xref: /netbsd-src/sys/compat/linux32/common/linux32_exec_elf32.c (revision 56a34939419542e88b386b2229be7565f4f45461)
1 /*	$NetBSD: linux32_exec_elf32.c,v 1.8 2008/04/28 20:23:44 martin 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 1.8 2008/04/28 20:23:44 martin 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/malloc.h>
42 #include <sys/vnode.h>
43 #include <sys/exec.h>
44 #include <sys/exec_elf.h>
45 #include <sys/kauth.h>
46 #include <sys/kernel.h>
47 #include <sys/resourcevar.h>
48 #include <sys/signal.h>
49 #include <sys/signalvar.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/frame.h>
57 
58 #ifdef DEBUG_LINUX
59 #define DPRINTF(a)      uprintf a
60 #else
61 #define DPRINTF(a)
62 #endif
63 
64 int linux32_copyinargs(struct exec_package *, struct ps_strings *,
65 			void *, size_t, const void *, const void *);
66 
67 int
68 ELFNAME2(linux32,probe)(l, epp, eh, itp, pos)
69 	struct lwp *l;
70 	struct exec_package *epp;
71 	void *eh;
72 	char *itp;
73 	vaddr_t *pos;
74 {
75 	int error;
76 
77 	if (((error = ELFNAME2(linux,signature)(l, epp, eh, itp)) != 0) &&
78 #ifdef LINUX32_GCC_SIGNATURE
79 	    ((error = ELFNAME2(linux,gcc_signature)(l, epp, eh)) != 0) &&
80 #endif
81 #ifdef LINUX32_ATEXIT_SIGNATURE
82 	    ((error = ELFNAME2(linux,atexit_signature)(l, epp, eh)) != 0) &&
83 #endif
84 #ifdef LINUX32_DEBUGLINK_SIGNATURE
85 	    ((error = ELFNAME2(linux,debuglink_signature)(l, epp, eh)) != 0) &&
86 #endif
87 	    1)
88 			return error;
89 
90 	if (itp) {
91 		if ((error = emul_find_interp(l, epp, itp)))
92 			return (error);
93 	}
94 #if 0
95 	DPRINTF(("linux32_probe: returning 0\n"));
96 #endif
97 
98 	epp->ep_flags |= EXEC_32;
99 	epp->ep_vm_minaddr = VM_MIN_ADDRESS;
100 	epp->ep_vm_maxaddr = USRSTACK32;
101 
102 	return 0;
103 }
104 
105 /* round up and down to page boundaries. */
106 #define	ELF_ROUND(a, b)		(((a) + (b) - 1) & ~((b) - 1))
107 #define	ELF_TRUNC(a, b)		((a) & ~((b) - 1))
108 
109 /*
110  * Copy arguments onto the stack in the normal way, but add some
111  * extra information in case of dynamic binding.
112  */
113 int
114 linux32_elf32_copyargs(struct lwp *l, struct exec_package *pack,
115     struct ps_strings *arginfo, char **stackp, void *argp)
116 {
117 	struct linux32_extra_stack_data *esdp, esd;
118 	struct elf_args *ap;
119 	struct vattr *vap;
120 	Elf_Ehdr *eh;
121 	Elf_Phdr *ph;
122 	Elf_Addr phdr = 0;
123 	u_long phsize;
124 	int error;
125 	int i;
126 
127 	if ((error = netbsd32_copyargs(l, pack, arginfo, stackp, argp)) != 0)
128 		return error;
129 
130 	/*
131 	 * Push extra arguments on the stack needed by dynamically
132 	 * linked binaries and static binaries as well.
133 	 */
134 	memset(&esd, 0, sizeof(esd));
135 	esdp = (struct linux32_extra_stack_data *)(*stackp);
136 	ap = (struct elf_args *)pack->ep_emul_arg;
137 	vap = pack->ep_vap;
138 	eh = (Elf_Ehdr *)pack->ep_hdr;
139 
140 	/*
141 	 * We forgot this, so we ned to reload it now. XXX keep track of it?
142 	 */
143 	if (ap == NULL) {
144 		phsize = eh->e_phnum * sizeof(Elf_Phdr);
145 		ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
146 		error = exec_read_from(l, pack->ep_vp, eh->e_phoff, ph, phsize);
147 		if (error != 0) {
148 			for (i = 0; i < eh->e_phnum; i++) {
149 				if (ph[i].p_type == PT_PHDR) {
150 					phdr = ph[i].p_vaddr;
151 					break;
152 				}
153 			}
154 		}
155 		free(ph, M_TEMP);
156 	}
157 
158 
159 	/*
160 	 * The exec_package doesn't have a proc pointer and it's not
161 	 * exactly trivial to add one since the credentials are
162 	 * changing. XXX Linux uses curlwp's credentials.
