[unix-history] / usr / src / usr.bin / gcore / gcore.c

#ifndef lint
static char sccsid[] = "@(#)gcore.c	4.3 (Berkeley) %G%";
#endif

/*
 * gcore - get core images of running processes
 *
 * Author: Eric Cooper
 * Written: Fall 1981.
 *
 * Inspired by a version 6 program by Len Levin, 1978.
 * Several pieces of code lifted from Bill Joy's 4BSD ps.
 *
 * Permission to copy or modify this program in whole or in part is hereby
 * granted, provided that the above credits are preserved.
 *
 * This code performs a simple simulation of the virtual memory system in user
 * code.  If the virtual memory system changes, this program must be modified
 * accordingly.  It must also be recompiled whenever system data structures
 * change.
 */
#include <stdio.h>
#include <nlist.h>
#include <sys/param.h>
#include <sys/dir.h>
#include <sys/user.h>
#include <sys/proc.h>
#include <machine/pte.h>
#include <sys/vm.h>
#include <setjmp.h>

/* Various macros for efficiency. */

#define	min(a, b)	(a < b ? a : b)

#define	Seek(f, pos) {\
	if (lseek(f, (long) (pos), 0) != (long) (pos)) \
		panic("seek error"); \
}

#define	Read(f, addr, n) {\
	if (read(f, (char *) (addr), (int) (n)) != (int) (n)) \
		panic("read error"); \
}

#define	Get(f, pos, addr, n) {\
	Seek(f, pos); \
	Read(f, addr, n); \
}

struct	nlist nl[] = {
	{ "_proc" },
#define	X_PROC		0
	{ "_Usrptmap" },
#define	X_USRPTMA	1
	{ "_usrpt" },
#define	X_USRPT		2
	{ "_nswap" },
#define	X_NSWAP		3
	{ "_nproc" },
#define	X_NPROC		4
	{ "_dmmin" },
#define	X_DMMIN		5
	{ "_dmmax" },
#define	X_DMMAX		6
	{ 0 },
};

#define FEW	20		/* for fewer system calls */
struct	proc proc[FEW];

union {
	struct user user;
	char upages[UPAGES][NBPG];
} user;
#define u	user.user
#define uarea	user.upages

#define NLIST	"/vmunix"
#define KMEM	"/dev/kmem"
#define MEM	"/dev/mem"
#define SWAP	"/dev/drum"	/* "/dev/swap" on some systems */

int	nproc;
int	nswap;
int	dmmin, dmmax;
struct	pte *Usrptmap, *usrpt;
char	coref[20];
int	kmem, mem, swap, cor;
jmp_buf	cont_frame;

main(argc, argv)
	int argc;
	char **argv;
{
	register int i, j;
	register struct proc *p;
	off_t procbase, procp;
	int pid, uid;
	char c;

	if (argc < 2) {
		printf("Usage: %s pid ...\n", argv[0]);
		exit(1);
	}
	openfiles();
	getkvars();
	procbase = getw(nl[X_PROC].n_value);
	nproc = getw(nl[X_NPROC].n_value);
	nswap = getw(nl[X_NSWAP].n_value);
	dmmin = getw(nl[X_DMMIN].n_value);
	dmmax = getw(nl[X_DMMAX].n_value);
	while (--argc > 0) {
		if ((pid = atoi(*++argv)) <= 0 || setjmp(cont_frame))
			continue;
		printf("%d: ", pid);
		procp = procbase;
		for (i = 0; i < nproc; i += FEW) {
			Seek(kmem, procp);
			j = nproc - i;
			if (j > FEW)
				j = FEW;
			j *= sizeof(struct proc);
			Read(kmem, (char *) proc, j);
			procp += j;
			for (j = j / sizeof(struct proc) - 1; j >= 0; j--) {
				p = &proc[j];
				if (p->p_pid == pid)
					goto found;
			}
		}
		printf("Process not found.\n");
		continue;
	found:
		if (p->p_uid != (uid = getuid()) && uid != 0) {
			printf("Not owner.\n");
			continue;
		}
		if (p->p_stat == SZOMB) {
			printf("Zombie.\n");
			continue;
		}
		if (p->p_flag & SWEXIT) {
			printf("Process exiting.\n");
			continue;
		}
		if (p->p_flag & SSYS) {
			printf("System process.\n");
			/* i.e. swapper or pagedaemon */
			continue;
		}
		sprintf(coref, "core.%d", pid);
		if ((cor = creat(coref, 0666)) < 0) {
			perror(coref);
			exit(1);
		}
		core(p);
		close(cor);
		printf("%s dumped\n", coref);
	}
}

getw(loc)
	off_t loc;
{
	int word;

