sys/kern/imgact_resident.c

   1 /*
   2  * Copyright (c) 2003,2004 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $DragonFly: src/sys/kern/imgact_resident.c,v 1.8 2006/03/02 19:07:59 dillon Exp $
  35  */
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/kernel.h>
  40 #include <sys/sysproto.h>
  41 #include <sys/exec.h>
  42 #include <sys/imgact.h>
  43 #include <sys/imgact_aout.h>
  44 #include <sys/mman.h>
  45 #include <sys/proc.h>
  46 #include <sys/resourcevar.h>
  47 #include <sys/sysent.h>
  48 #include <sys/systm.h>
  49 #include <sys/stat.h>
  50 #include <sys/vnode.h>
  51 #include <sys/inflate.h>
  52 #include <sys/sysctl.h>
  53 #include <sys/lock.h>
  54 #include <sys/resident.h>
  55
  56 #include <vm/vm.h>
  57 #include <vm/vm_param.h>
  58 #include <vm/pmap.h>
  59 #include <vm/vm_map.h>
  60 #include <vm/vm_kern.h>
  61 #include <vm/vm_extern.h>
  62
  63 static int exec_res_id = 0;
  64
  65 static TAILQ_HEAD(,vmresident) exec_res_list;
  66
  67 static MALLOC_DEFINE(M_EXEC_RES, "vmresident", "resident execs");
  68
  69 /* lockmgr lock for protecting the exec_res_list */
  70 static struct lock exec_list_lock;
  71
  72 static void
  73 vm_resident_init(void *__dummy)
  74 {
  75         lockinit(&exec_list_lock, "vmres", 0, 0);
  76         TAILQ_INIT(&exec_res_list);
  77 }
  78 SYSINIT(vmres, SI_SUB_VM, SI_ORDER_ANY, vm_resident_init, 0);
  79
  80 static int
  81 fill_xresident(struct vmresident *vr, struct xresident *in, struct thread *td)
  82 {
  83         struct stat st;
  84         struct vnode *vrtmp;
  85         int error = 0;
  86
  87         vrtmp = vr->vr_vnode;
  88
  89         in->res_entry_addr = vr->vr_entry_addr;
  90         in->res_id = vr->vr_id;
  91         if (vrtmp) {
  92                 char *freepath, *fullpath;
  93                 error = vn_fullpath(td->td_proc, vrtmp, &fullpath, &freepath);
  94                 if (error != 0) {
  95                         /* could not retrieve cached path, return zero'ed string */
  96                         bzero(in->res_file, MAXPATHLEN);
  97                         error = 0;
  98                 } else {
  99                         strlcpy(in->res_file, fullpath, sizeof(in->res_file));
 100                         free(freepath, M_TEMP);
 101                 }
 102
 103                 /* indicate that we are using the vnode */
 104                 error = vget(vrtmp, LK_EXCLUSIVE, td);
 105                 if (error)
 106                         goto done;
 107
 108                 /* retrieve underlying stat information and release vnode */
 109                 error = vn_stat(vrtmp, &st, td);
 110                 vput(vrtmp);
 111                 if (error)
 112                         goto done;
 113
 114                 in->res_stat = st;
 115         }
 116
 117 done:
 118         if (error)
 119                 printf("fill_xresident, error = %d\n", error);
 120         return (error);
 121 }
 122
 123 static int
 124 sysctl_vm_resident(SYSCTL_HANDLER_ARGS)
 125 {
 126         struct vmresident *vmres;
 127         struct thread *td;
 128         int error;
 129         int count;
 130
 131         /* only super-user should call this sysctl */
 132         td = req->td;
 133         if ((suser(td)) != 0)
 134                 return EPERM;
 135
 136         error = count = 0;
 137
 138         if (exec_res_id == 0)
 139             return error;
 140
 141         /* client queried for number of resident binaries */
 142         if (!req->oldptr)
 143             return SYSCTL_OUT(req, 0, exec_res_id);
 144
 145         lockmgr(&exec_list_lock, LK_SHARED, NULL, td);
 146         TAILQ_FOREACH(vmres, &exec_res_list, vr_link) {
 147                 struct xresident xres;
 148                 error = fill_xresident(vmres, &xres, td);
 149                 if (error != 0)
 150                         break;
 151
 152                 error = SYSCTL_OUT(req, (void *)&xres,
 153                                 sizeof(struct xresident));
 154                 if (error != 0)
 155                         break;
 156         }
 157         lockmgr(&exec_list_lock, LK_RELEASE, NULL, td);
 158
 159         return (error);
 160 }
 161 SYSCTL_PROC(_vm, OID_AUTO, resident, CTLTYPE_OPAQUE|CTLFLAG_RD, 0, 0,
 162   sysctl_vm_resident, "S,xresident", "resident executables (sys/resident.h)");
 163
 164 int
 165 exec_resident_imgact(struct image_params *imgp)
 166 {
 167         struct vmresident *vmres;
 168
 169         /*
 170          * resident image activator
 171          */
 172         if ((vmres = imgp->vp->v_resident) == NULL)
 173             return(-1);
 174         exec_new_vmspace(imgp, vmres->vr_vmspace);
 175         imgp->resident = 1;
 176         imgp->interpreted = 0;
 177         imgp->proc->p_sysent = vmres->vr_sysent;
 178         imgp->entry_addr = vmres->vr_entry_addr;
 179         return(0);
 180 }
 181
 182 /*
 183  * exec_sys_register(entry)
 184  *
 185  * Register ourselves for resident execution.  Only root can do this.  This
 186  * will snapshot the vmspace and cause future exec's of the specified binary
 187  * to use the snapshot directly rather then load & relocate a new copy.
