xref: /netbsd-src/sys/kern/exec_subr.c (revision d9158b13b5dfe46201430699a3f7a235ecf28df3)
1 /*
2  * Copyright (c) 1993, 1994 Christopher G. Demetriou
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *      This product includes software developed by Christopher G. Demetriou.
16  * 4. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  *
30  *	$Id: exec_subr.c,v 1.7 1994/05/23 03:04:57 cgd Exp $
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 <vm/vm.h>
43 
44 #ifdef DEBUG
45 /*
46  * new_vmcmd():
47  *	create a new vmcmd structure and fill in its fields based
48  *	on function call arguments.  make sure objects ref'd by
49  *	the vmcmd are 'held'.
50  *
51  * If not debugging, this is a macro, so it's expanded inline.
52  */
53 
54 void
55 new_vmcmd(evsp, proc, len, addr, vp, offset, prot)
56 	struct	exec_vmcmd_set *evsp;
57 	int	(*proc) __P((struct proc * p, struct exec_vmcmd *));
58 	u_long	len;
59 	u_long	addr;
60 	struct	vnode *vp;
61 	u_long	offset;
62 	u_int	prot;
63 {
64 	struct exec_vmcmd    *vcp;
65 
66 	if (evsp->evs_used >= evsp->evs_cnt)
67 		vmcmdset_extend(evsp);
68 	vcp = &evsp->evs_cmds[evsp->evs_used++];
69 	vcp->ev_proc = proc;
70 	vcp->ev_len = len;
71 	vcp->ev_addr = addr;
72 	if ((vcp->ev_vp = vp) != NULL)
73 		vref(vp);
74 	vcp->ev_offset = offset;
75 	vcp->ev_prot = prot;
76 }
77 #endif /* DEBUG */
78 
79 void
80 vmcmdset_extend(evsp)
81 	struct	exec_vmcmd_set *evsp;
82 {
83 	struct exec_vmcmd *nvcp;
84 	u_int ocnt;
85 
86 #ifdef DIAGNOSTIC
87 	if (evsp->evs_used < evsp->evs_cnt)
88 		panic("vmcmdset_extend: not necessary");
89 #endif
90 
91 	/* figure out number of entries in new set */
92 	ocnt = evsp->evs_cnt;
93 	evsp->evs_cnt += ocnt ? ocnt : EXEC_DEFAULT_VMCMD_SETSIZE;
94 
95 	/* allocate it */
96 	MALLOC(nvcp, struct exec_vmcmd *,
97 	    (evsp->evs_cnt * sizeof(struct exec_vmcmd)), M_EXEC, M_WAITOK);
98 
99 	/* free the old struct, if there was one, and record the new one */
100 	if (ocnt) {
101 		bcopy(evsp->evs_cmds, nvcp, (ocnt * sizeof(struct exec_vmcmd)));
102 		FREE(evsp->evs_cmds, M_EXEC);
103 	}
104 	evsp->evs_cmds = nvcp;
105 }
106 
107 void
108 kill_vmcmds(evsp)
109 	struct	exec_vmcmd_set *evsp;
110 {
111 	struct exec_vmcmd *vcp;
112 	int i;
113 
114 	if (evsp->evs_cnt == 0)
115 		return;
116 
117 	for (i = 0; i < evsp->evs_used; i++) {
118 		vcp = &evsp->evs_cmds[i];
119 		if (vcp->ev_vp != NULLVP)
120 			vrele(vcp->ev_vp);
121 	}
122 	evsp->evs_used = evsp->evs_cnt = 0;
123 	FREE(evsp->evs_cmds, M_EXEC);
124 }
125 
126 /*
127  * vmcmd_map_pagedvn():
128  *	handle vmcmd which specifies that a vnode should be mmap'd.
129  *	appropriate for handling demand-paged text and data segments.
130  */
131 
132 int
133 vmcmd_map_pagedvn(p, cmd)
134 	struct proc *p;
135 	struct exec_vmcmd *cmd;
136 {
137 	/*
138 	 * note that if you're going to map part of an process as being
139 	 * paged from a vnode, that vnode had damn well better be marked as
140 	 * VTEXT.  that's handled in the routine which sets up the vmcmd to
141 	 * call this routine.
142 	 */
143 	return vm_mmap(&p->p_vmspace->vm_map, &cmd->ev_addr, cmd->ev_len,
144 	    cmd->ev_prot, VM_PROT_ALL, MAP_FIXED|MAP_COPY, (caddr_t)cmd->ev_vp,
145 	    cmd->ev_offset);
146 }
147 
148 /*
149  * vmcmd_map_readvn():
150  *	handle vmcmd which specifies that a vnode should be read from.
151  *	appropriate for non-demand-paged text/data segments, i.e. impure
152  *	objects (a la OMAGIC and NMAGIC).
153  */
154 int
155 vmcmd_map_readvn(p, cmd)
156 	struct proc *p;
157 	struct exec_vmcmd *cmd;
158 {
159 	int error;
160 
161 	error = vm_allocate(&p->p_vmspace->vm_map, &cmd->ev_addr,
162 	    cmd->ev_len, 0);
163 	if (error)
164 		return error;
165 
166 	error = vn_rdwr(UIO_READ, cmd->ev_vp, (caddr_t)cmd->ev_addr,
167 	    cmd->ev_len, cmd->ev_offset, UIO_USERSPACE, IO_UNIT|IO_NODELOCKED,
168 	    p->p_ucred, (int *)0, p);
169 	if (error)
170 		return error;
171 
172 	return vm_map_protect(&p->p_vmspace->vm_map, trunc_page(cmd->ev_addr),
173 	    round_page(cmd->ev_addr + cmd->ev_len), cmd->ev_prot, FALSE);
174 }
175 
176 /*
177  * vmcmd_map_zero():
178  *	handle vmcmd which specifies a zero-filled address space region.  The
179  *	address range must be first allocated, then protected appropriately.
180  */
181 
182 int
183 vmcmd_map_zero(p, cmd)
184 	struct proc *p;
185 	struct exec_vmcmd *cmd;
186 {
187 	int error;
188 
189 	error = vm_allocate(&p->p_vmspace->vm_map, &cmd->ev_addr,
190 	    cmd->ev_len, 0);
191 	if (error)
192 		return error;
193 
194 	return vm_map_protect(&p->p_vmspace->vm_map, trunc_page(cmd->ev_addr),
195 	    round_page(cmd->ev_addr + cmd->ev_len), cmd->ev_prot, FALSE);
196 }
197 
198 void
199 exec_closefd(p, fd)
200 	struct proc *p;
201 	int fd;
202 {
203 	if (p->p_fd->fd_lastfile == fd)
204 		p->p_fd->fd_lastfile--;
205 	if (p->p_fd->fd_freefile > fd)
206 		p->p_fd->fd_freefile = fd;
207 	closef(p->p_fd->fd_ofiles[fd], p);
208 	p->p_fd->fd_ofiles[fd] = 0;
209 }
210