/* $OpenBSD: kvm.c,v 1.5 1997/01/17 07:11:59 millert Exp $ */ /* $NetBSD: kvm.c,v 1.43 1996/05/05 04:31:59 gwr Exp $ */ /*- * 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) #if 0 static char sccsid[] = "@(#)kvm.c 8.2 (Berkeley) 2/13/94"; #else static char *rcsid = "$OpenBSD: kvm.c,v 1.5 1997/01/17 07:11:59 millert Exp $"; #endif #endif /* LIBC_SCCS and not lint */ #include #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" static int kvm_dbopen __P((kvm_t *, const char *)); static int _kvm_get_header __P((kvm_t *)); static kvm_t *_kvm_open __P((kvm_t *, const char *, const char *, const char *, int, char *)); static int clear_gap __P((kvm_t *, FILE *, int)); static off_t Lseek __P((kvm_t *, int, off_t, int)); static ssize_t Read __P(( kvm_t *, int, void *, size_t)); char * kvm_geterr(kd) kvm_t *kd; { return (kd->errbuf); } #if __STDC__ #include #else #include #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); } /* * Wrappers for Lseek/Read system calls. They check for errors and * call _kvm_syserr() if appropriate. */ static off_t Lseek(kd, fd, offset, whence) kvm_t *kd; int fd, whence; off_t offset; { off_t off; errno = 0; if ((off = lseek(fd, offset, whence)) == -1 && errno != 0) { _kvm_syserr(kd, kd->program, "Lseek"); return (-1); } return (off); } static ssize_t Read(kd, fd, buf, nbytes) kvm_t *kd; int fd; void *buf; size_t nbytes; { ssize_t rv; errno = 0; if ((rv = read(fd, buf, nbytes)) != nbytes && errno != 0) _kvm_syserr(kd, kd->program, "Read"); return (rv); } 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->db = 0; kd->pmfd = -1; kd->vmfd = -1; kd->swfd = -1; kd->nlfd = -1; kd->procbase = 0; kd->nbpg = getpagesize(); kd->swapspc = 0; kd->argspc = 0; kd->argbuf = 0; kd->argv = 0; kd->vmst = 0; kd->vm_page_buckets = 0; kd->kcore_hdr = 0; kd->cpu_dsize = 0; kd->cpu_data = 0; kd->dump_off = 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 there is no valid core header, fail silently here. * The address translations however will fail without * header. Things can be made to run by calling * kvm_dump_mkheader() before doing any translation. */ if (_kvm_get_header(kd) == 0) { 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); } /* * The kernel dump file (from savecore) contains: * kcore_hdr_t kcore_hdr; * kcore_seg_t cpu_hdr; * (opaque) cpu_data; (size is cpu_hdr.c_size) * kcore_seg_t mem_hdr; * (memory) mem_data; (size is mem_hdr.c_size) * * Note: khdr is padded to khdr.c_hdrsize; * cpu_hdr and mem_hdr are padded to khdr.c_seghdrsize */ static int _kvm_get_header(kd) kvm_t *kd; { kcore_hdr_t kcore_hdr; kcore_seg_t cpu_hdr; kcore_seg_t mem_hdr; size_t offset; ssize_t sz; /* * Read the kcore_hdr_t */ if (Lseek(kd, kd->pmfd, (off_t)0, SEEK_SET) == -1) return (-1); sz = Read(kd, kd->pmfd, &kcore_hdr, sizeof(kcore_hdr)); if (sz != sizeof(kcore_hdr)) return (-1); /* * Currently, we only support dump-files made by the current * architecture... */ if ((CORE_GETMAGIC(kcore_hdr) != KCORE_MAGIC) || (CORE_GETMID(kcore_hdr) != MID_MACHINE)) return (-1); /* * Currently, we only support exactly 2 segments: cpu-segment * and data-segment in exactly that order. */ if (kcore_hdr.c_nseg != 2) return (-1); /* * Save away the kcore_hdr. All errors after this * should do a to "goto fail" to deallocate things. */ kd->kcore_hdr = _kvm_malloc(kd, sizeof(kcore_hdr)); memcpy(kd->kcore_hdr, &kcore_hdr, sizeof(kcore_hdr)); offset = kcore_hdr.c_hdrsize; /* * Read the CPU segment header */ if (Lseek(kd, kd->pmfd, (off_t)offset, SEEK_SET) == -1) goto