/* $NetBSD: kern_lkm.c,v 1.60 2002/09/18 22:59:36 lha Exp $ */ /* * Copyright (c) 1994 Christopher G. Demetriou * Copyright (c) 1992 Terrence R. Lambert. * 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. */ /* * 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 __KERNEL_RCSID(0, "$NetBSD: kern_lkm.c,v 1.60 2002/09/18 22:59:36 lha Exp $"); #include "opt_ddb.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DDB #include #include #endif #include #if !defined(DEBUG) && defined(LKMDEBUG) # define DEBUG #endif #ifdef DEBUG # define LKMDB_INFO 0x01 # define LKMDB_LOAD 0x02 int lkmdebug = 0; #endif #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_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 */ static void lkmunreserve __P((void)); static int _lkm_syscall __P((struct lkm_table *, int)); static int _lkm_vfs __P((struct lkm_table *, int)); static int _lkm_dev __P((struct lkm_table *, int)); #ifdef STREAMS static int _lkm_strmod __P((struct lkm_table *, int)); #endif static int _lkm_exec __P((struct lkm_table *, int)); static int _lkm_compat __P((struct lkm_table *, int)); dev_type_open(lkmopen); dev_type_close(lkmclose); dev_type_ioctl(lkmioctl); const struct cdevsw lkm_cdevsw = { lkmopen, lkmclose, noread, nowrite, lkmioctl, nostop, notty, nopoll, nommap, }; /*ARGSUSED*/ int lkmopen(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; if (curp && curp->syms) { #ifdef DDB db_del_symbol_table(curp->private.lkm_any->lkm_name); #endif uvm_km_free(kernel_map, curp->syms, curp->sym_size);/**/ curp->syms = 0; } /* * Actually unreserve the memory */ if (curp && curp->area) { uvm_km_free(kernel_map, curp->area, curp->size);/**/ curp->area = 0; } lkm_state = LKMS_IDLE; } int lkmclose(dev, flag, mode, p) dev_t dev; int flag; int mode; struct proc *p; { if (!(lkm_v & LKM_ALLOC)) { #ifdef DEBUG if (lkmdebug & LKMDB_INFO) 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 lkmioctl(dev, cmd, data, flag, p) dev_t dev; u_long cmd; caddr_t data; int flag; struct proc *p; { int error = 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 */ case LMRESERV_O: /* reserve pages for a module */ if (securelevel > 0) return EPERM; 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) { error = ENOMEM; /* no slots available */ break; } curp = &lkmods[i]; curp->id = i; /* self reference slot offset */ curp->ver = (cmd == LMRESERV) ? LKM_VERSION : LKM_OLDVERSION; resrvp->slot = i; /* return slot */ /* * Get memory for module */ curp->size = resrvp->size; curp->area = uvm_km_alloc(kernel_map, curp->size);/**/ curp->offset = 0; /* load offset */ resrvp->addr = curp->area; /* ret kernel addr */ if (cmd == LMRESERV && resrvp->sym_size) { curp->sym_size = resrvp->sym_size; curp->sym_symsize = resrvp->sym_symsize; curp->syms = (u_long)uvm_km_alloc(kernel_map, curp->sym_size);/**/ curp->sym_offset = 0; resrvp->sym_addr = curp->syms; /* ret symbol addr */ } else { curp->sym_size = 0; curp->syms = 0; curp->sym_offset = 0; if (cmd == LMRESERV) resrvp->sym_addr = 0; } #ifdef DEBUG if (lkmdebug & LKMDB_INFO) { printf("LKM: LMRESERV (actual = 0x%08lx)\n", curp->area); printf("LKM: LMRESERV (syms = 0x%08lx)\n", curp->syms); printf("LKM: LMRESERV (adjusted = 0x%08lx)\n", trunc_page(curp->area)); } #endif /* DEBUG */ lkm_state = LKMS_RESERVED; break; case LMLOADBUF: /* Copy in; stateful, follows LMRESERV */ if (securelevel > 0) return EPERM; 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) { error = ENOMEM; break; } /* copy in buffer full of data */ error = copyin(loadbufp->data, (caddr_t)curp->area + curp->offset, i); if (error) break; if ((curp->offset + i) < curp->size) { lkm_state = LKMS_LOADING; #ifdef DEBUG if (lkmdebug & LKMDB_LOAD) printf("LKM: LMLOADBUF (loading @ %ld of %ld, i = %d)\n", curp->offset, curp->size, i); #endif /* DEBUG */ } curp->offset += i; break; case LMLOADSYMS: /* 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_LOADING) || i < 0 || i > MODIOBUF || i > curp->sym_size - curp->sym_offset) { error = ENOMEM; break; } /* copy in buffer full of data*/ if ((error = copyin(loadbufp->data, (caddr_t)(curp->syms) + curp->sym_offset, i)) != 0) break; if ((curp->sym_offset + i) < curp->sym_size) { lkm_state = LKMS_LOADING; #ifdef DEBUG if (lkmdebug & LKMDB_LOAD) printf( "LKM: LMLOADSYMS (loading @ %ld of %ld, i = %d)\n", curp->sym_offset, curp->sym_size, i); #endif /* DEBUG*/ } curp->sym_offset += i; break; case LMUNRESRV: /* discard reserved pages for a module */ if (securelevel > 0) return EPERM; if ((flag & FWRITE) == 0) /* only allow this if writing */ return EPERM; lkmunreserve(); /* coerce state to LKM_IDLE */ #ifdef DEBUG if (lkmdebug & LKMDB_INFO) printf("LKM: LMUNRESERV\n"); #endif /* DEBUG */ break; case LMREADY: /* module loaded: call entry */ if (securelevel > 0) return EPERM; if ((flag & FWRITE) == 0) /* only allow this if writing */ return EPERM; if (lkm_state != LKMS_LOADING) { #ifdef DEBUG if (lkmdebug & LKMDB_INFO) printf("lkm_state is %02x\n", lkm_state); #endif /* DEBUG */ return ENXIO; } if (curp->size - curp->offset > 0) /* The remainder must be bss, so we clear it */ memset((caddr_t)curp->area + curp->offset, 0, curp->size - curp->offset); curp->entry = (int (*) __P((struct lkm_table *, int, int))) (*((long *) (data))); /* call entry(load)... (assigns "private" portion) */ error = (*(curp->entry))(curp, LKM_E_LOAD, curp->ver); if (error) { /* * Module may refuse loading or may have a * version mismatch... */ lkm_state = LKMS_UNLOADING; /* for lkmunreserve */ lkmunreserve(); /* free memory */ curp->used = 0; /* free slot */ #ifdef DEBUG if (lkmdebug & LKMDB_INFO) printf("lkm entry point failed with error %d\n", error); #endif /* DEBUG */ break; } curp->used = 1; #ifdef DEBUG if (lkmdebug & LKMDB_INFO) printf("LKM: LMREADY\n"); #endif /* DEBUG */ #ifdef DDB if (curp->syms && curp->sym_offset >= curp->sym_size) { db_add_symbol_table((caddr_t)curp->syms, (caddr_t)curp->syms + curp->sym_symsize, curp->private.lkm_any->lkm_name, (caddr_t)curp->syms); #ifdef DEBUG if (lkmdebug & LKMDB_INFO) printf( "DDB symbols added!\n" ); #endif } #endif lkm_state = LKMS_IDLE; break; case LMUNLOAD: /* unload a module */ if (securelevel > 0) return EPERM; 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. */ error = copyinstr(unloadp->name, istr, MAXLKMNAME-1, NULL); if (error) 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) { error = EINVAL; break; } curp = &lkmods[i]; if (!curp->used) { error = ENOENT; break; } /* call entry(unload) */ if ((*(curp->entry))(curp, LKM_E_UNLOAD, curp->ver)) { error = 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, (size_t *)0); /* * 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 */ error = ENOENT; break; } } /* * Range check the value; on failure, return EINVAL */ if (i < 0 || i >= MAXLKMS) { error = EINVAL; break; } curp = &lkmods[i]; if (!curp->used) { /* Not found */ error = ENOENT; break; } if ((error = (*curp->entry)(curp, LKM_E_STAT, curp->ver))) 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, (size_t *)0); break; default: /* bad ioctl()... */ error = ENOTTY; break; } return (error); } /* * 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 sys_lkmnosys(p, v, retval) struct proc *p; void *v; register_t *retval; { return (sys_nosys(p, v, retval)); } /* * A placeholder function for load/unload/stat calls; simply returns zero. * Used where people don't want to specify a special function. */ int lkm_nofunc(lkmtp, cmd) struct