BSD 4.4 Lite Lib Sources

1 files changed, 540 insertions, 0 deletions

diff --git a/lib/libkvm/kvm.c b/lib/libkvm/kvm.c
new file mode 100644
index 0000000..a76f61e
--- /dev/null
+++ b/lib/libkvm/kvm.c
@@ -0,0 +1,540 @@
+/*-
+ * Copyright (c) 1989, 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software developed by the Computer Systems
+ * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
+ * BG 91-66 and contributed to Berkeley.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)kvm.c	8.2 (Berkeley) 2/13/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/param.h>
+#include <sys/user.h>
+#include <sys/proc.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/sysctl.h>
+
+#include <vm/vm.h>
+#include <vm/vm_param.h>
+#include <vm/swap_pager.h>
+
+#include <machine/vmparam.h>
+
+#include <ctype.h>
+#include <db.h>
+#include <fcntl.h>
+#include <kvm.h>
+#include <limits.h>
+#include <nlist.h>
+#include <paths.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "kvm_private.h"
+
+static int kvm_dbopen __P((kvm_t *, const char *));
+
+char *
+kvm_geterr(kd)
+	kvm_t *kd;
+{
+	return (kd->errbuf);
+}
+
+#if __STDC__
+#include <stdarg.h>
+#else
+#include <varargs.h>
+#endif
+
+/*
+ * Report an error using printf style arguments.  "program" is kd->program
+ * on hard errors, and 0 on soft errors, so that under sun error emulation,
+ * only hard errors are printed out (otherwise, programs like gdb will
+ * generate tons of error messages when trying to access bogus pointers).
+ */
+void
+#if __STDC__
+_kvm_err(kvm_t *kd, const char *program, const char *fmt, ...)
+#else
+_kvm_err(kd, program, fmt, va_alist)
+	kvm_t *kd;
+	char *program, *fmt;
+	va_dcl
+#endif
+{
+	va_list ap;
+
+#ifdef __STDC__
+	va_start(ap, fmt);
+#else
+	va_start(ap);
+#endif
+	if (program != NULL) {
+		(void)fprintf(stderr, "%s: ", program);
+		(void)vfprintf(stderr, fmt, ap);
+		(void)fputc('\n', stderr);
+	} else
+		(void)vsnprintf(kd->errbuf,
+		    sizeof(kd->errbuf), (char *)fmt, ap);
+
+	va_end(ap);
+}
+
+void
+#if __STDC__
+_kvm_syserr(kvm_t *kd, const char *program, const char *fmt, ...)
+#else
+_kvm_syserr(kd, program, fmt, va_alist)
+	kvm_t *kd;
+	char *program, *fmt;
+	va_dcl
+#endif
+{
+	va_list ap;
+	register int n;
+
+#if __STDC__
+	va_start(ap, fmt);
+#else
+	va_start(ap);
+#endif
+	if (program != NULL) {
+		(void)fprintf(stderr, "%s: ", program);
+		(void)vfprintf(stderr, fmt, ap);
+		(void)fprintf(stderr, ": %s\n", strerror(errno));
+	} else {
+		register char *cp = kd->errbuf;
+
+		(void)vsnprintf(cp, sizeof(kd->errbuf), (char *)fmt, ap);
+		n = strlen(cp);
+		(void)snprintf(&cp[n], sizeof(kd->errbuf) - n, ": %s",
