xref: /netbsd-src/sys/compat/linux32/common/linux32_exec_elf32.c (revision deb6f0161a9109e7de9b519dc8dfb9478668dcdd)
1 /*	$NetBSD: linux32_exec_elf32.c,v 1.19 2016/08/06 15:13:13 maxv Exp $ */
2 
3 /*-
4  * Copyright (c) 1995, 1998, 2000, 2001,2006 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, Eric Haszlakiewicz and
9  * Emmanuel Dreyfus.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: linux32_exec_elf32.c,v 1.19 2016/08/06 15:13:13 maxv Exp $");
35 
36 #define	ELFSIZE		32
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/proc.h>
41 #include <sys/vnode.h>
42 #include <sys/exec.h>
43 #include <sys/exec_elf.h>
44 #include <sys/kauth.h>
45 #include <sys/kernel.h>
46 #include <sys/resourcevar.h>
47 #include <sys/signal.h>
48 #include <sys/signalvar.h>
49 #include <sys/cprng.h>
50 
51 #include <compat/linux/common/linux_exec.h>
52 #include <compat/netbsd32/netbsd32.h>
53 #include <compat/netbsd32/netbsd32_exec.h>
54 #include <compat/linux32/common/linux32_exec.h>
55 
56 #include <machine/cpuvar.h>
57 #include <machine/frame.h>
58 
59 #ifdef DEBUG_LINUX
60 #define DPRINTF(a)      uprintf a
61 #else
62 #define DPRINTF(a)
63 #endif
64 
65 int linux32_copyinargs(struct exec_package *, struct ps_strings *,
66 			void *, size_t, const void *, const void *);
67 
68 int
69 ELFNAME2(linux32,probe)(struct lwp *l, struct exec_package *epp,
70 			void *eh, char *itp, vaddr_t *pos)
71 {
72 	int error;
73 
74 	if (((error = ELFNAME2(linux,signature)(l, epp, eh, itp)) != 0) &&
75 #ifdef LINUX32_GCC_SIGNATURE
76 	    ((error = ELFNAME2(linux,gcc_signature)(l, epp, eh)) != 0) &&
77 #endif
78 #ifdef LINUX32_ATEXIT_SIGNATURE
79 	    ((error = ELFNAME2(linux,atexit_signature)(l, epp, eh)) != 0) &&
80 #endif
81 #ifdef LINUX32_DEBUGLINK_SIGNATURE
82 	    ((error = ELFNAME2(linux,debuglink_signature)(l, epp, eh)) != 0) &&
83 #endif
84 	    1)
85 			return error;
86 
87 	if (itp) {
88 		if ((error = emul_find_interp(l, epp, itp)))
89 			return (error);
90 	}
91 #if 0
92 	DPRINTF(("linux32_probe: returning 0\n"));
93 #endif
94 
95 	epp->ep_flags |= EXEC_32 | EXEC_FORCEAUX;
96 	epp->ep_vm_minaddr = exec_vm_minaddr(VM_MIN_ADDRESS);
97 	epp->ep_vm_maxaddr = USRSTACK32;
98 
99 	return 0;
100 }
101 
102 /*
103  * Copy arguments onto the stack in the normal way, but add some
104  * extra information in case of dynamic binding.
105  */
106 int
107 linux32_elf32_copyargs(struct lwp *l, struct exec_package *pack,
108     struct ps_strings *arginfo, char **stackp, void *argp)
109 {
110 	Aux32Info ai[LINUX32_ELF_AUX_ENTRIES], *a;
111 	uint32_t randbytes[4];
112 	struct elf_args *ap;
113 	struct vattr *vap;
114 	size_t len;
115 	int error;
116 
117 	if ((error = netbsd32_copyargs(l, pack, arginfo, stackp, argp)) != 0)
118 		return error;
119 
120 	a = ai;
121 
122 	memset(ai, 0, sizeof(ai));
123 
124 	/*
125 	 * Push extra arguments on the stack needed by dynamically
126 	 * linked binaries and static binaries as well.
