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 1.17 2007/04/30 07:18:53 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 #include <sys/sysref2.h>
  64
  65 static int exec_res_id = 0;
  66
  67 static TAILQ_HEAD(,vmresident) exec_res_list;
  68
  69 static MALLOC_DEFINE(M_EXEC_RES, "vmresident", "resident execs");
  70
  71 /* lockmgr lock for protecting the exec_res_list */
  72 static struct lock exec_list_lock;
  73
  74 static void
  75 vm_resident_init(void *__dummy)
  76 {
  77         lockinit(&exec_list_lock, "vmres", 0, 0);
  78         TAILQ_INIT(&exec_res_list);
  79 }
  80 SYSINIT(vmres, SI_BOOT1_LOCK, SI_ORDER_ANY, vm_resident_init, 0);
  81
  82 static int
  83 fill_xresident(struct vmresident *vr, struct xresident *in, struct thread *td)
  84 {
  85         struct stat st;
  86         struct vnode *vrtmp;
  87         int error = 0;
  88
  89         vrtmp = vr->vr_vnode;
  90
  91         in->res_entry_addr = vr->vr_entry_addr;
  92         in->res_id = vr->vr_id;
  93         if (vrtmp) {
  94                 char *freepath, *fullpath;
  95                 error = vn_fullpath(td->td_proc, vrtmp, &fullpath, &freepath);
  96                 if (error != 0) {
  97                         /* could not retrieve cached path, return zero'ed string */
  98                         bzero(in->res_file, MAXPATHLEN);
  99                         error = 0;
 100                 } else {
 101                         strlcpy(in->res_file, fullpath, sizeof(in->res_file));
 102                         kfree(freepath, M_TEMP);
 103                 }
 104
 105                 /* indicate that we are using the vnode */
 106                 error = vget(vrtmp, LK_EXCLUSIVE);
 107                 if (error)
 108                         goto done;
 109
 110                 /* retrieve underlying stat information and release vnode */
 111                 error = vn_stat(vrtmp, &st, td->td_proc->p_ucred);
 112                 vput(vrtmp);
 113                 if (error)
 114                         goto done;
 115
 116                 in->res_stat = st;
 117         }
 118
 119 done:
 120         if (error)
 121                 kprintf("fill_xresident, error = %d\n", error);
 122         return (error);
 123 }
 124
 125 static int
 126 sysctl_vm_resident(SYSCTL_HANDLER_ARGS)
 127 {
 128         struct vmresident *vmres;
 129         struct thread *td;
 130         int error;
 131         int count;
 132
 133         /* only super-user should call this sysctl */
 134         td = req->td;
 135         if ((suser(td)) != 0)
 136                 return EPERM;
 137
 138         error = count = 0;
 139
 140         if (exec_res_id == 0)
 141             return error;
 142
 143         /* client queried for number of resident binaries */
 144         if (!req->oldptr)
 145             return SYSCTL_OUT(req, 0, exec_res_id);
 146
 147         lockmgr(&exec_list_lock, LK_SHARED);
 148         TAILQ_FOREACH(vmres, &exec_res_list, vr_link) {
 149                 struct xresident xres;
 150                 error = fill_xresident(vmres, &xres, td);
 151                 if (error != 0)
 152                         break;
 153
 154                 error = SYSCTL_OUT(req, (void *)&xres,
 155                                 sizeof(struct xresident));
 156                 if (error != 0)
 157                         break;
 158         }
 159         lockmgr(&exec_list_lock, LK_RELEASE);
 160
 161         return (error);
 162 }
 163 SYSCTL_PROC(_vm, OID_AUTO, resident, CTLTYPE_OPAQUE|CTLFLAG_RD, 0, 0,
 164   sysctl_vm_resident, "S,xresident", "resident executables (sys/resident.h)");
 165
 166 int
 167 exec_resident_imgact(struct image_params *imgp)
 168 {
 169         struct vmresident *vmres;
 170
 171         /*
 172          * resident image activator
 173          */
 174         if ((vmres = imgp->vp->v_resident) == NULL)
 175             return(-1);
 176         exec_new_vmspace(imgp, vmres->vr_vmspace);
 177         imgp->resident = 1;
 178         imgp->interpreted = 0;
 179         imgp->proc->p_sysent = vmres->vr_sysent;
 180         imgp->entry_addr = vmres->vr_entry_addr;
 181         return(0);
 182 }
 183
 184 /*
 185  * exec_sys_register(entry)
 186  *
 187  * Register ourselves for resident execution.  Only root can do this.  This
 188  * will snapshot the vmspace and cause future exec's of the specified binary
 189  * to use the snapshot directly rather then load & relocate a new copy.
