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freebsd-skq/sys/kern/kern_linker.c

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/*-
* Copyright (c) 1997 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.
*
* $Id: kern_linker.c,v 1.14 1998/11/04 15:20:56 peter Exp $
*/
#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 <machine/cpu.h>
#include <machine/bootinfo.h>
#include <sys/module.h>
#include <sys/linker.h>
#include <sys/unistd.h>
#include <sys/fcntl.h>
#include <sys/libkern.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/sysctl.h>
#ifdef KLD_DEBUG
int kld_debug = 0;
#endif
MALLOC_DEFINE(M_LINKER, "kld", "kernel linker");
linker_file_t linker_current_file;
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 files;
static int next_file_id = 1;
static void
linker_init(void* arg)
{
lockinit(&lock, PVM, "klink", 0, 0);
TAILQ_INIT(&classes);
TAILQ_INIT(&files);
}
SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0);
int
linker_add_class(const char* desc, void* priv,
struct linker_class_ops* ops)
{
linker_class_t lc;
lc = malloc(sizeof(struct linker_class), M_LINKER, M_NOWAIT);
if (!lc)
return ENOMEM;
bzero(lc, sizeof(*lc));
lc->desc = desc;
lc->priv = priv;
lc->ops = ops;
TAILQ_INSERT_HEAD(&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;
moduledata_t *moddata;
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;
/* HACK ALERT! */
for (sipp = (struct sysinit **)sysinits->ls_items; *sipp; sipp++) {
if ((*sipp)->func == module_register_init) {
moddata = (*sipp)->udata;
moddata->_file = lf;
}
}
/*
* 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.
*
* The last item on the list is expected to be the scheduler,
* which will not return.
*/
for( sipp = (struct sysinit **)sysinits->ls_items; *sipp; sipp++) {
if( (*sipp)->subsystem == SI_SUB_DUMMY)
continue; /* skip dummy task(s)*/
switch( (*sipp)->type) {
case SI_TYPE_DEFAULT:
/* no special processing*/
(*((*sipp)->func))( (*sipp)->udata);
break;
case SI_TYPE_KTHREAD:
#if !defined(SMP)
/* kernel thread*/
if (fork1(&proc0, RFFDG|RFPROC|RFMEM))
panic("fork kernel thread");
cpu_set_fork_handler(pfind(proc0.p_retval[0]),
(*sipp)->func, (*sipp)->udata);
break;
#endif
case SI_TYPE_KPROCESS:
/* kernel thread*/
if (fork1(&proc0, RFFDG|RFPROC))
panic("fork kernel process");
cpu_set_fork_handler(pfind(proc0.p_retval[0]),
(*sipp)->func, (*sipp)->udata);
break;
default:
panic( "linker_file_sysinit: unrecognized init type");
}
}
}
int
linker_load_file(const char* filename, linker_file_t* result)
{
linker_class_t lc;
linker_file_t lf;
int error = 0;
char *koname = NULL;
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;
}
koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
if (koname == NULL) {
error = ENOMEM;
goto out;
}
sprintf(koname, "%s.ko", filename);
lf = NULL;
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 = lc->ops->load_file(koname, &lf);
if (lf == NULL && error && error != ENOENT)
goto out;
if (lf == NULL)
error = lc->ops->load_file(filename, &lf);
if (lf == NULL && error && error != ENOENT)
goto out;
if (lf) {
linker_file_sysinit(lf);
*result = lf;
error = 0;
goto out;
}
}
error = ENOEXEC; /* format not recognised */
out:
if (koname)
free(koname, M_LINKER);
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(&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(&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, void* priv, struct linker_file_ops* ops)
{
linker_file_t lf = 0;
int namelen;
const char *filename;
filename = rindex(pathname, '/');
if (filename && filename[1])
filename++;
else
filename = pathname;
KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename));
lockmgr(&lock, LK_EXCLUSIVE|LK_RETRY, 0, curproc);
namelen = strlen(filename) + 1;
lf = malloc(sizeof(struct linker_file) + namelen, M_LINKER, M_WAITOK);
if (!lf)
goto out;
bzero(lf, sizeof(*lf));
lf->refs = 1;
lf->userrefs = 0;
lf->filename = (char*) (lf + 1);
strcpy(lf->filename, filename);
lf->id = next_file_id++;
lf->ndeps = 0;
lf->deps = NULL;
STAILQ_INIT(&lf->common);
TAILQ_INIT(&lf->modules);
lf->priv = priv;
lf->ops = ops;
TAILQ_INSERT_TAIL(&files, lf, link);
out:
lockmgr(&lock, LK_RELEASE, 0, curproc);
return lf;
}
int
linker_file_unload(linker_file_t file)
{
module_t mod, next;
struct common_symbol* cp;
int error = 0;
int i;
KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
lockmgr(&lock, LK_EXCLUSIVE|LK_RETRY, 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)) {
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;
}
TAILQ_REMOVE(&files, file, link);
lockmgr(&lock, LK_RELEASE, 0, curproc);
for (i = 0; i < file->ndeps; i++)
linker_file_unload(file->deps[i]);
free(file->deps, M_LINKER);
for (cp = STAILQ_FIRST(&file->common); cp;
cp = STAILQ_FIRST(&file->common)) {
STAILQ_REMOVE(&file->common, cp, common_symbol, link);
free(cp, M_LINKER);
}
file->ops->unload(file);
free(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)
{
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 (file->ops->lookup_symbol(file, name, &sym) == 0) {
file->ops->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(char *symstr, linker_sym_t *sym)
{
linker_file_t lf;
for (lf = TAILQ_FIRST(&files); lf; lf = TAILQ_NEXT(lf, link)) {
if (lf->ops->lookup_symbol(lf, symstr, sym) == 0)
return 0;
}
return ENOENT;
}
int
linker_ddb_search_symbol(caddr_t value, linker_sym_t *sym, long *diffp)
{
linker_file_t lf;
u_long off = (u_long)value;
u_long diff, bestdiff;
linker_sym_t best;
linker_sym_t es;
best = 0;
bestdiff = off;
for (lf = TAILQ_FIRST(&files); lf; lf = TAILQ_NEXT(lf, link)) {
if (lf->ops->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(linker_sym_t sym, linker_symval_t *symval)
{
linker_file_t lf;
for (lf = TAILQ_FIRST(&files); lf; lf = TAILQ_NEXT(lf, link)) {
if (lf->ops->symbol_values(lf, sym, symval) == 0)
return 0;
}
return ENOENT;
}
#endif
/*
* Syscalls.
