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0b1c18e4cf
freebsd/sys/kern/kern_linker.c
Archie Cobbs 6c66bbed1a Move the securelevel check before loading KLD's into linker_load_file(), 
instead of requiring every caller of linker_load_file() to perform the
check itself. This avoids netgraph loading KLD's when securelevel > 0,
not to mention any future code that may call linker_load_file().

Reviewed by:	dfr
2000-06-29 17:57:04 +00:00

1380 lines
34 KiB
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/*-
* 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.
*
* $FreeBSD$
*/
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/sysproto.h>
#include <sys/sysent.h>
#include <sys/proc.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/linker.h>
#include <sys/fcntl.h>
#include <sys/libkern.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/sysctl.h>
#include "linker_if.h"
#ifdef KLD_DEBUG
int kld_debug = 0;
#endif
static char *linker_search_path(const char *name);
static const char *linker_basename(const char* path);
MALLOC_DEFINE(M_LINKER, "linker", "kernel linker");
linker_file_t linker_kernel_file;
static struct lock lock; /* lock for the file list */
static linker_class_list_t classes;
static linker_file_list_t linker_files;
static int next_file_id = 1;
/* 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;
};
typedef struct modlist *modlist_t;
static modlisthead_t found_modules;
static char *
linker_strdup(const char *str)
{
char *result;
if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL)
strcpy(result, str);
return(result);
}
static void
linker_init(void* arg)
{
lockinit(&lock, PVM, "klink", 0, 0);
TAILQ_INIT(&classes);
TAILQ_INIT(&linker_files);
}
SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0);
int
linker_add_class(linker_class_t lc)
{
kobj_class_compile((kobj_class_t) lc);
TAILQ_INSERT_TAIL(&classes, lc, link);
return 0;
}
static void
linker_file_sysinit(linker_file_t lf)
{
struct linker_set* sysinits;
struct sysinit** sipp;
struct sysinit** xipp;
struct sysinit* save;
KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
lf->filename));
sysinits = (struct linker_set*)
linker_file_lookup_symbol(lf, "sysinit_set", 0);
KLD_DPF(FILE, ("linker_file_sysinit: SYSINITs %p\n", sysinits));
if (!sysinits)
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 = (struct sysinit **)sysinits->ls_items; *sipp; sipp++) {
for (xipp = sipp + 1; *xipp; 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.
*/
for (sipp = (struct sysinit **)sysinits->ls_items; *sipp; sipp++) {
if ((*sipp)->subsystem == SI_SUB_DUMMY)
continue; /* skip dummy task(s)*/
/* Call function */
(*((*sipp)->func))((*sipp)->udata);
}
}
static void
linker_file_sysuninit(linker_file_t lf)
{
struct linker_set* sysuninits;
struct sysinit** sipp;
struct sysinit** xipp;
struct sysinit* save;
KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
lf->filename));
sysuninits = (struct linker_set*)
linker_file_lookup_symbol(lf, "sysuninit_set", 0);
KLD_DPF(FILE, ("linker_file_sysuninit: SYSUNINITs %p\n", sysuninits));
if (!sysuninits)
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 = (struct sysinit **)sysuninits->ls_items; *sipp; sipp++) {
for (xipp = sipp + 1; *xipp; 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.