127 	 */
128 
129 	a->a_type = AT_PAGESZ;
130 	a->a_v = PAGE_SIZE;
131 	a++;
132 
133 	if ((ap = (struct elf_args *)pack->ep_emul_arg)) {
134 
135 		a->a_type = AT_PHDR;
136 		a->a_v = ap->arg_phaddr;
137 		a++;
138 
139 		a->a_type = AT_PHENT;
140 		a->a_v = ap->arg_phentsize;
141 		a++;
142 
143 		a->a_type = AT_PHNUM;
144 		a->a_v = ap->arg_phnum;
145 		a++;
146 
147 		a->a_type = AT_BASE;
148 		a->a_v = ap->arg_interp;
149 		a++;
150 
151 		a->a_type = AT_FLAGS;
152 		a->a_v = 0;
153 		a++;
154 
155 		a->a_type = AT_ENTRY;
156 		a->a_v = ap->arg_entry;
157 		a++;
158 
159 		exec_free_emul_arg(pack);
160 	}
161 
162 	/* Linux-specific items */
163 	a->a_type = LINUX_AT_CLKTCK;
164 	a->a_v = hz;
165 	a++;
166 
167 	vap = pack->ep_vap;
168 
169 	a->a_type = LINUX_AT_UID;
170 	a->a_v = kauth_cred_getuid(l->l_cred);
171 	a++;
172 
173 	a->a_type = LINUX_AT_EUID;
174 	a->a_v = ((vap->va_mode & S_ISUID) ?
175 	    vap->va_uid : kauth_cred_geteuid(l->l_cred));
176 	a++;
177 
178 	a->a_type = LINUX_AT_GID;
179 	a->a_v = kauth_cred_getgid(l->l_cred);
180 	a++;
181 
182 	a->a_type = LINUX_AT_EGID;
183 	a->a_v = ((vap->va_mode & S_ISGID) ?
184 	    vap->va_gid : kauth_cred_getegid(l->l_cred));
185 	a++;
186 
187 	a->a_type = LINUX_AT_SECURE;
188 	a->a_v = 0;
189 	a++;
190 
191 	a->a_type = LINUX_AT_RANDOM;
192 	a->a_v = NETBSD32PTR32I(*stackp);
193 	a++;
194 
195 #if 0
196 	/* XXX: increase LINUX32_ELF_AUX_ENTRIES if we enable those things */
197 
198 	a->a_type = LINUX_AT_SYSINFO;
199 	a->a_v = NETBSD32PTR32I(&esdp->kernel_vsyscall[0]);
200 	a++;
201 
202 	a->a_type = LINUX_AT_SYSINFO_EHDR;
203 	a->a_v = NETBSD32PTR32I(&esdp->elfhdr);
204 	a++;
205 
206 	a->a_type = LINUX_AT_HWCAP;
207 	a->a_v = LINUX32_CPUCAP;
208 	a++;
209 
210 	a->a_type = LINUX_AT_PLATFORM;
211 	a->a_v = NETBSD32PTR32I(&esdp->hw_platform[0]);
212 	a++;
213 #endif
214 
215 	a->a_type = AT_NULL;
216 	a->a_v = 0;
217 	a++;
218 
219 	randbytes[0] = cprng_strong32();
220 	randbytes[1] = cprng_strong32();
221 	randbytes[2] = cprng_strong32();
222 	randbytes[3] = cprng_strong32();
223 
224 	len = sizeof(randbytes);
225 	if ((error = copyout(randbytes, *stackp, len)) != 0)
226 		return error;
227 	*stackp += len;
228 
229 #if 0
230 	memcpy(esd.kernel_vsyscall, linux32_kernel_vsyscall,
231 	    sizeof(linux32_kernel_vsyscall));
232 
233 	memcpy(&esd.elfhdr, eh, sizeof(*eh));
234 
235 	strcpy(esd.hw_platform, LINUX32_PLATFORM);
236 
237 	/*
238 	 * Copy out the ELF auxiliary table and hw platform name
239 	 */
240 	if ((error = copyout(&esd, esdp, sizeof(esd))) != 0)
241 		return error;
242 	*stackp += sizeof(esd);
243 #endif
244 
245 	len = (a - ai) * sizeof(Aux32Info);
246 	KASSERT(len <= LINUX32_ELF_AUX_ENTRIES * sizeof(Aux32Info));
247 	if ((error = copyout(ai, *stackp, len)) != 0)
248 		return error;
249 	*stackp += len;
250 
251 	return 0;
252 }
253