xref: /netbsd-src/sys/kern/exec_subr.c (revision dc306354b0b29af51801a7632f1e95265a68cd81)
1 /*	$NetBSD: exec_subr.c,v 1.15 1998/08/04 04:03:11 perry 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 "opt_uvm.h"
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/proc.h>
38 #include <sys/malloc.h>
39 #include <sys/vnode.h>
40 #include <sys/filedesc.h>
41 #include <sys/exec.h>
42 #include <sys/mman.h>
43 
44 #include <vm/vm.h>
45 
46 #if defined(UVM)
47 #include <uvm/uvm.h>
48 #endif
49 
50 /*
51  * XXX cgd 960926: this module should collect simple statistics
52  * (calls, extends, kills).
53  */
54 
55 #ifdef DEBUG
56 /*
57  * new_vmcmd():
58  *	create a new vmcmd structure and fill in its fields based
59  *	on function call arguments.  make sure objects ref'd by
60  *	the vmcmd are 'held'.
61  *
62  * If not debugging, this is a macro, so it's expanded inline.
63  */
64 
65 void
66 new_vmcmd(evsp, proc, len, addr, vp, offset, prot)
67 	struct	exec_vmcmd_set *evsp;
68 	int	(*proc) __P((struct proc * p, struct exec_vmcmd *));
69 	u_long	len;
70 	u_long	addr;
71 	struct	vnode *vp;
72 	u_long	offset;
73 	u_int	prot;
74 {
75 	struct exec_vmcmd    *vcp;
76 
77 	if (evsp->evs_used >= evsp->evs_cnt)
78 		vmcmdset_extend(evsp);
79 	vcp = &evsp->evs_cmds[evsp->evs_used++];
80 	vcp->ev_proc = proc;
81 	vcp->ev_len = len;
82 	vcp->ev_addr = addr;
83 	if ((vcp->ev_vp = vp) != NULL)
84 		vref(vp);
85 	vcp->ev_offset = offset;
86 	vcp->ev_prot = prot;
87 }
88 #endif /* DEBUG */
89 
90 void
91 vmcmdset_extend(evsp)
92 	struct	exec_vmcmd_set *evsp;
93 {
94 	struct exec_vmcmd *nvcp;
95 	u_int ocnt;
96 
97 #ifdef DIAGNOSTIC
98 	if (evsp->evs_used < evsp->evs_cnt)
99 		panic("vmcmdset_extend: not necessary");
100 #endif
101 
102 	/* figure out number of entries in new set */
103 	ocnt = evsp->evs_cnt;
104 	evsp->evs_cnt += ocnt ? ocnt : EXEC_DEFAULT_VMCMD_SETSIZE;
105 
106 	/* allocate it */
107 	MALLOC(nvcp, struct exec_vmcmd *,
108 	    (evsp->evs_cnt * sizeof(struct exec_vmcmd)), M_EXEC, M_WAITOK);
109 
110 	/* free the old struct, if there was one, and record the new one */
111 	if (ocnt) {
112 		memcpy(nvcp, evsp->evs_cmds, (ocnt * sizeof(struct exec_vmcmd)));
113 		FREE(evsp->evs_cmds, M_EXEC);
114 	}
115 	evsp->evs_cmds = nvcp;
116 }
117 
118 void
119 kill_vmcmds(evsp)
120 	struct	exec_vmcmd_set *evsp;
121 {
122 	struct exec_vmcmd *vcp;
123 	int i;
124 
125 	if (evsp->evs_cnt == 0)
126 		return;
127 
128 	for (i = 0; i < evsp->evs_used; i++) {
129 		vcp = &evsp->evs_cmds[i];
130 		if (vcp->ev_vp != NULLVP)
131 			vrele(vcp->ev_vp);
132 	}
133 	evsp->evs_used = evsp->evs_cnt = 0;
134 	FREE(evsp->evs_cmds, M_EXEC);
135 }
136 
137 /*
138  * vmcmd_map_pagedvn():
139  *	handle vmcmd which specifies that a vnode should be mmap'd.
140  *	appropriate for handling demand-paged text and data segments.
141  */
142 
143 int
144 vmcmd_map_pagedvn(p, cmd)
145 	struct proc *p;
146 	struct exec_vmcmd *cmd;
147 {
148 	/*
149 	 * note that if you're going to map part of an process as being
150 	 * paged from a vnode, that vnode had damn well better be marked as
151 	 * VTEXT.  that's handled in the routine which sets up the vmcmd to
152 	 * call this routine.
153 	 */
154 #if defined(UVM)
155         struct uvm_object *uobj;
156 	int retval;
157 
158 	/*
159 	 * map the vnode in using uvm_map.
