diff options
| -rw-r--r-- | Documentation/vm/hwpoison.txt | 3 | ||||
| -rw-r--r-- | mm/hwpoison-inject.c | 41 | ||||
| -rw-r--r-- | mm/internal.h | 2 |
3 files changed, 43 insertions, 3 deletions
diff --git a/Documentation/vm/hwpoison.txt b/Documentation/vm/hwpoison.txt index fdf5804..4ef7bb3 100644 --- a/Documentation/vm/hwpoison.txt +++ b/Documentation/vm/hwpoison.txt @@ -103,7 +103,8 @@ hwpoison-inject module through debugfs corrupt-pfn -Inject hwpoison fault at PFN echoed into this file. +Inject hwpoison fault at PFN echoed into this file. This does +some early filtering to avoid corrupted unintended pages in test suites. unpoison-pfn diff --git a/mm/hwpoison-inject.c b/mm/hwpoison-inject.c index ac692a9..2b6b320 100644 --- a/mm/hwpoison-inject.c +++ b/mm/hwpoison-inject.c @@ -3,16 +3,53 @@ #include <linux/debugfs.h> #include <linux/kernel.h> #include <linux/mm.h> +#include <linux/swap.h> +#include <linux/pagemap.h> #include "internal.h" static struct dentry *hwpoison_dir; static int hwpoison_inject(void *data, u64 val) { + unsigned long pfn = val; + struct page *p; + int err; + if (!capable(CAP_SYS_ADMIN)) return -EPERM; - printk(KERN_INFO "Injecting memory failure at pfn %Lx\n", val); - return __memory_failure(val, 18, 0); + + if (!pfn_valid(pfn)) + return -ENXIO; + + p = pfn_to_page(pfn); + /* + * This implies unable to support free buddy pages. + */ + if (!get_page_unless_zero(p)) + return 0; + + if (!PageLRU(p)) + shake_page(p); + /* + * This implies unable to support non-LRU pages. + */ + if (!PageLRU(p)) + return 0; + + /* + * do a racy check with elevated page count, to make sure PG_hwpoison + * will only be set for the targeted owner (or on a free page). + * We temporarily take page lock for try_get_mem_cgroup_from_page(). + * __memory_failure() will redo the check reliably inside page lock. + */ + lock_page(p); + err = hwpoison_filter(p); + unlock_page(p); + if (err) + return 0; + + printk(KERN_INFO "Injecting memory failure at pfn %lx\n", pfn); + return __memory_failure(pfn, 18, MF_COUNT_INCREASED); } static int hwpoison_unpoison(void *data, u64 val) diff --git a/mm/internal.h b/mm/internal.h index 814da33..04bbce8 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -251,5 +251,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, #define ZONE_RECLAIM_SUCCESS 1 #endif +extern int hwpoison_filter(struct page *p); + extern u32 hwpoison_filter_dev_major; extern u32 hwpoison_filter_dev_minor; |
