/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 1997-2000 Doug Rabson * All rights reserved. * * 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 #include "opt_ddb.h" #include "opt_kld.h" #include "opt_hwpmc_hooks.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DDB #include #endif #include #include #include "linker_if.h" #ifdef HWPMC_HOOKS #include #endif #ifdef KLD_DEBUG int kld_debug = 0; SYSCTL_INT(_debug, OID_AUTO, kld_debug, CTLFLAG_RWTUN, &kld_debug, 0, "Set various levels of KLD debug"); #endif /* These variables are used by kernel debuggers to enumerate loaded files. */ const int kld_off_address = offsetof(struct linker_file, address); const int kld_off_filename = offsetof(struct linker_file, filename); const int kld_off_pathname = offsetof(struct linker_file, pathname); const int kld_off_next = offsetof(struct linker_file, link.tqe_next); /* * static char *linker_search_path(const char *name, struct mod_depend * *verinfo); */ static const char *linker_basename(const char *path); /* * Find a currently loaded file given its filename. */ static linker_file_t linker_find_file_by_name(const char* _filename); /* * Find a currently loaded file given its file id. */ static linker_file_t linker_find_file_by_id(int _fileid); /* Metadata from the static kernel */ SET_DECLARE(modmetadata_set, struct mod_metadata); MALLOC_DEFINE(M_LINKER, "linker", "kernel linker"); linker_file_t linker_kernel_file; static struct sx kld_sx; /* kernel linker lock */ static u_int kld_busy; static struct thread *kld_busy_owner; /* * Load counter used by clients to determine if a linker file has been * re-loaded. This counter is incremented for each file load. */ static int loadcnt; static linker_class_list_t classes; static linker_file_list_t linker_files; static int next_file_id = 1; static int linker_no_more_classes = 0; #define LINKER_GET_NEXT_FILE_ID(a) do { \ linker_file_t lftmp; \ \ if (!cold) \ sx_assert(&kld_sx, SA_XLOCKED); \ retry: \ TAILQ_FOREACH(lftmp, &linker_files, link) { \ if (next_file_id == lftmp->id) { \ next_file_id++; \ goto retry; \ } \ } \ (a) = next_file_id; \ } while (0) /* XXX wrong name; we're looking at version provision tags here, not modules */ typedef TAILQ_HEAD(, modlist) modlisthead_t; struct modlist { TAILQ_ENTRY(modlist) link; /* chain together all modules */ linker_file_t container; const char *name; int version; }; typedef struct modlist *modlist_t; static modlisthead_t found_modules; static void linker_file_add_dependency(linker_file_t file, linker_file_t dep); static caddr_t linker_file_lookup_symbol_internal(linker_file_t file, const char* name, int deps); static int linker_load_module(const char *kldname, const char *modname, struct linker_file *parent, const struct mod_depend *verinfo, struct linker_file **lfpp); static modlist_t modlist_lookup2(const char *name, const struct mod_depend *verinfo); static void linker_init(void *arg) { sx_init(&kld_sx, "kernel linker"); TAILQ_INIT(&classes); TAILQ_INIT(&linker_files); } SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, NULL); static void linker_stop_class_add(void *arg) { linker_no_more_classes = 1; } SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL); int linker_add_class(linker_class_t lc) { /* * We disallow any class registration past SI_ORDER_ANY * of SI_SUB_KLD. We bump the reference count to keep the * ops from being freed. */ if (linker_no_more_classes == 1) return (EPERM); kobj_class_compile((kobj_class_t) lc); ((kobj_class_t)lc)->refs++; /* XXX: kobj_mtx */ TAILQ_INSERT_TAIL(&classes, lc, link); return (0); } static void linker_file_sysinit(linker_file_t lf) { struct sysinit **start, **stop, **sipp, **xipp, *save; int last; KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", lf->filename)); sx_assert(&kld_sx, SA_XLOCKED); if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0) return; /* * Perform a bubble sort of the system initialization objects by * their subsystem (primary key) and order (secondary key). * * Since some things care about execution order, this is the operation * which ensures continued function. */ for (sipp = start; sipp < stop; sipp++) { for (xipp = sipp + 1; xipp < stop; xipp++) { if ((*sipp)->subsystem < (*xipp)->subsystem || ((*sipp)->subsystem == (*xipp)->subsystem && (*sipp)->order <= (*xipp)->order)) continue; /* skip */ save = *sipp; *sipp = *xipp; *xipp = save; } } /* * Traverse the (now) ordered list of system initialization tasks. * Perform each task, and continue on to the next task. */ last = SI_SUB_DUMMY; sx_xunlock(&kld_sx); mtx_lock(&Giant); for (sipp = start; sipp < stop; sipp++) { if ((*sipp)->subsystem == SI_SUB_DUMMY) continue; /* skip dummy task(s) */ if ((*sipp)->subsystem > last) BOOTTRACE("%s: sysinit 0x%7x", lf->filename, (*sipp)->subsystem); /* Call function */ (*((*sipp)->func)) ((*sipp)->udata); last = (*sipp)->subsystem; } mtx_unlock(&Giant); sx_xlock(&kld_sx); } static void linker_file_sysuninit(linker_file_t lf) { struct sysinit **start, **stop, **sipp, **xipp, *save; int last; KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n", lf->filename)); sx_assert(&kld_sx, SA_XLOCKED); if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop, NULL) != 0) return; /* * Perform a reverse bubble sort of the system initialization objects * by their subsystem (primary key) and order (secondary key). * * Since some things care about execution order, this is the operation * which ensures continued function. */ for (sipp = start; sipp < stop; sipp++) { for (xipp = sipp + 1; xipp < stop; xipp++) { if ((*sipp)->subsystem > (*xipp)->subsystem || ((*sipp)->subsystem == (*xipp)->subsystem && (*sipp)->order >= (*xipp)->order)) continue; /* skip */ save = *sipp; *sipp = *xipp; *xipp = save; } } /* * Traverse the (now) ordered list of system initialization tasks. * Perform each task, and continue on to the next task. */ sx_xunlock(&kld_sx); mtx_lock(&Giant); last = SI_SUB_DUMMY; for (sipp = start; sipp < stop; sipp++) { if ((*sipp)->subsystem == SI_SUB_DUMMY) continue; /* skip dummy task(s) */ if ((*sipp)->subsystem > last) BOOTTRACE("%s: sysuninit 0x%7x", lf->filename, (*sipp)->subsystem); /* Call function */ (*((*sipp)->func)) ((*sipp)->udata); last = (*sipp)->subsystem; } mtx_unlock(&Giant); sx_xlock(&kld_sx); } static void linker_file_register_sysctls(linker_file_t lf, bool enable) { struct sysctl_oid **start, **stop, **oidp; KLD_DPF(FILE, ("linker_file_register_sysctls: registering SYSCTLs for %s\n", lf->filename)); sx_assert(&kld_sx, SA_XLOCKED); if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) return; sx_xunlock(&kld_sx); sysctl_wlock(); for (oidp = start; oidp < stop; oidp++) { if (enable) sysctl_register_oid(*oidp); else sysctl_register_disabled_oid(*oidp); } sysctl_wunlock(); sx_xlock(&kld_sx); } /* * Invoke the LINKER_CTF_GET implementation for this file. Existing * implementations will load CTF info from the filesystem upon the first call * and cache it in the kernel thereafter. */ static void linker_ctf_load_file(linker_file_t file) { linker_ctf_t lc; int error; error = linker_ctf_get(file, &lc); if (error == 0) return; if (bootverbose) { printf("failed to load CTF for %s: %d\n", file->filename, error); } } static void linker_file_enable_sysctls(linker_file_t lf) { struct sysctl_oid **start, **stop, **oidp; KLD_DPF(FILE, ("linker_file_enable_sysctls: enable SYSCTLs for %s\n", lf->filename)); sx_assert(&kld_sx, SA_XLOCKED); if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) return; sx_xunlock(&kld_sx); sysctl_wlock(); for (oidp = start; oidp < stop; oidp++) sysctl_enable_oid(*oidp); sysctl_wunlock(); sx_xlock(&kld_sx); } static void linker_file_unregister_sysctls(linker_file_t lf) { struct sysctl_oid **start, **stop, **oidp; KLD_DPF(FILE, ("linker_file_unregister_sysctls: unregistering SYSCTLs" " for %s\n", lf->filename)); sx_assert(&kld_sx, SA_XLOCKED); if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) return; sx_xunlock(&kld_sx); sysctl_wlock(); for (oidp = start; oidp < stop; oidp++) sysctl_unregister_oid(*oidp); sysctl_wunlock(); sx_xlock(&kld_sx); } static int linker_file_register_modules(linker_file_t lf) { struct mod_metadata **start, **stop, **mdp; const moduledata_t *moddata; int first_error, error; KLD_DPF(FILE, ("linker_file_register_modules: registering modules" " in %s\n", lf->filename)); sx_assert(&kld_sx, SA_XLOCKED); if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, NULL) != 0) { /* * This fallback should be unnecessary, but if we get booted * from boot2 instead of loader and we are missing our * metadata then we have to try the best we can. */ if (lf == linker_kernel_file) { start = SET_BEGIN(modmetadata_set); stop = SET_LIMIT(modmetadata_set); } else return (0); } first_error = 0; for (mdp = start; mdp < stop; mdp++) { if ((*mdp)->md_type != MDT_MODULE) continue; moddata = (*mdp)->md_data; KLD_DPF(FILE, ("Registering module %s in %s\n", moddata->name, lf->filename)); error = module_register(moddata, lf); if (error) { printf("Module %s failed to register: %d\n", moddata->name, error); if (first_error == 0) first_error = error; } } return (first_error); } static void linker_init_kernel_modules(void) { sx_xlock(&kld_sx); linker_file_register_modules(linker_kernel_file); sx_xunlock(&kld_sx); } SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, NULL); static int linker_load_file(const char *filename, linker_file_t *result) { linker_class_t lc; linker_file_t lf; int foundfile, error, modules; /* Refuse to load modules if securelevel raised */ if (prison0.pr_securelevel > 0) return (EPERM); sx_assert(&kld_sx, SA_XLOCKED); lf = linker_find_file_by_name(filename); if (lf) { KLD_DPF(FILE, ("linker_load_file: file %s is already loaded," " incrementing refs\n", filename)); *result = lf; lf->refs++; return (0); } foundfile = 0; error = 0; /* * We do not need to protect (lock) classes here because there is * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY) * and there is no class deregistration mechanism at this time. */ TAILQ_FOREACH(lc, &classes, link) { KLD_DPF(FILE, ("linker_load_file: trying to load %s\n", filename)); error = LINKER_LOAD_FILE(lc, filename, &lf); /* * If we got something other than ENOENT, then it exists but * we cannot load it for some other reason. */ if (error != ENOENT) { foundfile = 1; if (error == EEXIST) break; } if (lf) { error = linker_file_register_modules(lf); if (error == EEXIST) { linker_file_unload(lf, LINKER_UNLOAD_FORCE); return (error); } modules = !TAILQ_EMPTY(&lf->modules); linker_file_register_sysctls(lf, false); #ifdef VIMAGE LINKER_PROPAGATE_VNETS(lf); #endif linker_file_sysinit(lf); lf->flags |= LINKER_FILE_LINKED; /* * If all of the modules in this file failed * to load, unload the file and return an * error of ENOEXEC. */ if (modules && TAILQ_EMPTY(&lf->modules)) { linker_file_unload(lf, LINKER_UNLOAD_FORCE); return (ENOEXEC); } linker_file_enable_sysctls(lf); /* * Ask the linker to load CTF data for this file. */ linker_ctf_load_file(lf); EVENTHANDLER_INVOKE(kld_load, lf); *result = lf; return (0); } } /* * Less than ideal, but tells the user whether it failed to load or * the module was not found. */ if (foundfile) { /* * If the file type has not been recognized by the last try * printout a message before to fail. */ if (error == ENOSYS) printf("%s: %s - unsupported file type\n", __func__, filename); /* * Format not recognized or otherwise unloadable. * When loading a module that is statically built into * the kernel EEXIST percolates back up as the return * value. Preserve this so that apps like sysinstall * can recognize this special case and not post bogus * dialog boxes. */ if (error != EEXIST) error = ENOEXEC; } else error = ENOENT; /* Nothing found */ return (error); } int linker_reference_module(const char *modname, struct mod_depend *verinfo, linker_file_t *result) { modlist_t mod; int error; sx_xlock(&kld_sx); if ((mod = modlist_lookup2(modname, verinfo)) != NULL) { *result = mod->container; (*result)->refs++; sx_xunlock(&kld_sx); return (0); } error = linker_load_module(NULL, modname, NULL, verinfo, result); sx_xunlock(&kld_sx); return (error); } int linker_release_module(const char *modname, struct mod_depend *verinfo, linker_file_t lf) { modlist_t mod; int error; sx_xlock(&kld_sx); if (lf == NULL) { KASSERT(modname != NULL, ("linker_release_module: no file or name")); mod = modlist_lookup2(modname, verinfo); if (mod == NULL) { sx_xunlock(&kld_sx); return (ESRCH); } lf = mod->container; } else KASSERT(modname == NULL && verinfo == NULL, ("linker_release_module: both file and name")); error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL); sx_xunlock(&kld_sx); return (error); } static linker_file_t linker_find_file_by_name(const char *filename) { linker_file_t lf; char *koname; koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK); sprintf(koname, "%s.ko", filename); sx_assert(&kld_sx, SA_XLOCKED); TAILQ_FOREACH(lf, &linker_files, link) { if (strcmp(lf->filename, koname) == 0) break; if (strcmp(lf->filename, filename) == 0) break; } free(koname, M_LINKER); return (lf); } static linker_file_t linker_find_file_by_id(int fileid) { linker_file_t