*/
for (sipp = (struct sysinit **)sysuninits->ls_items; *sipp; sipp++) {
if ((*sipp)->subsystem == SI_SUB_DUMMY)
continue; /* skip dummy task(s)*/
/* Call function */
(*((*sipp)->func))((*sipp)->udata);
}
}
static void
linker_file_register_sysctls(linker_file_t lf)
{
struct linker_set* sysctls;
KLD_DPF(FILE, ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
lf->filename));
sysctls = (struct linker_set*)
linker_file_lookup_symbol(lf, "sysctl_set", 0);
KLD_DPF(FILE, ("linker_file_register_sysctls: SYSCTLs %p\n", sysctls));
if (!sysctls)
return;
sysctl_register_set(sysctls);
}
static void
linker_file_unregister_sysctls(linker_file_t lf)
{
struct linker_set* sysctls;
KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs for %s\n",
lf->filename));
sysctls = (struct linker_set*)
linker_file_lookup_symbol(lf, "sysctl_set", 0);
KLD_DPF(FILE, ("linker_file_unregister_sysctls: SYSCTLs %p\n", sysctls));
if (!sysctls)
return;
sysctl_unregister_set(sysctls);
}
static int
linker_file_register_modules(linker_file_t lf)
{
int error, mcount;
struct linker_set *modules;
struct mod_metadata **mdpp;
const moduledata_t *moddata;
struct sysinit **sipp;
KLD_DPF(FILE, ("linker_file_register_modules: registering modules in %s\n",
lf->filename));
modules = (struct linker_set*)
linker_file_lookup_symbol(lf, "modmetadata_set", 0);
mcount = 0;
if (modules) {
for (mdpp = (struct mod_metadata**)modules->ls_items; *mdpp; mdpp++) {
if ((*mdpp)->md_type != MDT_MODULE)
continue;
mcount++;
moddata = (*mdpp)->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 (mcount)
return mcount; /* Do not mix old and new style */
/* Hack - handle old kld's without metadata */
modules = (struct linker_set*)
linker_file_lookup_symbol(lf, "sysinit_set", 0);
if (modules) {
for (sipp = (struct sysinit **)modules->ls_items; *sipp; sipp++) {
if ((*sipp)->func != module_register_init)
continue;
mcount++;
moddata = (*sipp)->udata;
printf("Old-style KLD file %s found\n", moddata->name);
error = module_register(moddata, lf);
if (error)
printf("Old-style KLD file %s failed to register: %d\n", moddata->name, error);
}
}
return mcount;
}
static void
linker_init_kernel_modules(void)
{
linker_file_register_modules(linker_kernel_file);
}
SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 0);
int
linker_load_file(const char* filename, linker_file_t* result)
{
linker_class_t lc;
linker_file_t lf;
int foundfile, error = 0;
/* Refuse to load modules if securelevel raised */
if (securelevel > 0)
return EPERM;
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++;
goto out;
}
lf = NULL;
foundfile = 0;
for (lc = TAILQ_FIRST(&classes); lc; lc = TAILQ_NEXT(lc, link)) {
KLD_DPF(FILE, ("linker_load_file: trying to load %s as %s\n",
filename, lc->desc));
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 (lf) {
linker_file_register_modules(lf);
linker_file_register_sysctls(lf);
linker_file_sysinit(lf);
lf->flags |= LINKER_FILE_LINKED;
*result = lf;
error = 0;
goto out;
}
}
/*
* Less than ideal, but tells the user whether it failed to load or
* the module was not found.
*/
if (foundfile)
error = ENOEXEC; /* Format not recognised (or unloadable) */
else
error = ENOENT; /* Nothing found */
out:
return error;
}
linker_file_t
linker_find_file_by_name(const char* filename)
{
linker_file_t lf = 0;
char *koname;
koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
if (koname == NULL)
goto out;
sprintf(koname, "%s.ko", filename);
lockmgr(&lock, LK_SHARED, 0, curproc);
for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
if (!strcmp(lf->filename, koname))
break;
if (!strcmp(lf->filename, filename))
break;
}
lockmgr(&lock, LK_RELEASE, 0, curproc);
out:
if (koname)
free(koname, M_LINKER);
return lf;
}
linker_file_t
linker_find_file_by_id(int fileid)
{
linker_file_t lf = 0;
lockmgr(&lock, LK_SHARED, 0, curproc);
for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link))
if (lf->id == fileid)
break;
lockmgr(&lock, LK_RELEASE, 0, curproc);
return lf;
}
linker_file_t
linker_make_file(const char* pathname, linker_class_t lc)
{
linker_file_t lf = 0;
const char *filename;
filename = linker_basename(pathname);
KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename));
lockmgr(&lock, LK_EXCLUSIVE, 0, curproc);
lf = (linker_file_t) kobj_create((kobj_class_t) lc, M_LINKER, M_WAITOK);
if (!lf)
goto out;
lf->refs = 1;
lf->userrefs = 0;
lf->flags = 0;
lf->filename = linker_strdup(filename);
lf->id = next_file_id++;
lf->ndeps = 0;
lf->deps = NULL;
STAILQ_INIT(&lf->common);
TAILQ_INIT(&lf->modules);
TAILQ_INSERT_TAIL(&linker_files, lf, link);
out:
lockmgr(&lock, LK_RELEASE, 0, curproc);
return lf;
}
int
linker_file_unload(linker_file_t file)
{
module_t mod, next;
modlist_t ml, nextml;
struct common_symbol* cp;
int error = 0;
int i;
/* Refuse to unload modules if securelevel raised */
if (securelevel > 0)
return EPERM;
KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
lockmgr(&lock, LK_EXCLUSIVE, 0, curproc);
if (file->refs == 1) {
KLD_DPF(FILE, ("linker_file_unload: file is unloading, informing modules\n"));
/*
* Inform any modules associated with this file.