 188  */
 189 int
 190 exec_sys_register(struct exec_sys_register_args *uap)
 191 {
 192     struct vmresident *vmres;
 193     struct vnode *vp;
 194     struct proc *p;
 195     int error;
 196
 197     p = curproc;
 198     if ((error = suser(p->p_thread)) != 0)
 199         return(error);
 200     if ((vp = p->p_textvp) == NULL)
 201         return(ENOENT);
 202     if (vp->v_resident)
 203         return(EEXIST);
 204     vhold(vp);
 205     vmres = malloc(sizeof(*vmres), M_EXEC_RES, M_WAITOK);
 206     vp->v_resident = vmres;
 207     vmres->vr_vnode = vp;
 208     vmres->vr_sysent = p->p_sysent;
 209     vmres->vr_id = ++exec_res_id;
 210     vmres->vr_entry_addr = (intptr_t)uap->entry;
 211     vmres->vr_vmspace = vmspace_fork(p->p_vmspace); /* XXX order */
 212
 213     lockmgr(&exec_list_lock, LK_EXCLUSIVE, NULL, curthread);
 214     TAILQ_INSERT_TAIL(&exec_res_list, vmres, vr_link);
 215     lockmgr(&exec_list_lock, LK_RELEASE, NULL, curthread);
 216
 217     return(0);
 218 }
 219
 220 /*
 221  * exec_sys_unregister(id)
 222  *
 223  *      Unregister the specified id.  If an id of -1 is used unregister
 224  *      the registration associated with the current process.  An id of -2
 225  *      unregisters everything.
 226  */
 227 int
 228 exec_sys_unregister(struct exec_sys_unregister_args *uap)
 229 {
 230     struct vmresident *vmres;
 231     struct proc *p;
 232     int error;
 233     int id;
 234     int count;
 235
 236     p = curproc;
 237     if ((error = suser(p->p_thread)) != 0)
 238         return(error);
 239
 240     /*
 241      * If id is -1, unregister ourselves
 242      */
 243     if ((id = uap->id) == -1 && p->p_textvp && p->p_textvp->v_resident)
 244         id = p->p_textvp->v_resident->vr_id;
 245
 246     /*
 247      * Look for the registration
 248      */
 249     error = ENOENT;
 250     count = 0;
 251
 252     lockmgr(&exec_list_lock, LK_EXCLUSIVE, NULL, curthread);
 253 restart:
 254     TAILQ_FOREACH(vmres, &exec_res_list, vr_link) {
 255         if (id == -2 || vmres->vr_id == id) {
 256             TAILQ_REMOVE(&exec_res_list, vmres, vr_link);
 257             if (vmres->vr_vnode) {
 258                 vmres->vr_vnode->v_resident = NULL;
 259                 vdrop(vmres->vr_vnode);
 260                 vmres->vr_vnode = NULL;
 261             }
 262             if (vmres->vr_vmspace) {
 263                 vmspace_free(vmres->vr_vmspace);
 264                 vmres->vr_vmspace = NULL;
 265             }
 266             free(vmres, M_EXEC_RES);
 267             exec_res_id--;
 268             error = 0;
 269             ++count;
 270             goto restart;
 271         }
 272     }
 273     lockmgr(&exec_list_lock, LK_RELEASE, NULL, curthread);
 274     if (error == 0)
 275         uap->sysmsg_result = count;
 276     return(error);
 277 }
 278