lkm_table *lkmtp; int cmd; { return (0); } 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 error = 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 < SYS_MAXSYSCALL; i++) if (sysent[i].sy_call == sys_lkmnosys) break; /* found it! */ /* out of allocable slots? */ if (i == SYS_MAXSYSCALL) { error = ENFILE; break; } } else { /* assign */ if (i < 0 || i >= SYS_MAXSYSCALL) { error = EINVAL; break; } } /* save old */ memcpy(&args->lkm_oldent, &sysent[i], sizeof(struct sysent)); /* replace with new */ memcpy(&sysent[i], args->lkm_sysent, 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 */ memcpy(&sysent[i], &args->lkm_oldent, sizeof(struct sysent)); break; case LKM_E_STAT: /* no special handling... */ break; } return (error); } /* * 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; int error = 0; switch(cmd) { case LKM_E_LOAD: /* don't load twice! */ if (lkmexists(lkmtp)) return (EEXIST); /* Establish the file system. */ if ((error = vfs_attach(args->lkm_vfsops)) != 0) return (error); /* done! */ break; case LKM_E_UNLOAD: /* Disestablish the file system. */ if ((error = vfs_detach(args->lkm_vfsops)) != 0) return (error); break; case LKM_E_STAT: /* no special handling... */ break; } return (error); } /* * 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 error; switch(cmd) { case LKM_E_LOAD: /* don't load twice! */ if (lkmexists(lkmtp)) return (EEXIST); error = devsw_attach(args->lkm_devname, args->lkm_bdev, &args->lkm_bdevmaj, args->lkm_cdev, &args->lkm_cdevmaj); if (error != 0) return (error); args->lkm_offset = LKM_MAKEMAJOR(args->lkm_bdevmaj, args->lkm_cdevmaj); break; case LKM_E_UNLOAD: devsw_detach(args->lkm_bdev, args->lkm_cdev); args->lkm_bdevmaj = -1; args->lkm_cdevmaj = -1; break; case LKM_E_STAT: /* no special handling... */ break; } return (0); } #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 error = 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 (error); } #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 error = 0; switch(cmd) { case LKM_E_LOAD: /* don't load twice! */ if (lkmexists(lkmtp)) return (EEXIST); /* this would also fill in the emulation pointer in * args->lkm_execsw */ error = exec_add(args->lkm_execsw, args->lkm_emul); break; case LKM_E_UNLOAD: error = exec_remove(args->lkm_execsw); break; case LKM_E_STAT: /* no special handling... */ break; } return (error); } /* * For the loadable compat/emulation class described by the structure pointed to * by lkmtp, load/unload/stat it depending on the cmd requested. */ static int _lkm_compat(lkmtp, cmd) struct lkm_table *lkmtp; int cmd; { struct lkm_compat *args = lkmtp->private.lkm_compat; int error = 0; switch(cmd) { case LKM_E_LOAD: /* don't load twice! */ if (lkmexists(lkmtp)) return (EEXIST); error = emul_register(args->lkm_compat, 0); break; case LKM_E_UNLOAD: error = emul_unregister(args->lkm_compat->e_name); break; case LKM_E_STAT: /* no special handling... */ break; } return (error); } /* * 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 error = 0; /* default = success */ #ifdef DEBUG if (lkmdebug & LKMDB_INFO) printf( "lkmdispatch: %p %d\n", lkmtp, cmd ); #endif switch(lkmtp->private.lkm_any->lkm_type) { case LM_SYSCALL: error = _lkm_syscall(lkmtp, cmd); break; case LM_VFS: error = _lkm_vfs(lkmtp, cmd); break; case LM_DEV: error = _lkm_dev(lkmtp, cmd); break; #ifdef STREAMS case LM_STRMOD: { struct lkm_strmod *args = lkmtp->private.lkm_strmod; } break; #endif /* STREAMS */ case LM_EXEC: error = _lkm_exec(lkmtp, cmd); break; case LM_COMPAT: error = _lkm_compat(lkmtp, cmd); break; case LM_MISC: /* ignore content -- no "misc-specific" procedure */ break; default: error = ENXIO; /* unknown type */ break; } return (error); }