lf; sx_assert(&kld_sx, SA_XLOCKED); TAILQ_FOREACH(lf, &linker_files, link) if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED) break; return (lf); } int linker_file_foreach(linker_predicate_t *predicate, void *context) { linker_file_t lf; int retval = 0; sx_xlock(&kld_sx); TAILQ_FOREACH(lf, &linker_files, link) { retval = predicate(lf, context); if (retval != 0) break; } sx_xunlock(&kld_sx); return (retval); } linker_file_t linker_make_file(const char *pathname, linker_class_t lc) { linker_file_t lf; const char *filename; if (!cold) sx_assert(&kld_sx, SA_XLOCKED); filename = linker_basename(pathname); KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname)); lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK); if (lf == NULL) return (NULL); lf->ctors_addr = 0; lf->ctors_size = 0; lf->ctors_invoked = LF_NONE; lf->dtors_addr = 0; lf->dtors_size = 0; lf->refs = 1; lf->userrefs = 0; lf->flags = 0; lf->filename = strdup(filename, M_LINKER); lf->pathname = strdup(pathname, M_LINKER); LINKER_GET_NEXT_FILE_ID(lf->id); lf->ndeps = 0; lf->deps = NULL; lf->loadcnt = ++loadcnt; #ifdef __arm__ lf->exidx_addr = 0; lf->exidx_size = 0; #endif STAILQ_INIT(&lf->common); TAILQ_INIT(&lf->modules); TAILQ_INSERT_TAIL(&linker_files, lf, link); return (lf); } int linker_file_unload(linker_file_t file, int flags) { module_t mod, next; modlist_t ml, nextml; struct common_symbol *cp; int error, i; /* Refuse to unload modules if securelevel raised. */ if (prison0.pr_securelevel > 0) return (EPERM); sx_assert(&kld_sx, SA_XLOCKED); KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); /* Easy case of just dropping a reference. */ if (file->refs > 1) { file->refs--; return (0); } /* Give eventhandlers a chance to prevent the unload. */ error = 0; EVENTHANDLER_INVOKE(kld_unload_try, file, &error); if (error != 0) return (EBUSY); KLD_DPF(FILE, ("linker_file_unload: file is unloading," " informing modules\n")); /* * Quiesce all the modules to give them a chance to veto the unload. */ MOD_SLOCK; for (mod = TAILQ_FIRST(&file->modules); mod; mod = module_getfnext(mod)) { error = module_quiesce(mod); if (error != 0 && flags != LINKER_UNLOAD_FORCE) { KLD_DPF(FILE, ("linker_file_unload: module %s" " vetoed unload\n", module_getname(mod))); /* * XXX: Do we need to tell all the quiesced modules * that they can resume work now via a new module * event? */ MOD_SUNLOCK; return (error); } } MOD_SUNLOCK; /* * Inform any modules associated with this file that they are * being unloaded. */ MOD_XLOCK; for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { next = module_getfnext(mod); MOD_XUNLOCK; /* * Give the module a chance to veto the unload. */ if ((error = module_unload(mod)) != 0) { #ifdef KLD_DEBUG MOD_SLOCK; KLD_DPF(FILE, ("linker_file_unload: module %s" " failed unload\n", module_getname(mod))); MOD_SUNLOCK; #endif return (error); } MOD_XLOCK; module_release(mod); } MOD_XUNLOCK; TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) { if (ml->container == file) { TAILQ_REMOVE(&found_modules, ml, link); free(ml, M_LINKER); } } /* * Don't try to run SYSUNINITs if we are unloaded due to a * link error. */ if (file->flags & LINKER_FILE_LINKED) { file->flags &= ~LINKER_FILE_LINKED; linker_file_unregister_sysctls(file); linker_file_sysuninit(file); } TAILQ_REMOVE(&linker_files, file, link); if (file->deps) { for (i = 0; i < file->ndeps; i++) linker_file_unload(file->deps[i], flags); free(file->deps, M_LINKER); file->deps = NULL; } while ((cp = STAILQ_FIRST(&file->common)) != NULL) { STAILQ_REMOVE_HEAD(&file->common, link); free(cp, M_LINKER); } LINKER_UNLOAD(file); EVENTHANDLER_INVOKE(kld_unload, file->filename, file->address, file->size); if (file->filename) { free(file->filename, M_LINKER); file->filename = NULL; } if (file->pathname) { free(file->pathname, M_LINKER); file->pathname = NULL; } kobj_delete((kobj_t) file, M_LINKER); return (0); } int linker_ctf_get(linker_file_t file, linker_ctf_t *lc) { return (LINKER_CTF_GET(file, lc)); } int linker_ctf_lookup_typename_ddb(linker_ctf_t *lc, const char *typename) { #ifdef DDB linker_file_t lf; TAILQ_FOREACH (lf, &linker_files, link){ if (LINKER_CTF_LOOKUP_TYPENAME(lf, lc, typename) == 0) return (0); } #endif return (ENOENT); } int linker_ctf_lookup_sym_ddb(const char *symname, c_linker_sym_t *sym, linker_ctf_t *lc) { #ifdef DDB linker_file_t lf; TAILQ_FOREACH (lf, &linker_files, link){ if (LINKER_LOOKUP_DEBUG_SYMBOL_CTF(lf, symname, sym, lc) == 0) return (0); } #endif return (ENOENT); } static void linker_file_add_dependency(linker_file_t file, linker_file_t dep) { linker_file_t *newdeps; sx_assert(&kld_sx, SA_XLOCKED); file->deps = realloc(file->deps, (file->ndeps + 1) * sizeof(*newdeps), M_LINKER, M_WAITOK | M_ZERO); file->deps[file->ndeps] = dep; file->ndeps++; KLD_DPF(FILE, ("linker_file_add_dependency:" " adding %s as dependency for %s\n", dep->filename, file->filename)); } /* * Locate a linker set and its contents. This is a helper function to avoid * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **. * This function is used in this file so we can avoid having lots of (void **) * casts. */ int linker_file_lookup_set(linker_file_t file, const char *name, void *firstp, void *lastp, int *countp) { sx_assert(&kld_sx, SA_LOCKED); return (LINKER_LOOKUP_SET(file, name, firstp, lastp, countp)); } /* * List all functions in a file. */ int linker_file_function_listall(linker_file_t lf, linker_function_nameval_callback_t callback_func, void *arg) { return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg)); } caddr_t linker_file_lookup_symbol(linker_file_t file, const char *name, int deps) { caddr_t sym; int locked; locked = sx_xlocked(&kld_sx); if (!locked) sx_xlock(&kld_sx); sym = linker_file_lookup_symbol_internal(file, name, deps); if (!locked) sx_xunlock(&kld_sx); return (sym); } static caddr_t linker_file_lookup_symbol_internal(linker_file_t file, const char *name, int deps) { c_linker_sym_t sym; linker_symval_t symval; caddr_t address; size_t common_size = 0; int i; sx_assert(&kld_sx, SA_XLOCKED); KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n", file, name, deps)); /* * Treat the __this_linker_file as a special symbol. This is a * global that linuxkpi uses to populate the THIS_MODULE * value. In this case we can simply return the linker_file_t. * * Modules compiled statically into the kernel are assigned NULL. */ if (strcmp(name, "__this_linker_file") == 0) { address = (file == linker_kernel_file) ? NULL : (caddr_t)file; KLD_DPF(SYM, ("linker_file_lookup_symbol: resolving special " "symbol __this_linker_file to %p\n", address)); return (address); } if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { LINKER_SYMBOL_VALUES(file, sym, &symval); if (symval.value == 0) /* * For commons, first look them up in the * dependencies and only allocate space if not found * there. */ common_size = symval.size; else { KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol" ".value=%p\n", symval.value)); return (symval.value); } } if (deps) { for (i = 0; i < file->ndeps; i++) { address = linker_file_lookup_symbol_internal( file->deps[i], name, 0); if (address) { KLD_DPF(SYM, ("linker_file_lookup_symbol:" " deps value=%p\n", address)); return (address); } } } if (common_size > 0) { /* * This is a common symbol which was not found in the * dependencies. We maintain a simple common symbol table in * the file object. */ struct common_symbol *cp; STAILQ_FOREACH(cp, &file->common, link) { if (strcmp(cp->name, name) == 0) { KLD_DPF(SYM, ("linker_file_lookup_symbol:" " old common value=%p\n", cp->address)); return (cp->address); } } /* * Round the symbol size up to align. */ common_size = (common_size + sizeof(int) - 1) & -sizeof(int); cp = malloc(sizeof(struct common_symbol) + common_size + strlen(name) + 1, M_LINKER, M_WAITOK | M_ZERO); cp->address = (caddr_t)(cp + 1); cp->name = cp->address + common_size; strcpy(cp->name, name); bzero(cp->address, common_size); STAILQ_INSERT_TAIL(&file->common, cp, link); KLD_DPF(SYM, ("linker_file_lookup_symbol: new common" " value=%p\n", cp->address)); return (cp->address); } KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); return (0); } /* * Both DDB and stack(9) rely on the kernel linker to provide forward and * backward lookup of symbols. However, DDB and sometimes stack(9) need to * do this in a lockfree manner. We provide a set of internal helper * routines to perform these operations without locks, and then wrappers that * optionally lock. * * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB. */ #ifdef DDB static int linker_debug_lookup(const char *symstr, c_linker_sym_t *sym) { linker_file_t lf; TAILQ_FOREACH(lf, &linker_files, link) { if (LINKER_LOOKUP_DEBUG_SYMBOL(lf, symstr, sym) == 0) return (0); } return (ENOENT); } #endif static int linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) { linker_file_t lf; c_linker_sym_t best, es; u_long diff, bestdiff, off; best = 0; off = (uintptr_t)value; bestdiff = off; TAILQ_FOREACH(lf, &linker_files, link) { if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) continue; if (es != 0 && diff < bestdiff) { best = es; bestdiff = diff; } if (bestdiff == 0) break; } if (best) { *sym = best; *diffp = bestdiff; return (0); } else { *sym = 0; *diffp = off; return (ENOENT); } } static int linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) { linker_file_t lf; TAILQ_FOREACH(lf, &linker_files, link) { if (LINKER_DEBUG_SYMBOL_VALUES(lf, sym, symval) == 0) return (0); } return (ENOENT); } static int linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen, long *offset) { linker_symval_t symval; c_linker_sym_t sym; int error; *offset = 0; error = linker_debug_search_symbol(value, &sym, offset); if (error) return (error); error = linker_debug_symbol_values(sym, &symval); if (error) return (error); strlcpy(buf, symval.name, buflen); return (0); } /* * DDB Helpers. DDB has to look across multiple files with their own symbol * tables and string tables. * * Note that we do not obey list locking protocols here. We really don't need * DDB to hang because somebody's got the lock held. We'll take the chance * that the files list is inconsistent instead. */ #ifdef DDB int linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) { return (linker_debug_lookup(symstr, sym)); } #endif int linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) { return (linker_debug_search_symbol(value, sym, diffp)); } int linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) { return (linker_debug_symbol_values(sym, symval)); } int linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen, long *offset) { return (linker_debug_search_symbol_name(value, buf, buflen, offset)); } /* * stack(9) helper for non-debugging environemnts. Unlike DDB helpers, we do * obey locking protocols, and offer a significantly less complex interface. */ int linker_search_symbol_name_flags(caddr_t value, char *buf, u_int buflen, long *offset, int flags) { int error; KASSERT((flags & (M_NOWAIT | M_WAITOK)) != 0 && (flags & (M_NOWAIT | M_WAITOK)) != (M_NOWAIT | M_WAITOK), ("%s: bad flags: 0x%x", __func__, flags)); if (flags & M_NOWAIT) { if (!sx_try_slock(&kld_sx)) return (EWOULDBLOCK); } else sx_slock(&kld_sx); error = linker_debug_search_symbol_name(value, buf, buflen, offset); sx_sunlock(&kld_sx); return (error); } int linker_search_symbol_name(caddr_t value, char *buf, u_int buflen, long *offset) { return (linker_search_symbol_name_flags(value, buf, buflen, offset, M_WAITOK)); } int linker_kldload_busy(int flags) { int error; MPASS((flags & ~(LINKER_UB_UNLOCK | LINKER_UB_LOCKED | LINKER_UB_PCATCH)) == 0); if ((flags & LINKER_UB_LOCKED) != 0) sx_assert(&kld_sx, SA_XLOCKED); if ((flags & LINKER_UB_LOCKED) == 0) sx_xlock(&kld_sx); while (kld_busy > 0) { if (kld_busy_owner == curthread) break; error = sx_sleep(&kld_busy, &kld_sx, (flags & LINKER_UB_PCATCH) != 0 ? PCATCH : 0, "kldbusy", 0); if (error != 0) { if ((flags & LINKER_UB_UNLOCK) != 0) sx_xunlock(&kld_sx); return (error); } } kld_busy++; kld_busy_owner = curthread; if ((flags & LINKER_UB_UNLOCK) != 0) sx_xunlock(&kld_sx); return (0); } void linker_kldload_unbusy(int flags) { MPASS((flags & ~LINKER_UB_LOCKED) == 0); if ((flags & LINKER_UB_LOCKED) != 0) sx_assert(&kld_sx, SA_XLOCKED); if ((flags & LINKER_UB_LOCKED) == 0) sx_xlock(&kld_sx); MPASS(kld_busy > 0); if (kld_busy_owner != curthread) panic("linker_kldload_unbusy done by not owning thread %p", kld_busy_owner); kld_busy--; if (kld_busy == 0) { kld_busy_owner = NULL; wakeup(&kld_busy); } sx_xunlock(&kld_sx); } /* * Syscalls. */ int kern_kldload(struct thread *td, const char *file, int *fileid) { const char *kldname, *modname; linker_file_t lf; int error; if ((error = securelevel_gt(td->td_ucred, 0)) != 0) return (error); if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0) return (error); /* * If file does not contain a qualified name or any dot in it * (kldname.ko, or kldname.ver.ko) treat it as an interface * name. */ if (strchr(file, '/') || strchr(file, '.')) { kldname = file; modname = NULL; } else { kldname = NULL; modname = file; } error = linker_kldload_busy(LINKER_UB_PCATCH); if (error != 0) { sx_xunlock(&kld_sx); return (error); } /* * It is possible that kldloaded module will attach a new ifnet, * so vnet context