*/
for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
next = module_getfnext(mod);
/*
* Give the module a chance to veto the unload.
*/
if ((error = module_unload(mod)) != 0) {
KLD_DPF(FILE, ("linker_file_unload: module %x vetoes unload\n",
mod));
lockmgr(&lock, LK_RELEASE, 0, curproc);
goto out;
}
module_release(mod);
}
}
file->refs--;
if (file->refs > 0) {
lockmgr(&lock, LK_RELEASE, 0, curproc);
goto out;
}
for (ml = TAILQ_FIRST(&found_modules); ml; ml = nextml) {
nextml = TAILQ_NEXT(ml, link);
if (ml->container == file) {
TAILQ_REMOVE(&found_modules, ml, link);
}
}
/* Don't try to run SYSUNINITs if we are unloaded due to a link error */
if (file->flags & LINKER_FILE_LINKED) {
linker_file_sysuninit(file);
linker_file_unregister_sysctls(file);
}
TAILQ_REMOVE(&linker_files, file, link);
lockmgr(&lock, LK_RELEASE, 0, curproc);
if (file->deps) {
for (i = 0; i < file->ndeps; i++)
linker_file_unload(file->deps[i]);
free(file->deps, M_LINKER);
file->deps = NULL;
}
for (cp = STAILQ_FIRST(&file->common); cp;
cp = STAILQ_FIRST(&file->common)) {
STAILQ_REMOVE(&file->common, cp, common_symbol, link);
free(cp, M_LINKER);
}
LINKER_UNLOAD(file);
if (file->filename) {
free(file->filename, M_LINKER);
file->filename = NULL;
}
kobj_delete((kobj_t) file, M_LINKER);
out:
return error;
}
int
linker_file_add_dependancy(linker_file_t file, linker_file_t dep)
{
linker_file_t* newdeps;
newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t*),
M_LINKER, M_WAITOK);
if (newdeps == NULL)
return ENOMEM;
bzero(newdeps, (file->ndeps + 1) * sizeof(linker_file_t*));
if (file->deps) {
bcopy(file->deps, newdeps, file->ndeps * sizeof(linker_file_t*));
free(file->deps, M_LINKER);
}
file->deps = newdeps;
file->deps[file->ndeps] = dep;
file->ndeps++;
return 0;
}
caddr_t
linker_file_lookup_symbol(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;
KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%x, name=%s, deps=%d\n",
file, name, deps));
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 dependancies and
* only allocate space if not found there.
*/
common_size = symval.size;
else {
KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol.value=%x\n", symval.value));
return symval.value;
}
}
if (deps) {
for (i = 0; i < file->ndeps; i++) {
address = linker_file_lookup_symbol(file->deps[i], name, 0);
if (address) {
KLD_DPF(SYM, ("linker_file_lookup_symbol: deps value=%x\n", address));
return address;
}
}
}
if (common_size > 0) {
/*
* This is a common symbol which was not found in the
* dependancies. We maintain a simple common symbol table in
* the file object.
*/
struct common_symbol* cp;
for (cp = STAILQ_FIRST(&file->common); cp;
cp = STAILQ_NEXT(cp, link))
if (!strcmp(cp->name, name)) {
KLD_DPF(SYM, ("linker_file_lookup_symbol: old common value=%x\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);
if (!cp) {
KLD_DPF(SYM, ("linker_file_lookup_symbol: nomem\n"));
return 0;
}
bzero(cp, sizeof(struct common_symbol) + common_size + strlen(name)+ 1);
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=%x\n", cp->address));
return cp->address;
}
KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
return 0;
}
#ifdef DDB
/*
* 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 inconsistant instead.