 190  */
 191 int
 192 sys_exec_sys_register(struct exec_sys_register_args *uap)
 193 {
 194     struct vmresident *vmres;
 195     struct vnode *vp;
 196     struct proc *p;
 197     int error;
 198
 199     p = curproc;
 200     if ((error = suser_cred(p->p_ucred, 0)) != 0)
 201         return(error);
 202     if ((vp = p->p_textvp) == NULL)
 203         return(ENOENT);
 204     if (vp->v_resident)
 205         return(EEXIST);
 206     vhold(vp);
 207     vmres = kmalloc(sizeof(*vmres), M_EXEC_RES, M_WAITOK);
 208     vp->v_resident = vmres;
 209     vmres->vr_vnode = vp;
 210     vmres->vr_sysent = p->p_sysent;
 211     vmres->vr_id = ++exec_res_id;
 212     vmres->vr_entry_addr = (intptr_t)uap->entry;
 213     vmres->vr_vmspace = vmspace_fork(p->p_vmspace); /* XXX order */
 214
 215     lockmgr(&exec_list_lock, LK_EXCLUSIVE);
 216     TAILQ_INSERT_TAIL(&exec_res_list, vmres, vr_link);
 217     lockmgr(&exec_list_lock, LK_RELEASE);
 218
 219     return(0);
 220 }
 221
 222 /*
 223  * exec_sys_unregister(id)
 224  *
 225  *      Unregister the specified id.  If an id of -1 is used unregister
 226  *      the registration associated with the current process.  An id of -2
 227  *      unregisters everything.
 228  */
 229 int
 230 sys_exec_sys_unregister(struct exec_sys_unregister_args *uap)
 231 {
 232     struct vmresident *vmres;
 233     struct proc *p;
 234     int error;
 235     int id;
 236     int count;
 237
 238     p = curproc;
 239     if ((error = suser_cred(p->p_ucred, 0)) != 0)
 240         return(error);
 241
 242     /*
 243      * If id is -1, unregister ourselves
 244      */
 245     if ((id = uap->id) == -1 && p->p_textvp && p->p_textvp->v_resident)
 246         id = p->p_textvp->v_resident->vr_id;
 247
 248     /*
 249      * Look for the registration
 250      */
 251     error = ENOENT;
 252     count = 0;
 253
 254     lockmgr(&exec_list_lock, LK_EXCLUSIVE);
 255 restart:
 256     TAILQ_FOREACH(vmres, &exec_res_list, vr_link) {
 257         if (id == -2 || vmres->vr_id == id) {
 258             TAILQ_REMOVE(&exec_res_list, vmres, vr_link);
 259             if (vmres->vr_vnode) {
 260                 vmres->vr_vnode->v_resident = NULL;
 261                 vdrop(vmres->vr_vnode);
 262                 vmres->vr_vnode = NULL;
 263             }
 264             if (vmres->vr_vmspace) {
 265                 sysref_put(&vmres->vr_vmspace->vm_sysref);
 266                 vmres->vr_vmspace = NULL;
 267             }
 268             kfree(vmres, M_EXEC_RES);
 269             exec_res_id--;
 270             error = 0;
 271             ++count;
 272             goto restart;
 273         }
 274     }
 275     lockmgr(&exec_list_lock, LK_RELEASE);
 276     if (error == 0)
 277         uap->sysmsg_result = count;
 278     return(error);
 279 }
 280