freebsd-skq/sys/kern/kern_lkm.c
bde 76258d109c Call nosys() from lkmnosys() with the correct number and type of args
instead of with none.  The first (struct proc *) arg is used if lkmnosys()
if is actually called.

Implement lkmnosys() with the correct number and type of args so that
the first of them can be used and the others won't need to be fixed
lated.
1995-08-25 20:03:02 +00:00

931 lines
20 KiB
C

/*-
* Copyright (c) 1992 Terrence R. Lambert.
* Copyright (c) 1994 Christopher G. Demetriou
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Terrence R. Lambert.
* 4. The name Terrence R. Lambert may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY TERRENCE R. LAMBERT ``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 TERRENCE R. LAMBERT 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_lkm.c,v 1.13 1995/05/30 08:05:30 rgrimes Exp $
*/
/*
* XXX it's not really safe to unload *any* of the types which are
* currently loadable; e.g. you could unload a syscall which was being
* blocked in, etc. In the long term, a solution should be come up
* with, but "not right now." -- cgd
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/conf.h>
#include <sys/file.h>
#include <sys/proc.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/sysent.h>
#include <sys/exec.h>
#include <sys/imgact.h>
#include <sys/lkm.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#define PAGESIZE 1024 /* kmem_alloc() allocation quantum */
#define LKM_ALLOC 0x01
#define LKM_WANT 0x02
#define LKMS_IDLE 0x00
#define LKMS_RESERVED 0x01
#define LKMS_LOADING 0x02
#define LKMS_LOADED 0x04
#define LKMS_UNLOADING 0x08
static int lkm_v = 0;
static int lkm_state = LKMS_IDLE;
#ifndef MAXLKMS
#define MAXLKMS 20
#endif
static struct lkm_table lkmods[MAXLKMS]; /* table of loaded modules */
static struct lkm_table *curp; /* global for in-progress ops */
/*ARGSUSED*/
int
lkmcopen(dev, flag, devtype, p)
dev_t dev;
int flag;
int devtype;
struct proc *p;
{
int error;
if (minor(dev) != 0)
return(ENXIO); /* bad minor # */
/*
* Use of the loadable kernel module device must be exclusive; we
* may try to remove this restriction later, but it's really no
* hardship.
*/
while (lkm_v & LKM_ALLOC) {
if (flag & FNONBLOCK) /* don't hang */
return(EBUSY);
lkm_v |= LKM_WANT;
/*
* Sleep pending unlock; we use tsleep() to allow
* an alarm out of the open.
*/
error = tsleep((caddr_t)&lkm_v, TTIPRI|PCATCH, "lkmopn", 0);
if (error)
return(error); /* leave LKM_WANT set -- no problem */
}
lkm_v |= LKM_ALLOC;
return(0); /* pseudo-device open */
}
/*
* Unreserve the memory associated with the current loaded module; done on
* a coerced close of the lkm device (close on premature exit of modload)
* or explicitly by modload as a result of a link failure.
*/
static void
lkmunreserve()
{
if (lkm_state == LKMS_IDLE)
return;
/*
* Actually unreserve the memory
*/
if (curp && curp->area) {
kmem_free(kmem_map, curp->area, curp->size);/**/
curp->area = 0;
if (curp->private.lkm_any != NULL)
curp->private.lkm_any = NULL;
}
lkm_state = LKMS_IDLE;
}
int
lkmcclose(dev, flag, mode, p)
dev_t dev;
int flag;
int mode;
struct proc *p;
{
if (!(lkm_v & LKM_ALLOC)) {
#ifdef DEBUG
printf("LKM: close before open!\n");
#endif /* DEBUG */
return(EBADF);
}
/* do this before waking the herd... */
if (curp && !curp->used) {
/*
* If we close before setting used, we have aborted
* by way of error or by way of close-on-exit from
* a premature exit of "modload".
*/
lkmunreserve(); /* coerce state to LKM_IDLE */
}
lkm_v &= ~LKM_ALLOC;
wakeup((caddr_t)&lkm_v); /* thundering herd "problem" here */
return(0); /* pseudo-device closed */
}
/*ARGSUSED*/
int
lkmcioctl(dev, cmd, data, flag)
dev_t dev;
int cmd;
caddr_t data;
int flag;
{
int err = 0;
int i;
struct lmc_resrv *resrvp;
struct lmc_loadbuf *loadbufp;
struct lmc_unload *unloadp;
struct lmc_stat *statp;
char istr[MAXLKMNAME];
switch(cmd) {
case LMRESERV: /* reserve pages for a module */
if ((flag & FWRITE) == 0) /* only allow this if writing */
return EPERM;
resrvp = (struct lmc_resrv *)data;
/*
* Find a free slot.
