/* $NetBSD: kvm.c,v 1.103 2018/02/07 14:03:18 maxv 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. 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 #if defined(LIBC_SCCS) && !defined(lint) #if 0 static char sccsid[] = "@(#)kvm.c 8.2 (Berkeley) 2/13/94"; #else __RCSID("$NetBSD: kvm.c,v 1.103 2018/02/07 14:03:18 maxv 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 #include #include "kvm_private.h" static int _kvm_get_header(kvm_t *); static kvm_t *_kvm_open(kvm_t *, const char *, const char *, const char *, int, char *); static int clear_gap(kvm_t *, bool (*)(void *, const void *, size_t), void *, size_t); static off_t Lseek(kvm_t *, int, off_t, int); static ssize_t Pread(kvm_t *, int, void *, size_t, off_t); char * kvm_geterr(kvm_t *kd) { return (kd->errbuf); } const char * kvm_getkernelname(kvm_t *kd) { return kd->kernelname; } /* * 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; size_t 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 = malloc(n)) == NULL) _kvm_err(kd, kd->program, "%s", strerror(errno)); return (p); } /* * Wrapper around the lseek(2) system call; calls _kvm_syserr() for us * in the event of emergency. */ static off_t Lseek(kvm_t *kd, int fd, off_t offset, int whence) { off_t off; errno = 0; if ((off = lseek(fd, offset, whence)) == -1 && errno != 0) { _kvm_syserr(kd, kd->program, "Lseek"); return ((off_t)-1); } return (off); } ssize_t _kvm_pread(kvm_t *kd, int fd, void *buf, size_t size, off_t off) { ptrdiff_t moff; void *newbuf; size_t dsize; ssize_t rv; off_t doff; /* If aligned nothing to do. */ if (((off % kd->fdalign) | (size % kd->fdalign)) == 0) { return pread(fd, buf, size, off); } /* * Otherwise must buffer. We can't tolerate short reads in this * case (lazy bum). */ moff = (ptrdiff_t)off % kd->fdalign; doff = off - moff; dsize = moff + size + kd->fdalign - 1; dsize -= dsize % kd->fdalign; if (kd->iobufsz < dsize) { newbuf = realloc(kd->iobuf, dsize); if (newbuf == NULL) { _kvm_syserr(kd, 0, "cannot allocate I/O buffer"); return (-1); } kd->iobuf = newbuf; kd->iobufsz = dsize; } rv = pread(fd, kd->iobuf, dsize, doff); if (rv < size + moff) return -1; memcpy(buf, kd->iobuf + moff, size); return size; } /* * Wrapper around the pread(2) system call; calls _kvm_syserr() for us * in the event of emergency. */ static ssize_t Pread(kvm_t *kd, int fd, void *buf, size_t nbytes, off_t offset) { ssize_t rv; errno = 0; if ((rv = _kvm_pread(kd, fd, buf, nbytes, offset)) != nbytes && errno != 0) _kvm_syserr(kd, kd->program, "Pread"); return (rv); } static kvm_t * _kvm_open(kvm_t *kd, const char *uf, const char *mf, const char *sf, int flag, char *errout) { struct stat st; int ufgiven; kd->pmfd = -1; kd->vmfd = -1; kd->swfd = -1; kd->nlfd = -1; kd->alive = KVM_ALIVE_DEAD; kd->procbase = NULL; kd->procbase_len = 0; kd->procbase2 = NULL; kd->procbase2_len = 0; kd->lwpbase = NULL; kd->lwpbase_len = 0; kd->nbpg = getpagesize(); kd->swapspc = NULL; kd->argspc = NULL; kd->argspc_len = 0; kd->argbuf = NULL; kd->argv = NULL; kd->vmst = NULL; kd->vm_page_buckets = NULL; kd->kcore_hdr = NULL; kd->cpu_dsize = 0; kd->cpu_data = NULL; kd->dump_off = 0; kd->fdalign = 1; kd->iobuf = NULL; kd->iobufsz = 0; if (flag & KVM_NO_FILES) { kd->alive = KVM_ALIVE_SYSCTL; return(kd); } /* * Call the MD open hook. This sets: * usrstack, min_uva, max_uva */ if (_kvm_mdopen(kd)) { _kvm_err(kd, kd->program, "md