Boot Linux faster!

Check our new training course

Boot Linux faster!

Check our new training course
and Creative Commons CC-BY-SA
lecture and lab materials

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
/*
 *  linux/fs/proc/array.c
 *
 *  Copyright (C) 1992  by Linus Torvalds
 *  based on ideas by Darren Senn
 *
 * Fixes:
 * Michael. K. Johnson: stat,statm extensions.
 *                      <johnsonm@stolaf.edu>
 *
 * Pauline Middelink :  Made cmdline,envline only break at '\0's, to
 *                      make sure SET_PROCTITLE works. Also removed
 *                      bad '!' which forced addres recalculation for
 *                      EVERY character on the current page.
 *                      <middelin@calvin.iaf.nl>
 */

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/kernel_stat.h>
#include <linux/tty.h>
#include <linux/user.h>
#include <linux/a.out.h>
#include <linux/string.h>
#include <linux/mman.h>

#include <asm/segment.h>
#include <asm/io.h>

#define LOAD_INT(x) ((x) >> FSHIFT)
#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)

#ifdef CONFIG_DEBUG_MALLOC
int get_malloc(char * buffer);
#endif

static int read_core(struct inode * inode, struct file * file,char * buf, int count)
{
	unsigned long p = file->f_pos;
	int read;
	int count1;
	char * pnt;
	struct user dump;

	memset(&dump, 0, sizeof(struct user));
	dump.magic = CMAGIC;
	dump.u_dsize = high_memory >> 12;

	if (count < 0)
		return -EINVAL;
	if (p >= high_memory + PAGE_SIZE)
		return 0;
	if (count > high_memory + PAGE_SIZE - p)
		count = high_memory + PAGE_SIZE - p;
	read = 0;

	if (p < sizeof(struct user) && count > 0) {
		count1 = count;
		if (p + count1 > sizeof(struct user))
			count1 = sizeof(struct user)-p;
		pnt = (char *) &dump + p;
		memcpy_tofs(buf,(void *) pnt, count1);
		buf += count1;
		p += count1;
		count -= count1;
		read += count1;
	}

	while (p < 2*PAGE_SIZE && count > 0) {
		put_fs_byte(0,buf);
		buf++;
		p++;
		count--;
		read++;
	}
	memcpy_tofs(buf,(void *) (p - PAGE_SIZE),count);
	read += count;
	file->f_pos += read;
	return read;
}

static int get_loadavg(char * buffer)
{
	int a, b, c;

	a = avenrun[0] + (FIXED_1/200);
	b = avenrun[1] + (FIXED_1/200);
	c = avenrun[2] + (FIXED_1/200);
	return sprintf(buffer,"%d.%02d %d.%02d %d.%02d\n",
		LOAD_INT(a), LOAD_FRAC(a),
		LOAD_INT(b), LOAD_FRAC(b),
		LOAD_INT(c), LOAD_FRAC(c));
}

static int get_kstat(char * buffer)
{
	int i, len;
	unsigned sum = 0;

	for (i = 0 ; i < 16 ; i++)
		sum += kstat.interrupts[i];
	len = sprintf(buffer,
		"cpu  %u %u %u %lu\n"
		"disk %u %u %u %u\n"
		"page %u %u\n"
		"swap %u %u\n"
		"intr %u",
		kstat.cpu_user,
		kstat.cpu_nice,
		kstat.cpu_system,
		jiffies - (kstat.cpu_user + kstat.cpu_nice + kstat.cpu_system),
		kstat.dk_drive[0],
		kstat.dk_drive[1],
		kstat.dk_drive[2],
		kstat.dk_drive[3],
		kstat.pgpgin,
		kstat.pgpgout,
		kstat.pswpin,
		kstat.pswpout,
		sum);
	for (i = 0 ; i < 16 ; i++)
		len += sprintf(buffer + len, " %u", kstat.interrupts[i]);
	len += sprintf(buffer + len,
		"\nctxt %u\n"
		"btime %lu\n",
		kstat.context_swtch,
		xtime.tv_sec - jiffies / HZ);
	return len;
}


static int get_uptime(char * buffer)
{
	unsigned long uptime;
	unsigned long idle;