*/
for (i = 0; i < MAXLKMS; i++)
if (!lkmods[i].used)
break;
if (i == MAXLKMS) {
err = ENOMEM; /* no slots available */
break;
}
curp = &lkmods[i];
curp->id = i; /* self reference slot offset */
resrvp->slot = i; /* return slot */
/*
* Get memory for module
*/
curp->size = resrvp->size;
curp->area = kmem_alloc(kmem_map, curp->size);/**/
curp->offset = 0; /* load offset */
resrvp->addr = curp->area; /* ret kernel addr */
#ifdef DEBUG
printf("LKM: LMRESERV (actual = 0x%08x)\n", curp->area);
printf("LKM: LMRESERV (adjusted = 0x%08x)\n",
trunc_page(curp->area));
#endif /* DEBUG */
lkm_state = LKMS_RESERVED;
break;
case LMLOADBUF: /* Copy in; stateful, follows LMRESERV */
if ((flag & FWRITE) == 0) /* only allow this if writing */
return EPERM;
loadbufp = (struct lmc_loadbuf *)data;
i = loadbufp->cnt;
if ((lkm_state != LKMS_RESERVED && lkm_state != LKMS_LOADING)
|| i < 0
|| i > MODIOBUF
|| i > curp->size - curp->offset) {
err = ENOMEM;
break;
}
/* copy in buffer full of data */
err = copyin((caddr_t)loadbufp->data,
(caddr_t)curp->area + curp->offset, i);
if (err)
break;
if ((curp->offset + i) < curp->size) {
lkm_state = LKMS_LOADING;
#ifdef DEBUG
printf("LKM: LMLOADBUF (loading @ %d of %d, i = %d)\n",
curp->offset, curp->size, i);
#endif /* DEBUG */
} else {
lkm_state = LKMS_LOADED;
#ifdef DEBUG
printf("LKM: LMLOADBUF (loaded)\n");
#endif /* DEBUG */
}
curp->offset += i;
break;
case LMUNRESRV: /* discard reserved pages for a module */
if ((flag & FWRITE) == 0) /* only allow this if writing */
return EPERM;
lkmunreserve(); /* coerce state to LKM_IDLE */
#ifdef DEBUG
printf("LKM: LMUNRESERV\n");
#endif /* DEBUG */
break;
case LMREADY: /* module loaded: call entry */
if ((flag & FWRITE) == 0) /* only allow this if writing */
return EPERM;
switch (lkm_state) {
case LKMS_LOADED:
break;
case LKMS_LOADING:
/* The remainder must be bss, so we clear it */
bzero((caddr_t)curp->area + curp->offset,
curp->size - curp->offset);
break;
default:
#ifdef DEBUG
printf("lkm_state is %02x\n", lkm_state);
#endif /* DEBUG */
return ENXIO;
}
curp->entry = (int (*)()) (*((int *) (data)));
/* call entry(load)... (assigns "private" portion) */
err = (*(curp->entry))(curp, LKM_E_LOAD, LKM_VERSION);
if (err) {
/*
* Module may refuse loading or may have a
* version mismatch...
*/
lkm_state = LKMS_UNLOADING; /* for lkmunreserve */
lkmunreserve(); /* free memory */
curp->used = 0; /* free slot */
break;
}
/*
* It's possible for a user to load a module that doesn't
* initialize itself correctly. (You can even get away with
* using it for a while.) Unfortunately, we are faced with
* the following problems:
* - we can't tell a good module from a bad one until
* after we've run its entry function (if the private
* section is uninitalized after we return from the
* entry, then something's fishy)
* - now that we've called the entry function, we can't
* forcibly unload the module without risking a crash
* - since we don't know what the module's entry function
* did, we can't easily clean up the mess it may have
* made, so we can't know just how unstable the system
* may be
* So, being stuck between a rock and a hard place, we
* have no choice but to do this...
*/
if (curp->private.lkm_any == NULL)
panic("loadable module initialization failed");
curp->used = 1;
#ifdef DEBUG
printf("LKM: LMREADY\n");
#endif /* DEBUG */
lkm_state = LKMS_IDLE;
break;
case LMUNLOAD: /* unload a module */
if ((flag & FWRITE) == 0) /* only allow this if writing */
return EPERM;
unloadp = (struct lmc_unload *)data;
if ((i = unloadp->id) == -1) { /* unload by name */
/*
* Copy name and lookup id from all loaded
* modules. May fail.
*/
err =copyinstr(unloadp->name, istr, MAXLKMNAME-1, NULL);
if (err)
break;
/*
* look up id...
