1 /* $NetBSD: exec_subr.c,v 1.26 2000/11/27 08:39:42 chs Exp $ */ 2 3 /* 4 * Copyright (c) 1993, 1994, 1996 Christopher G. Demetriou 5 * All rights reserved. 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 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Christopher G. Demetriou. 18 * 4. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/proc.h> 36 #include <sys/malloc.h> 37 #include <sys/vnode.h> 38 #include <sys/filedesc.h> 39 #include <sys/exec.h> 40 #include <sys/mman.h> 41 42 #include <uvm/uvm.h> 43 44 /* 45 * XXX cgd 960926: this module should collect simple statistics 46 * (calls, extends, kills). 47 */ 48 49 #ifdef DEBUG 50 /* 51 * new_vmcmd(): 52 * create a new vmcmd structure and fill in its fields based 53 * on function call arguments. make sure objects ref'd by 54 * the vmcmd are 'held'. 55 * 56 * If not debugging, this is a macro, so it's expanded inline. 57 */ 58 59 void 60 new_vmcmd(struct exec_vmcmd_set *evsp, 61 int (*proc)(struct proc * p, struct exec_vmcmd *), 62 u_long len, u_long addr, struct vnode *vp, u_long offset, 63 u_int prot, int flags) 64 { 65 struct exec_vmcmd *vcp; 66 67 if (evsp->evs_used >= evsp->evs_cnt) 68 vmcmdset_extend(evsp); 69 vcp = &evsp->evs_cmds[evsp->evs_used++]; 70 vcp->ev_proc = proc; 71 vcp->ev_len = len; 72 vcp->ev_addr = addr; 73 if ((vcp->ev_vp = vp) != NULL) 74 vref(vp); 75 vcp->ev_offset = offset; 76 vcp->ev_prot = prot; 77 vcp->ev_flags = flags; 78 } 79 #endif /* DEBUG */ 80 81 void 82 vmcmdset_extend(struct exec_vmcmd_set *evsp) 83 { 84 struct exec_vmcmd *nvcp; 85 u_int ocnt; 86 87 #ifdef DIAGNOSTIC 88 if (evsp->evs_used < evsp->evs_cnt) 89 panic("vmcmdset_extend: not necessary"); 90 #endif 91 92 /* figure out number of entries in new set */ 93 ocnt = evsp->evs_cnt; 94 evsp->evs_cnt += ocnt ? ocnt : EXEC_DEFAULT_VMCMD_SETSIZE; 95 96 /* allocate it */ 97 nvcp = malloc(evsp->evs_cnt * sizeof(struct exec_vmcmd), 98 M_EXEC, M_WAITOK); 99 100 /* free the old struct, if there was one, and record the new one */ 101 if (ocnt) { 102 memcpy(nvcp, evsp->evs_cmds, 103 (ocnt * sizeof(struct exec_vmcmd))); 104 free(evsp->evs_cmds, M_EXEC); 105 } 106 evsp->evs_cmds = nvcp; 107 } 108 109 void 110 kill_vmcmds(struct exec_vmcmd_set *evsp) 111 { 112 struct exec_vmcmd *vcp; 113 int i; 114 115 if (evsp->evs_cnt == 0) 116 return; 117 118 for (i = 0; i < evsp->evs_used; i++) { 119 vcp = &evsp->evs_cmds[i]; 120 if (vcp->ev_vp != NULLVP) 121 vrele(vcp->ev_vp); 122 } 123 evsp->evs_used = evsp->evs_cnt = 0; 124 free(evsp->evs_cmds, M_EXEC); 125 } 126 127 /* 128 * vmcmd_map_pagedvn(): 129 * handle vmcmd which specifies that a vnode should be mmap'd. 130 * appropriate for handling demand-paged text and data segments. 131 */ 132 133 int 134 vmcmd_map_pagedvn(struct proc *p, struct exec_vmcmd *cmd) 135 { 136 /* 137 * note that if you're going to map part of an process as being 138 * paged from a vnode, that vnode had damn well better be marked as 139 * VTEXT. that's handled in the routine which sets up the vmcmd to 140 * call this routine. 