Index: stable/10/lib/libkvm/kvm.c =================================================================== --- stable/10/lib/libkvm/kvm.c (revision 316069) +++ stable/10/lib/libkvm/kvm.c (revision 316070) @@ -1,623 +1,627 @@ /*- * 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 *); char * kvm_geterr(kvm_t *kd) { 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 - (char *)buf); } Index: stable/10/lib/libkvm/kvm_open.3 =================================================================== --- stable/10/lib/libkvm/kvm_open.3 (revision 316069) +++ stable/10/lib/libkvm/kvm_open.3 (revision 316070) @@ -1,205 +1,224 @@ .\" Copyright (c) 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. .\" .\" @(#)kvm_open.3 8.3 (Berkeley) 4/19/94 .\" $FreeBSD$ .\" -.Dd January 29, 2004 +.Dd March 20, 2017 .Dt KVM_OPEN 3 .Os .Sh NAME .Nm kvm_open , .Nm kvm_openfiles , .Nm kvm_close .Nd initialize kernel virtual memory access .Sh LIBRARY .Lb libkvm .Sh SYNOPSIS .In fcntl.h .In kvm.h .Ft kvm_t * .Fn kvm_open "const char *execfile" "const char *corefile" "const char *swapfile" "int flags" "const char *errstr" .Ft kvm_t * .Fn kvm_openfiles "const char *execfile" "const char *corefile" "const char *swapfile" "int flags" "char *errbuf" .Ft int .Fn kvm_close "kvm_t *kd" .Sh DESCRIPTION The functions .Fn kvm_open and .Fn kvm_openfiles return a descriptor used to access kernel virtual memory via the .Xr kvm 3 library routines. Both active kernels and crash dumps are accessible through this interface. .Pp The .Fa execfile argument is the executable image of the kernel being examined. This file must contain a symbol table. If this argument is .Dv NULL , the currently running system is assumed, as determined from .Xr getbootfile 3 . .Pp The .Fa corefile argument is the kernel memory device file. It can be either .Pa /dev/mem or a crash dump core generated by .Xr savecore 8 . If .Fa corefile is .Dv NULL , the default indicated by .Dv _PATH_MEM from .In paths.h is used. It can also be set to a special value .Pa /dev/null by utilities like .Xr ps 1 that do not directly access kernel memory. .Pp The .Fa swapfile argument is currently unused. .Pp The .Fa flags argument indicates read/write access as in .Xr open 2 and applies only to the core file. Only .Dv O_RDONLY , .Dv O_WRONLY , and .Dv O_RDWR are permitted. .Pp There are two open routines which differ only with respect to the error mechanism. One provides backward compatibility with the SunOS kvm library, while the other provides an improved error reporting framework. .Pp The .Fn kvm_open function is the Sun kvm compatible open call. Here, the .Fa errstr argument indicates how errors should be handled. If it is .Dv NULL , no errors are reported and the application cannot know the specific nature of the failed kvm call. If it is not .Dv NULL , errors are printed to .Dv stderr with .Fa errstr prepended to the message, as in .Xr perror 3 . Normally, the name of the program is used here. The string is assumed to persist at least until the corresponding .Fn kvm_close call. .Pp The .Fn kvm_openfiles function provides .Bx style error reporting. Here, error messages are not printed out by the library. Instead, the application obtains the error message corresponding to the most recent kvm library call using .Fn kvm_geterr (see .Xr kvm_geterr 3 ) . The results are undefined if the most recent kvm call did not produce an error. Since .Fn kvm_geterr requires a kvm descriptor, but the open routines return .Dv NULL on failure, .Fn kvm_geterr cannot be used to get the error message if open fails. Thus, .Fn kvm_openfiles will place any error message in the .Fa errbuf argument. This buffer should be _POSIX2_LINE_MAX characters large (from ). .Sh RETURN VALUES The .Fn kvm_open and .Fn kvm_openfiles functions both return a descriptor to be used in all subsequent kvm library calls. The library is fully re-entrant. On failure, .Dv NULL is returned, in which case .Fn kvm_openfiles writes the error message into .Fa errbuf . .Pp +.Rv -std kvm_close +.Sh ERRORS The .Fn kvm_close -function returns 0 on success and -1 on failure. +function may fail and set the global variable +.Va errno +for any of the errors specified for +.Xr close 2 . +.Pp +The +.Fn kvm_close +function may also fail and set +.Va errno +if: +.Bl -tag -width Er +.It Bq Er EINVAL +The value passed via +.Fa kd +was +.Dv NULL . +.El .Sh SEE ALSO +.Xr close 2 , .Xr open 2 , .Xr kvm 3 , .Xr kvm_getargv 3 , .Xr kvm_getenvv 3 , .Xr kvm_geterr 3 , .Xr kvm_getprocs 3 , .Xr kvm_nlist 3 , .Xr kvm_read 3 , .Xr kvm_write 3 , .Xr kmem 4 , .Xr mem 4 .Sh BUGS There should not be two open calls. The ill-defined error semantics of the Sun library and the desire to have a backward-compatible library for .Bx left little choice. Index: stable/10 =================================================================== --- stable/10 (revision 316069) +++ stable/10 (revision 316070) Property changes on: stable/10 ___________________________________________________________________ Modified: svn:mergeinfo ## -0,0 +0,1 ## Merged /head:r315647