*/
for (i = 0; i < MAXLKMS; i++) {
if (!lkmods[i].used)
continue;
if (!strcmp(istr,
lkmods[i].private.lkm_any->lkm_name))
break;
}
}
/*
* Range check the value; on failure, return EINVAL
*/
if (i < 0 || i >= MAXLKMS) {
err = EINVAL;
break;
}
curp = &lkmods[i];
if (!curp->used) {
err = ENOENT;
break;
}
/* call entry(unload) */
if ((*(curp->entry))(curp, LKM_E_UNLOAD, LKM_VERSION)) {
err = EBUSY;
break;
}
lkm_state = LKMS_UNLOADING; /* non-idle for lkmunreserve */
lkmunreserve(); /* free memory */
curp->used = 0; /* free slot */
break;
case LMSTAT: /* stat a module by id/name */
/* allow readers and writers to stat */
statp = (struct lmc_stat *)data;
if ((i = statp->id) == -1) { /* stat by name */
/*
* Copy name and lookup id from all loaded
* modules.
*/
copystr(statp->name, istr, MAXLKMNAME-1, NULL);
/*
* look up id...
*/
for (i = 0; i < MAXLKMS; i++) {
if (!lkmods[i].used)
continue;
if (!strcmp(istr,
lkmods[i].private.lkm_any->lkm_name))
break;
}
if (i == MAXLKMS) { /* Not found */
err = ENOENT;
break;
}
}
/*
* Range check the value; on failure, return EINVAL
*/
if (i < 0 || i >= MAXLKMS) {
err = EINVAL;
break;
}
curp = &lkmods[i];
if (!curp->used) { /* Not found */
err = ENOENT;
break;
}
/*
* Copy out stat information for this module...
*/
statp->id = curp->id;
statp->offset = curp->private.lkm_any->lkm_offset;
statp->type = curp->private.lkm_any->lkm_type;
statp->area = curp->area;
statp->size = curp->size / PAGESIZE;
statp->private = (unsigned long)curp->private.lkm_any;
statp->ver = curp->private.lkm_any->lkm_ver;
copystr(curp->private.lkm_any->lkm_name,
statp->name,
MAXLKMNAME - 2,
NULL);
break;
default: /* bad ioctl()... */
err = ENOTTY;
break;
}
return (err);
}
/*
* Acts like "nosys" but can be identified in sysent for dynamic call
* number assignment for a limited number of calls.
*
* Place holder for system call slots reserved for loadable modules.
*/
int
lkmnosys(p, args, retval)
struct proc *p;
struct nosys_args *args;
int *retval;
{
return(nosys(p, args, retval));
}
/*
* Acts like "enodev", but can be identified in cdevsw and bdevsw for
* dynamic driver major number assignment for a limited number of
* drivers.
*
* Place holder for device switch slots reserved for loadable modules.
*/
int
lkmenodev()
{
return(enodev());
}
int
lkmexists(lkmtp)
struct lkm_table *lkmtp;
{
int i;
/*
* see if name exists...
*/
for (i = 0; i < MAXLKMS; i++) {
/*
* An unused module and the one we are testing are not
* considered.
*/
if (!lkmods[i].used || &lkmods[i] == lkmtp)
continue;
if (!strcmp(lkmtp->private.lkm_any->lkm_name,
lkmods[i].private.lkm_any->lkm_name))
return(1); /* already loaded... */
}
return(0); /* module not loaded... */
}
/*
* For the loadable system call described by the structure pointed to
* by lkmtp, load/unload/stat it depending on the cmd requested.
*/
static int
_lkm_syscall(lkmtp, cmd)
struct lkm_table *lkmtp;
int cmd;
{
struct lkm_syscall *args = lkmtp->private.lkm_syscall;
int i;
int err = 0;
switch(cmd) {
case LKM_E_LOAD:
/* don't load twice! */
if (lkmexists(lkmtp))
return(EEXIST);
if ((i = args->lkm_offset) == -1) { /* auto */
/*
* Search the table looking for a slot...