*/
int
linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
{
linker_file_t lf;
for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0)
return 0;
}
return ENOENT;
}
int
linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
{
linker_file_t lf;
u_long off = (uintptr_t)value;
u_long diff, bestdiff;
c_linker_sym_t best;
c_linker_sym_t es;
best = 0;
bestdiff = off;
for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, 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;
}
}
int
linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
{
linker_file_t lf;
for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) {
if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0)
return 0;
}
return ENOENT;
}
#endif
/*
* Syscalls.
*/
int
kldload(struct proc* p, struct kldload_args* uap)
{
char* pathname, *realpath;
const char *filename;
linker_file_t lf;
int error = 0;
p->p_retval[0] = -1;
if (securelevel > 0) /* redundant, but that's OK */
return EPERM;
if ((error = suser(p)) != 0)
return error;
realpath = NULL;
pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
if ((error = copyinstr(SCARG(uap, file), pathname, MAXPATHLEN, NULL)) != 0)
goto out;
realpath = linker_search_path(pathname);
if (realpath == NULL) {
error = ENOENT;
goto out;
}
/* Can't load more than one file with the same name */
filename = linker_basename(realpath);
if (linker_find_file_by_name(filename)) {
error = EEXIST;
goto out;
}
if ((error = linker_load_file(realpath, &lf)) != 0)
goto out;
lf->userrefs++;
p->p_retval[0] = lf->id;
out:
if (pathname)
free(pathname, M_TEMP);
if (realpath)
free(realpath, M_LINKER);
return error;
}
int
kldunload(struct proc* p, struct kldunload_args* uap)
{
linker_file_t lf;
int error = 0;
if (securelevel > 0) /* redundant, but that's OK */
return EPERM;
if ((error = suser(p)) != 0)
return error;
lf = linker_find_file_by_id(SCARG(uap, fileid));
if (lf) {
KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
if (lf->userrefs == 0) {
printf("kldunload: attempt to unload file that was loaded by the kernel\n");
error = EBUSY;
goto out;
}
lf->userrefs--;
error = linker_file_unload(lf);
if (error)
lf->userrefs++;
} else
error = ENOENT;
out:
return error;
}
int
kldfind(struct proc* p, struct kldfind_args* uap)
{
char* pathname;
const char *filename;
linker_file_t lf;
int error = 0;
p->p_retval[0] = -1;
pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
if ((error = copyinstr(SCARG(uap, file), pathname, MAXPATHLEN, NULL)) != 0)
goto out;
filename = linker_basename(pathname);
lf = linker_find_file_by_name(filename);
if (lf)
p->p_retval[0] = lf->id;
else
error = ENOENT;
out:
if (pathname)
free(pathname, M_TEMP);
return error;
}
int
kldnext(struct proc* p, struct kldnext_args* uap)
{
linker_file_t lf;
int error = 0;
if (SCARG(uap, fileid) == 0) {
if (TAILQ_FIRST(&linker_files))
p->p_retval[0] = TAILQ_FIRST(&linker_files)->id;
else
p->p_retval[0] = 0;
return 0;
}
lf = linker_find_file_by_id(SCARG(uap, fileid));
if (lf) {
if (TAILQ_NEXT(lf, link))
p->p_retval[0] = TAILQ_NEXT(lf, link)->id;
else
p->p_retval[0] = 0;
} else
error = ENOENT;
return error;
}
int
kldstat(struct proc* p, struct kldstat_args* uap)
{
linker_file_t lf;
int error = 0;
int version;
struct kld_file_stat* stat;
int namelen;
lf = linker_find_file_by_id(SCARG(uap, fileid));
if (!lf) {
error = ENOENT;
goto out;
}
stat = SCARG(uap, stat);
/*
* Check the version of the user's structure.