*/
int
kldload(struct proc* p, struct kldload_args* uap)
{
char* filename = NULL;
linker_file_t lf;
int error = 0;
p->p_retval[0] = -1;
if (securelevel > 0)
return EPERM;
if (error = suser(p->p_ucred, &p->p_acflag))
return error;
filename = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
if (error = copyinstr(SCARG(uap, file), filename, MAXPATHLEN, NULL))
goto out;
if (error = linker_load_file(filename, &lf))
goto out;
lf->userrefs++;
p->p_retval[0] = lf->id;
out:
if (filename)
free(filename, M_TEMP);
return error;
}
int
kldunload(struct proc* p, struct kldunload_args* uap)
{
linker_file_t lf;
int error = 0;
if (securelevel > 0)
return EPERM;
if (error = suser(p->p_ucred, &p->p_acflag))
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("linkerunload: attempt to unload file which was not loaded by user\n");
error = EBUSY;
goto out;
}
lf->userrefs--;
error = linker_file_unload(lf);
} else
error = ENOENT;
out:
return error;
}
int
kldfind(struct proc* p, struct kldfind_args* uap)
{
char* filename = NULL;
linker_file_t lf;
int error = 0;
p->p_retval[0] = -1;
filename = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
if (error = copyinstr(SCARG(uap, file), filename, MAXPATHLEN, NULL))
goto out;
lf = linker_find_file_by_name(filename);
if (lf)
p->p_retval[0] = lf->id;
else
error = ENOENT;
out:
if (filename)
free(filename, 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(&files))
p->p_retval[0] = TAILQ_FIRST(&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)))
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))
goto out;
if (error = copyout(&lf->refs, &stat->refs, sizeof(int)))
goto out;
if (error = copyout(&lf->id, &stat->id, sizeof(int)))
goto out;
if (error = copyout(&lf->address, &stat->address, sizeof(caddr_t)))
goto out;
if (error = copyout(&lf->size, &stat->size, sizeof(size_t)))
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;
}
/*
* Preloaded module support
*/
static void
linker_preload(void* arg)
{
caddr_t modptr;
char *modname;
char *modtype;
linker_file_t lf;
linker_class_t lc;
int error;
struct linker_set *sysinits;
struct sysinit **sipp;
moduledata_t *moddata;
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 = linker_find_file_by_name(modname);
if (lf) {
lf->userrefs++;
continue;
}
lf = NULL;
for (lc = TAILQ_FIRST(&classes); lc; lc = TAILQ_NEXT(lc, link)) {
error = lc->ops->load_file(modname, &lf);
if (error) {
lf = NULL;
break;
}
}
if (lf) {
lf->userrefs++;
sysinits = (struct linker_set*)
linker_file_lookup_symbol(lf, "sysinit_set", 0);
if (sysinits) {
/* HACK ALERT!
* This is to set the sysinit moduledata so that the module
* can attach itself to the correct containing file.
* The sysinit could be run at *any* time.
*/
for (sipp = (struct sysinit **)sysinits->ls_items; *sipp; sipp++) {
if ((*sipp)->func == module_register_init) {
moddata = (*sipp)->udata;
moddata->_file = lf;
}
}
sysinit_add((struct sysinit **)sysinits->ls_items);
}
}
}
}
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 + 1] = "/;/boot/;/modules/";
SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
sizeof(linker_path), "module load search path");
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);
}
char *
linker_search_path(const char *name)
{
struct nameidata nd;
struct proc *p = curproc; /* XXX */
char *cp, *ep, *result;
int error;
enum vtype type;
/* qualified at all? */
if (index(name, '/'))
return(linker_strdup(name));
/* traverse the linker path */
cp = linker_path;
for (;;) {
/* find the end of this component */
for (ep = cp; (*ep != 0) && (*ep != ';'); ep++)
;
result = malloc((strlen(name) + (ep - cp) + 1), M_LINKER, M_WAITOK);
if (result == NULL) /* actually ENOMEM */
return(NULL);
strncpy(result, cp, ep - cp);
strcpy(result + (ep - cp), name);
/*
* 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) {
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);
}
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