diff options
Diffstat (limited to 'fs')
-rw-r--r-- | fs/proc/proc_misc.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c index 3462bfde89f6..19b69f931bef 100644 --- a/fs/proc/proc_misc.c +++ b/fs/proc/proc_misc.c | |||
@@ -46,6 +46,7 @@ | |||
46 | #include <linux/vmalloc.h> | 46 | #include <linux/vmalloc.h> |
47 | #include <linux/crash_dump.h> | 47 | #include <linux/crash_dump.h> |
48 | #include <linux/pid_namespace.h> | 48 | #include <linux/pid_namespace.h> |
49 | #include <linux/bootmem.h> | ||
49 | #include <asm/uaccess.h> | 50 | #include <asm/uaccess.h> |
50 | #include <asm/pgtable.h> | 51 | #include <asm/pgtable.h> |
51 | #include <asm/io.h> | 52 | #include <asm/io.h> |
@@ -675,6 +676,54 @@ static const struct file_operations proc_sysrq_trigger_operations = { | |||
675 | }; | 676 | }; |
676 | #endif | 677 | #endif |
677 | 678 | ||
679 | #define KPMSIZE sizeof(u64) | ||
680 | #define KPMMASK (KPMSIZE - 1) | ||
681 | /* /proc/kpagecount - an array exposing page counts | ||
682 | * | ||
683 | * Each entry is a u64 representing the corresponding | ||
684 | * physical page count. | ||
685 | */ | ||
686 | static ssize_t kpagecount_read(struct file *file, char __user *buf, | ||
687 | size_t count, loff_t *ppos) | ||
688 | { | ||
689 | u64 __user *out = (u64 __user *)buf; | ||
690 | struct page *ppage; | ||
691 | unsigned long src = *ppos; | ||
692 | unsigned long pfn; | ||
693 | ssize_t ret = 0; | ||
694 | u64 pcount; | ||
695 | |||
696 | pfn = src / KPMSIZE; | ||
697 | count = min_t(size_t, count, (max_pfn * KPMSIZE) - src); | ||
698 | if (src & KPMMASK || count & KPMMASK) | ||
699 | return -EIO; | ||
700 | |||
701 | while (count > 0) { | ||
702 | ppage = pfn_to_page(pfn++); | ||
703 | if (!ppage) | ||
704 | pcount = 0; | ||
705 | else | ||
706 | pcount = atomic_read(&ppage->_count); | ||
707 | |||
708 | if (put_user(pcount, out++)) { | ||
709 | ret = -EFAULT; | ||
710 | break; | ||
711 | } | ||
712 | |||
713 | count -= KPMSIZE; | ||
714 | } | ||
715 | |||
716 | *ppos += (char __user *)out - buf; | ||
717 | if (!ret) | ||
718 | ret = (char __user *)out - buf; | ||
719 | return ret; | ||
720 | } | ||
721 | |||
722 | static struct file_operations proc_kpagecount_operations = { | ||
723 | .llseek = mem_lseek, | ||
724 | .read = kpagecount_read, | ||
725 | }; | ||
726 | |||
678 | struct proc_dir_entry *proc_root_kcore; | 727 | struct proc_dir_entry *proc_root_kcore; |
679 | 728 | ||
680 | void create_seq_entry(char *name, mode_t mode, const struct file_operations *f) | 729 | void create_seq_entry(char *name, mode_t mode, const struct file_operations *f) |
@@ -755,6 +804,7 @@ void __init proc_misc_init(void) | |||
755 | (size_t)high_memory - PAGE_OFFSET + PAGE_SIZE; | 804 | (size_t)high_memory - PAGE_OFFSET + PAGE_SIZE; |
756 | } | 805 | } |
757 | #endif | 806 | #endif |
807 | create_seq_entry("kpagecount", S_IRUSR, &proc_kpagecount_operations); | ||
758 | #ifdef CONFIG_PROC_VMCORE | 808 | #ifdef CONFIG_PROC_VMCORE |
759 | proc_vmcore = create_proc_entry("vmcore", S_IRUSR, NULL); | 809 | proc_vmcore = create_proc_entry("vmcore", S_IRUSR, NULL); |
760 | if (proc_vmcore) | 810 | if (proc_vmcore) |