	Get(kmem, loc, &word, sizeof(int));
	return (word);
}

openfiles()
{
	kmem = open(KMEM, 0);
	if (kmem < 0) {
		perror(KMEM);
		exit(1);
	}
	mem = open(MEM, 0);
	if (mem < 0) {
		perror(MEM);
		exit(1);
	}
	swap = open(SWAP, 0);
	if (swap < 0) {
		perror(SWAP);
		exit(1);
	}
}

getkvars()
{
	nlist(NLIST, nl);
	if (nl[0].n_type == 0) {
		printf("%s: No namelist\n", NLIST);
		exit(1);
	}
	Usrptmap = (struct pte *) nl[X_USRPTMA].n_value;
	usrpt = (struct pte *) nl[X_USRPT].n_value;
}

/*
 * Get the system page table entries (mapping the user page table).
 * These are the entries Usrptmap[i .. i + szpt],
 * where i = btokmx(p->p_p0br) and szpt = p->p_szpt.
 * For our purposes, we can skip over the ptes mapping
 * the text segment ptes.
 */
struct pte	*syspt;		/* pte's from Usrptmap */
int		nsysptes;

getsyspt(p)
	register struct proc *p;
{
	nsysptes = p->p_szpt - (p->p_tsize / NPTEPG);
	syspt = (struct pte *) malloc(nsysptes * sizeof(struct pte));
	if (syspt == NULL)
		panic("can't alloc %d page table entries", nsysptes);
	Get(kmem, &Usrptmap[btokmx(p->p_p0br) + (p->p_tsize / NPTEPG)],
		syspt, nsysptes * sizeof(struct pte));
}

/*
 * Get the user page table for a segment.
 * seg 0 = p0 (not including text)
 * seg 1 = p1 (stack and u area)
 * The system pt is consulted to find each page of user ptes.
 */
struct pte *
getpt(p, seg)
	register struct proc *p;
	int seg;
{
	register int i;
	register struct pte *spt;
	struct pte *pt;
	int nptes, offset, n;

	if (seg == 0) {
		nptes = p->p_dsize;
		spt = syspt;
		offset = p->p_tsize % NPTEPG;
	} else {
		nptes = p->p_ssize + UPAGES;
		spt = syspt + (nsysptes - ctopt(nptes));
		offset = -nptes % NPTEPG;
		if (offset < 0)
			offset += NPTEPG;
	}
	pt = (struct pte *) malloc(nptes * sizeof(struct pte));
	if (pt == NULL)
		panic("can't alloc %d page table entries", nptes);
	for (i = 0; i < nptes; i += n) {
		n = min(NPTEPG - offset, nptes - i);
		Get(mem, ctob(spt->pg_pfnum) + offset * sizeof(struct pte),
		     pt + i, n * sizeof(struct pte));
		spt++;
		offset = 0;
	}
	return (pt);
}

/*
 * Build the core file.
 */
core(p)
	register struct proc *p;
{
	register struct pte *p0, *p1;

	if (p->p_flag & SLOAD) {		/* page tables are resident */
		getsyspt(p);
		p0 = getpt(p, 0);
		p1 = getpt(p, 1);
#ifdef	DEBUG
		showpt(syspt, nsysptes, "system");
		showpt(p0, p->p_dsize, "p0");
		showpt(p1, p->p_ssize + UPAGES, "p1");
#endif
	}
	getu(p, &p1[p->p_ssize]);			/* u area */
	getseg(p, p->p_dsize, p0, &u.u_dmap, 0);	/* data */
	getseg(p, p->p_ssize, p1, &u.u_smap, 1);	/* stack */
	if (p->p_flag & SLOAD) {
		free((char *) syspt);
		free((char *) p0);
		free((char *) p1);
	}
}

