fs/proc/proc_misc.c

   1 /*
   2  *  linux/fs/proc/proc_misc.c
   3  *
   4  *  linux/fs/proc/array.c
   5  *  Copyright (C) 1992  by Linus Torvalds
   6  *  based on ideas by Darren Senn
   7  *
   8  *  This used to be the part of array.c. See the rest of history and credits
   9  *  there. I took this into a separate file and switched the thing to generic
  10  *  proc_file_inode_operations, leaving in array.c only per-process stuff.
  11  *  Inumbers allocation made dynamic (via create_proc_entry()).  AV, May 1999.
  12  *
  13  * Changes:
  14  * Fulton Green      :  Encapsulated position metric calculations.
  15  *                      <kernel@FultonGreen.com>
  16  */
  17
  18 #include <linux/types.h>
  19 #include <linux/errno.h>
  20 #include <linux/time.h>
  21 #include <linux/kernel.h>
  22 #include <linux/kernel_stat.h>
  23 #include <linux/fs.h>
  24 #include <linux/tty.h>
  25 #include <linux/string.h>
  26 #include <linux/mman.h>
  27 #include <linux/quicklist.h>
  28 #include <linux/proc_fs.h>
  29 #include <linux/ioport.h>
  30 #include <linux/mm.h>
  31 #include <linux/mmzone.h>
  32 #include <linux/pagemap.h>
  33 #include <linux/irq.h>
  34 #include <linux/interrupt.h>
  35 #include <linux/swap.h>
  36 #include <linux/slab.h>
  37 #include <linux/genhd.h>
  38 #include <linux/smp.h>
  39 #include <linux/signal.h>
  40 #include <linux/module.h>
  41 #include <linux/init.h>
  42 #include <linux/seq_file.h>
  43 #include <linux/times.h>
  44 #include <linux/profile.h>
  45 #include <linux/utsname.h>
  46 #include <linux/blkdev.h>
  47 #include <linux/hugetlb.h>
  48 #include <linux/jiffies.h>
  49 #include <linux/vmalloc.h>
  50 #include <linux/crash_dump.h>
  51 #include <linux/pid_namespace.h>
  52 #include <linux/bootmem.h>
  53 #include <asm/uaccess.h>
  54 #include <asm/pgtable.h>
  55 #include <asm/io.h>
  56 #include <asm/tlb.h>
  57 #include <asm/div64.h>
  58 #include "internal.h"
  59
  60 #ifdef CONFIG_PROC_PAGE_MONITOR
  61 #define KPMSIZE sizeof(u64)
  62 #define KPMMASK (KPMSIZE - 1)
  63 /* /proc/kpagecount - an array exposing page counts
  64  *
  65  * Each entry is a u64 representing the corresponding
  66  * physical page count.
  67  */
  68 static ssize_t kpagecount_read(struct file *file, char __user *buf,
  69                              size_t count, loff_t *ppos)
  70 {
  71         u64 __user *out = (u64 __user *)buf;
  72         struct page *ppage;
  73         unsigned long src = *ppos;
  74         unsigned long pfn;
  75         ssize_t ret = 0;
  76         u64 pcount;
  77
  78         pfn = src / KPMSIZE;
  79         count = min_t(size_t, count, (max_pfn * KPMSIZE) - src);
  80         if (src & KPMMASK || count & KPMMASK)
  81                 return -EINVAL;
  82
  83         while (count > 0) {
  84                 ppage = NULL;
  85                 if (pfn_valid(pfn))
  86                         ppage = pfn_to_page(pfn);
  87                 pfn++;
  88                 if (!ppage)
  89                         pcount = 0;
  90                 else
  91                         pcount = page_mapcount(ppage);
  92
  93                 if (put_user(pcount, out++)) {
  94                         ret = -EFAULT;
  95                         break;
  96                 }
  97
  98                 count -= KPMSIZE;
  99         }
 100
 101         *ppos += (char __user *)out - buf;
 102         if (!ret)
 103                 ret = (char __user *)out - buf;
 104         return ret;
 105 }
 106
 107 static struct file_operations proc_kpagecount_operations = {
 108         .llseek = mem_lseek,
 109         .read = kpagecount_read,
 110 };
 111
 112 /* /proc/kpageflags - an array exposing page flags
 113  *
 114  * Each entry is a u64 representing the corresponding
 115  * physical page flags.