fail; sz = Read(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr)); if (sz != sizeof(cpu_hdr)) goto fail; if ((CORE_GETMAGIC(cpu_hdr) != KCORESEG_MAGIC) || (CORE_GETFLAG(cpu_hdr) != CORE_CPU)) goto fail; offset += kcore_hdr.c_seghdrsize; /* * Read the CPU segment DATA. */ kd->cpu_dsize = cpu_hdr.c_size; kd->cpu_data = _kvm_malloc(kd, cpu_hdr.c_size); if (kd->cpu_data == NULL) goto fail; if (Lseek(kd, kd->pmfd, (off_t)offset, SEEK_SET) == -1) goto fail; sz = Read(kd, kd->pmfd, kd->cpu_data, cpu_hdr.c_size); if (sz != cpu_hdr.c_size) goto fail; offset += cpu_hdr.c_size; /* * Read the next segment header: data segment */ if (Lseek(kd, kd->pmfd, (off_t)offset, SEEK_SET) == -1) goto fail; sz = Read(kd, kd->pmfd, &mem_hdr, sizeof(mem_hdr)); if (sz != sizeof(mem_hdr)) goto fail; offset += kcore_hdr.c_seghdrsize; if ((CORE_GETMAGIC(mem_hdr) != KCORESEG_MAGIC) || (CORE_GETFLAG(mem_hdr) != CORE_DATA)) goto fail; kd->dump_off = offset; return (0); fail: if (kd->kcore_hdr != NULL) { free(kd->kcore_hdr); kd->kcore_hdr = NULL; } if (kd->cpu_data != NULL) { free(kd->cpu_data); kd->cpu_data = NULL; kd->cpu_dsize = 0; } } /* * The format while on the dump device is: (new format) * kcore_seg_t cpu_hdr; * (opaque) cpu_data; (size is cpu_hdr.c_size) * kcore_seg_t mem_hdr; * (memory) mem_data; (size is mem_hdr.c_size) */ int kvm_dump_mkheader(kd, dump_off) kvm_t *kd; off_t dump_off; { kcore_seg_t cpu_hdr; int hdr_size, sz; if (kd->kcore_hdr != NULL) { _kvm_err(kd, kd->program, "already has a dump header"); return (-1); } if (ISALIVE(kd)) { _kvm_err(kd, kd->program, "don't use on live kernel"); return (-1); } /* * Validate new format crash dump */ if (Lseek(kd, kd->pmfd, dump_off, SEEK_SET) == -1) return (-1); sz = Read(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr)); if (sz != sizeof(cpu_hdr)) return (-1); if (CORE_GETMAGIC(cpu_hdr) != KCORE_MAGIC) return (-1); if (CORE_GETMID(cpu_hdr) != MID_MACHINE) return (-1); hdr_size = ALIGN(sizeof(cpu_hdr)); /* * Read the CPU segment. */ kd->cpu_dsize = cpu_hdr.c_size; kd->cpu_data = _kvm_malloc(kd, kd->cpu_dsize); if (kd->cpu_data == NULL) goto fail; if (Lseek(kd, kd->pmfd, dump_off+hdr_size, SEEK_SET) == -1) goto fail; sz = Read(kd, kd->pmfd, kd->cpu_data, cpu_hdr.c_size); if (sz != cpu_hdr.c_size) goto fail; hdr_size += kd->cpu_dsize; /* * Leave phys mem pointer at beginning of memory data */ kd->dump_off = dump_off + hdr_size; if (Lseek(kd, kd->pmfd, kd->dump_off, SEEK_SET) == -1) goto fail; /* * Create a kcore_hdr. */ kd->kcore_hdr = _kvm_malloc(kd, sizeof(kcore_hdr_t)); if (kd->kcore_hdr == NULL) goto fail; kd->kcore_hdr->c_hdrsize = ALIGN(sizeof(kcore_hdr_t)); kd->kcore_hdr->c_seghdrsize = ALIGN(sizeof(kcore_seg_t)); kd->kcore_hdr->c_nseg = 2; CORE_SETMAGIC(*(kd->kcore_hdr), KCORE_MAGIC, MID_MACHINE,0); /* * Now that we have a valid header, enable translations. */ _kvm_initvtop(kd); return(hdr_size); fail: if (kd->kcore_hdr != NULL) { free(kd->kcore_hdr); kd->kcore_hdr = NULL; } if (kd->cpu_data != NULL) { free(kd->cpu_data); kd->cpu_data = NULL; kd->cpu_dsize = 0; } return (-1); } static int clear_gap(kd, fp, size) kvm_t *kd; FILE *fp; int size; { if (size <= 0) /* XXX - < 0 should never happen */ return (0); while (size-- > 0) { if (fputc(0, fp) == EOF) { _kvm_syserr(kd, kd->program, "clear_gap"); return (-1); } } return (0); } /* * Write the dump header info to 'fp'. Note that we can't use fseek(3) here * because 'fp' might be a file pointer obtained by zopen(). */ int