/*
 * Get the u area.
 * Keeps around the u structure for later use
 * (the data and stack disk map structures).
 */
getu(p, pages)
	register struct proc *p;
	register struct pte *pages;
{
	register int i;

	if ((p->p_flag & SLOAD) == 0) {
		Get(swap, ctob(p->p_swaddr), uarea, ctob(UPAGES));
		write(cor, uarea, ctob(UPAGES));
		return;
	}
	for (i = 0; i < UPAGES; i += CLSIZE) {
		Get(mem, ctob(pages[i].pg_pfnum), uarea[i], ctob(CLSIZE));
		write(cor, uarea[i], ctob(CLSIZE));
	}
}

/*
 * Copy a segment to the core file.
 * The segment is described by its size in clicks,
 * its page table, its disk map, and whether or not
 * it grows backwards.
 * Note that the page table address is allowed to be meaningless
 * if the process is swapped out.
 */
getseg(p, segsize, pages, map, rev)
	register struct proc *p;
	int segsize;
	register struct pte *pages;
	struct dmap *map;
{
	register int i;
	struct dblock db;
	int size;
	char buf[ctob(CLSIZE)];

	for (i = 0; i < segsize; i += CLSIZE) {
		size = min(CLSIZE, segsize - i);
		if ((p->p_flag & SLOAD) == 0 || pages[i].pg_fod ||
		    pages[i].pg_pfnum == 0) {
			vstodb(i, size, map, &db, rev);
			Get(swap, ctob(db.db_base), buf, ctob(size));
			write(cor, buf, ctob(size));
		} else {
			Get(mem, ctob(pages[i].pg_pfnum), buf, ctob(size));
			write(cor, buf, ctob(size));
		}
	}
}

/*
 * Given a base/size pair in virtual swap area,
 * return a physical base/size pair which is the
 * (largest) initial, physically contiguous block.
 */
vstodb(vsbase, vssize, dmp, dbp, rev)
	register int vsbase;
	int vssize;
	struct dmap *dmp;
	register struct dblock *dbp;
{
	register int blk = dmmin;
	register swblk_t *ip = dmp->dm_map;

	if (vsbase < 0 || vsbase + vssize > dmp->dm_size)
		panic("can't make sense out of virtual memory (gcore probably needs to be recompiled)");
	while (vsbase >= blk) {
		vsbase -= blk;
		if (blk < dmmax)
			blk *= 2;
		ip++;
	}
	if (*ip <= 0 || *ip + blk > nswap)
		panic("vstodb *ip");
	dbp->db_size = MIN(vssize, blk - vsbase);
	dbp->db_base = *ip + (rev ? blk - (vsbase + dbp->db_size) : vsbase);
}

/*VARARGS1*/
panic(cp, a, b, c, d)
	char *cp;
{
	printf(cp, a, b, c, d);
	printf("\n");
	longjmp(cont_frame, 1);
}

/* 
 * Debugging routine to print out page table.
 */
#ifdef	DEBUG
showpt(pt, n, s)
	struct pte *pt;
	int n;
	char *s;
{
	register struct pte *p;
	register int i;