*/
if ((error = copyin(&stat->version, &version, sizeof(version))) != 0)
goto out;
if (version != sizeof(struct kld_file_stat)) {
error = EINVAL;
goto out;
}
namelen = strlen(lf->filename) + 1;
if (namelen > MAXPATHLEN)
namelen = MAXPATHLEN;
if ((error = copyout(lf->filename, &stat->name[0], namelen)) != 0)
goto out;
if ((error = copyout(&lf->refs, &stat->refs, sizeof(int))) != 0)
goto out;
if ((error = copyout(&lf->id, &stat->id, sizeof(int))) != 0)
goto out;
if ((error = copyout(&lf->address, &stat->address, sizeof(caddr_t))) != 0)
goto out;
if ((error = copyout(&lf->size, &stat->size, sizeof(size_t))) != 0)
goto out;
p->p_retval[0] = 0;
out:
return error;
}
int
kldfirstmod(struct proc* p, struct kldfirstmod_args* uap)
{
linker_file_t lf;
int error = 0;
lf = linker_find_file_by_id(SCARG(uap, fileid));
if (lf) {
if (TAILQ_FIRST(&lf->modules))
p->p_retval[0] = module_getid(TAILQ_FIRST(&lf->modules));
else
p->p_retval[0] = 0;
} else
error = ENOENT;
return error;
}
int
kldsym(struct proc *p, 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;
if ((error = copyin(SCARG(uap, data), &lookup, sizeof(lookup))) != 0)
goto out;
if (lookup.version != sizeof(lookup) || SCARG(uap, cmd) != KLDSYM_LOOKUP) {
error = EINVAL;
goto out;
}
symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
goto out;
if (SCARG(uap, fileid) != 0) {
lf = linker_find_file_by_id(SCARG(uap, fileid));
if (lf == NULL) {
error = ENOENT;
goto out;
}
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, SCARG(uap, data), sizeof(lookup));
} else
error = ENOENT;
} else {
for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, 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, SCARG(uap, data), sizeof(lookup));
break;
}
}
if (!lf)
error = ENOENT;
}
out:
if (symstr)
free(symstr, M_TEMP);
return error;
}
/*
* Preloaded module support
*/
static modlist_t
modlist_lookup(const char *name)
{
modlist_t mod;
for (mod = TAILQ_FIRST(&found_modules); mod; mod = TAILQ_NEXT(mod, link)) {
if (!strcmp(mod->name, name))
return mod;
}
return NULL;
}
/*
* This routine is cheap and nasty but will work for data pointers.
*/
static void *
linker_reloc_ptr(linker_file_t lf, void *offset)
{
return lf->address + (uintptr_t)offset;
}
static void
linker_preload(void* arg)
{
caddr_t modptr;
char *modname;
char *modtype;
linker_file_t lf;
linker_class_t lc;
int error, mcount;
struct linker_set *sysinits;
linker_file_list_t loaded_files;
linker_file_list_t depended_files;
struct linker_set *deps;
struct mod_metadata *mp;
int i;
int resolves;
modlist_t mod;
TAILQ_INIT(&loaded_files);
TAILQ_INIT(&depended_files);
TAILQ_INIT(&found_modules);
error = 0;
modptr = NULL;
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;
}
printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, modptr);
lf = NULL;
for (lc = TAILQ_FIRST(&classes); lc; lc = TAILQ_NEXT(lc, link)) {
error = LINKER_LINK_PRELOAD(lc, modname, &lf);
if (error) {
lf = NULL;
break;
}
}
if (lf)
TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
}
/*
* First get a list of stuff in the kernel.
*/
deps = (struct linker_set*)
linker_file_lookup_symbol(linker_kernel_file, MDT_SETNAME, 0);
if (deps) {
for (i = 0; i < deps->ls_length; i++) {
mp = deps->ls_items[i];
if (mp->md_type != MDT_VERSION)
continue;
modname = mp->md_cval;
if (modlist_lookup(modname) != NULL) {
printf("module %s already present!\n", modname);
/* XXX what can we do? this is a build error. :-( */
continue;
}
mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT);
if (mod == NULL)
panic("no memory for module list");
bzero(mod, sizeof(*mod));
mod->container = linker_kernel_file;
mod->name = modname;
TAILQ_INSERT_TAIL(&found_modules, mod, link);
}
}
/*
* this is a once-off kinky bubble sort
* resolve relocation dependency requirements
*/
restart:
for (lf = TAILQ_FIRST(&loaded_files); lf; lf = TAILQ_NEXT(lf, loaded)) {
deps = (struct linker_set*)
linker_file_lookup_symbol(lf, MDT_SETNAME, 0);
/*
* First, look to see if we would successfully link with this stuff.
