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authorAndi Kleen <ak@linux.intel.com>2010-10-06 21:45:00 +0200
committerAndi Kleen <ak@linux.intel.com>2010-10-08 09:32:46 +0200
commitaa50d3a7aa8147b9e14dc9d5972a5d2359db4ef8 (patch)
tree68fae5060333dcc24c17e9dd00a87bd760d883e9 /include/linux/mm.h
parent6f39ce056ab2ab2d29b2fae4aed61ed0b485972f (diff)
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Encode huge page size for VM_FAULT_HWPOISON errors
This fixes a problem introduced with the hugetlb hwpoison handling The user space SIGBUS signalling wants to know the size of the hugepage that caused a HWPOISON fault. Unfortunately the architecture page fault handlers do not have easy access to the struct page. Pass the information out in the fault error code instead. I added a separate VM_FAULT_HWPOISON_LARGE bit for this case and encode the hpage index in some free upper bits of the fault code. The small page hwpoison keeps stays with the VM_FAULT_HWPOISON name to minimize changes. Also add code to hugetlb.h to convert that index into a page shift. Will be used in a further patch. Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: fengguang.wu@intel.com Signed-off-by: Andi Kleen <ak@linux.intel.com>
Diffstat (limited to 'include/linux/mm.h')
-rw-r--r--include/linux/mm.h12
1 files changed, 10 insertions, 2 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 74949fbef8c6..f7e9efc6720b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -718,12 +718,20 @@ static inline int page_mapped(struct page *page)
#define VM_FAULT_SIGBUS 0x0002
#define VM_FAULT_MAJOR 0x0004
#define VM_FAULT_WRITE 0x0008 /* Special case for get_user_pages */
-#define VM_FAULT_HWPOISON 0x0010 /* Hit poisoned page */
+#define VM_FAULT_HWPOISON 0x0010 /* Hit poisoned small page */
+#define VM_FAULT_HWPOISON_LARGE 0x0020 /* Hit poisoned large page. Index encoded in upper bits */
#define VM_FAULT_NOPAGE 0x0100 /* ->fault installed the pte, not return page */
#define VM_FAULT_LOCKED 0x0200 /* ->fault locked the returned page */
-#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON)
+#define VM_FAULT_HWPOISON_LARGE_MASK 0xf000 /* encodes hpage index for large hwpoison */
+
+#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON | \
+ VM_FAULT_HWPOISON_LARGE)
+
+/* Encode hstate index for a hwpoisoned large page */
+#define VM_FAULT_SET_HINDEX(x) ((x) << 12)
+#define VM_FAULT_GET_HINDEX(x) (((x) >> 12) & 0xf)
/*
* Can be called by the pagefault handler when it gets a VM_FAULT_OOM.