*/
for (i = 0; i < aout_sysvec.sv_size; i++)
if (aout_sysvec.sv_table[i].sy_call == lkmnosys)
break; /* found it! */
/* out of allocable slots? */
if (i == aout_sysvec.sv_size) {
err = ENFILE;
break;
}
} else { /* assign */
if (i < 0 || i >= aout_sysvec.sv_size) {
err = EINVAL;
break;
}
}
/* save old */
bcopy(&aout_sysvec.sv_table[i],
&(args->lkm_oldent),
sizeof(struct sysent));
/* replace with new */
bcopy(args->lkm_sysent,
&aout_sysvec.sv_table[i],
sizeof(struct sysent));
/* done! */
args->lkm_offset = i; /* slot in sysent[] */
break;
case LKM_E_UNLOAD:
/* current slot... */
i = args->lkm_offset;
/* replace current slot contents with old contents */
bcopy(&(args->lkm_oldent),
&aout_sysvec.sv_table[i],
sizeof(struct sysent));
break;
case LKM_E_STAT: /* no special handling... */
break;
}
return(err);
}
/*
* For the loadable virtual file system described by the structure pointed
* to by lkmtp, load/unload/stat it depending on the cmd requested.
*/
static int
_lkm_vfs(lkmtp, cmd)
struct lkm_table *lkmtp;
int cmd;
{
struct lkm_vfs *args = lkmtp->private.lkm_vfs;
struct vfsconf *vfc = args->lkm_vfsconf;
int i;
int err = 0;
switch(cmd) {
case LKM_E_LOAD:
/* don't load twice! */
if (lkmexists(lkmtp))
return(EEXIST);
for(i = 0; i < MOUNT_MAXTYPE; i++) {
if(!strcmp(vfc->vfc_name, vfsconf[i]->vfc_name)) {
return EEXIST;
}
}
i = args->lkm_offset = vfc->vfc_index;
if (i < 0) {
for (i = MOUNT_MAXTYPE - 1; i >= 0; i--) {
if(vfsconf[i] == &void_vfsconf)
break;
}
}
if (i < 0) {
return EINVAL;
}
args->lkm_offset = vfc->vfc_index = i;
vfsconf[i] = vfc;
vfssw[i] = vfc->vfc_vfsops;
/* like in vfs_op_init */
for(i = 0; args->lkm_vnodeops->ls_items[i]; i++) {
struct vnodeopv_desc *opv =
(struct vnodeopv_desc *)args->lkm_vnodeops->ls_items[i];
*(opv->opv_desc_vector_p) = NULL;
}
vfs_opv_init((struct vnodeopv_desc **)args->lkm_vnodeops->ls_items);
/*
* Call init function for this VFS...
*/
(*(vfssw[vfc->vfc_index]->vfs_init))();
/* done! */
break;
case LKM_E_UNLOAD:
/* current slot... */
i = args->lkm_offset;
if (vfsconf[i]->vfc_refcount) {
return EBUSY;
}
/* replace current slot contents with old contents */
vfssw[i] = (struct vfsops *)0;
vfsconf[i] = &void_vfsconf;
break;
case LKM_E_STAT: /* no special handling... */
break;
}
return(err);
}
/*
* For the loadable device driver described by the structure pointed to
* by lkmtp, load/unload/stat it depending on the cmd requested.
*/
static int
_lkm_dev(lkmtp, cmd)
struct lkm_table *lkmtp;
int cmd;
{
struct lkm_dev *args = lkmtp->private.lkm_dev;
int i;
int err = 0;
switch(cmd) {
case LKM_E_LOAD:
/* don't load twice! */
if (lkmexists(lkmtp))
return(EEXIST);
switch(args->lkm_devtype) {
case LM_DT_BLOCK:
if ((i = args->lkm_offset) == -1) { /* auto */
/*
* Search the table looking for a slot...
*/
for (i = 0; i < nblkdev; i++)
if (bdevsw[i].d_open == lkmenodev)
break; /* found it! */
/* out of allocable slots? */
if (i == nblkdev) {
err = ENFILE;
break;
}
} else { /* assign */
if (i < 0 || i >= nblkdev) {
err = EINVAL;
break;
}
}
/* save old */
bcopy(&bdevsw[i], &(args->lkm_olddev.bdev), sizeof(struct bdevsw));
/* replace with new */
bcopy(args->lkm_dev.bdev, &bdevsw[i], sizeof(struct bdevsw));
/* done! */
args->lkm_offset = i; /* slot in bdevsw[] */
break;
case LM_DT_CHAR:
if ((i = args->lkm_offset) == -1) { /* auto */
/*
* Search the table looking for a slot...
