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 static int zoneinfo_open(struct inode *inode, struct file *file)
  61 {
  62         return seq_open(file, &zoneinfo_op);
  63 }
  64
  65 static const struct file_operations proc_zoneinfo_file_operations = {
  66         .open           = zoneinfo_open,
  67         .read           = seq_read,
  68         .llseek         = seq_lseek,
  69         .release        = seq_release,
  70 };
  71
  72 #ifdef CONFIG_BLOCK
  73 static int diskstats_open(struct inode *inode, struct file *file)
  74 {
  75         return seq_open(file, &diskstats_op);
  76 }
  77 static const struct file_operations proc_diskstats_operations = {
  78         .open           = diskstats_open,
  79         .read           = seq_read,
  80         .llseek         = seq_lseek,
  81         .release        = seq_release,
  82 };
  83 #endif
  84
  85 #ifdef CONFIG_MODULES
  86 extern const struct seq_operations modules_op;
  87 static int modules_open(struct inode *inode, struct file *file)
  88 {
  89         return seq_open(file, &modules_op);
  90 }
  91 static const struct file_operations proc_modules_operations = {
  92         .open           = modules_open,
  93         .read           = seq_read,
  94         .llseek         = seq_lseek,
  95         .release        = seq_release,
  96 };
  97 #endif
  98
  99 #ifdef CONFIG_PROC_PAGE_MONITOR
 100 #define KPMSIZE sizeof(u64)
 101 #define KPMMASK (KPMSIZE - 1)
 102 /* /proc/kpagecount - an array exposing page counts
 103  *
 104  * Each entry is a u64 representing the corresponding
 105  * physical page count.
 106  */
 107 static ssize_t kpagecount_read(struct file *file, char __user *buf,
 108                              size_t count, loff_t *ppos)
 109 {
 110         u64 __user *out = (u64 __user *)buf;
 111         struct page *ppage;
 112         unsigned long src = *ppos;
 113         unsigned long pfn;
 114         ssize_t ret = 0;
 115         u64 pcount;
 116
 117         pfn = src / KPMSIZE;
 118         count = min_t(size_t, count, (max_pfn * KPMSIZE) - src);
 119         if (src & KPMMASK || count & KPMMASK)
 120                 return -EINVAL;
 121
 122         while (count > 0) {
 123                 ppage = NULL;
 124                 if (pfn_valid(pfn))
 125                         ppage = pfn_to_page(pfn);
 126                 pfn++;
 127                 if (!ppage)
 128                         pcount = 0;
 129                 else
 130                         pcount = page_mapcount(ppage);
 131
 132                 if (put_user(pcount, out++)) {
 133                         ret = -EFAULT;
 134                         break;
 135                 }
 136
 137                 count -= KPMSIZE;
 138         }
 139
 140         *ppos += (char __user *)out - buf;
 141         if (!ret)
 142                 ret = (char __user *)out - buf;
 143         return ret;
 144 }
 145
 146 static struct file_operations proc_kpagecount_operations = {
 147         .llseek = mem_lseek,
 148         .read = kpagecount_read,
 149 };
 150
 151 /* /proc/kpageflags - an array exposing page flags
 152  *
 153  * Each entry is a u64 representing the corresponding
 154  * physical page flags.