	uptime = jiffies;
	idle = task[0]->utime + task[0]->stime;
	return sprintf(buffer,"%lu.%02lu %lu.%02lu\n",
		uptime / HZ,
		uptime % HZ,
		idle / HZ,
		idle % HZ);
}

static int get_meminfo(char * buffer)
{
	struct sysinfo i;

	si_meminfo(&i);
	si_swapinfo(&i);
	return sprintf(buffer, "        total:   used:    free:   shared:  buffers:\n"
		"Mem:  %8lu %8lu %8lu %8lu %8lu\n"
		"Swap: %8lu %8lu %8lu\n",
		i.totalram, i.totalram-i.freeram, i.freeram, i.sharedram, i.bufferram,
		i.totalswap, i.totalswap-i.freeswap, i.freeswap);
}

static int get_version(char * buffer)
{
	extern char *linux_banner;

	strcpy(buffer, linux_banner);
	return strlen(buffer);
}

static struct task_struct ** get_task(pid_t pid)
{
	struct task_struct ** p;

	p = task;
	while (++p < task+NR_TASKS) {
		if (*p && (*p)->pid == pid)
			return p;
	}
	return NULL;
}

static unsigned long get_phys_addr(struct task_struct ** p, unsigned long ptr)
{
	unsigned long page;

	if (!p || !*p || ptr >= TASK_SIZE)
		return 0;
	page = *PAGE_DIR_OFFSET((*p)->tss.cr3,ptr);
	if (!(page & PAGE_PRESENT))
		return 0;
	page &= PAGE_MASK;
	page += PAGE_PTR(ptr);
	page = *(unsigned long *) page;
	if (!(page & PAGE_PRESENT))
		return 0;
	page &= PAGE_MASK;
	page += ptr & ~PAGE_MASK;
	return page;
}

static int get_array(struct task_struct ** p, unsigned long start, unsigned long end, char * buffer)
{
	unsigned long addr;
	int size = 0, result = 0;
	char c;

	if (start >= end)
		return result;
	for (;;) {
		addr = get_phys_addr(p, start);
		if (!addr)
			goto ready;
		do {
			c = *(char *) addr;
			if (!c)
				result = size;
			if (size < PAGE_SIZE)
				buffer[size++] = c;
			else
				goto ready;
			addr++;
			start++;
			if (!c && start >= end)
				goto ready;
		} while (addr & ~PAGE_MASK);
	}
ready:
	/* remove the trailing blanks, used to fillout argv,envp space */
	while (result>0 && buffer[result-1]==' ')
		result--;
	return result;
}

static int get_env(int pid, char * buffer)
{
	struct task_struct ** p = get_task(pid);

	if (!p || !*p)
		return 0;
	return get_array(p, (*p)->env_start, (*p)->env_end, buffer);
}

static int get_arg(int pid, char * buffer)
{
	struct task_struct ** p = get_task(pid);

	if (!p || !*p)
		return 0;
	return get_array(p, (*p)->arg_start, (*p)->arg_end, buffer);
}

static unsigned long get_wchan(struct task_struct *p)
{
	unsigned long ebp, eip;
	unsigned long stack_page;
	int count = 0;

	if (!p || p == current || p->state == TASK_RUNNING)
		return 0;
	stack_page = p->kernel_stack_page;
	if (!stack_page)
		return 0;
	ebp = p->tss.ebp;
	do {
		if (ebp < stack_page || ebp >= 4092+stack_page)
			return 0;
		eip = *(unsigned long *) (ebp+4);
		if ((void *)eip != sleep_on &&
		    (void *)eip != interruptible_sleep_on)
			return eip;
		ebp = *(unsigned long *) ebp;
	} while (count++ < 16);
	return 0;
}

#define	KSTK_EIP(stack)	(((unsigned long *)stack)[1019])
#define	KSTK_ESP(stack)	(((unsigned long *)stack)[1022])

static int get_stat(int pid, char * buffer)
{
	struct task_struct ** p = get_task(pid);
	unsigned long sigignore=0, sigcatch=0, bit=1, wchan;
	unsigned long vsize, eip, esp;
	int i,tty_pgrp;
	char state;