*/
resolves = 1; /* unless we know otherwise */
if (deps) {
for (i = 0; i < deps->ls_length; i++) {
mp = linker_reloc_ptr(lf, deps->ls_items[i]);
if (mp->md_type != MDT_DEPEND)
continue;
modname = linker_reloc_ptr(lf, mp->md_cval);
if (modlist_lookup(modname) == NULL) {
/* ok, the module isn't here yet, we are not finished */
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 (deps) {
for (i = 0; i < deps->ls_length; i++) {
mp = linker_reloc_ptr(lf, deps->ls_items[i]);
if (mp->md_type != MDT_VERSION)
continue;
modname = linker_reloc_ptr(lf, mp->md_cval);
if (modlist_lookup(modname) != NULL) {
printf("module %s already present!\n", modname);
linker_file_unload(lf);
TAILQ_REMOVE(&loaded_files, lf, loaded);
goto restart; /* we changed the tailq next ptr */
}
mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT);
if (mod == NULL)
panic("no memory for module list");
bzero(mod, sizeof(*mod));
mod->container = lf;
mod->name = modname;
TAILQ_INSERT_TAIL(&found_modules, mod, link);
}
}
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..
*/
for (lf = TAILQ_FIRST(&loaded_files); lf; lf = TAILQ_NEXT(lf, loaded)) {
printf("KLD file %s is missing dependencies\n", lf->filename);
linker_file_unload(lf);
TAILQ_REMOVE(&loaded_files, lf, loaded);
}
/*
* We made it. Finish off the linking in the order we determined.
*/
for (lf = TAILQ_FIRST(&depended_files); lf; lf = TAILQ_NEXT(lf, loaded)) {
if (linker_kernel_file) {
linker_kernel_file->refs++;
error = linker_file_add_dependancy(lf, linker_kernel_file);
if (error)
panic("cannot add dependency");
}
lf->userrefs++; /* so we can (try to) kldunload it */
deps = (struct linker_set*)
linker_file_lookup_symbol(lf, MDT_SETNAME, 0);
if (deps) {
for (i = 0; i < deps->ls_length; i++) {
mp = linker_reloc_ptr(lf, deps->ls_items[i]);
if (mp->md_type != MDT_DEPEND)
continue;
modname = linker_reloc_ptr(lf, mp->md_cval);
mod = modlist_lookup(modname);
mod->container->refs++;
error = linker_file_add_dependancy(lf, mod->container);
if (error)
panic("cannot add dependency");
}
}
/* 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);
linker_file_unload(lf);
continue;
}
mcount = linker_file_register_modules(lf);
sysinits = (struct linker_set*)
linker_file_lookup_symbol(lf, "sysinit_set", 0);
if (sysinits)
sysinit_add((struct sysinit **)sysinits->ls_items);
linker_file_register_sysctls(lf);
lf->flags |= LINKER_FILE_LINKED;
}
/* woohoo! we made it! */
}
SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
/*
* 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_path[MAXPATHLEN] = "/;/boot/;/modules/";
SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
sizeof(linker_path), "module load search path");
static char *linker_ext_list[] = {
".ko",
"",
NULL
};
static char *
linker_search_path(const char *name)
{
struct nameidata nd;
struct proc *p = curproc; /* XXX */
char *cp, *ep, *result, **cpp;
int error, extlen, len;
enum vtype type;
/* qualified at all? */
if (index(name, '/'))
return(linker_strdup(name));
extlen = 0;
for (cpp = linker_ext_list; *cpp; cpp++) {
len = strlen(*cpp);
if (len > extlen)
extlen = len;
}
extlen++; /* trailing '\0' */
/* traverse the linker path */
cp = linker_path;
len = strlen(name);
for (;;) {
/* find the end of this component */
for (ep = cp; (*ep != 0) && (*ep != ';'); ep++)
;
result = malloc((len + (ep - cp) + extlen), M_LINKER, M_WAITOK);
if (result == NULL) /* actually ENOMEM */
return(NULL);
for (cpp = linker_ext_list; *cpp; cpp++) {
strncpy(result, cp, ep - cp);
strcpy(result + (ep - cp), name);
strcat(result, *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, p);
error = vn_open(&nd, FREAD, 0);
if (error == 0) {
NDFREE(&nd, NDF_ONLY_PNBUF);
type = nd.ni_vp->v_type;
VOP_UNLOCK(nd.ni_vp, 0, p);
vn_close(nd.ni_vp, FREAD, p->p_ucred, p);
if (type == VREG)
return(result);
}
}
free(result, M_LINKER);
if (*ep == 0)
break;
cp = ep + 1;
}
return(NULL);
}
static const char *
linker_basename(const char* path)
{
const char *filename;
filename = rindex(path, '/');
if (filename == NULL)
return path;
if (filename[1])
filename++;
return filename;
}
/*
* 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 *modname, struct linker_file *parent)
{
linker_file_t lfdep;
const char *filename;
char *pathname;
int error;
/*
* There will be a system to look up or guess a file name from
* a module name.
