/*- * 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. * 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. */ #include __FBSDID("$FreeBSD$"); #if defined(LIBC_SCCS) && !defined(lint) #if 0 static char sccsid[] = "@(#)kvm.c 8.2 (Berkeley) 2/13/94"; #endif #endif /* LIBC_SCCS and not lint */ #include #define _WANT_VNET #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "kvm_private.h" /* from src/lib/libc/gen/nlist.c */ int __fdnlist(int, struct nlist *); static char _kd_is_null[] = ""; char * kvm_geterr(kvm_t *kd) { if (kd == NULL) return (_kd_is_null); return (kd->errbuf); } #include /* * 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 _kvm_err(kvm_t *kd, const char *program, const char *fmt, ...) { va_list ap; va_start(ap, fmt); 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), fmt, ap); va_end(ap); } void _kvm_syserr(kvm_t *kd, const char *program, const char *fmt, ...) { va_list ap; int n; va_start(ap, fmt); if (program != NULL) { (void)fprintf(stderr, "%s: ", program); (void)vfprintf(stderr, fmt, ap); (void)fprintf(stderr, ": %s\n", strerror(errno)); } else { char *cp = kd->errbuf; (void)vsnprintf(cp, sizeof(kd->errbuf), fmt, ap); n = strlen(cp); (void)snprintf(&cp[n], sizeof(kd->errbuf) - n, ": %s", strerror(errno)); } va_end(ap); } void * _kvm_malloc(kvm_t *kd, size_t n) { void *p; if ((p = calloc(n, sizeof(char))) == NULL) _kvm_err(kd, kd->program, "can't allocate %zu bytes: %s", n, strerror(errno)); return (p); } static kvm_t * _kvm_open(kvm_t *kd, const char *uf, const char *mf, int flag, char *errout) { struct stat st; kd->vmfd = -1; kd->pmfd = -1; kd->nlfd = -1; kd->vmst = 0; kd->procbase = 0; kd->argspc = 0; kd->argv = 0; if (uf == 0) uf = getbootfile(); 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 ((kd->pmfd = open(mf, flag | O_CLOEXEC, 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_ISREG(st.st_mode) && st.st_size <= 0) { errno = EINVAL; _kvm_syserr(kd, kd->program, "empty file"); 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_DEVNULL) == 0) { kd->vmfd = open(_PATH_DEVNULL, O_RDONLY | O_CLOEXEC); return (kd); } else if (strcmp(mf, _PATH_MEM) == 0) { if ((kd->vmfd = open(_PATH_KMEM, flag | O_CLOEXEC)) < 0) { _kvm_syserr(kd, kd->program, "%s", _PATH_KMEM); goto failed; } return (kd); } } /* * This is either a crash dump or a remote live system with its physical * memory fully accessible via a special device. * Initialize the virtual address translation machinery, * but first setup the namelist fd. */ if ((kd->nlfd = open(uf, O_RDONLY | O_CLOEXEC, 0)) < 0) { _kvm_syserr(kd, kd->program, "%s", uf); goto failed; } if (strncmp(mf, _PATH_FWMEM, strlen(_PATH_FWMEM)) == 0 || strncmp(mf, _PATH_DEVVMM, strlen(_PATH_DEVVMM)) == 0) { kd->rawdump = 1; kd->writable = 1; } if (_kvm_initvtop(kd) < 0) goto failed; return (kd); failed: /* * Copy out the error if doing sane error semantics. */ if (errout != 0) strlcpy(errout, kd->errbuf, _POSIX2_LINE_MAX); (void)kvm_close(kd); return (NULL); } kvm_t * kvm_openfiles(const char *uf, const char *mf, const char *sf __unused, int flag, char *errout) { kvm_t *kd; if ((kd = calloc(1, sizeof(*kd))) == NULL) { (void)strlcpy(errout, strerror(errno), _POSIX2_LINE_MAX); return (NULL); } kd->program = 0; return (_kvm_open(kd, uf, mf, flag, errout)); } kvm_t * kvm_open(const char *uf, const char *mf, const char *sf __unused, int flag, const char *errstr) { kvm_t *kd; if ((kd = calloc(1, sizeof(*kd))) == NULL) { if (errstr != NULL) (void)fprintf(stderr, "%s: %s\n", errstr, strerror(errno)); return (NULL); } kd->program = errstr; return (_kvm_open(kd, uf, mf, flag, NULL)); } int kvm_close(kvm_t *kd) { int error = 0; if (kd == NULL) { errno = EINVAL; return (-1); } 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->vmst) _kvm_freevtop(kd); if (kd->procbase != 0) free((void *)kd->procbase); if (kd->argbuf != 0) free((void *) kd->argbuf); if (kd->argspc != 0) free((void *) kd->argspc); if (kd->argv != 0) free((void *)kd->argv); free((void *)kd); return (error); } /* * Walk the list of unresolved symbols, generate a new list and prefix the * symbol names, try again, and merge back what we could resolve. */ static int kvm_fdnlist_prefix(kvm_t *kd, struct nlist *nl, int missing, const char *prefix, uintptr_t (*validate_fn)(kvm_t *, uintptr_t)) { struct nlist *n, *np, *p; char *cp, *ce; const char *ccp; size_t len; int slen, unresolved; /* * Calculate the space we need to malloc for nlist and names. * We are going to store the name twice for later lookups: once * with the prefix and once the unmodified name delmited by \0. */ len = 0; unresolved = 0; for (p = nl; p->n_name && p->n_name[0]; ++p) { if (p->n_type != N_UNDF) continue; len += sizeof(struct nlist) + strlen(prefix) + 2 * (strlen(p->n_name) + 1); unresolved++; } if (unresolved == 0) return (unresolved); /* Add space for the terminating nlist entry. */ len += sizeof(struct nlist); unresolved++; /* Alloc one chunk for (nlist, [names]) and setup pointers. */ n = np = malloc(len); bzero(n, len); if (n == NULL) return (missing); cp = ce = (char *)np; cp += unresolved * sizeof(struct nlist); ce += len; /* Generate shortened nlist with special prefix. */ unresolved = 0; for (p = nl; p->n_name && p->n_name[0]; ++p) { if (p->n_type != N_UNDF) continue; bcopy(p, np, sizeof(struct nlist)); /* Save the new\0orig. name so we can later match it again. */ slen = snprintf(cp, ce - cp, "%s%s%c%s", prefix, (prefix[0] != '\0' && p->n_name[0] == '_') ? (p->n_name + 1) : p->n_name, '\0', p->n_name); if (slen < 0 || slen >= ce - cp) continue; np->n_name = cp; cp += slen + 1; np++; unresolved++; } /* Do lookup on the reduced list. */ np = n; unresolved = __fdnlist(kd->nlfd, np); /* Check if we could resolve further symbols and update the list. */ if (unresolved >= 0 && unresolved < missing) { /* Find the first freshly resolved entry. */ for (; np->n_name && np->n_name[0]; np++) if (np->n_type != N_UNDF) break; /* * The lists are both in the same order, * so we can walk them in parallel. */ for (p = nl; np->n_name && np->n_name[0] && p->n_name && p->n_name[0]; ++p) { if (p->n_type != N_UNDF) continue; /* Skip expanded name and compare to orig. one. */ ccp = np->n_name + strlen(np->n_name) + 1; if (strcmp(ccp, p->n_name) != 0) continue; /* Update nlist with new, translated results. */ p->n_type = np->n_type; p->n_other = np->n_other; p->n_desc = np->n_desc; if (validate_fn) p->n_value = (*validate_fn)(kd, np->n_value); else p->n_value = np->n_value; missing--; /* Find next freshly resolved entry. */ for (np++; np->n_name && np->n_name[0]; np++) if (np->n_type != N_UNDF) break; } } /* We could assert missing = unresolved here. */ free(n); return (unresolved); } int _kvm_nlist(kvm_t *kd, struct nlist *nl, int initialize) { struct nlist *p; int nvalid; struct kld_sym_lookup lookup; int error; const char *prefix = ""; char symname[1024]; /* XXX-BZ symbol name length limit? */ int tried_vnet, tried_dpcpu; /* * If we can't use the kld symbol lookup, revert to the * slow library call. */ if (!ISALIVE(kd)) { error = __fdnlist(kd->nlfd, nl); if (error <= 0) /* Hard error or success. */ return (error); if (_kvm_vnet_initialized(kd, initialize)) error = kvm_fdnlist_prefix(kd, nl, error, VNET_SYMPREFIX, _kvm_vnet_validaddr); if (error > 0 && _kvm_dpcpu_initialized(kd, initialize)) error = kvm_fdnlist_prefix(kd, nl, error, DPCPU_SYMPREFIX, _kvm_dpcpu_validaddr); return (error); } /* * We can use the kld lookup syscall. Go through each nlist entry * and look it up with a kldsym(2) syscall. */ nvalid = 0; tried_vnet = 0; tried_dpcpu = 0; again: for (p = nl; p->n_name && p->n_name[0]; ++p) { if (p->n_type != N_UNDF) continue; lookup.version = sizeof(lookup); lookup.symvalue = 0; lookup.symsize = 0; error = snprintf(symname, sizeof(symname), "%s%s", prefix, (prefix[0] != '\0' && p->n_name[0] == '_') ? (p->n_name + 1) : p->n_name); if (error < 0 || error >= (int)sizeof(symname)) continue; lookup.symname = symname; if (lookup.symname[0] == '_') lookup.symname++; if (kldsym(0, KLDSYM_LOOKUP, &lookup) != -1) { p->n_type = N_TEXT; p->n_other = 0; p->n_desc = 0; if (_kvm_vnet_initialized(kd, initialize) && strcmp(prefix, VNET_SYMPREFIX) == 0) p->n_value = _kvm_vnet_validaddr(kd, lookup.symvalue); else if (_kvm_dpcpu_initialized(kd, initialize) && strcmp(prefix, DPCPU_SYMPREFIX) == 0) p->n_value = _kvm_dpcpu_validaddr(kd, lookup.symvalue); else p->n_value = lookup.symvalue; ++nvalid; /* lookup.symsize */ } } /* * Check the number of entries that weren't found. If they exist, * try again with a prefix for virtualized or DPCPU symbol names. */ error = ((p - nl) - nvalid); if (error && _kvm_vnet_initialized(kd, initialize) && !tried_vnet) { tried_vnet = 1; prefix = VNET_SYMPREFIX; goto again; } if (error && _kvm_dpcpu_initialized(kd, initialize) && !tried_dpcpu) { tried_dpcpu = 1; prefix = DPCPU_SYMPREFIX; goto again; } /* * Return the number of entries that weren't found. If they exist, * also fill internal error buffer. */ error = ((p - nl) - nvalid); if (error) _kvm_syserr(kd, kd->program, "kvm_nlist"); return (error); } int kvm_nlist(kvm_t *kd, struct nlist *nl) { /* * If called via the public interface, permit intialization of * further virtualized modules on demand. */ return (_kvm_nlist(kd, nl, 1)); } ssize_t kvm_read(kvm_t *kd, u_long kva, void *buf, size_t len) { int cc; ssize_t cr; off_t pa; char *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 (%lx)", kva); return (-1); } cr = read(kd->vmfd, buf, len); if (cr < 0) { _kvm_syserr(kd, 0, "kvm_read"); return (-1); } else if (cr < (ssize_t)len) _kvm_err(kd, kd->program, "short read"); return (cr); } cp = buf; while (len > 0) { cc = _kvm_kvatop(kd, kva, &pa); if (cc == 0) return (-1); if (cc > (ssize_t)len) cc = len; errno = 0; if (lseek(kd->pmfd, pa, 0) == -1 && errno != 0) { _kvm_syserr(kd, 0, _PATH_MEM); break; } cr = read(kd->pmfd, cp, cc); if (cr < 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 (cr == 0) break; cp += cr; kva += cr; len -= cr; } return (cp - (char *)buf); } ssize_t kvm_write(kvm_t *kd, u_long kva, const void *buf, size_t len) { int cc; ssize_t cw; off_t pa; const char *cp; if (!ISALIVE(kd) && !kd->writable) { _kvm_err(kd, kd->program, "kvm_write not implemented for dead kernels"); return (-1); } 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 (%lx)", kva); return (-1); } cc = write(kd->vmfd, buf, len); if (cc < 0) { _kvm_syserr(kd, 0, "kvm_write"); return (-1); } else if ((size_t)cc < len) _kvm_err(kd, kd->program, "short write"); return (cc); } cp = buf; while (len > 0) { cc = _kvm_kvatop(kd, kva, &pa); if (cc == 0) return (-1); if (cc > (ssize_t)len) cc = len; errno = 0; if (lseek(kd->pmfd, pa, 0) == -1 && errno != 0) { _kvm_syserr(kd, 0, _PATH_MEM); break; } cw = write(kd->pmfd, cp, cc); if (cw < 0) { _kvm_syserr(kd, kd->program, "kvm_write"); break; } /* * If ka_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 (cw == 0) break; cp += cw; kva += cw; len -= cw; } return (cp - (const char *)buf); }