must be set when this ocurs. */ CURVNET_SET(TD_TO_VNET(td)); error = linker_load_module(kldname, modname, NULL, NULL, &lf); CURVNET_RESTORE(); if (error == 0) { lf->userrefs++; if (fileid != NULL) *fileid = lf->id; } linker_kldload_unbusy(LINKER_UB_LOCKED); return (error); } int sys_kldload(struct thread *td, struct kldload_args *uap) { char *pathname = NULL; int error, fileid; td->td_retval[0] = -1; pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL); if (error == 0) { error = kern_kldload(td, pathname, &fileid); if (error == 0) td->td_retval[0] = fileid; } free(pathname, M_TEMP); return (error); } int kern_kldunload(struct thread *td, int fileid, int flags) { linker_file_t lf; int error = 0; if ((error = securelevel_gt(td->td_ucred, 0)) != 0) return (error); if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0) return (error); error = linker_kldload_busy(LINKER_UB_PCATCH); if (error != 0) { sx_xunlock(&kld_sx); return (error); } CURVNET_SET(TD_TO_VNET(td)); lf = linker_find_file_by_id(fileid); if (lf) { KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); if (lf->userrefs == 0) { /* * XXX: maybe LINKER_UNLOAD_FORCE should override ? */ printf("kldunload: attempt to unload file that was" " loaded by the kernel\n"); error = EBUSY; } else if (lf->refs > 1) { error = EBUSY; } else { lf->userrefs--; error = linker_file_unload(lf, flags); if (error) lf->userrefs++; } } else error = ENOENT; CURVNET_RESTORE(); linker_kldload_unbusy(LINKER_UB_LOCKED); return (error); } int sys_kldunload(struct thread *td, struct kldunload_args *uap) { return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL)); } int sys_kldunloadf(struct thread *td, struct kldunloadf_args *uap) { if (uap->flags != LINKER_UNLOAD_NORMAL && uap->flags != LINKER_UNLOAD_FORCE) return (EINVAL); return (kern_kldunload(td, uap->fileid, uap->flags)); } int sys_kldfind(struct thread *td, struct kldfind_args *uap) { char *pathname; const char *filename; linker_file_t lf; int error; #ifdef MAC error = mac_kld_check_stat(td->td_ucred); if (error) return (error); #endif td->td_retval[0] = -1; pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0) goto out; filename = linker_basename(pathname); sx_xlock(&kld_sx); lf = linker_find_file_by_name(filename); if (lf) td->td_retval[0] = lf->id; else error = ENOENT; sx_xunlock(&kld_sx); out: free(pathname, M_TEMP); return (error); } int sys_kldnext(struct thread *td, struct kldnext_args *uap) { linker_file_t lf; int error = 0; #ifdef MAC error = mac_kld_check_stat(td->td_ucred); if (error) return (error); #endif sx_xlock(&kld_sx); if (uap->fileid == 0) lf = TAILQ_FIRST(&linker_files); else { lf = linker_find_file_by_id(uap->fileid); if (lf == NULL) { error = ENOENT; goto out; } lf = TAILQ_NEXT(lf, link); } /* Skip partially loaded files. */ while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED)) lf = TAILQ_NEXT(lf, link); if (lf) td->td_retval[0] = lf->id; else td->td_retval[0] = 0; out: sx_xunlock(&kld_sx); return (error); } int sys_kldstat(struct thread *td, struct kldstat_args *uap) { struct kld_file_stat *stat; int error, version; /* * Check the version of the user's structure. */ if ((error = copyin(&uap->stat->version, &version, sizeof(version))) != 0) return (error); if (version != sizeof(struct kld_file_stat_1) && version != sizeof(struct kld_file_stat)) return (EINVAL); stat = malloc(sizeof(*stat), M_TEMP, M_WAITOK | M_ZERO); error = kern_kldstat(td, uap->fileid, stat); if (error == 0) error = copyout(stat, uap->stat, version); free(stat, M_TEMP); return (error); } int kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat) { linker_file_t lf; int namelen; #ifdef MAC int error; error = mac_kld_check_stat(td->td_ucred); if (error) return (error); #endif sx_xlock(&kld_sx); lf = linker_find_file_by_id(fileid); if (lf == NULL) { sx_xunlock(&kld_sx); return (ENOENT); } /* Version 1 fields: */ namelen = strlen(lf->filename) + 1; if (namelen > sizeof(stat->name)) namelen = sizeof(stat->name); bcopy(lf->filename, &stat->name[0], namelen); stat->refs = lf->refs; stat->id = lf->id; stat->address = lf->address; stat->size = lf->size; /* Version 2 fields: */ namelen = strlen(lf->pathname) + 1; if (namelen > sizeof(stat->pathname)) namelen = sizeof(stat->pathname); bcopy(lf->pathname, &stat->pathname[0], namelen); sx_xunlock(&kld_sx); td->td_retval[0] = 0; return (0); } #ifdef DDB DB_COMMAND_FLAGS(kldstat, db_kldstat, DB_CMD_MEMSAFE) { linker_file_t lf; #define POINTER_WIDTH ((int)(sizeof(void *) * 2 + 2)) db_printf("Id Refs Address%*c Size Name\n", POINTER_WIDTH - 7, ' '); #undef POINTER_WIDTH TAILQ_FOREACH(lf, &linker_files, link) { if (db_pager_quit) return; db_printf("%2d %4d %p %-8zx %s\n", lf->id, lf->refs, lf->address, lf->size, lf->filename); } } #endif /* DDB */ int sys_kldfirstmod(struct thread *td, struct kldfirstmod_args *uap) { linker_file_t lf; module_t mp; int error = 0; #ifdef MAC error = mac_kld_check_stat(td->td_ucred); if (error) return (error); #endif sx_xlock(&kld_sx); lf = linker_find_file_by_id(uap->fileid); if (lf) { MOD_SLOCK; mp = TAILQ_FIRST(&lf->modules); if (mp != NULL) td->td_retval[0] = module_getid(mp); else td->td_retval[0] = 0; MOD_SUNLOCK; } else error = ENOENT; sx_xunlock(&kld_sx); return (error); } int sys_kldsym(struct thread *td, struct kldsym_args *uap) { char *symstr = NULL; c_linker_sym_t sym; linker_symval_t symval; linker_file_t lf; struct kld_sym_lookup lookup; int error = 0; #ifdef MAC error = mac_kld_check_stat(td->td_ucred); if (error) return (error); #endif if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0) return (error); if (lookup.version != sizeof(lookup) || uap->cmd != KLDSYM_LOOKUP) return (EINVAL); symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) goto out; sx_xlock(&kld_sx); if (uap->fileid != 0) { lf = linker_find_file_by_id(uap->fileid); if (lf == NULL) error = ENOENT; else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { lookup.symvalue = (uintptr_t) symval.value; lookup.symsize = symval.size; error = copyout(&lookup, uap->data, sizeof(lookup)); } else error = ENOENT; } else { TAILQ_FOREACH(lf, &linker_files, link) { if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { lookup.symvalue = (uintptr_t)symval.value; lookup.symsize = symval.size; error = copyout(&lookup, uap->data, sizeof(lookup)); break; } } if (lf == NULL) error = ENOENT; } sx_xunlock(&kld_sx); out: free(symstr, M_TEMP); return (error); } /* * Preloaded module support */ static modlist_t modlist_lookup(const char *name, int ver) { modlist_t mod; TAILQ_FOREACH(mod, &found_modules, link) { if (strcmp(mod->name, name) == 0 && (ver == 0 || mod->version == ver)) return (mod); } return (NULL); } static modlist_t modlist_lookup2(const char *name, const struct mod_depend *verinfo) { modlist_t mod, bestmod; int ver; if (verinfo == NULL) return (modlist_lookup(name, 0)); bestmod = NULL; TAILQ_FOREACH(mod, &found_modules, link) { if (strcmp(mod->name, name) != 0) continue; ver = mod->version; if (ver == verinfo->md_ver_preferred) return (mod); if (ver >= verinfo->md_ver_minimum && ver <= verinfo->md_ver_maximum && (bestmod == NULL || ver > bestmod->version)) bestmod = mod; } return (bestmod); } static modlist_t modlist_newmodule(const char *modname, int version, linker_file_t container) { modlist_t mod; mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO); if (mod == NULL) panic("no memory for module list"); mod->container = container; mod->name = modname; mod->version = version; TAILQ_INSERT_TAIL(&found_modules, mod, link); return (mod); } static void linker_addmodules(linker_file_t lf, struct mod_metadata **start, struct mod_metadata **stop, int preload) { struct mod_metadata *mp, **mdp; const char *modname; int ver; for (mdp = start; mdp < stop; mdp++) { mp = *mdp; if (mp->md_type != MDT_VERSION) continue; modname = mp->md_cval; ver = ((const struct mod_version *)mp->md_data)->mv_version; if (modlist_lookup(modname, ver) != NULL) { printf("module %s already present!\n", modname); /* XXX what can we do? this is a build error. :-( */ continue; } modlist_newmodule(modname, ver, lf); } } static void linker_preload(void *arg) { caddr_t modptr; const char *modname, *nmodname; char *modtype; linker_file_t lf, nlf; linker_class_t lc; int error; linker_file_list_t loaded_files; linker_file_list_t depended_files; struct mod_metadata *mp, *nmp; struct mod_metadata **start, **stop, **mdp, **nmdp; const struct mod_depend *verinfo; int nver; int resolves; modlist_t mod; struct sysinit **si_start, **si_stop; TAILQ_INIT(&loaded_files); TAILQ_INIT(&depended_files); TAILQ_INIT(&found_modules); error = 0; modptr = NULL; sx_xlock(&kld_sx); while ((modptr = preload_search_next_name(modptr)) != NULL) { modname = (char *)preload_search_info(modptr, MODINFO_NAME); modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); if (modname == NULL) { printf("Preloaded module at %p does not have a" " name!\n", modptr); continue; } if (modtype == NULL) { printf("Preloaded module at %p does not have a type!\n", modptr); continue; } if (bootverbose) printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, modptr); lf = NULL; TAILQ_FOREACH(lc, &classes, link) { error = LINKER_LINK_PRELOAD(lc, modname, &lf); if (!error) break; lf = NULL; } if (lf) TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); } /* * First get a list of stuff in the kernel. */ if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start, &stop, NULL) == 0) linker_addmodules(linker_kernel_file, start, stop, 1); /* * This is a once-off kinky bubble sort to resolve relocation * dependency requirements. */ restart: TAILQ_FOREACH(lf, &loaded_files, loaded) { error = linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, NULL); /* * First, look to see if we would successfully link with this * stuff. */ resolves = 1; /* unless we know otherwise */ if (!error) { for (mdp = start; mdp < stop; mdp++) { mp = *mdp; if (mp->md_type != MDT_DEPEND) continue; modname = mp->md_cval; verinfo = mp->md_data; for (nmdp = start; nmdp < stop; nmdp++) { nmp = *nmdp; if (nmp->md_type != MDT_VERSION) continue; nmodname = nmp->md_cval; if (strcmp(modname, nmodname) == 0) break; } if (nmdp < stop) /* it's a self reference */ continue; /* * ok, the module isn't here yet, we * are not finished */ if (modlist_lookup2(modname, verinfo) == NULL) resolves = 0; } } /* * OK, if we found our modules, we can link. So, "provide" * the modules inside and add it to the end of the link order * list. */ if (resolves) { if (!error) { for (mdp = start; mdp < stop; mdp++) { mp = *mdp; if (mp->md_type != MDT_VERSION) continue; modname = mp->md_cval; nver = ((const struct mod_version *) mp->md_data)->mv_version; if (modlist_lookup(modname, nver) != NULL) { printf("module %s already" " present!\n", modname); TAILQ_REMOVE(&loaded_files, lf, loaded); linker_file_unload(lf, LINKER_UNLOAD_FORCE); /* we changed tailq next ptr */ goto restart; } modlist_newmodule(modname, nver, lf); } } TAILQ_REMOVE(&loaded_files, lf, loaded); TAILQ_INSERT_TAIL(&depended_files, lf, loaded); /* * Since we provided modules, we need to restart the * sort so that the previous files that depend on us * have a chance. Also, we've busted the tailq next * pointer with the REMOVE. */ goto restart; } } /* * At this point, we check to see what could not be resolved.. */ while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) { TAILQ_REMOVE(&loaded_files, lf, loaded); printf("KLD file %s is missing dependencies\n", lf->filename); linker_file_unload(lf, LINKER_UNLOAD_FORCE); } /* * We made it. Finish off the linking in the order we determined. */ TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) { if (linker_kernel_file) { linker_kernel_file->refs++; linker_file_add_dependency(lf, linker_kernel_file); } error = linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, NULL); if (!error) { for (mdp = start; mdp < stop; mdp++) { mp = *mdp; if (mp->md_type != MDT_DEPEND) continue; modname = mp->md_cval; verinfo = mp->md_data; mod = modlist_lookup2(modname, verinfo); if (mod == NULL) { printf("KLD file %s - cannot find " "dependency \"%s\"\n", lf->filename, modname); goto fail; } /* Don't count self-dependencies */ if (lf == mod->container) continue; mod->container->refs++; linker_file_add_dependency(lf, mod->container); } } /* * Now do relocation etc using the symbol search paths * established by the dependencies */ error = LINKER_LINK_PRELOAD_FINISH(lf); if (error) { printf("KLD file %s - could not finalize loading\n", lf->filename); goto fail; } linker_file_register_modules(lf); if (!TAILQ_EMPTY(&lf->modules)) lf->flags |= LINKER_FILE_MODULES; if (linker_file_lookup_set(lf, "sysinit_set", &si_start, &si_stop, NULL) == 0) sysinit_add(si_start, si_stop); linker_file_register_sysctls(lf, true); lf->flags |= LINKER_FILE_LINKED; continue; fail: TAILQ_REMOVE(&depended_files, lf, loaded); linker_file_unload(lf, LINKER_UNLOAD_FORCE); } sx_xunlock(&kld_sx); /* woohoo! we made it! */ } SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, NULL); static void linker_mountroot(void *arg __unused) { linker_file_t lf; sx_xlock(&kld_sx); TAILQ_FOREACH (lf, &linker_files, link) { linker_ctf_load_file(lf); } sx_xunlock(&kld_sx); } EVENTHANDLER_DEFINE(mountroot, linker_mountroot, NULL, 