*/
for (i = 0; i < nchrdev; i++)
if (cdevsw[i].d_open == lkmenodev)
break; /* found it! */
/* out of allocable slots? */
if (i == nchrdev) {
err = ENFILE;
break;
}
} else { /* assign */
if (i < 0 || i >= nchrdev) {
err = EINVAL;
break;
}
}
/* save old */
bcopy(&cdevsw[i], &(args->lkm_olddev.cdev), sizeof(struct cdevsw));
/* replace with new */
bcopy(args->lkm_dev.cdev, &cdevsw[i], sizeof(struct cdevsw));
/* done! */
args->lkm_offset = i; /* slot in cdevsw[] */
break;
default:
err = ENODEV;
break;
}
break;
case LKM_E_UNLOAD:
/* current slot... */
i = args->lkm_offset;
switch(args->lkm_devtype) {
case LM_DT_BLOCK:
/* replace current slot contents with old contents */
bcopy(&(args->lkm_olddev.bdev), &bdevsw[i], sizeof(struct bdevsw));
break;
case LM_DT_CHAR:
/* replace current slot contents with old contents */
bcopy(&(args->lkm_olddev.cdev), &cdevsw[i], sizeof(struct cdevsw));
break;
default:
err = ENODEV;
break;
}
break;
case LKM_E_STAT: /* no special handling... */
break;
}
return(err);
}
#ifdef STREAMS
/*
* For the loadable streams module described by the structure pointed to
* by lkmtp, load/unload/stat it depending on the cmd requested.
*/
static int
_lkm_strmod(lkmtp, cmd)
struct lkm_table *lkmtp;
int cmd;
{
struct lkm_strmod *args = lkmtp->private.lkm_strmod;
int i;
int err = 0;
switch(cmd) {
case LKM_E_LOAD:
/* don't load twice! */
if (lkmexists(lkmtp))
return(EEXIST);
break;
case LKM_E_UNLOAD:
break;
case LKM_E_STAT: /* no special handling... */
break;
}
return(err);
}
#endif /* STREAMS */
/*
* For the loadable execution class described by the structure pointed to
* by lkmtp, load/unload/stat it depending on the cmd requested.
*/
static int
_lkm_exec(lkmtp, cmd)
struct lkm_table *lkmtp;
int cmd;
{
struct lkm_exec *args = lkmtp->private.lkm_exec;
int i;
int err = 0;
const struct execsw **execsw =
(const struct execsw **)&execsw_set.ls_items[0];
#if 1
switch(cmd) {
case LKM_E_LOAD:
/* don't load twice! */
if (lkmexists(lkmtp))
return(EEXIST);
if ((i = args->lkm_offset) == -1) { /* auto */
/*
* Search the table looking for a slot...
*/
for (i = 0; execsw[i] != NULL; i++)
if (execsw[i]->ex_imgact == NULL)
break; /* found it! */
/* out of allocable slots? */
if (execsw[i] == NULL) {
err = ENFILE;
break;
}
} else { /* assign */
err = EINVAL;
break;
}
/* save old */
bcopy(&execsw[i], &(args->lkm_oldexec), sizeof(struct execsw*));
/* replace with new */
bcopy(&(args->lkm_exec), &execsw[i], sizeof(struct execsw*));
/* done! */
args->lkm_offset = i; /* slot in execsw[] */
break;
case LKM_E_UNLOAD:
/* current slot... */
i = args->lkm_offset;
/* replace current slot contents with old contents */
bcopy(&(args->lkm_oldexec), &execsw[i], sizeof(struct execsw*));
break;
case LKM_E_STAT: /* no special handling... */
break;
}
#else
err = EINVAL;
#endif
return(err);
}
static const struct execsw lkm_exec_dummy = { NULL, "lkm" };
TEXT_SET(execsw_set, lkm_exec_dummy);
TEXT_SET(execsw_set, lkm_exec_dummy);
TEXT_SET(execsw_set, lkm_exec_dummy);
TEXT_SET(execsw_set, lkm_exec_dummy);
/*
* This code handles the per-module type "wiring-in" of loadable modules
* into existing kernel tables. For "LM_MISC" modules, wiring and unwiring
* is assumed to be done in their entry routines internal to the module
* itself.
*/
int
lkmdispatch(lkmtp, cmd)
struct lkm_table *lkmtp;
int cmd;
{
int err = 0; /* default = success */
switch(lkmtp->private.lkm_any->lkm_type) {
case LM_SYSCALL:
err = _lkm_syscall(lkmtp, cmd);
break;
case LM_VFS:
err = _lkm_vfs(lkmtp, cmd);
break;
case LM_DEV:
err = _lkm_dev(lkmtp, cmd);
break;
#ifdef STREAMS
case LM_STRMOD:
{
struct lkm_strmod *args = lkmtp->private.lkm_strmod;
}
break;
#endif /* STREAMS */
case LM_EXEC:
err = _lkm_exec(lkmtp, cmd);
break;
case LM_MISC: /* ignore content -- no "misc-specific" procedure */
if (lkmexists(lkmtp))
err = EEXIST;
break;
default:
err = ENXIO; /* unknown type */
break;
}
return(err);
}