+		    strerror(errno));
+	}
+	va_end(ap);
+}
+
+void *
+_kvm_malloc(kd, n)
+	register kvm_t *kd;
+	register size_t n;
+{
+	void *p;
+
+	if ((p = malloc(n)) == NULL)
+		_kvm_err(kd, kd->program, strerror(errno));
+	return (p);
+}
+
+static kvm_t *
+_kvm_open(kd, uf, mf, sf, flag, errout)
+	register kvm_t *kd;
+	const char *uf;
+	const char *mf;
+	const char *sf;
+	int flag;
+	char *errout;
+{
+	struct stat st;
+
+	kd->vmfd = -1;
+	kd->pmfd = -1;
+	kd->swfd = -1;
+	kd->nlfd = -1;
+	kd->vmst = 0;
+	kd->db = 0;
+	kd->procbase = 0;
+	kd->argspc = 0;
+	kd->argv = 0;
+
+	if (uf == 0)
+		uf = _PATH_UNIX;
+	else if (strlen(uf) >= MAXPATHLEN) {
+		_kvm_err(kd, kd->program, "exec file name too long");
+		goto failed;
+	}
+	if (flag & ~O_RDWR) {
+		_kvm_err(kd, kd->program, "bad flags arg");
+		goto failed;
+	}
+	if (mf == 0)
+		mf = _PATH_MEM;
+	if (sf == 0)
+		sf = _PATH_DRUM;
+
+	if ((kd->pmfd = open(mf, flag, 0)) < 0) {
+		_kvm_syserr(kd, kd->program, "%s", mf);
+		goto failed;
+	}
+	if (fstat(kd->pmfd, &st) < 0) {
+		_kvm_syserr(kd, kd->program, "%s", mf);
+		goto failed;
+	}
+	if (S_ISCHR(st.st_mode)) {
+		/*
+		 * If this is a character special device, then check that
+		 * it's /dev/mem.  If so, open kmem too.  (Maybe we should
+		 * make it work for either /dev/mem or /dev/kmem -- in either
+		 * case you're working with a live kernel.)
+		 */
+		if (strcmp(mf, _PATH_MEM) != 0) {	/* XXX */
+			_kvm_err(kd, kd->program,
+				 "%s: not physical memory device", mf);
+			goto failed;
+		}
+		if ((kd->vmfd = open(_PATH_KMEM, flag)) < 0) {
+			_kvm_syserr(kd, kd->program, "%s", _PATH_KMEM);
+			goto failed;
+		}
+		if ((kd->swfd = open(sf, flag, 0)) < 0) {
+			_kvm_syserr(kd, kd->program, "%s", sf);
+			goto failed;
+		}
+		/*
+		 * Open kvm nlist database.  We go ahead and do this
+		 * here so that we don't have to hold on to the vmunix
+		 * path name.  Since a kvm application will surely do
+		 * a kvm_nlist(), this probably won't be a wasted effort.
+		 * If the database cannot be opened, open the namelist
+		 * argument so we revert to slow nlist() calls.
+		 */
+		if (kvm_dbopen(kd, uf) < 0 && 
+		    (kd->nlfd = open(uf, O_RDONLY, 0)) < 0) {
+			_kvm_syserr(kd, kd->program, "%s", uf);
+			goto failed;
+		}
+	} else {
+		/*
+		 * This is a crash dump.
+		 * Initalize the virtual address translation machinery,
+		 * but first setup the namelist fd.
+		 */
+		if ((kd->nlfd = open(uf, O_RDONLY, 0)) < 0) {
+			_kvm_syserr(kd, kd->program, "%s", uf);
+			goto failed;
+		}
+		if (_kvm_initvtop(kd) < 0)
+			goto failed;
+	}
+	return (kd);
+failed:
+	/*
+	 * Copy out the error if doing sane error semantics.