163 	 * Why can't we use them too? XXXad we do now; what's different
164 	 * about Linux's LWP creds?
165 	 */
166 
167 	i = 0;
168 	esd.ai[i].a_type = LINUX_AT_SYSINFO;
169 	esd.ai[i++].a_v = NETBSD32PTR32I(&esdp->kernel_vsyscall[0]);
170 
171 	esd.ai[i].a_type = LINUX_AT_SYSINFO_EHDR;
172 	esd.ai[i++].a_v = NETBSD32PTR32I(&esdp->elfhdr);
173 
174 	esd.ai[i].a_type = LINUX_AT_HWCAP;
175 	esd.ai[i++].a_v = LINUX32_CPUCAP;
176 
177 	esd.ai[i].a_type = AT_PAGESZ;
178 	esd.ai[i++].a_v = PAGE_SIZE;
179 
180 	esd.ai[i].a_type = LINUX_AT_CLKTCK;
181 	esd.ai[i++].a_v = hz;
182 
183 	esd.ai[i].a_type = AT_PHDR;
184 	esd.ai[i++].a_v = (ap ? ap->arg_phaddr: phdr);
185 
186 	esd.ai[i].a_type = AT_PHENT;
187 	esd.ai[i++].a_v = (ap ? ap->arg_phentsize : eh->e_phentsize);
188 
189 	esd.ai[i].a_type = AT_PHNUM;
190 	esd.ai[i++].a_v = (ap ? ap->arg_phnum : eh->e_phnum);
191 
192 	esd.ai[i].a_type = AT_BASE;
193 	esd.ai[i++].a_v = (ap ? ap->arg_interp : 0);
194 
195 	esd.ai[i].a_type = AT_FLAGS;
196 	esd.ai[i++].a_v = 0;
197 
198 	esd.ai[i].a_type = AT_ENTRY;
199 	esd.ai[i++].a_v = (ap ? ap->arg_entry : eh->e_entry);
200 
201 	esd.ai[i].a_type = LINUX_AT_EGID;
202 	esd.ai[i++].a_v = ((vap->va_mode & S_ISGID) ?
203 	    vap->va_gid : kauth_cred_getegid(l->l_cred));
204 
205 	esd.ai[i].a_type = LINUX_AT_GID;
206 	esd.ai[i++].a_v = kauth_cred_getgid(l->l_cred);
207 
208 	esd.ai[i].a_type = LINUX_AT_EUID;
209 	esd.ai[i++].a_v = ((vap->va_mode & S_ISUID) ?
210 	    vap->va_uid : kauth_cred_geteuid(l->l_cred));
211 
212 	esd.ai[i].a_type = LINUX_AT_UID;
213 	esd.ai[i++].a_v = kauth_cred_getuid(l->l_cred);
214 
215 	esd.ai[i].a_type = LINUX_AT_SECURE;
216 	esd.ai[i++].a_v = 0;
217 
218 	esd.ai[i].a_type = LINUX_AT_PLATFORM;
219 	esd.ai[i++].a_v = NETBSD32PTR32I(&esdp->hw_platform[0]);
220 
221 	esd.ai[i].a_type = AT_NULL;
222 	esd.ai[i++].a_v = 0;
223 
224 #ifdef DEBUG_LINUX
225 	if (i != LINUX32_ELF_AUX_ENTRIES) {
226 		printf("linux32_elf32_copyargs: %d Aux entries\n", i);
227 		return EINVAL;
228 	}
229 #endif
230 
231 	memcpy(esd.kernel_vsyscall, linux32_kernel_vsyscall,
232 	    sizeof(linux32_kernel_vsyscall));
233 
234 	memcpy(&esd.elfhdr, eh, sizeof(*eh));
235 
236 	strcpy(esd.hw_platform, LINUX32_PLATFORM);
237 
238 	if (ap) {
239 		free((char *)ap, M_TEMP);
240 		pack->ep_emul_arg = NULL;
241 	}
242 
243 	/*
244 	 * Copy out the ELF auxiliary table and hw platform name
245 	 */
246 	if ((error = copyout(&esd, esdp, sizeof(esd))) != 0)
247 		return error;
248 	*stackp += sizeof(esd);
249 	return 0;
250 }
251 
252