	if (!p || !*p)
		return 0;
	if ((*p)->state < 0 || (*p)->state > 5)
		state = '.';
	else
		state = "RSDZTD"[(*p)->state];
	eip = esp = 0;
	vsize = (*p)->kernel_stack_page;
	if (vsize) {
		eip = KSTK_EIP(vsize);
		esp = KSTK_ESP(vsize);
		vsize = (*p)->brk - (*p)->start_code + PAGE_SIZE-1;
		if (esp)
			vsize += TASK_SIZE - esp;
	}
	wchan = get_wchan(*p);
	for(i=0; i<32; ++i) {
		switch((int) (*p)->sigaction[i].sa_handler) {
		case 1: sigignore |= bit; break;
		case 0: break;
		default: sigcatch |= bit;
		} bit <<= 1;
	}
	tty_pgrp = (*p)->tty;
	if (tty_pgrp > 0 && tty_table[tty_pgrp])
		tty_pgrp = tty_table[tty_pgrp]->pgrp;
	else
		tty_pgrp = -1;
	return sprintf(buffer,"%d (%s) %c %d %d %d %d %d %lu %lu \
%lu %lu %lu %ld %ld %ld %ld %ld %ld %lu %lu %ld %lu %u %u %lu %lu %lu %lu %lu %lu \
%lu %lu %lu %lu\n",
		pid,
		(*p)->comm,
		state,
		(*p)->p_pptr->pid,
		(*p)->pgrp,
		(*p)->session,
		(*p)->tty,
		tty_pgrp,
		(*p)->flags,
		(*p)->min_flt,
		(*p)->cmin_flt,
		(*p)->maj_flt,
		(*p)->cmaj_flt,
		(*p)->utime,
		(*p)->stime,
		(*p)->cutime,
		(*p)->cstime,
		(*p)->counter,  /* this is the kernel priority ---
				   subtract 30 in your user-level program. */
		(*p)->priority, /* this is the nice value ---
				   subtract 15 in your user-level program. */
		(*p)->timeout,
		(*p)->it_real_value,
		(*p)->start_time,
		vsize,
		(*p)->rss, /* you might want to shift this left 3 */
		(*p)->rlim[RLIMIT_RSS].rlim_cur,
		(*p)->start_code,
		(*p)->end_code,
		(*p)->start_stack,
		esp,
		eip,
		(*p)->signal,
		(*p)->blocked,
		sigignore,
		sigcatch,
		wchan);
}

static int get_statm(int pid, char * buffer)
{
	struct task_struct ** p = get_task(pid);
	int i, tpag;
	int size=0, resident=0, share=0, trs=0, lrs=0, drs=0, dt=0;
	unsigned long ptbl, *buf, *pte, *pagedir, map_nr;

	if (!p || !*p)
		return 0;
	tpag = (*p)->end_code / PAGE_SIZE;
	if ((*p)->state != TASK_ZOMBIE) {
	  pagedir = (unsigned long *) (*p)->tss.cr3;
	  for (i = 0; i < 0x300; ++i) {
	    if ((ptbl = pagedir[i]) == 0) {
	      tpag -= PTRS_PER_PAGE;
	      continue;
	    }
	    buf = (unsigned long *)(ptbl & PAGE_MASK);
	    for (pte = buf; pte < (buf + PTRS_PER_PAGE); ++pte) {
	      if (*pte != 0) {
		++size;
		if (*pte & 1) {
		  ++resident;
		  if (tpag > 0)
		    ++trs;
		  else
		    ++drs;
		  if (i >= 15 && i < 0x2f0) {
		    ++lrs;
		    if (*pte & 0x40)
		      ++dt;
		    else
		      --drs;
		  }
		  map_nr = MAP_NR(*pte);
		  if (map_nr < (high_memory / PAGE_SIZE) && mem_map[map_nr] > 1)
		    ++share;
		}
	      }
	      --tpag;
	    }
	  }
	}
	return sprintf(buffer,"%d %d %d %d %d %d %d\n",
		       size, resident, share, trs, lrs, drs, dt);
}

static int get_maps(int pid, char *buf)
{
	int sz = 0;
	struct task_struct **p = get_task(pid);
	struct vm_area_struct *map;

	if (!p || !*p)
		return 0;

	for(map = (*p)->mmap; map != NULL; map = map->vm_next) {
		char str[7], *cp = str;
		int prot = map->vm_page_prot;
		int perms, flags;
		int end = sz + 80;	/* Length of line */
		dev_t dev;
		unsigned long ino;