 155  */
 156
 157 /* These macros are used to decouple internal flags from exported ones */
 158
 159 #define KPF_LOCKED     0
 160 #define KPF_ERROR      1
 161 #define KPF_REFERENCED 2
 162 #define KPF_UPTODATE   3
 163 #define KPF_DIRTY      4
 164 #define KPF_LRU        5
 165 #define KPF_ACTIVE     6
 166 #define KPF_SLAB       7
 167 #define KPF_WRITEBACK  8
 168 #define KPF_RECLAIM    9
 169 #define KPF_BUDDY     10
 170
 171 #define kpf_copy_bit(flags, srcpos, dstpos) (((flags >> srcpos) & 1) << dstpos)
 172
 173 static ssize_t kpageflags_read(struct file *file, char __user *buf,
 174                              size_t count, loff_t *ppos)
 175 {
 176         u64 __user *out = (u64 __user *)buf;
 177         struct page *ppage;
 178         unsigned long src = *ppos;
 179         unsigned long pfn;
 180         ssize_t ret = 0;
 181         u64 kflags, uflags;
 182
 183         pfn = src / KPMSIZE;
 184         count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src);
 185         if (src & KPMMASK || count & KPMMASK)
 186                 return -EINVAL;
 187
 188         while (count > 0) {
 189                 ppage = NULL;
 190                 if (pfn_valid(pfn))
 191                         ppage = pfn_to_page(pfn);
 192                 pfn++;
 193                 if (!ppage)
 194                         kflags = 0;
 195                 else
 196                         kflags = ppage->flags;
 197
 198                 uflags = kpf_copy_bit(KPF_LOCKED, PG_locked, kflags) |
 199                         kpf_copy_bit(kflags, KPF_ERROR, PG_error) |
 200                         kpf_copy_bit(kflags, KPF_REFERENCED, PG_referenced) |
 201                         kpf_copy_bit(kflags, KPF_UPTODATE, PG_uptodate) |
 202                         kpf_copy_bit(kflags, KPF_DIRTY, PG_dirty) |
 203                         kpf_copy_bit(kflags, KPF_LRU, PG_lru) |
 204                         kpf_copy_bit(kflags, KPF_ACTIVE, PG_active) |
 205                         kpf_copy_bit(kflags, KPF_SLAB, PG_slab) |
 206                         kpf_copy_bit(kflags, KPF_WRITEBACK, PG_writeback) |
 207                         kpf_copy_bit(kflags, KPF_RECLAIM, PG_reclaim) |
 208                         kpf_copy_bit(kflags, KPF_BUDDY, PG_buddy);
 209
 210                 if (put_user(uflags, out++)) {
 211                         ret = -EFAULT;
 212                         break;
 213                 }
 214
 215                 count -= KPMSIZE;
 216         }
 217
 218         *ppos += (char __user *)out - buf;
 219         if (!ret)
 220                 ret = (char __user *)out - buf;
 221         return ret;
 222 }
 223
 224 static struct file_operations proc_kpageflags_operations = {
 225         .llseek = mem_lseek,
 226         .read = kpageflags_read,
 227 };
 228 #endif /* CONFIG_PROC_PAGE_MONITOR */
 229
 230 struct proc_dir_entry *proc_root_kcore;
 231
 232 void __init proc_misc_init(void)
 233 {
 234         proc_symlink("mounts", NULL, "self/mounts");
 235
 236         /* And now for trickier ones */
 237         proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
 238 #ifdef CONFIG_BLOCK
 239         proc_create("diskstats", 0, NULL, &proc_diskstats_operations);
 240 #endif
 241 #ifdef CONFIG_MODULES
 242         proc_create("modules", 0, NULL, &proc_modules_operations);
 243 #endif
 244 #ifdef CONFIG_SCHEDSTATS
 245         proc_create("schedstat", 0, NULL, &proc_schedstat_operations);
 246 #endif
 247 #ifdef CONFIG_PROC_KCORE
 248         proc_root_kcore = proc_create("kcore", S_IRUSR, NULL, &proc_kcore_operations);
 249         if (proc_root_kcore)
 250                 proc_root_kcore->size =
 251                                 (size_t)high_memory - PAGE_OFFSET + PAGE_SIZE;
 252 #endif
 253 #ifdef CONFIG_PROC_PAGE_MONITOR
 254         proc_create("kpagecount", S_IRUSR, NULL, &proc_kpagecount_operations);
 255         proc_create("kpageflags", S_IRUSR, NULL, &proc_kpageflags_operations);
 256 #endif
 257 #ifdef CONFIG_PROC_VMCORE
 258         proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &proc_vmcore_operations);
 259 #endif
 260 }