1 /* $NetBSD: linux_uselib.c,v 1.33 2014/11/09 17:48:08 maxv Exp $ */
2
3 /*-
4 * Copyright (c) 1995, 1998 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Christos Zoulas, Frank van der Linden and Eric Haszlakiewicz.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: linux_uselib.c,v 1.33 2014/11/09 17:48:08 maxv Exp $");
34
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/proc.h>
39 #include <sys/namei.h>
40 #include <sys/vnode.h>
41 #include <sys/mount.h>
42 #include <sys/exec.h>
43 #include <sys/exec_aout.h>
44
45 #include <sys/mman.h>
46 #include <sys/syscallargs.h>
47
48 #include <sys/cpu.h>
49 #include <machine/reg.h>
50
51 #include <compat/linux/common/linux_types.h>
52 #include <compat/linux/common/linux_signal.h>
53 #include <compat/linux/common/linux_util.h>
54 #include <compat/linux/common/linux_exec.h>
55 #include <compat/linux/common/linux_machdep.h>
56 #include <compat/linux/common/linux_ipc.h>
57 #include <compat/linux/common/linux_sem.h>
58
59 #ifndef EXEC_AOUT
60 /* define EXEC_AOUT to get prototype from linux_syscall.h */
61 #define EXEC_AOUT
62 #endif
63
64 #include <compat/linux/linux_syscallargs.h>
65 #include <compat/linux/linux_syscall.h>
66
67 /*
68 * The Linux system call to load shared libraries, a.out version. The
69 * a.out shared libs are just files that are mapped onto a fixed
70 * address in the process' address space. The address is given in
71 * a_entry. Read in the header, set up some VM commands and run them.
72 *
73 * Yes, both text and data are mapped at once, so we're left with
74 * writable text for the shared libs. The Linux crt0 seemed to break
75 * sometimes when data was mapped separately. It munmapped a uselib()
76 * of ld.so by hand, which failed with shared text and data for ld.so
77 * Yuck.
78 *
79 * Because of the problem with ZMAGIC executables (text starts
80 * at 0x400 in the file, but needs to be mapped at 0), ZMAGIC
81 * shared libs are not handled very efficiently :-(
82 */
83
84 int
linux_sys_uselib(struct lwp * l,const struct linux_sys_uselib_args * uap,register_t * retval)85 linux_sys_uselib(struct lwp *l, const struct linux_sys_uselib_args *uap, register_t *retval)
86 {
87 /* {
88 syscallarg(const char *) path;
89 } */
90 long bsize, dsize, tsize, taddr, baddr, daddr;
91 struct vnode *vp;
92 struct exec hdr;
93 struct exec_vmcmd_set vcset;
94 int i, magic, error;
95 size_t rem;
96
97 error = namei_simple_user(SCARG(uap, path),
98 NSM_FOLLOW_TRYEMULROOT, &vp);
99 if (error != 0)
100 return error;
101
102 if (vp->v_type != VREG) {
103 error = EINVAL;
104 goto out;
105 }
106
107 if ((error = vn_rdwr(UIO_READ, vp, (void *) &hdr, LINUX_AOUT_HDR_SIZE,
108 0, UIO_SYSSPACE, IO_NODELOCKED, l->l_cred,
109 &rem, NULL))) {
110 goto out;
111 }
112
113 if (rem != 0) {
114 error = ENOEXEC;
115 goto out;
116 }
117
118 if (LINUX_N_MACHTYPE(&hdr) != LINUX_MID_MACHINE) {
119 error = ENOEXEC;
120 goto out;
121 }
122
123 magic = LINUX_N_MAGIC(&hdr);
124 taddr = hdr.a_entry & (~(PAGE_SIZE - 1));
125 tsize = hdr.a_text;
126 daddr = taddr + tsize;
127 dsize = hdr.a_data + hdr.a_bss;
128
129 error = vn_marktext(vp);
130 if (error)
131 goto out;
132
133 vcset.evs_cnt = 0;
134 vcset.evs_used = 0;
135
136 NEW_VMCMD(&vcset,
137 magic == ZMAGIC ? vmcmd_map_readvn : vmcmd_map_pagedvn,
138 hdr.a_text + hdr.a_data, taddr,
139 vp, LINUX_N_TXTOFF(hdr, magic),
140 VM_PROT_READ|VM_PROT_EXECUTE|VM_PROT_WRITE);
141
142 baddr = roundup(daddr + hdr.a_data, PAGE_SIZE);
143 bsize = daddr + dsize - baddr;
144 if (bsize > 0) {
145 NEW_VMCMD(&vcset, vmcmd_map_zero, bsize, baddr,
146 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
147 }
148
149 for (i = 0; i < vcset.evs_used && !error; i++) {
150 struct exec_vmcmd *vcp;
151
152 vcp = &vcset.evs_cmds[i];
153 error = (*vcp->ev_proc)(l, vcp);
154 }
155
156 kill_vmcmds(&vcset);
157
158 out:
159 vrele(vp);
160 return error;
161 }
162