From 69ebb83e13e514222b0ae4f8bd813a17679ed876 Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Sun, 30 Jan 2011 11:15:48 +0800 Subject: 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 Cc: Andrew Morton Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- arch/alpha/include/asm/errno.h | 2 ++ arch/mips/include/asm/errno.h | 2 ++ arch/parisc/include/asm/errno.h | 2 ++ arch/sparc/include/asm/errno.h | 2 ++ include/asm-generic/errno.h | 2 ++ include/linux/mm.h | 1 + mm/memory.c | 13 ++++++++++--- 7 files changed, 21 insertions(+), 3 deletions(-) diff --git a/arch/alpha/include/asm/errno.h b/arch/alpha/include/asm/errno.h index 98099bda9370..e5f29ca28180 100644 --- a/arch/alpha/include/asm/errno.h +++ b/arch/alpha/include/asm/errno.h @@ -122,4 +122,6 @@ #define ERFKILL 138 /* Operation not possible due to RF-kill */ +#define EHWPOISON 139 /* Memory page has hardware error */ + #endif diff --git a/arch/mips/include/asm/errno.h b/arch/mips/include/asm/errno.h index a0efc73819e4..6dcd3583ed04 100644 --- a/arch/mips/include/asm/errno.h +++ b/arch/mips/include/asm/errno.h @@ -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__ diff --git a/arch/parisc/include/asm/errno.h b/arch/parisc/include/asm/errno.h index 9992abdd782d..135ad6047e51 100644 --- a/arch/parisc/include/asm/errno.h +++ b/arch/parisc/include/asm/errno.h @@ -122,4 +122,6 @@ #define ERFKILL 256 /* Operation not possible due to RF-kill */ +#define EHWPOISON 257 /* Memory page has hardware error */ + #endif diff --git a/arch/sparc/include/asm/errno.h b/arch/sparc/include/asm/errno.h index 4e2bc490d714..c351aba997b7 100644 --- a/arch/sparc/include/asm/errno.h +++ b/arch/sparc/include/asm/errno.h @@ -112,4 +112,6 @@ #define ERFKILL 134 /* Operation not possible due to RF-kill */ +#define EHWPOISON 135 /* Memory page has hardware error */ + #endif 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); diff --git a/mm/memory.c b/mm/memory.c index 806a37ec71bd..346ee7e041fd 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -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(); } -- cgit v1.2.3