1 /* $NetBSD: exec_subr.c,v 1.33 2003/01/30 20:03:46 atatat 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/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: exec_subr.c,v 1.33 2003/01/30 20:03:46 atatat Exp $"); 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/proc.h> 39 #include <sys/malloc.h> 40 #include <sys/vnode.h> 41 #include <sys/filedesc.h> 42 #include <sys/exec.h> 43 #include <sys/mman.h> 44 45 #include <uvm/uvm.h> 46 47 /* 48 * XXX cgd 960926: this module should collect simple statistics 49 * (calls, extends, kills). 50 */ 51 52 #ifdef DEBUG 53 /* 54 * new_vmcmd(): 55 * create a new vmcmd structure and fill in its fields based 56 * on function call arguments. make sure objects ref'd by 57 * the vmcmd are 'held'. 58 * 59 * If not debugging, this is a macro, so it's expanded inline. 60 */ 61 62 void 63 new_vmcmd(struct exec_vmcmd_set *evsp, 64 int (*proc)(struct proc * p, struct exec_vmcmd *), 65 u_long len, u_long addr, struct vnode *vp, u_long offset, 66 u_int prot, int flags) 67 { 68 struct exec_vmcmd *vcp; 69 70 if (evsp->evs_used >= evsp->evs_cnt) 71 vmcmdset_extend(evsp); 72 vcp = &evsp->evs_cmds[evsp->evs_used++]; 73 vcp->ev_proc = proc; 74 vcp->ev_len = len; 75 vcp->ev_addr = addr; 76 if ((vcp->ev_vp = vp) != NULL) 77 vref(vp); 78 vcp->ev_offset = offset; 79 vcp->ev_prot = prot; 80 vcp->ev_flags = flags; 81 } 82 #endif /* DEBUG */ 83 84 void 85 vmcmdset_extend(struct exec_vmcmd_set *evsp) 86 { 87 struct exec_vmcmd *nvcp; 88 u_int ocnt; 89 90 #ifdef DIAGNOSTIC 91 if (evsp->evs_used < evsp->evs_cnt) 92 panic("vmcmdset_extend: not necessary"); 93 #endif 94 95 /* figure out number of entries in new set */ 96 ocnt = evsp->evs_cnt; 97 evsp->evs_cnt += ocnt ? ocnt : EXEC_DEFAULT_VMCMD_SETSIZE; 98 99 /* allocate it */ 100 nvcp = malloc(evsp->evs_cnt * sizeof(struct exec_vmcmd), 101 M_EXEC, M_WAITOK); 102 103 /* free the old struct, if there was one, and record the new one */ 104 if (ocnt) { 105 memcpy(nvcp, evsp->evs_cmds, 106 (ocnt * sizeof(struct exec_vmcmd))); 107 free(evsp->evs_cmds, M_EXEC); 108 } 109 evsp->evs_cmds = nvcp; 110 } 111 112 void 113 kill_vmcmds(struct exec_vmcmd_set *evsp) 114 { 115 struct exec_vmcmd *vcp; 116 u_int i; 117 118 if (evsp->evs_cnt == 0) 119 return; 120 121 for (i = 0; i < evsp->evs_used; i++) { 122 vcp = &evsp->evs_cmds[i]; 123 if (vcp->ev_vp != NULLVP) 124 vrele(vcp->ev_vp); 125 } 126 evsp->evs_used = evsp->evs_cnt = 0; 127 free(evsp->evs_cmds, M_EXEC); 128 } 129 130 /* 131 * vmcmd_map_pagedvn(): 132 * handle vmcmd which specifies that a vnode should be mmap'd. 133 * appropriate for handling demand-paged text and data segments. 134 */ 135 136 int 137 vmcmd_map_pagedvn(struct proc *p, struct exec_vmcmd *cmd) 138 { 139 struct uvm_object *uobj; 140 int error; 141 const int fixed = (cmd->ev_flags & VMCMD_FIXED) ? UVM_FLAG_FIXED : 0; 142 143 KASSERT(cmd->ev_vp->v_flag & VTEXT); 144 145 /* 146 * map the vnode in using uvm_map. 147 */ 148 149 if (cmd->ev_len == 0) 150 return(0); 151 if (cmd->ev_offset & PAGE_MASK) 152 return(EINVAL); 153 if (cmd->ev_addr & PAGE_MASK) 154 return(EINVAL); 155 if (cmd->ev_len & PAGE_MASK) 156 return(EINVAL); 157 158 /* 159 * first, attach to the object 160 */ 161 162 uobj = uvn_attach(cmd->ev_vp, VM_PROT_READ|VM_PROT_EXECUTE); 163 if (uobj == NULL) 164 return(ENOMEM); 165 VREF(cmd->ev_vp); 166 167 /* 168 * do the map 169 */ 170 171 error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, cmd->ev_len, 172 uobj, cmd->ev_offset, 0, 173 UVM_MAPFLAG(cmd->ev_prot, VM_PROT_ALL, UVM_INH_COPY, 174 UVM_ADV_NORMAL, UVM_FLAG_COPYONW|fixed)); 175 if (error) { 176 uobj->pgops->pgo_detach(uobj); 177 } 178 return error; 179 } 180 181 /* 182 * vmcmd_map_readvn(): 183 * handle vmcmd which specifies that a vnode should be read from. 184 * appropriate for non-demand-paged text/data segments, i.e. impure 185 * objects (a la OMAGIC and NMAGIC). 186 */ 187 int 188 vmcmd_map_readvn(struct proc *p, struct exec_vmcmd *cmd) 189 { 190 int error; 191 long diff; 192 const int fixed = (cmd->ev_flags & VMCMD_FIXED) ? UVM_FLAG_FIXED : 0; 193 194 if (cmd->ev_len == 0) 195 return 0; 196 197 diff = cmd->ev_addr - trunc_page(cmd->ev_addr); 198 cmd->ev_addr -= diff; /* required by uvm_map */ 199 cmd->ev_offset -= diff; 200 cmd->ev_len += diff; 201 202 error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, 203 round_page(cmd->ev_len), NULL, UVM_UNKNOWN_OFFSET, 0, 204 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_COPY, 205 UVM_ADV_NORMAL, 206 fixed|UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW)); 207 208 if (error) 209 return error; 210 211 return vmcmd_readvn(p, cmd); 212 } 213 214 int 215 vmcmd_readvn(struct proc *p, struct exec_vmcmd *cmd) 216 { 217 int error; 218 219 error = vn_rdwr(UIO_READ, cmd->ev_vp, (caddr_t)cmd->ev_addr, 220 cmd->ev_len, cmd->ev_offset, UIO_USERSPACE, IO_UNIT, 221 p->p_ucred, NULL, p); 222 if (error) 223 return error; 224 225 #ifdef PMAP_NEED_PROCWR 226 /* 227 * we had to write the process, make sure the pages are synched 228 * with the instruction cache. 229 */ 230 if (cmd->ev_prot & VM_PROT_EXECUTE) 231 pmap_procwr(p, cmd->ev_addr, cmd->ev_len); 232 #endif 233 234 if (cmd->ev_prot != (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE)) { 235 236 /* 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 */ 242 243 return uvm_map_protect(&p->p_vmspace->vm_map, 244 trunc_page(cmd->ev_addr), 245 round_page(cmd->ev_addr + cmd->ev_len), 246 cmd->ev_prot, FALSE); 247 } 248 return 0; 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 const int fixed = (cmd->ev_flags & VMCMD_FIXED) ? UVM_FLAG_FIXED : 0; 263 264 diff = cmd->ev_addr - trunc_page(cmd->ev_addr); 265 cmd->ev_addr -= diff; /* required by uvm_map */ 266 cmd->ev_len += diff; 267 268 error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, 269 round_page(cmd->ev_len), NULL, UVM_UNKNOWN_OFFSET, 0, 270 UVM_MAPFLAG(cmd->ev_prot, UVM_PROT_ALL, UVM_INH_COPY, 271 UVM_ADV_NORMAL, 272 fixed|UVM_FLAG_COPYONW)); 273 return error; 274 } 275 276 /* 277 * exec_read_from(): 278 * 279 * Read from vnode into buffer at offset. 280 */ 281 int 282 exec_read_from(struct proc *p, struct vnode *vp, u_long off, void *buf, 283 size_t size) 284 { 285 int error; 286 size_t resid; 287 288 if ((error = vn_rdwr(UIO_READ, vp, buf, size, off, UIO_SYSSPACE, 289 0, p->p_ucred, &resid, p)) != 0) 290 return error; 291 /* 292 * See if we got all of it 293 */ 294 if (resid != 0) 295 return ENOEXEC; 296 return 0; 297 } 298 299