kvm_dump_wrtheader(kd, fp, dumpsize) kvm_t *kd; FILE *fp; int dumpsize; { kcore_seg_t seghdr; long offset; int gap; if (kd->kcore_hdr == NULL || kd->cpu_data == NULL) { _kvm_err(kd, kd->program, "no valid dump header(s)"); return (-1); } /* * Write the generic header */ offset = 0; if (fwrite((void*)kd->kcore_hdr, sizeof(kcore_hdr_t), 1, fp) <= 0) { _kvm_syserr(kd, kd->program, "kvm_dump_wrtheader"); return (-1); } offset += kd->kcore_hdr->c_hdrsize; gap = kd->kcore_hdr->c_hdrsize - sizeof(kcore_hdr_t); if (clear_gap(kd, fp, gap) == -1) return (-1); /* * Write the cpu header */ CORE_SETMAGIC(seghdr, KCORESEG_MAGIC, 0, CORE_CPU); seghdr.c_size = ALIGN(kd->cpu_dsize); if (fwrite((void*)&seghdr, sizeof(seghdr), 1, fp) <= 0) { _kvm_syserr(kd, kd->program, "kvm_dump_wrtheader"); return (-1); } offset += kd->kcore_hdr->c_seghdrsize; gap = kd->kcore_hdr->c_seghdrsize - sizeof(seghdr); if (clear_gap(kd, fp, gap) == -1) return (-1); if (fwrite((void*)kd->cpu_data, kd->cpu_dsize, 1, fp) <= 0) { _kvm_syserr(kd, kd->program, "kvm_dump_wrtheader"); return (-1); } offset += seghdr.c_size; gap = seghdr.c_size - kd->cpu_dsize; if (clear_gap(kd, fp, gap) == -1) return (-1); /* * Write the actual dump data segment header */ CORE_SETMAGIC(seghdr, KCORESEG_MAGIC, 0, CORE_DATA); seghdr.c_size = dumpsize; if (fwrite((void*)&seghdr, sizeof(seghdr), 1, fp) <= 0) { _kvm_syserr(kd, kd->program, "kvm_dump_wrtheader"); return (-1); } offset += kd->kcore_hdr->c_seghdrsize; gap = kd->kcore_hdr->c_seghdrsize - sizeof(seghdr); if (clear_gap(kd, fp, gap) == -1) return (-1); return (offset); } 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); kd->cpu_dsize = 0; if (kd->cpu_data != NULL) free((void *)kd->cpu_data); if (kd->kcore_hdr != NULL) free((void *)kd->kcore_hdr); if (kd->procbase != 0) free((void *)kd->procbase); if (kd->swapspc != 0) free((void *)kd->swapspc); if (kd->argspc != 0) free((void *)kd->argspc); if (kd->argbuf != 0) free((void *)kd->argbuf); 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 = strrchr(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; /* * Make sure that n_value = 0 when the symbol isn't found */ p->n_value = 0; 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); } int kvm_dump_inval(kd) kvm_t *kd; { struct nlist nlist[2]; u_long pa; if (ISALIVE(kd)) { _kvm_err(kd, kd->program, "clearing dump on live kernel"); return (-1); } nlist[0].n_name = "_dumpmag"; nlist[1].n_name = NULL; if (kvm_nlist(kd, nlist) == -1) { _kvm_err(kd, 0, "bad namelist"); return (-1); } if (_kvm_kvatop(kd, (u_long)nlist[0].n_value, &pa) == 0) return (-1); errno = 0; if (lseek(kd->pmfd, _kvm_pa2off(kd, pa), SEEK_SET) == -1 && errno != 0) { _kvm_err(kd, 0, "cannot invalidate dump - lseek"); return (-1); } pa = 0; if (write(kd->pmfd, &pa, sizeof(pa)) != sizeof(pa)) { _kvm_err(kd, 0, "cannot invalidate dump - write"); return (-1); } return (0); } 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, SEEK_SET) == -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 { if ((kd->kcore_hdr == NULL) || (kd->cpu_data == NULL)) { _kvm_err(kd, kd->program, "no valid dump header"); return (0); } cp = buf; while (len > 0) { u_long pa; off_t foff; cc = _kvm_kvatop(kd, kva, &pa); if (cc == 0) return (0); if (cc > len) cc = len; foff = _kvm_pa2off(kd, pa); errno = 0; if (lseek(kd->pmfd, foff, SEEK_SET) == -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; cp = (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, SEEK_SET) == -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 */ }