1 /* $NetBSD: exec_subr.c,v 1.31 2002/10/05 22:34:05 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/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: exec_subr.c,v 1.31 2002/10/05 22:34:05 chs 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; 141 142 KASSERT(cmd->ev_vp->v_flag & VTEXT); 143 144 /* 145 * map the vnode in using uvm_map. 146 */ 147 148 if (cmd->ev_len == 0) 149 return(0); 150 if (cmd->ev_offset & PAGE_MASK) 151 return(EINVAL); 152 if (cmd->ev_addr & PAGE_MASK) 153 return(EINVAL); 154 if (cmd->ev_len & PAGE_MASK) 155 return(EINVAL); 156 157 /* 158 * first, attach to the object 159 */ 160 161 uobj = uvn_attach(cmd->ev_vp, VM_PROT_READ|VM_PROT_EXECUTE); 162 if (uobj == NULL) 163 return(ENOMEM); 164 VREF(cmd->ev_vp); 165 166 /* 167 * do the map 168 */ 169 170 error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, cmd->ev_len, 171 uobj, cmd->ev_offset, 0, 172 UVM_MAPFLAG(cmd->ev_prot, VM_PROT_ALL, UVM_INH_COPY, 173 UVM_ADV_NORMAL, UVM_FLAG_COPYONW|UVM_FLAG_FIXED)); 174 if (error) { 175 uobj->pgops->pgo_detach(uobj); 176 } 177 return error; 178 } 179 180 /* 181 * vmcmd_map_readvn(): 182 * handle vmcmd which specifies that a vnode should be read from. 183 * appropriate for non-demand-paged text/data segments, i.e. impure 184 * objects (a la OMAGIC and NMAGIC). 185 */ 186 int 187 vmcmd_map_readvn(struct proc *p, struct exec_vmcmd *cmd) 188 { 189 int error; 190 long diff; 191 192 if (cmd->ev_len == 0) 193 return 0; 194 195 diff = cmd->ev_addr - trunc_page(cmd->ev_addr); 196 cmd->ev_addr -= diff; /* required by uvm_map */ 197 cmd->ev_offset -= diff; 198 cmd->ev_len += diff; 199 200 error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, 201 round_page(cmd->ev_len), NULL, UVM_UNKNOWN_OFFSET, 0, 202 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_COPY, 203 UVM_ADV_NORMAL, 204 UVM_FLAG_FIXED|UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW)); 205 206 if (error) 207 return error; 208 209 return vmcmd_readvn(p, cmd); 210 } 211 212 int 213 vmcmd_readvn(struct proc *p, struct exec_vmcmd *cmd) 214 { 215 int error; 216 217 error = vn_rdwr(UIO_READ, cmd->ev_vp, (caddr_t)cmd->ev_addr, 218 cmd->ev_len, cmd->ev_offset, UIO_USERSPACE, IO_UNIT, 219 p->p_ucred, NULL, p); 220 if (error) 221 return error; 222 223 if (cmd->ev_prot != (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE)) { 224 225 /* 226 * we had to map in the area at PROT_ALL so that vn_rdwr() 227 * could write to it. however, the caller seems to want 228 * it mapped read-only, so now we are going to have to call 229 * uvm_map_protect() to fix up the protection. ICK. 230 */ 231 232 return uvm_map_protect(&p->p_vmspace->vm_map, 233 trunc_page(cmd->ev_addr), 234 round_page(cmd->ev_addr + cmd->ev_len), 235 cmd->ev_prot, FALSE); 236 } 237 return 0; 238 } 239 240 /* 241 * vmcmd_map_zero(): 242 * handle vmcmd which specifies a zero-filled address space region. The 243 * address range must be first allocated, then protected appropriately. 244 */ 245 246 int 247 vmcmd_map_zero(struct proc *p, struct exec_vmcmd *cmd) 248 { 249 int error; 250 long diff; 251 252 diff = cmd->ev_addr - trunc_page(cmd->ev_addr); 253 cmd->ev_addr -= diff; /* required by uvm_map */ 254 cmd->ev_len += diff; 255 256 error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, 257 round_page(cmd->ev_len), NULL, UVM_UNKNOWN_OFFSET, 0, 258 UVM_MAPFLAG(cmd->ev_prot, UVM_PROT_ALL, UVM_INH_COPY, 259 UVM_ADV_NORMAL, 260 UVM_FLAG_FIXED|UVM_FLAG_COPYONW)); 261 return error; 262 } 263 264 /* 265 * exec_read_from(): 266 * 267 * Read from vnode into buffer at offset. 268 */ 269 int 270 exec_read_from(struct proc *p, struct vnode *vp, u_long off, void *buf, 271 size_t size) 272 { 273 int error; 274 size_t resid; 275 276 if ((error = vn_rdwr(UIO_READ, vp, buf, size, off, UIO_SYSSPACE, 277 0, p->p_ucred, &resid, p)) != 0) 278 return error; 279 /* 280 * See if we got all of it 281 */ 282 if (resid != 0) 283 return ENOEXEC; 284 return 0; 285 } 286 287