* For now we just try to load a file with the same name.
*/
pathname = linker_search_path(modname);
if (pathname == NULL)
return ENOENT;
/* Can't load more than one file with the same basename */
filename = linker_basename(pathname);
if (linker_find_file_by_name(filename)) {
error = EEXIST;
goto out;
}
do {
error = linker_load_file(pathname, &lfdep);
if (error)
break;
if (parent) {
error = linker_file_add_dependancy(parent, lfdep);
if (error)
break;
}
} while(0);
out:
if (pathname)
free(pathname, M_LINKER);
return error;
}
/*
* This routine is responsible for finding dependencies of userland
* initiated kldload(2)'s of files.
*/
int
linker_load_dependancies(linker_file_t lf)
{
linker_file_t lfdep;
struct linker_set *deps;
struct mod_metadata *mp, *nmp;
modlist_t mod;
char *modname, *nmodname;
int i, j, error = 0;
/*
* All files are dependant on /kernel.
*/
if (linker_kernel_file) {
linker_kernel_file->refs++;
error = linker_file_add_dependancy(lf, linker_kernel_file);
if (error)
return error;
}
deps = (struct linker_set*)
linker_file_lookup_symbol(lf, MDT_SETNAME, 0);
if (deps != NULL) {
for (i = 0; i < deps->ls_length; i++) {
mp = linker_reloc_ptr(lf, deps->ls_items[i]);
if (mp->md_type != MDT_VERSION)
continue;
modname = linker_reloc_ptr(lf, mp->md_cval);
if (modlist_lookup(modname) != NULL) {
printf("module %s already present!\n", modname);
return EEXIST;
}
}
}
if (deps != NULL) {
for (i = 0; i < deps->ls_length; i++) {
mp = linker_reloc_ptr(lf, deps->ls_items[i]);
if (mp->md_type != MDT_DEPEND)
continue;
modname = linker_reloc_ptr(lf, mp->md_cval);
nmodname = NULL;
for (j = 0; j < deps->ls_length; j++) {
nmp = linker_reloc_ptr(lf, deps->ls_items[j]);
if (nmp->md_type != MDT_VERSION)
continue;
nmodname = linker_reloc_ptr(lf, nmp->md_cval);
if (strcmp(modname, nmodname) == 0)
break;
}
if (j < deps->ls_length) /* early exit, it's a self reference */
continue;
mod = modlist_lookup(modname);
if (mod) { /* woohoo, it's loaded already */
lfdep = mod->container;
lfdep->refs++;
error = linker_file_add_dependancy(lf, lfdep);
if (error)
break;
continue;
}
error = linker_load_module(modname, lf);
if (error) {
printf("KLD %s: depends on %s - not available\n",
lf->filename, modname);
break;
}
}
}
if (error == 0 && deps) {
for (i = 0; i < deps->ls_length; i++) {
mp = linker_reloc_ptr(lf, deps->ls_items[i]);
if (mp->md_type != MDT_VERSION)
continue;
modname = linker_reloc_ptr(lf, mp->md_cval);
mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT);
if (mod == NULL)
panic("no memory for module list");
bzero(mod, sizeof(*mod));
mod->container = lf;
mod->name = modname;
TAILQ_INSERT_TAIL(&found_modules, mod, link);
}
}
return error;
}
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