page from general FAULT page, while other
callers will still get -EFAULT for pages, so the user space interface
need not to be changed.
get_user_pages_hwpoison is added as a variant of get_user_pages that
can return -EHWPOISON for HWPOISON page.
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@xxxxxxxxx>
Cc: Andrew Morton<akpm@xxxxxxxxxxxxxxxxxxxx>
+#ifdef CONFIG_MEMORY_FAILURE
+int get_user_pages_hwpoison(struct task_struct *tsk, struct mm_struct *mm,
+ unsigned long start, int nr_pages, int write,
+ int force, struct page **pages,
+ struct vm_area_struct **vmas);
+#else