diff options
Diffstat (limited to 'fs/proc/page.c')
| -rw-r--r-- | fs/proc/page.c | 54 |
1 files changed, 39 insertions, 15 deletions
diff --git a/fs/proc/page.c b/fs/proc/page.c index 7c952ee732e6..f909243d4a66 100644 --- a/fs/proc/page.c +++ b/fs/proc/page.c @@ -21,6 +21,21 @@ #define KPMMASK (KPMSIZE - 1) #define KPMBITS (KPMSIZE * BITS_PER_BYTE) +static inline unsigned long get_max_dump_pfn(void) +{ +#ifdef CONFIG_SPARSEMEM + /* + * The memmap of early sections is completely populated and marked + * online even if max_pfn does not fall on a section boundary - + * pfn_to_online_page() will succeed on all pages. Allow inspecting + * these memmaps. + */ + return round_up(max_pfn, PAGES_PER_SECTION); +#else + return max_pfn; +#endif +} + /* /proc/kpagecount - an array exposing page counts * * Each entry is a u64 representing the corresponding @@ -29,6 +44,7 @@ static ssize_t kpagecount_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { + const unsigned long max_dump_pfn = get_max_dump_pfn(); u64 __user *out = (u64 __user *)buf; struct page *ppage; unsigned long src = *ppos; @@ -37,9 +53,11 @@ static ssize_t kpagecount_read(struct file *file, char __user *buf, u64 pcount; pfn = src / KPMSIZE; - count = min_t(size_t, count, (max_pfn * KPMSIZE) - src); if (src & KPMMASK || count & KPMMASK) return -EINVAL; + if (src >= max_dump_pfn * KPMSIZE) + return 0; + count = min_t(unsigned long, count, (max_dump_pfn * KPMSIZE) - src); while (count > 0) { /* @@ -71,9 +89,9 @@ static ssize_t kpagecount_read(struct file *file, char __user *buf, return ret; } -static const struct file_operations proc_kpagecount_operations = { - .llseek = mem_lseek, - .read = kpagecount_read, +static const struct proc_ops kpagecount_proc_ops = { + .proc_lseek = mem_lseek, + .proc_read = kpagecount_read, }; /* /proc/kpageflags - an array exposing page flags @@ -206,6 +224,7 @@ u64 stable_page_flags(struct page *page) static ssize_t kpageflags_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { + const unsigned long max_dump_pfn = get_max_dump_pfn(); u64 __user *out = (u64 __user *)buf; struct page *ppage; unsigned long src = *ppos; @@ -213,9 +232,11 @@ static ssize_t kpageflags_read(struct file *file, char __user *buf, ssize_t ret = 0; pfn = src / KPMSIZE; - count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src); if (src & KPMMASK || count & KPMMASK) return -EINVAL; + if (src >= max_dump_pfn * KPMSIZE) + return 0; + count = min_t(unsigned long, count, (max_dump_pfn * KPMSIZE) - src); while (count > 0) { /* @@ -242,15 +263,16 @@ static ssize_t kpageflags_read(struct file *file, char __user *buf, return ret; } -static const struct file_operations proc_kpageflags_operations = { - .llseek = mem_lseek, - .read = kpageflags_read, +static const struct proc_ops kpageflags_proc_ops = { + .proc_lseek = mem_lseek, + .proc_read = kpageflags_read, }; #ifdef CONFIG_MEMCG static ssize_t kpagecgroup_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { + const unsigned long max_dump_pfn = get_max_dump_pfn(); u64 __user *out = (u64 __user *)buf; struct page *ppage; unsigned long src = *ppos; @@ -259,9 +281,11 @@ static ssize_t kpagecgroup_read(struct file *file, char __user *buf, u64 ino; pfn = src / KPMSIZE; - count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src); if (src & KPMMASK || count & KPMMASK) return -EINVAL; + if (src >= max_dump_pfn * KPMSIZE) + return 0; + count = min_t(unsigned long, count, (max_dump_pfn * KPMSIZE) - src); while (count > 0) { /* @@ -293,18 +317,18 @@ static ssize_t kpagecgroup_read(struct file *file, char __user *buf, return ret; } -static const struct file_operations proc_kpagecgroup_operations = { - .llseek = mem_lseek, - .read = kpagecgroup_read, +static const struct proc_ops kpagecgroup_proc_ops = { + .proc_lseek = mem_lseek, + .proc_read = kpagecgroup_read, }; #endif /* CONFIG_MEMCG */ static int __init proc_page_init(void) { - proc_create("kpagecount", S_IRUSR, NULL, &proc_kpagecount_operations); - proc_create("kpageflags", S_IRUSR, NULL, &proc_kpageflags_operations); + proc_create("kpagecount", S_IRUSR, NULL, &kpagecount_proc_ops); + proc_create("kpageflags", S_IRUSR, NULL, &kpageflags_proc_ops); #ifdef CONFIG_MEMCG - proc_create("kpagecgroup", S_IRUSR, NULL, &proc_kpagecgroup_operations); + proc_create("kpagecgroup", S_IRUSR, NULL, &kpagecgroup_proc_ops); #endif return 0; } |