+	 */
+	if (errout != 0)
+		strcpy(errout, kd->errbuf);
+	(void)kvm_close(kd);
+	return (0);
+}
+
+kvm_t *
+kvm_openfiles(uf, mf, sf, flag, errout)
+	const char *uf;
+	const char *mf;
+	const char *sf;
+	int flag;
+	char *errout;
+{
+	register kvm_t *kd;
+
+	if ((kd = malloc(sizeof(*kd))) == NULL) {
+		(void)strcpy(errout, strerror(errno));
+		return (0);
+	}
+	kd->program = 0;
+	return (_kvm_open(kd, uf, mf, sf, flag, errout));
+}
+
+kvm_t *
+kvm_open(uf, mf, sf, flag, program)
+	const char *uf;
+	const char *mf;
+	const char *sf;
+	int flag;
+	const char *program;
+{
+	register kvm_t *kd;
+
+	if ((kd = malloc(sizeof(*kd))) == NULL && program != NULL) {
+		(void)fprintf(stderr, "%s: %s\n", strerror(errno));
+		return (0);
+	}
+	kd->program = program;
+	return (_kvm_open(kd, uf, mf, sf, flag, NULL));
+}
+
+int
+kvm_close(kd)
+	kvm_t *kd;
+{
+	register int error = 0;
+
+	if (kd->pmfd >= 0)
+		error |= close(kd->pmfd);
+	if (kd->vmfd >= 0)
+		error |= close(kd->vmfd);
+	if (kd->nlfd >= 0)
+		error |= close(kd->nlfd);
+	if (kd->swfd >= 0)
+		error |= close(kd->swfd);
+	if (kd->db != 0)
+		error |= (kd->db->close)(kd->db);
+	if (kd->vmst)
+		_kvm_freevtop(kd);
+	if (kd->procbase != 0)
+		free((void *)kd->procbase);
+	if (kd->argv != 0)
+		free((void *)kd->argv);
+	free((void *)kd);
+
+	return (0);
+}
+
+/*
+ * Set up state necessary to do queries on the kernel namelist
+ * data base.  If the data base is out-of-data/incompatible with 
+ * given executable, set up things so we revert to standard nlist call.
+ * Only called for live kernels.  Return 0 on success, -1 on failure.
+ */
+static int
+kvm_dbopen(kd, uf)
+	kvm_t *kd;
+	const char *uf;
+{
+	char *cp;
+	DBT rec;
+	int dbversionlen;
+	struct nlist nitem;
+	char dbversion[_POSIX2_LINE_MAX];
+	char kversion[_POSIX2_LINE_MAX];
+	char dbname[MAXPATHLEN];
+
+	if ((cp = rindex(uf, '/')) != 0)
+		uf = cp + 1;
+
+	(void)snprintf(dbname, sizeof(dbname), "%skvm_%s.db", _PATH_VARDB, uf);
+	kd->db = dbopen(dbname, O_RDONLY, 0, DB_HASH, NULL);
+	if (kd->db == 0)
+		return (-1);
+	/*
+	 * read version out of database
+	 */
+	rec.data = VRS_KEY;
+	rec.size = sizeof(VRS_KEY) - 1;
+	if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0))
+		goto close;
+	if (rec.data == 0 || rec.size > sizeof(dbversion))
+		goto close;
+
+	bcopy(rec.data, dbversion, rec.size);
+	dbversionlen = rec.size;
+	/*
+	 * Read version string from kernel memory.
+	 * Since we are dealing with a live kernel, we can call kvm_read()
+	 * at this point.
+	 */
+	rec.data = VRS_SYM;
+	rec.size = sizeof(VRS_SYM) - 1;
+	if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0))
+		goto close;
+	if (rec.data == 0 || rec.size != sizeof(struct nlist))
+		goto close;
+	bcopy((char *)rec.data, (char *)&nitem, sizeof(nitem));
+	if (kvm_read(kd, (u_long)nitem.n_value, kversion, dbversionlen) != 
+	    dbversionlen)
+		goto close;
+	/*
+	 * If they match, we win - otherwise clear out kd->db so
+	 * we revert to slow nlist().
+	 */
+	if (bcmp(dbversion, kversion, dbversionlen) == 0)
+		return (0);
+close:
+	(void)(kd->db->close)(kd->db);
+	kd->db = 0;
+
+	return (-1);
+}
+
+int
+kvm_nlist(kd, nl)
+	kvm_t *kd;
+	struct nlist *nl;
+{
+	register struct nlist *p;
+	register int nvalid;
+
+	/*
+	 * If we can't use the data base, revert to the 
+	 * slow library call.