	printf("*** %s page table\n", s);
	for (i = 0, p = pt; i < n; i++, p++)
		if (! p->pg_fod)
			printf("%d: %x\n", i, p->pg_pfnum);
}
#endif
Commit	Line	Data
68d13ee3 SL	1	#ifndef lint
	2	static char sccsid[] = "@(#)gcore.c 4.3 (Berkeley) %G%";
	3	#endif
4f626618 KM	4
	5	/*
	6	* gcore - get core images of running processes
	7	*
	8	* Author: Eric Cooper
	9	* Written: Fall 1981.
	10	*
	11	* Inspired by a version 6 program by Len Levin, 1978.
	12	* Several pieces of code lifted from Bill Joy's 4BSD ps.
	13	*
	14	* Permission to copy or modify this program in whole or in part is hereby
	15	* granted, provided that the above credits are preserved.
	16	*
	17	* This code performs a simple simulation of the virtual memory system in user
	18	* code. If the virtual memory system changes, this program must be modified
	19	* accordingly. It must also be recompiled whenever system data structures
	20	* change.
	21	*/
	22	#include <stdio.h>
	23	#include <nlist.h>
	24	#include <sys/param.h>
	25	#include <sys/dir.h>
	26	#include <sys/user.h>
	27	#include <sys/proc.h>
57ee57ff	28	#include <machine/pte.h>
4f626618 KM	29	#include <sys/vm.h>
	30	#include <setjmp.h>
	31
	32	/* Various macros for efficiency. */
	33
	34	#define min(a, b) (a < b ? a : b)
	35
	36	#define Seek(f, pos) {\
	37	if (lseek(f, (long) (pos), 0) != (long) (pos)) \
	38	panic("seek error"); \
	39	}
	40
	41	#define Read(f, addr, n) {\
	42	if (read(f, (char *) (addr), (int) (n)) != (int) (n)) \
	43	panic("read error"); \
	44	}
	45
	46	#define Get(f, pos, addr, n) {\
	47	Seek(f, pos); \
	48	Read(f, addr, n); \
	49	}
	50
	51	struct nlist nl[] = {
	52	{ "_proc" },
	53	#define X_PROC 0
	54	{ "_Usrptmap" },
	55	#define X_USRPTMA 1
	56	{ "_usrpt" },
	57	#define X_USRPT 2
	58	{ "_nswap" },
	59	#define X_NSWAP 3
	60	{ "_nproc" },
	61	#define X_NPROC 4
68d13ee3 SL	62	{ "_dmmin" },
	63	#define X_DMMIN 5
	64	{ "_dmmax" },
	65	#define X_DMMAX 6
4f626618 KM	66	{ 0 },
	67	};
	68
	69	#define FEW 20 /* for fewer system calls */
	70	struct proc proc[FEW];
	71
	72	union {
	73	struct user user;
	74	char upages[UPAGES][NBPG];
	75	} user;
	76	#define u user.user
	77	#define uarea user.upages
	78
	79	#define NLIST "/vmunix"
	80	#define KMEM "/dev/kmem"
	81	#define MEM "/dev/mem"
	82	#define SWAP "/dev/drum" /* "/dev/swap" on some systems */
	83
	84	int nproc;
	85	int nswap;
68d13ee3	86	int dmmin, dmmax;
4f626618 KM	87	struct pte Usrptmap, usrpt;
	88	char coref[20];
	89	int kmem, mem, swap, cor;
	90	jmp_buf cont_frame;
	91
	92	main(argc, argv)
	93	int argc;
	94	char **argv;
	95	{
	96	register int i, j;
	97	register struct proc *p;
	98	off_t procbase, procp;
	99	int pid, uid;
	100	char c;
	101
	102	if (argc < 2) {
	103	printf("Usage: %s pid ...\n", argv[0]);
	104	exit(1);
	105	}
	106	openfiles();
	107	getkvars();
	108	procbase = getw(nl[X_PROC].n_value);
	109	nproc = getw(nl[X_NPROC].n_value);
	110	nswap = getw(nl[X_NSWAP].n_value);
68d13ee3 SL	111	dmmin = getw(nl[X_DMMIN].n_value);
68d13ee3 SL	112	dmmax = getw(nl[X_DMMAX].n_value);
4f626618 KM	113	while (--argc > 0) {
	114	if ((pid = atoi(*++argv)) <= 0 \|\| setjmp(cont_frame))
	115	continue;
	116	printf("%d: ", pid);
	117	procp = procbase;
	118	for (i = 0; i < nproc; i += FEW) {
	119	Seek(kmem, procp);
	120	j = nproc - i;
	121	if (j > FEW)
	122	j = FEW;
	123	j *= sizeof(struct proc);
	124	Read(kmem, (char *) proc, j);
	125	procp += j;