init failed"); goto failed; } ufgiven = (uf != NULL); if (!ufgiven) { #ifdef CPU_BOOTED_KERNEL /* 130 is 128 + '/' + '\0' */ static char booted_kernel[130]; int mib[2], rc; size_t len; mib[0] = CTL_MACHDEP; mib[1] = CPU_BOOTED_KERNEL; booted_kernel[0] = '/'; booted_kernel[1] = '\0'; len = sizeof(booted_kernel) - 2; rc = sysctl(&mib[0], 2, &booted_kernel[1], &len, NULL, 0); booted_kernel[sizeof(booted_kernel) - 1] = '\0'; uf = (booted_kernel[1] == '/') ? &booted_kernel[1] : &booted_kernel[0]; if (rc != -1) rc = stat(uf, &st); if (rc != -1 && !S_ISREG(st.st_mode)) rc = -1; if (rc == -1) #endif /* CPU_BOOTED_KERNEL */ 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; /* * Open the kernel namelist. If /dev/ksyms doesn't * exist, open the current kernel. */ if (ufgiven == 0) kd->nlfd = open(_PATH_KSYMS, O_RDONLY | O_CLOEXEC, 0); if (kd->nlfd < 0) { if ((kd->nlfd = open(uf, O_RDONLY | O_CLOEXEC, 0)) < 0) { _kvm_syserr(kd, kd->program, "%s", uf); goto failed; } strlcpy(kd->kernelname, uf, sizeof(kd->kernelname)); } else { strlcpy(kd->kernelname, _PATH_KSYMS, sizeof(kd->kernelname)); } 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_ISCHR(st.st_mode) && strcmp(mf, _PATH_MEM) == 0) { /* * If this is /dev/mem, 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 ((kd->vmfd = open(_PATH_KMEM, flag | O_CLOEXEC, 0)) < 0) { _kvm_syserr(kd, kd->program, "%s", _PATH_KMEM); goto failed; } kd->alive = KVM_ALIVE_FILES; if ((kd->swfd = open(sf, flag | O_CLOEXEC, 0)) < 0) { if (errno != ENXIO) { _kvm_syserr(kd, kd->program, "%s", sf); goto failed; } /* swap is not configured? not fatal */ } } else { kd->fdalign = DEV_BSIZE; /* XXX */ /* * This is a crash dump. * Initialize the virtual address translation machinery. * * 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) (void)strlcpy(errout, kd->errbuf, _POSIX2_LINE_MAX); (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(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 */ sz = Pread(kd, kd->pmfd, &kcore_hdr, sizeof(kcore_hdr), (off_t)0); 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 */ sz = Pread(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr), (off_t)offset); 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; sz = Pread(kd, kd->pmfd, kd->cpu_data, cpu_hdr.c_size, (off_t)offset); if (sz != cpu_hdr.c_size) goto fail; offset += cpu_hdr.c_size; /* * Read the next segment header: data segment */ sz = Pread(kd, kd->pmfd, &mem_hdr, sizeof(mem_hdr), (off_t)offset); 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; } return (-1); } /* * 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(kvm_t *kd, off_t dump_off) { kcore_seg_t cpu_hdr; size_t hdr_size; ssize_t 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 */ sz = Pread(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr), dump_off); if (sz != sizeof(cpu_hdr)) { if (sz == -1) _kvm_err(kd, 0, "read %zx bytes at offset %"PRIx64 " for cpu_hdr failed: %s", sizeof(cpu_hdr), dump_off, strerror(errno)); else _kvm_err(kd, 0, "read %zx bytes at offset %"PRIx64 " for cpu_hdr instead of requested %zu", sz, dump_off, sizeof(cpu_hdr)); return (-1); } if ((CORE_GETMAGIC(cpu_hdr) != KCORE_MAGIC) || (CORE_GETMID(cpu_hdr) != MID_MACHINE)) { _kvm_err(kd, 0, "invalid magic in cpu_hdr"); return (0); } 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) { _kvm_err(kd, kd->program, "no