141 */ 142 struct uvm_object *uobj; 143 int retval; 144 145 /* 146 * map the vnode in using uvm_map. 147 */ 148 149 /* checks imported from uvm_mmap, needed? */ 150 if (cmd->ev_len == 0) 151 return(0); 152 if (cmd->ev_offset & PAGE_MASK) 153 return(EINVAL); 154 if (cmd->ev_addr & PAGE_MASK) 155 return(EINVAL); 156 if (cmd->ev_len & PAGE_MASK) 157 return(EINVAL); 158 159 /* 160 * first, attach to the object 161 */ 162 163 uobj = uvn_attach((void *) cmd->ev_vp, VM_PROT_READ|VM_PROT_EXECUTE); 164 if (uobj == NULL) 165 return(ENOMEM); 166 VREF(cmd->ev_vp); 167 168 /* 169 * do the map 170 */ 171 172 retval = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, cmd->ev_len, 173 uobj, cmd->ev_offset, 0, 174 UVM_MAPFLAG(cmd->ev_prot, VM_PROT_ALL, UVM_INH_COPY, 175 UVM_ADV_NORMAL, UVM_FLAG_COPYONW|UVM_FLAG_FIXED)); 176 177 /* 178 * check for error 179 */ 180 181 if (retval == KERN_SUCCESS) 182 return(0); 183 184 /* 185 * error: detach from object 186 */ 187 188 uobj->pgops->pgo_detach(uobj); 189 return (EINVAL); 190 } 191 192 /* 193 * vmcmd_map_readvn(): 194 * handle vmcmd which specifies that a vnode should be read from. 195 * appropriate for non-demand-paged text/data segments, i.e. impure 196 * objects (a la OMAGIC and NMAGIC). 197 */ 198 int 199 vmcmd_map_readvn(struct proc *p, struct exec_vmcmd *cmd) 200 { 201 int error; 202 long diff; 203 204 if (cmd->ev_len == 0) 205 return(KERN_SUCCESS); /* XXXCDC: should it happen? */ 206 207 diff = cmd->ev_addr - trunc_page(cmd->ev_addr); 208 cmd->ev_addr -= diff; /* required by uvm_map */ 209 cmd->ev_offset -= diff; 210 cmd->ev_len += diff; 211 212 error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, 213 round_page(cmd->ev_len), NULL, UVM_UNKNOWN_OFFSET, 0, 214 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_COPY, 215 UVM_ADV_NORMAL, 216 UVM_FLAG_FIXED|UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW)); 217 218 if (error) 219 return error; 220 221 return vmcmd_readvn(p, cmd); 222 } 223 224 int 225 vmcmd_readvn(struct proc *p, struct exec_vmcmd *cmd) 226 { 227 int error; 228 229 error = vn_rdwr(UIO_READ, cmd->ev_vp, (caddr_t)cmd->ev_addr, 230 cmd->ev_len, cmd->ev_offset, UIO_USERSPACE, IO_UNIT, 231 p->p_ucred, NULL, p); 232 if (error) 233 return error; 234 235 if (cmd->ev_prot != (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE)) { 236 /* 237 * we had to map in the area at PROT_ALL so that vn_rdwr() 238 * could write to it. however, the caller seems to want 239 * it mapped read-only, so now we are going to have to call 240 * uvm_map_protect() to fix up the protection. ICK. 241 */ 242 return(uvm_map_protect(&p->p_vmspace->vm_map, 243 trunc_page(cmd->ev_addr), 244 round_page(cmd->ev_addr + cmd->ev_len), 245 cmd->ev_prot, FALSE)); 246 } else { 247 return (KERN_SUCCESS); 248 } 249 } 250 251 /* 252 * vmcmd_map_zero(): 253 * handle vmcmd which specifies a zero-filled address space region. The 254 * address range must be first allocated, then protected appropriately. 255 */ 256 257 int 258 vmcmd_map_zero(struct proc *p, struct exec_vmcmd *cmd) 259 { 260 int error; 261 long diff; 262 263 if (cmd->ev_len == 0) 264 return(KERN_SUCCESS); /* XXXCDC: should it happen? */ 265 266 diff = cmd->ev_addr - trunc_page(cmd->ev_addr); 267 cmd->ev_addr -= diff; /* required by uvm_map */ 268 cmd->ev_len += diff; 269 270 error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, 271 round_page(cmd->ev_len), NULL, UVM_UNKNOWN_OFFSET, 0, 272 UVM_MAPFLAG(cmd->ev_prot, UVM_PROT_ALL, UVM_INH_COPY, 273 UVM_ADV_NORMAL, 274 UVM_FLAG_FIXED|UVM_FLAG_COPYONW)); 275 276 if (error) 277 return error; 278 return (KERN_SUCCESS); 279 } 280