	126	for (j = j / sizeof(struct proc) - 1; j >= 0; j--) {
	127	p = &proc[j];
	128	if (p->p_pid == pid)
	129	goto found;
	130	}
	131	}
	132	printf("Process not found.\n");
	133	continue;
	134	found:
	135	if (p->p_uid != (uid = getuid()) && uid != 0) {
	136	printf("Not owner.\n");
	137	continue;
	138	}
	139	if (p->p_stat == SZOMB) {
	140	printf("Zombie.\n");
	141	continue;
	142	}
	143	if (p->p_flag & SWEXIT) {
	144	printf("Process exiting.\n");
	145	continue;
	146	}
	147	if (p->p_flag & SSYS) {
	148	printf("System process.\n");
	149	/* i.e. swapper or pagedaemon */
	150	continue;
	151	}
	152	sprintf(coref, "core.%d", pid);
	153	if ((cor = creat(coref, 0666)) < 0) {
	154	perror(coref);
	155	exit(1);
	156	}
	157	core(p);
	158	close(cor);
	159	printf("%s dumped\n", coref);
	160	}
	161	}
	162
	163	getw(loc)
	164	off_t loc;
	165	{
	166	int word;
	167
	168	Get(kmem, loc, &word, sizeof(int));
	169	return (word);
	170	}
	171
	172	openfiles()
	173	{
	174	kmem = open(KMEM, 0);
	175	if (kmem < 0) {
	176	perror(KMEM);
177	exit(1);
178	}
179	mem = open(MEM, 0);
180	if (mem < 0) {
181	perror(MEM);
182	exit(1);
183	}
184	swap = open(SWAP, 0);
185	if (swap < 0) {
186	perror(SWAP);
187	exit(1);
188	}
189	}
190
191	getkvars()
192	{
193	nlist(NLIST, nl);
194	if (nl[0].n_type == 0) {
195	printf("%s: No namelist\n", NLIST);
196	exit(1);
197	}
198	Usrptmap = (struct pte *) nl[X_USRPTMA].n_value;
199	usrpt = (struct pte *) nl[X_USRPT].n_value;
200	}
201
202	/*
203	* Get the system page table entries (mapping the user page table).
204	* These are the entries Usrptmap[i .. i + szpt],
205	* where i = btokmx(p->p_p0br) and szpt = p->p_szpt.
206	* For our purposes, we can skip over the ptes mapping
207	* the text segment ptes.
208	*/
209	struct pte syspt; / pte's from Usrptmap */
210	int nsysptes;
211
212	getsyspt(p)
213	register struct proc *p;
214	{
215	nsysptes = p->p_szpt - (p->p_tsize / NPTEPG);
216	syspt = (struct pte ) malloc(nsysptes sizeof(struct pte));
217	if (syspt == NULL)
218	panic("can't alloc %d page table entries", nsysptes);
219	Get(kmem, &Usrptmap[btokmx(p->p_p0br) + (p->p_tsize / NPTEPG)],
220	syspt, nsysptes * sizeof(struct pte));
221	}
222
223	/*
224	* Get the user page table for a segment.
225	* seg 0 = p0 (not including text)
226	* seg 1 = p1 (stack and u area)
227	* The system pt is consulted to find each page of user ptes.
228	*/
229	struct pte *
230	getpt(p, seg)
231	register struct proc *p;
232	int seg;
233	{
234	register int i;
235	register struct pte *spt;
236	struct pte *pt;
237	int nptes, offset, n;
238
239	if (seg == 0) {
240	nptes = p->p_dsize;
241	spt = syspt;
242	offset = p->p_tsize % NPTEPG;
243	} else {
244	nptes = p->p_ssize + UPAGES;
245	spt = syspt + (nsysptes - ctopt(nptes));
246	offset = -nptes % NPTEPG;
247	if (offset < 0)
248	offset += NPTEPG;
249	}
250	pt = (struct pte ) malloc(nptes sizeof(struct pte));
251	if (pt == NULL)
252	panic("can't alloc %d page table entries", nptes);
253	for (i = 0; i < nptes; i += n) {
254	n = min(NPTEPG - offset, nptes - i);
255	Get(mem, ctob(spt->pg_pfnum) + offset * sizeof(struct pte),
256	pt + i, n * sizeof(struct pte));
257	spt++;
258	offset = 0;
259	}
260	return (pt);
261	}
262
263	/*
264	* Build the core file.
265	*/
266	core(p)
267	register struct proc *p;
268	{
269	register struct pte p0, p1;
270
271	if (p->p_flag & SLOAD) { /* page tables are resident */
272	getsyspt(p);