cpu_data"); goto fail; } sz = Pread(kd, kd->pmfd, kd->cpu_data, cpu_hdr.c_size, dump_off + hdr_size); if (sz != cpu_hdr.c_size) { _kvm_err(kd, kd->program, "size %zu != cpu_hdr.csize %"PRIu32, 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) { _kvm_err(kd, kd->program, "failed to seek to %" PRId64, (int64_t)kd->dump_off); goto fail; } /* * Create a kcore_hdr. */ kd->kcore_hdr = _kvm_malloc(kd, sizeof(kcore_hdr_t)); if (kd->kcore_hdr == NULL) { _kvm_err(kd, kd->program, "failed to allocate header"); 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. */ if (_kvm_initvtop(kd) == 0) /* Success */ 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(kvm_t *kd, bool (*write_buf)(void *, const void *, size_t), void *cookie, size_t size) { char buf[1024]; size_t len; (void)memset(buf, 0, size > sizeof(buf) ? sizeof(buf) : size); while (size > 0) { len = size > sizeof(buf) ? sizeof(buf) : size; if (!(*write_buf)(cookie, buf, len)) { _kvm_syserr(kd, kd->program, "clear_gap"); return -1; } size -= len; } return 0; } /* * Write the dump header by calling write_buf with cookie as first argument. */ int kvm_dump_header(kvm_t *kd, bool (*write_buf)(void *, const void *, size_t), void *cookie, int dumpsize) { kcore_seg_t seghdr; long offset; size_t 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 (!(*write_buf)(cookie, kd->kcore_hdr, sizeof(kcore_hdr_t))) { _kvm_syserr(kd, kd->program, "kvm_dump_header"); return (-1); } offset += kd->kcore_hdr->c_hdrsize; gap = kd->kcore_hdr->c_hdrsize - sizeof(kcore_hdr_t); if (clear_gap(kd, write_buf, cookie, gap) == -1) return (-1); /* * Write the CPU header */ CORE_SETMAGIC(seghdr, KCORESEG_MAGIC, 0, CORE_CPU); seghdr.c_size = ALIGN(kd->cpu_dsize); if (!(*write_buf)(cookie, &seghdr, sizeof(seghdr))) { _kvm_syserr(kd, kd->program, "kvm_dump_header"); return (-1); } offset += kd->kcore_hdr->c_seghdrsize; gap = kd->kcore_hdr->c_seghdrsize - sizeof(seghdr); if (clear_gap(kd, write_buf, cookie, gap) == -1) return (-1); if (!(*write_buf)(cookie, kd->cpu_data, kd->cpu_dsize)) { _kvm_syserr(kd, kd->program, "kvm_dump_header"); return (-1); } offset += seghdr.c_size; gap = seghdr.c_size - kd->cpu_dsize; if (clear_gap(kd, write_buf, cookie, gap) == -1) return (-1); /* * Write the actual dump data segment header */ CORE_SETMAGIC(seghdr, KCORESEG_MAGIC, 0, CORE_DATA); seghdr.c_size = dumpsize; if (!(*write_buf)(cookie, &seghdr, sizeof(seghdr))) { _kvm_syserr(kd, kd->program, "kvm_dump_header"); return (-1); } offset += kd->kcore_hdr->c_seghdrsize; gap = kd->kcore_hdr->c_seghdrsize - sizeof(seghdr); if (clear_gap(kd, write_buf, cookie, gap) == -1) return (-1); return (int)offset; } static bool kvm_dump_header_stdio(void *cookie, const void *buf, size_t len) { return fwrite(buf, len, 1, (FILE *)cookie) == 1; } int kvm_dump_wrtheader(kvm_t *kd, FILE *fp, int dumpsize) { return kvm_dump_header(kd, kvm_dump_header_stdio, fp, dumpsize); } kvm_t * kvm_openfiles(const char *uf, const char *mf, const char *sf, int flag, char *errout) { kvm_t *kd; if ((kd = malloc(sizeof(*kd))) == NULL) { (void)strlcpy(errout, strerror(errno), _POSIX2_LINE_MAX); return (0); } kd->program = 0; return (_kvm_open(kd, uf, mf, sf, flag, errout)); } kvm_t * kvm_open(const char *uf, const char *mf, const char *sf, int flag, const char *program) { kvm_t *kd; if ((kd = malloc(sizeof(*kd))) == NULL) { (void)fprintf(stderr, "%s: %s\n", program ? program : getprogname(), strerror(errno)); return (0); } kd->program = program; return (_kvm_open(kd, uf, mf, sf, flag, NULL)); } int kvm_close(kvm_t *kd) { 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->vmst) _kvm_freevtop(kd); kd->cpu_dsize = 0; if (kd->cpu_data != NULL) free(kd->cpu_data); if (kd->kcore_hdr != NULL) free(kd->kcore_hdr); if (kd->procbase != 0) free(kd->procbase); if (kd->procbase2 != 0) free(kd->procbase2); if (kd->lwpbase != 0) free(kd->lwpbase); if (kd->swapspc != 0) free(kd->swapspc); if (kd->argspc != 0) free(kd->argspc); if (kd->argbuf != 0) free(kd->argbuf); if (kd->argv != 0) free(kd->argv); if (kd->iobuf != 0) free(kd->iobuf); free(kd); return (error); } int kvm_nlist(kvm_t *kd, struct nlist *nl) { int rv; /* * Call the nlist(3) routines to retrieve the given namelist. */ rv = __fdnlist(kd->nlfd, nl); if (rv == -1) _kvm_err(kd, 0, "bad namelist"); return (rv); } int kvm_dump_inval(kvm_t *kd) { struct nlist nl[2]; paddr_t pa; size_t dsize; off_t doff; void *newbuf; if (ISALIVE(kd)) { _kvm_err(kd, kd->program, "clearing dump on live kernel"); return (-1); } nl[0].n_name = "_dumpmag"; nl[1].n_name = NULL; if (kvm_nlist(kd, nl) == -1) { _kvm_err(kd, 0, "bad namelist"); return (-1); } if (_kvm_kvatop(kd, (vaddr_t)nl[0].n_value, &pa) == 0) return (-1); errno = 0; dsize = MAX(kd->fdalign, sizeof(u_long)); if (kd->iobufsz < dsize) { newbuf = realloc(kd->iobuf, dsize); if (newbuf == NULL) { _kvm_syserr(kd, 0, "cannot allocate I/O buffer"); return (-1); } kd->iobuf = newbuf; kd->iobufsz = dsize; } memset(kd->iobuf, 0, dsize); doff = _kvm_pa2off(kd, pa); doff -= doff % kd->fdalign; if (pwrite(kd->pmfd, kd->iobuf, dsize, doff) == -1) { _kvm_syserr(kd, 0, "cannot invalidate dump - pwrite"); return (-1); } return (0); } ssize_t kvm_read(kvm_t *kd, u_long kva, void *buf, size_t len) { int cc; void *cp; if (ISKMEM(kd)) { /* * We're using /dev/kmem. Just read straight from the * device and let the active kernel do the address translation. */ errno = 0; cc = _kvm_pread(kd, kd->vmfd, buf, len, (off_t)kva); if (cc < 0) { _kvm_syserr(kd, 0, "kvm_read"); return (-1); } else if (cc < len) _kvm_err(kd, kd->program, "short read"); return (cc); } else if (ISSYSCTL(kd)) { _kvm_err(kd, kd->program, "kvm_open called with KVM_NO_FILES, " "can't use kvm_read"); return (-1); } else { if ((kd->kcore_hdr == NULL) || (kd->cpu_data == NULL)) { _kvm_err(kd, kd->program, "no valid dump header"); return (-1); } cp = buf; while (len > 0) { paddr_t pa; off_t foff; cc = _kvm_kvatop(kd, (vaddr_t)kva, &pa); if (cc == 0) return (-1); if (cc > len) cc = len; foff = _kvm_pa2off(kd, pa); errno = 0; cc = _kvm_pread(kd, kd->pmfd, cp, (size_t)cc, foff); 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(kvm_t *kd, u_long kva, const void *buf, size_t len) { int cc; if (ISKMEM(kd)) { /* * Just like kvm_read, only we write. */ errno = 0; cc = pwrite(kd->vmfd, buf, len, (off_t)kva); if (cc < 0) { _kvm_syserr(kd, 0, "kvm_write"); return (-1); } else if (cc < len) _kvm_err(kd, kd->program, "short write"); return (cc); } else if (ISSYSCTL(kd)) { _kvm_err(kd, kd->program, "kvm_open called with KVM_NO_FILES, " "can't use kvm_write"); return (-1); } else { _kvm_err(kd, kd->program, "kvm_write not implemented for dead kernels"); return (-1); } /* NOTREACHED */ }