160 	 */
161 
162 	/* checks imported from uvm_mmap, needed? */
163         if (cmd->ev_len == 0)
164                 return(0);
165         if (cmd->ev_offset & PAGE_MASK)
166                 return(EINVAL);
167 	if (cmd->ev_addr & PAGE_MASK)
168 		return(EINVAL);
169 
170 	/*
171 	 * first, attach to the object
172 	 */
173 
174         uobj = uvn_attach((void *) cmd->ev_vp, VM_PROT_READ|VM_PROT_EXECUTE);
175         if (uobj == NULL)
176                 return(ENOMEM);
177 
178 	/*
179 	 * do the map
180 	 */
181 
182 	retval = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, cmd->ev_len,
183 		uobj, cmd->ev_offset,
184 		UVM_MAPFLAG(cmd->ev_prot, VM_PROT_ALL, UVM_INH_COPY,
185 			UVM_ADV_NORMAL, UVM_FLAG_COPYONW|UVM_FLAG_FIXED));
186 
187 	/*
188 	 * check for error
189 	 */
190 
191 	if (retval == KERN_SUCCESS)
192 		return(0);
193 
194 	/*
195 	 * error: detach from object
196 	 */
197 
198 	uobj->pgops->pgo_detach(uobj);
199 	return(EINVAL);
200 
201 #else
202 	return vm_mmap(&p->p_vmspace->vm_map, &cmd->ev_addr, cmd->ev_len,
203 	    cmd->ev_prot, VM_PROT_ALL, MAP_FIXED|MAP_COPY, (caddr_t)cmd->ev_vp,
204 	    cmd->ev_offset);
205 #endif
206 }
207 
208 /*
209  * vmcmd_map_readvn():
210  *	handle vmcmd which specifies that a vnode should be read from.
211  *	appropriate for non-demand-paged text/data segments, i.e. impure
212  *	objects (a la OMAGIC and NMAGIC).
213  */
214 int
215 vmcmd_map_readvn(p, cmd)
216 	struct proc *p;
217 	struct exec_vmcmd *cmd;
218 {
219 	int error;
220 
221 #if defined(UVM)
222 	if (cmd->ev_len == 0)
223 		return(KERN_SUCCESS); /* XXXCDC: should it happen? */
224 
225 	cmd->ev_addr = trunc_page(cmd->ev_addr); /* required by uvm_map */
226 	error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr,
227 			round_page(cmd->ev_len), NULL, UVM_UNKNOWN_OFFSET,
228 			UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_COPY,
229 			UVM_ADV_NORMAL,
230 			UVM_FLAG_FIXED|UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW));
231 
232 #else
233 	error = vm_allocate(&p->p_vmspace->vm_map, &cmd->ev_addr,
234 	    cmd->ev_len, 0);
235 #endif
236 	if (error)
237 		return error;
238 
239 	error = vn_rdwr(UIO_READ, cmd->ev_vp, (caddr_t)cmd->ev_addr,
240 	    cmd->ev_len, cmd->ev_offset, UIO_USERSPACE, IO_UNIT,
241 	    p->p_ucred, NULL, p);
242 	if (error)
243 		return error;
244 
245 #if defined(UVM)
246 	if (cmd->ev_prot != (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE)) {
247 		/*
248 		 * we had to map in the area at PROT_ALL so that vn_rdwr()
249 		 * could write to it.   however, the caller seems to want
250 		 * it mapped read-only, so now we are going to have to call
251 		 * uvm_map_protect() to fix up the protection.  ICK.
252 		 */
253 		return(uvm_map_protect(&p->p_vmspace->vm_map,
254 				trunc_page(cmd->ev_addr),
255 				round_page(cmd->ev_addr + cmd->ev_len),
256 				cmd->ev_prot, FALSE));
257 	} else {
258 		return(KERN_SUCCESS);
259 	}
260 #else
261 	return vm_map_protect(&p->p_vmspace->vm_map, trunc_page(cmd->ev_addr),
262 	    round_page(cmd->ev_addr + cmd->ev_len), cmd->ev_prot, FALSE);
263 #endif
264 }
265 
266 /*
267  * vmcmd_map_zero():
268  *	handle vmcmd which specifies a zero-filled address space region.  The
269  *	address range must be first allocated, then protected appropriately.
270  */
271 
272 int
273 vmcmd_map_zero(p, cmd)
274 	struct proc *p;
275 	struct exec_vmcmd *cmd;
276 {
277 	int error;
278 
279 #if defined(UVM)
280 	if (cmd->ev_len == 0)
281 		return(KERN_SUCCESS); /* XXXCDC: should it happen? */
282 
283 	cmd->ev_addr = trunc_page(cmd->ev_addr); /* required by uvm_map */
284 	error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr,
285 			round_page(cmd->ev_len), NULL, UVM_UNKNOWN_OFFSET,
286 			UVM_MAPFLAG(cmd->ev_prot, UVM_PROT_ALL, UVM_INH_COPY,
287 			UVM_ADV_NORMAL,
288 			UVM_FLAG_FIXED|UVM_FLAG_COPYONW));
289 
290 #else
291 	error = vm_allocate(&p->p_vmspace->vm_map, &cmd->ev_addr,
292 	    cmd->ev_len, 0);
293 #endif
294 	if (error)
295 		return error;
296 
297 #if !defined(UVM)
298 	if (cmd->ev_prot != VM_PROT_DEFAULT)
299 		return vm_map_protect(&p->p_vmspace->vm_map,
300 			trunc_page(cmd->ev_addr),
301 	    		round_page(cmd->ev_addr + cmd->ev_len),
302 			cmd->ev_prot, FALSE);
303 #endif
304 	return(KERN_SUCCESS);
305 }
306