273	p0 = getpt(p, 0);
274	p1 = getpt(p, 1);
275	#ifdef DEBUG
276	showpt(syspt, nsysptes, "system");
277	showpt(p0, p->p_dsize, "p0");
278	showpt(p1, p->p_ssize + UPAGES, "p1");
279	#endif
280	}
281	getu(p, &p1[p->p_ssize]); /* u area */
282	getseg(p, p->p_dsize, p0, &u.u_dmap, 0); /* data */
283	getseg(p, p->p_ssize, p1, &u.u_smap, 1); /* stack */
284	if (p->p_flag & SLOAD) {
285	free((char *) syspt);
286	free((char *) p0);
287	free((char *) p1);
288	}
289	}
290
291	/*
292	* Get the u area.
293	* Keeps around the u structure for later use
294	* (the data and stack disk map structures).
295	*/
296	getu(p, pages)
297	register struct proc *p;
298	register struct pte *pages;
299	{
300	register int i;
301
302	if ((p->p_flag & SLOAD) == 0) {
303	Get(swap, ctob(p->p_swaddr), uarea, ctob(UPAGES));
304	write(cor, uarea, ctob(UPAGES));
305	return;
306	}
307	for (i = 0; i < UPAGES; i += CLSIZE) {
308	Get(mem, ctob(pages[i].pg_pfnum), uarea[i], ctob(CLSIZE));
309	write(cor, uarea[i], ctob(CLSIZE));
310	}
311	}
312
313	/*
314	* Copy a segment to the core file.
315	* The segment is described by its size in clicks,
316	* its page table, its disk map, and whether or not
317	* it grows backwards.
318	* Note that the page table address is allowed to be meaningless
319	* if the process is swapped out.
320	*/
321	getseg(p, segsize, pages, map, rev)
322	register struct proc *p;
323	int segsize;
324	register struct pte *pages;
325	struct dmap *map;
326	{
327	register int i;
328	struct dblock db;
329	int size;
330	char buf[ctob(CLSIZE)];
331
332	for (i = 0; i < segsize; i += CLSIZE) {
333	size = min(CLSIZE, segsize - i);
334	if ((p->p_flag & SLOAD) == 0 \|\| pages[i].pg_fod \|\|
335	pages[i].pg_pfnum == 0) {
336	vstodb(i, size, map, &db, rev);
337	Get(swap, ctob(db.db_base), buf, ctob(size));
338	write(cor, buf, ctob(size));
339	} else {
340	Get(mem, ctob(pages[i].pg_pfnum), buf, ctob(size));
341	write(cor, buf, ctob(size));
342	}
343	}
344	}
345
346	/*
347	* Given a base/size pair in virtual swap area,
348	* return a physical base/size pair which is the
349	* (largest) initial, physically contiguous block.
350	*/
351	vstodb(vsbase, vssize, dmp, dbp, rev)
352	register int vsbase;
353	int vssize;
354	struct dmap *dmp;
355	register struct dblock *dbp;
356	{
68d13ee3	357	register int blk = dmmin;
4f626618 KM	358	register swblk_t *ip = dmp->dm_map;
	359
	360	if (vsbase < 0 \|\| vsbase + vssize > dmp->dm_size)
	361	panic("can't make sense out of virtual memory (gcore probably needs to be recompiled)");
	362	while (vsbase >= blk) {
	363	vsbase -= blk;
68d13ee3	364	if (blk < dmmax)
4f626618 KM	365	blk *= 2;
	366	ip++;
	367	}
	368	if (ip <= 0 \|\| ip + blk > nswap)
	369	panic("vstodb *ip");
	370	dbp->db_size = MIN(vssize, blk - vsbase);
	371	dbp->db_base = *ip + (rev ? blk - (vsbase + dbp->db_size) : vsbase);
	372	}
	373
	374	/VARARGS1/
	375	panic(cp, a, b, c, d)
	376	char *cp;
	377	{
	378	printf(cp, a, b, c, d);
	379	printf("\n");
	380	longjmp(cont_frame, 1);
	381	}
	382
	383	/*
	384	* Debugging routine to print out page table.
	385	*/
	386	#ifdef DEBUG
	387	showpt(pt, n, s)
	388	struct pte *pt;
	389	int n;
	390	char *s;
	391	{
	392	register struct pte *p;
	393	register int i;
	394
	395	printf("*** %s page table\n", s);
	396	for (i = 0, p = pt; i < n; i++, p++)
	397	if (! p->pg_fod)
	398	printf("%d: %x\n", i, p->pg_pfnum);
	399	}
	400	#endif