		/*
		 * This tries to get an "rwxsp" string out of silly
		 * intel page permissions.  The vm_area_struct should
		 * probably have the original mmap args preserved.
		 */
		
		flags = perms = 0;

		if ((prot & PAGE_READONLY) == PAGE_READONLY)
			perms |= PROT_READ | PROT_EXEC;
		if (prot & (PAGE_COW|PAGE_RW)) {
			perms |= PROT_WRITE | PROT_READ;
			flags = prot & PAGE_COW ? MAP_PRIVATE : MAP_SHARED;
		}

		*cp++ = perms & PROT_READ ? 'r' : '-';
		*cp++ = perms & PROT_WRITE ? 'w' : '-';
		*cp++ = perms & PROT_EXEC ? 'x' : '-';
		*cp++ = flags & MAP_SHARED ? 's' : '-';
		*cp++ = flags & MAP_PRIVATE ? 'p' : '-';
		*cp++ = 0;
		
		if (end >= PAGE_SIZE) {
			sprintf(buf+sz, "...\n");
			break;
		}
		
		if (map->vm_inode != NULL) {
			dev = map->vm_inode->i_dev;
			ino = map->vm_inode->i_ino;
		} else {
			dev = 0;
			ino = 0;
		}

		sz += sprintf(buf+sz, "%08lx-%08lx %s %08lx %02x:%02x %lu\n",
			      map->vm_start, map->vm_end, str, map->vm_offset,
			      MAJOR(dev),MINOR(dev), ino);
		if (sz > end) {
			printk("get_maps: end(%d) < sz(%d)\n", end, sz);
			break;
		}
	}
	
	return sz;
}

extern int get_module_list(char *);

static int array_read(struct inode * inode, struct file * file,char * buf, int count)
{
	char * page;
	int length;
	int end;
	unsigned int type, pid;

	if (count < 0)
		return -EINVAL;
	if (!(page = (char*) __get_free_page(GFP_KERNEL)))
		return -ENOMEM;
	type = inode->i_ino;
	pid = type >> 16;
	type &= 0x0000ffff;
	switch (type) {
		case 2:
			length = get_loadavg(page);
			break;
		case 3:
			length = get_uptime(page);
			break;
		case 4:
			length = get_meminfo(page);
			break;
		case 6:
			length = get_version(page);
			break;
		case 9:
			length = get_env(pid, page);
			break;
		case 10:
			length = get_arg(pid, page);
			break;
		case 11:
			length = get_stat(pid, page);
			break;
		case 12:
			length = get_statm(pid, page);
			break;
#ifdef CONFIG_DEBUG_MALLOC
		case 13:
			length = get_malloc(page);
			break;
#endif
		case 14:
			free_page((unsigned long) page);
			return read_core(inode, file, buf, count);
		case 15:
			length = get_maps(pid, page);
			break;
		case 16:
			length = get_module_list(page);
			break;
		case 17:
			length = get_kstat(page);
			break;
		default:
			free_page((unsigned long) page);
			return -EBADF;
	}
	if (file->f_pos >= length) {
		free_page((unsigned long) page);
		return 0;
	}
	if (count + file->f_pos > length)
		count = length - file->f_pos;
	end = count + file->f_pos;
	memcpy_tofs(buf, page + file->f_pos, count);
	free_page((unsigned long) page);
	file->f_pos = end;
	return count;
}

static struct file_operations proc_array_operations = {
	NULL,		/* array_lseek */
	array_read,
	NULL,		/* array_write */
	NULL,		/* array_readdir */
	NULL,		/* array_select */
	NULL,		/* array_ioctl */
	NULL,		/* mmap */
	NULL,		/* no special open code */
	NULL,		/* no special release code */
	NULL		/* can't fsync */
};

struct inode_operations proc_array_inode_operations = {
	&proc_array_operations,	/* default base directory file-ops */
	NULL,			/* create */
	NULL,			/* lookup */
	NULL,			/* link */
	NULL,			/* unlink */
	NULL,			/* symlink */
	NULL,			/* mkdir */
	NULL,			/* rmdir */
	NULL,			/* mknod */
	NULL,			/* rename */
	NULL,			/* readlink */
	NULL,			/* follow_link */
	NULL,			/* bmap */
	NULL,			/* truncate */
	NULL			/* permission */
};