0); /* * Handle preload files that failed to load any modules. */ static void linker_preload_finish(void *arg) { linker_file_t lf, nlf; sx_xlock(&kld_sx); TAILQ_FOREACH_SAFE(lf, &linker_files, link, nlf) { if (lf == linker_kernel_file) continue; /* * If all of the modules in this file failed to load, unload * the file and return an error of ENOEXEC. (Parity with * linker_load_file.) */ if ((lf->flags & LINKER_FILE_MODULES) != 0 && TAILQ_EMPTY(&lf->modules)) { linker_file_unload(lf, LINKER_UNLOAD_FORCE); continue; } lf->flags &= ~LINKER_FILE_MODULES; lf->userrefs++; /* so we can (try to) kldunload it */ } sx_xunlock(&kld_sx); } /* * Attempt to run after all DECLARE_MODULE SYSINITs. Unfortunately they can be * scheduled at any subsystem and order, so run this as late as possible. init * becomes runnable in SI_SUB_KTHREAD_INIT, so go slightly before that. */ SYSINIT(preload_finish, SI_SUB_KTHREAD_INIT - 100, SI_ORDER_MIDDLE, linker_preload_finish, NULL); /* * Search for a not-loaded module by name. * * Modules may be found in the following locations: * * - preloaded (result is just the module name) - on disk (result is full path * to module) * * If the module name is qualified in any way (contains path, etc.) the we * simply return a copy of it. * * The search path can be manipulated via sysctl. Note that we use the ';' * character as a separator to be consistent with the bootloader. */ static char linker_hintfile[] = "linker.hints"; static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules"; SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RWTUN, linker_path, sizeof(linker_path), "module load search path"); TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); static const char * const linker_ext_list[] = { "", ".ko", NULL }; /* * Check if file actually exists either with or without extension listed in * the linker_ext_list. (probably should be generic for the rest of the * kernel) */ static char * linker_lookup_file(const char *path, int pathlen, const char *name, int namelen, struct vattr *vap) { struct nameidata nd; struct thread *td = curthread; /* XXX */ const char * const *cpp, *sep; char *result; int error, len, extlen, reclen, flags; __enum_uint8(vtype) type; extlen = 0; for (cpp = linker_ext_list; *cpp; cpp++) { len = strlen(*cpp); if (len > extlen) extlen = len; } extlen++; /* trailing '\0' */ sep = (path[pathlen - 1] != '/') ? "/" : ""; reclen = pathlen + strlen(sep) + namelen + extlen + 1; result = malloc(reclen, M_LINKER, M_WAITOK); for (cpp = linker_ext_list; *cpp; cpp++) { snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep, namelen, name, *cpp); /* * Attempt to open the file, and return the path if * we succeed and it's a regular file. */ NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result); flags = FREAD; error = vn_open(&nd, &flags, 0, NULL); if (error == 0) { NDFREE_PNBUF(&nd); type = nd.ni_vp->v_type; if (vap) VOP_GETATTR(nd.ni_vp, vap, td->td_ucred); VOP_UNLOCK(nd.ni_vp); vn_close(nd.ni_vp, FREAD, td->td_ucred, td); if (type == VREG) return (result); } } free(result, M_LINKER); return (NULL); } #define INT_ALIGN(base, ptr) ptr = \ (base) + roundup2((ptr) - (base), sizeof(int)) /* * Lookup KLD which contains requested module in the "linker.hints" file. If * version specification is available, then try to find the best KLD. * Otherwise just find the latest one. */ static char * linker_hints_lookup(const char *path, int pathlen, const char *modname, int modnamelen, const struct mod_depend *verinfo) { struct thread *td = curthread; /* XXX */ struct ucred *cred = td ? td->td_ucred : NULL; struct nameidata nd; struct vattr vattr, mattr; const char *best, *sep; u_char *hints = NULL; u_char *cp, *recptr, *bufend, *result, *pathbuf; int error, ival, bestver, *intp, found, flags, clen, blen; ssize_t reclen; result = NULL; bestver = found = 0; sep = (path[pathlen - 1] != '/') ? "/" : ""; reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen + strlen(sep) + 1; pathbuf = malloc(reclen, M_LINKER, M_WAITOK); snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep, linker_hintfile); NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf); flags = FREAD; error = vn_open(&nd, &flags, 0, NULL); if (error) goto bad; NDFREE_PNBUF(&nd); if (nd.ni_vp->v_type != VREG) goto bad; best = cp = NULL; error = VOP_GETATTR(nd.ni_vp, &vattr, cred); if (error) goto bad; /* * XXX: we need to limit this number to some reasonable value */ if (vattr.va_size > LINKER_HINTS_MAX) { printf("linker.hints file too large %ld\n", (long)vattr.va_size); goto bad; } if (vattr.va_size < sizeof(ival)) { printf("linker.hints file truncated\n"); goto bad; } hints = malloc(vattr.va_size, M_TEMP, M_WAITOK); error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0, UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td); if (error) goto bad; VOP_UNLOCK(nd.ni_vp); vn_close(nd.ni_vp, FREAD, cred, td); nd.ni_vp = NULL; if (reclen != 0) { printf("can't read %zd\n", reclen); goto bad; } intp = (int *)hints; ival = *intp++; if (ival != LINKER_HINTS_VERSION) { printf("linker.hints file version mismatch %d\n", ival); goto bad; } bufend = hints + vattr.va_size; recptr = (u_char *)intp; clen = blen = 0; while (recptr < bufend && !found) { intp = (int *)recptr; reclen = *intp++; ival = *intp++; cp = (char *)intp; switch (ival) { case MDT_VERSION: clen = *cp++; if (clen != modnamelen || bcmp(cp, modname, clen) != 0) break; cp += clen; INT_ALIGN(hints, cp); ival = *(int *)cp; cp += sizeof(int); clen = *cp++; if (verinfo == NULL || ival == verinfo->md_ver_preferred) { found = 1; break; } if (ival >= verinfo->md_ver_minimum && ival <= verinfo->md_ver_maximum && ival > bestver) { bestver = ival; best = cp; blen = clen; } break; default: break; } recptr += reclen + sizeof(int); } /* * Finally check if KLD is in the place */ if (found) result = linker_lookup_file(path, pathlen, cp, clen, &mattr); else if (best) result = linker_lookup_file(path, pathlen, best, blen, &mattr); /* * KLD is newer than hints file. What we should do now? */ if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >)) printf("warning: KLD '%s' is newer than the linker.hints" " file\n", result); bad: free(pathbuf, M_LINKER); if (hints) free(hints, M_TEMP); if (nd.ni_vp != NULL) { VOP_UNLOCK(nd.ni_vp); vn_close(nd.ni_vp, FREAD, cred, td); } /* * If nothing found or hints is absent - fallback to the old * way by using "kldname[.ko]" as module name. */ if (!found && !bestver && result == NULL) result = linker_lookup_file(path, pathlen, modname, modnamelen, NULL); return (result); } /* * Lookup