+	 */
+	if (kd->db == 0)
+		return (__fdnlist(kd->nlfd, nl));
+
+	/*
+	 * We can use the kvm data base.  Go through each nlist entry
+	 * and look it up with a db query.
+	 */
+	nvalid = 0;
+	for (p = nl; p->n_name && p->n_name[0]; ++p) {
+		register int len;
+		DBT rec;
+
+		if ((len = strlen(p->n_name)) > 4096) {
+			/* sanity */
+			_kvm_err(kd, kd->program, "symbol too large");
+			return (-1);
+		}
+		rec.data = p->n_name;
+		rec.size = len;
+		if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0))
+			continue;
+		if (rec.data == 0 || rec.size != sizeof(struct nlist))
+			continue;
+		++nvalid;
+		/*
+		 * Avoid alignment issues.
+		 */
+		bcopy((char *)&((struct nlist *)rec.data)->n_type,
+		      (char *)&p->n_type, 
+		      sizeof(p->n_type));
+		bcopy((char *)&((struct nlist *)rec.data)->n_value,
+		      (char *)&p->n_value, 
+		      sizeof(p->n_value));
+	}
+	/*
+	 * Return the number of entries that weren't found.
+	 */
+	return ((p - nl) - nvalid);
+}
+
+ssize_t
+kvm_read(kd, kva, buf, len)
+	kvm_t *kd;
+	register u_long kva;
+	register void *buf;
+	register size_t len;
+{
+	register int cc;
+	register void *cp;
+
+	if (ISALIVE(kd)) {
+		/*
+		 * We're using /dev/kmem.  Just read straight from the
+		 * device and let the active kernel do the address translation.
+		 */
+		errno = 0;
+		if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) {
+			_kvm_err(kd, 0, "invalid address (%x)", kva);
+			return (0);
+		}
+		cc = read(kd->vmfd, buf, len);
+		if (cc < 0) {
+			_kvm_syserr(kd, 0, "kvm_read");
+			return (0);
+		} else if (cc < len)
+			_kvm_err(kd, kd->program, "short read");
+		return (cc);
+	} else {
+		cp = buf;
+		while (len > 0) {
+			u_long pa;
+		
+			cc = _kvm_kvatop(kd, kva, &pa);
+			if (cc == 0)
+				return (0);
+			if (cc > len)
+				cc = len;
+			errno = 0;
+			if (lseek(kd->pmfd, (off_t)pa, 0) == -1 && errno != 0) {
+				_kvm_syserr(kd, 0, _PATH_MEM);
+				break;
+			}
+			cc = read(kd->pmfd, cp, cc);
+			if (cc < 0) {
+				_kvm_syserr(kd, kd->program, "kvm_read");
+				break;
+			}
+			/*
+			 * If kvm_kvatop returns a bogus value or our core
+			 * file is truncated, we might wind up seeking beyond
+			 * the end of the core file in which case the read will
+			 * return 0 (EOF).
+			 */
+			if (cc == 0)
+				break;
+			(char *)cp += cc;
+			kva += cc;
+			len -= cc;
+		}
+		return ((char *)cp - (char *)buf);
+	}
+	/* NOTREACHED */
+}
+
+ssize_t
+kvm_write(kd, kva, buf, len)
+	kvm_t *kd;
+	register u_long kva;
+	register const void *buf;
+	register size_t len;
+{
+	register int cc;
+
+	if (ISALIVE(kd)) {
+		/*
+		 * Just like kvm_read, only we write.
+		 */
+		errno = 0;
+		if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) {
+			_kvm_err(kd, 0, "invalid address (%x)", kva);
+			return (0);
+		}
+		cc = write(kd->vmfd, buf, len);
+		if (cc < 0) {
+			_kvm_syserr(kd, 0, "kvm_write");
+			return (0);
+		} else if (cc < len)
+			_kvm_err(kd, kd->program, "short write");
+		return (cc);
+	} else {
+		_kvm_err(kd, kd->program,
+		    "kvm_write not implemented for dead kernels");
+		return (0);
+	}
+	/* NOTREACHED */
+}