 116  */
 117
 118 /* These macros are used to decouple internal flags from exported ones */
 119
 120 #define KPF_LOCKED     0
 121 #define KPF_ERROR      1
 122 #define KPF_REFERENCED 2
 123 #define KPF_UPTODATE   3
 124 #define KPF_DIRTY      4
 125 #define KPF_LRU        5
 126 #define KPF_ACTIVE     6
 127 #define KPF_SLAB       7
 128 #define KPF_WRITEBACK  8
 129 #define KPF_RECLAIM    9
 130 #define KPF_BUDDY     10
 131
 132 #define kpf_copy_bit(flags, srcpos, dstpos) (((flags >> srcpos) & 1) << dstpos)
 133
 134 static ssize_t kpageflags_read(struct file *file, char __user *buf,
 135                              size_t count, loff_t *ppos)
 136 {
 137         u64 __user *out = (u64 __user *)buf;
 138         struct page *ppage;
 139         unsigned long src = *ppos;
 140         unsigned long pfn;
 141         ssize_t ret = 0;
 142         u64 kflags, uflags;
 143
 144         pfn = src / KPMSIZE;
 145         count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src);
 146         if (src & KPMMASK || count & KPMMASK)
 147                 return -EINVAL;
 148
 149         while (count > 0) {
 150                 ppage = NULL;
 151                 if (pfn_valid(pfn))
 152                         ppage = pfn_to_page(pfn);
 153                 pfn++;
 154                 if (!ppage)
 155                         kflags = 0;
 156                 else
 157                         kflags = ppage->flags;
 158
 159                 uflags = kpf_copy_bit(KPF_LOCKED, PG_locked, kflags) |
 160                         kpf_copy_bit(kflags, KPF_ERROR, PG_error) |
 161                         kpf_copy_bit(kflags, KPF_REFERENCED, PG_referenced) |
 162                         kpf_copy_bit(kflags, KPF_UPTODATE, PG_uptodate) |
 163                         kpf_copy_bit(kflags, KPF_DIRTY, PG_dirty) |
 164                         kpf_copy_bit(kflags, KPF_LRU, PG_lru) |
 165                         kpf_copy_bit(kflags, KPF_ACTIVE, PG_active) |
 166                         kpf_copy_bit(kflags, KPF_SLAB, PG_slab) |
 167                         kpf_copy_bit(kflags, KPF_WRITEBACK, PG_writeback) |
 168                         kpf_copy_bit(kflags, KPF_RECLAIM, PG_reclaim) |
 169                         kpf_copy_bit(kflags, KPF_BUDDY, PG_buddy);
 170
 171                 if (put_user(uflags, out++)) {
 172                         ret = -EFAULT;
 173                         break;
 174                 }
 175
 176                 count -= KPMSIZE;
 177         }
 178
 179         *ppos += (char __user *)out - buf;
 180         if (!ret)
 181                 ret = (char __user *)out - buf;
 182         return ret;
 183 }
 184
 185 static struct file_operations proc_kpageflags_operations = {
 186         .llseek = mem_lseek,
 187         .read = kpageflags_read,
 188 };
 189 #endif /* CONFIG_PROC_PAGE_MONITOR */
 190
 191 void __init proc_misc_init(void)
 192 {
 193         proc_symlink("mounts", NULL, "self/mounts");
 194
 195         /* And now for trickier ones */
 196 #ifdef CONFIG_PROC_PAGE_MONITOR
 197         proc_create("kpagecount", S_IRUSR, NULL, &proc_kpagecount_operations);
 198         proc_create("kpageflags", S_IRUSR, NULL, &proc_kpageflags_operations);
 199 #endif
 200 #ifdef CONFIG_PROC_VMCORE
 201         proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &proc_vmcore_operations);
 202 #endif
 203 }