KLD which contains requested module in the all directories. */ static char * linker_search_module(const char *modname, int modnamelen, const struct mod_depend *verinfo) { char *cp, *ep, *result; /* * traverse the linker path */ for (cp = linker_path; *cp; cp = ep + 1) { /* find the end of this component */ for (ep = cp; (*ep != 0) && (*ep != ';'); ep++); result = linker_hints_lookup(cp, ep - cp, modname, modnamelen, verinfo); if (result != NULL) return (result); if (*ep == 0) break; } return (NULL); } /* * Search for module in all directories listed in the linker_path. */ static char * linker_search_kld(const char *name) { char *cp, *ep, *result; int len; /* qualified at all? */ if (strchr(name, '/')) return (strdup(name, M_LINKER)); /* traverse the linker path */ len = strlen(name); for (ep = linker_path; *ep; ep++) { cp = ep; /* find the end of this component */ for (; *ep != 0 && *ep != ';'; ep++); result = linker_lookup_file(cp, ep - cp, name, len, NULL); if (result != NULL) return (result); } return (NULL); } static const char * linker_basename(const char *path) { const char *filename; filename = strrchr(path, '/'); if (filename == NULL) return path; if (filename[1]) filename++; return (filename); } #ifdef HWPMC_HOOKS /* * Inform hwpmc about the set of kernel modules currently loaded. */ void * linker_hwpmc_list_objects(void) { linker_file_t lf; struct pmckern_map_in *kobase; int i, nmappings; nmappings = 0; sx_slock(&kld_sx); TAILQ_FOREACH(lf, &linker_files, link) nmappings++; /* Allocate nmappings + 1 entries. */ kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in), M_LINKER, M_WAITOK | M_ZERO); i = 0; TAILQ_FOREACH(lf, &linker_files, link) { /* Save the info for this linker file. */ kobase[i].pm_file = lf->pathname; kobase[i].pm_address = (uintptr_t)lf->address; i++; } sx_sunlock(&kld_sx); KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?")); /* The last entry of the malloced area comprises of all zeros. */ KASSERT(kobase[i].pm_file == NULL, ("linker_hwpmc_list_objects: last object not NULL")); return ((void *)kobase); } #endif /* check if root file system is not mounted */ static bool linker_root_mounted(void) { struct pwd *pwd; bool ret; if (rootvnode == NULL) return (false); pwd = pwd_hold(curthread); ret = pwd->pwd_rdir != NULL; pwd_drop(pwd); return (ret); } /* * Find a file which contains given module and load it, if "parent" is not * NULL, register a reference to it. */ static int linker_load_module(const char *kldname, const char *modname, struct linker_file *parent, const struct mod_depend *verinfo, struct linker_file **lfpp) { linker_file_t lfdep; const char *filename; char *pathname; int error; sx_assert(&kld_sx, SA_XLOCKED); if (modname == NULL) { /* * We have to load KLD */ KASSERT(verinfo == NULL, ("linker_load_module: verinfo" " is not NULL")); if (!linker_root_mounted()) return (ENXIO); pathname = linker_search_kld(kldname); } else { if (modlist_lookup2(modname, verinfo) != NULL) return (EEXIST); if (!linker_root_mounted()) return (ENXIO); if (kldname != NULL) pathname = strdup(kldname, M_LINKER); else /* * Need to find a KLD with required module */ pathname = linker_search_module(modname, strlen(modname), verinfo); } if (pathname == NULL) return (ENOENT); /* * Can't load more than one file with the same basename XXX: * Actually it should be possible to have multiple KLDs with * the same basename but different path because they can * provide different versions of the same modules. */ filename = linker_basename(pathname); if (linker_find_file_by_name(filename)) error = EEXIST; else do { error = linker_load_file(pathname, &lfdep); if (error) break; if (modname && verinfo && modlist_lookup2(modname, verinfo) == NULL) { linker_file_unload(lfdep, LINKER_UNLOAD_FORCE); error = ENOENT; break; } if (parent) linker_file_add_dependency(parent, lfdep); if (lfpp) *lfpp = lfdep; } while (0); free(pathname, M_LINKER); return (error); } /* * This routine is responsible for finding dependencies of userland initiated * kldload(2)'s of files. */ int linker_load_dependencies(linker_file_t lf) { linker_file_t lfdep; struct mod_metadata **start, **stop, **mdp, **nmdp; struct mod_metadata *mp, *nmp; const struct mod_depend *verinfo; modlist_t mod; const char *modname, *nmodname; int ver, error = 0; /* * All files are dependent on /kernel. */ sx_assert(&kld_sx, SA_XLOCKED); if (linker_kernel_file) { linker_kernel_file->refs++; linker_file_add_dependency(lf, linker_kernel_file); } if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, NULL) != 0) return (0); for (mdp = start; mdp < stop; mdp++) { mp = *mdp; if (mp->md_type != MDT_VERSION) continue; modname = mp->md_cval; ver = ((const struct mod_version *)mp->md_data)->mv_version; mod = modlist_lookup(modname, ver); if (mod != NULL) { printf("interface %s.%d already present in the KLD" " '%s'!\n", modname, ver, mod->container->filename); return (EEXIST); } } for (mdp = start; mdp < stop; mdp++) { mp = *mdp; if (mp->md_type != MDT_DEPEND) continue; modname = mp->md_cval; verinfo = mp->md_data; nmodname = NULL; for (nmdp = start; nmdp < stop; nmdp++) { nmp = *nmdp; if (nmp->md_type != MDT_VERSION) continue; nmodname = nmp->md_cval; if (strcmp(modname, nmodname) == 0) break; } if (nmdp < stop)/* early exit, it's a self reference */ continue; mod = modlist_lookup2(modname, verinfo); if (mod) { /* woohoo, it's loaded already */ lfdep = mod->container; lfdep->refs++; linker_file_add_dependency(lf, lfdep); continue; } error = linker_load_module(NULL, modname, lf, verinfo, NULL); if (error) { printf("KLD %s: depends on %s - not available or" " version mismatch\n", lf->filename, modname); break; } } if (error) return (error); linker_addmodules(lf, start, stop, 0); return (error); } static int sysctl_kern_function_list_iterate(const char *name, void *opaque) { struct sysctl_req *req; req = opaque; return (SYSCTL_OUT(req, name, strlen(name) + 1)); } /* * Export a nul-separated, double-nul-terminated list of all function names * in the kernel. */ static int sysctl_kern_function_list(SYSCTL_HANDLER_ARGS) { linker_file_t lf; int error; #ifdef MAC error = mac_kld_check_stat(req->td->td_ucred); if (error) return (error); #endif error = sysctl_wire_old_buffer(req, 0); if (error != 0) return (error); sx_xlock(&kld_sx); TAILQ_FOREACH(lf, &linker_files, link) { error = LINKER_EACH_FUNCTION_NAME(lf, sysctl_kern_function_list_iterate, req); if (error) { sx_xunlock(&kld_sx); return (error); } } sx_xunlock(&kld_sx); return (SYSCTL_OUT(req, "", 1)); } SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_function_list, "", "kernel function list");