xref: /netbsd-src/sys/compat/linux32/common/linux32_exec_elf32.c (revision b5677b36047b601b9addaaa494a58ceae82c2a6c)
1 /*	$NetBSD: linux32_exec_elf32.c,v 1.9 2009/03/15 15:56:50 cegger 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 1.9 2009/03/15 15:56:50 cegger 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)(struct lwp *l, struct exec_package *epp,
69 			void *eh, char *itp, vaddr_t *pos)
70 {
71 	int error;
72 
73 	if (((error = ELFNAME2(linux,signature)(l, epp, eh, itp)) != 0) &&
74 #ifdef LINUX32_GCC_SIGNATURE
75 	    ((error = ELFNAME2(linux,gcc_signature)(l, epp, eh)) != 0) &&
76 #endif
77 #ifdef LINUX32_ATEXIT_SIGNATURE
78 	    ((error = ELFNAME2(linux,atexit_signature)(l, epp, eh)) != 0) &&
79 #endif
80 #ifdef LINUX32_DEBUGLINK_SIGNATURE
81 	    ((error = ELFNAME2(linux,debuglink_signature)(l, epp, eh)) != 0) &&
82 #endif
83 	    1)
84 			return error;
85 
86 	if (itp) {
87 		if ((error = emul_find_interp(l, epp, itp)))
88 			return (error);
89 	}
90 #if 0
91 	DPRINTF(("linux32_probe: returning 0\n"));
92 #endif
93 
94 	epp->ep_flags |= EXEC_32;
95 	epp->ep_vm_minaddr = VM_MIN_ADDRESS;
96 	epp->ep_vm_maxaddr = USRSTACK32;
97 
98 	return 0;
99 }
100 
101 /* round up and down to page boundaries. */
102 #define	ELF_ROUND(a, b)		(((a) + (b) - 1) & ~((b) - 1))
103 #define	ELF_TRUNC(a, b)		((a) & ~((b) - 1))
104 
105 /*
106  * Copy arguments onto the stack in the normal way, but add some
107  * extra information in case of dynamic binding.
108  */
109 int
110 linux32_elf32_copyargs(struct lwp *l, struct exec_package *pack,
111     struct ps_strings *arginfo, char **stackp, void *argp)
112 {
113 	struct linux32_extra_stack_data *esdp, esd;
114 	struct elf_args *ap;
115 	struct vattr *vap;
116 	Elf_Ehdr *eh;
117 	Elf_Phdr *ph;
118 	Elf_Addr phdr = 0;
119 	u_long phsize;
120 	int error;
121 	int i;
122 
123 	if ((error = netbsd32_copyargs(l, pack, arginfo, stackp, argp)) != 0)
124 		return error;
125 
126 	/*
127 	 * Push extra arguments on the stack needed by dynamically
128 	 * linked binaries and static binaries as well.
129 	 */
130 	memset(&esd, 0, sizeof(esd));
131 	esdp = (struct linux32_extra_stack_data *)(*stackp);
132 	ap = (struct elf_args *)pack->ep_emul_arg;
133 	vap = pack->ep_vap;
134 	eh = (Elf_Ehdr *)pack->ep_hdr;
135 
136 	/*
137 	 * We forgot this, so we ned to reload it now. XXX keep track of it?
138 	 */
139 	if (ap == NULL) {
140 		phsize = eh->e_phnum * sizeof(Elf_Phdr);
141 		ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
142 		error = exec_read_from(l, pack->ep_vp, eh->e_phoff, ph, phsize);
143 		if (error != 0) {
144 			for (i = 0; i < eh->e_phnum; i++) {
145 				if (ph[i].p_type == PT_PHDR) {
146 					phdr = ph[i].p_vaddr;
147 					break;
148 				}
149 			}
150 		}
151 		free(ph, M_TEMP);
152 	}
153 
154 
155 	/*
156 	 * The exec_package doesn't have a proc pointer and it's not
157 	 * exactly trivial to add one since the credentials are
158 	 * changing. XXX Linux uses curlwp's credentials.
159 	 * Why can't we use them too? XXXad we do now; what's different
160 	 * about Linux's LWP creds?
161 	 */
162 
163 	i = 0;
164 	esd.ai[i].a_type = LINUX_AT_SYSINFO;
165 	esd.ai[i++].a_v = NETBSD32PTR32I(&esdp->kernel_vsyscall[0]);
166 
167 	esd.ai[i].a_type = LINUX_AT_SYSINFO_EHDR;
168 	esd.ai[i++].a_v = NETBSD32PTR32I(&esdp->elfhdr);
169 
170 	esd.ai[i].a_type = LINUX_AT_HWCAP;
171 	esd.ai[i++].a_v = LINUX32_CPUCAP;
172 
173 	esd.ai[i].a_type = AT_PAGESZ;
174 	esd.ai[i++].a_v = PAGE_SIZE;
175 
176 	esd.ai[i].a_type = LINUX_AT_CLKTCK;
177 	esd.ai[i++].a_v = hz;
178 
179 	esd.ai[i].a_type = AT_PHDR;
180 	esd.ai[i++].a_v = (ap ? ap->arg_phaddr: phdr);
181 
182 	esd.ai[i].a_type = AT_PHENT;
183 	esd.ai[i++].a_v = (ap ? ap->arg_phentsize : eh->e_phentsize);
184 
185 	esd.ai[i].a_type = AT_PHNUM;
186 	esd.ai[i++].a_v = (ap ? ap->arg_phnum : eh->e_phnum);
187 
188 	esd.ai[i].a_type = AT_BASE;
189 	esd.ai[i++].a_v = (ap ? ap->arg_interp : 0);
190 
191 	esd.ai[i].a_type = AT_FLAGS;
192 	esd.ai[i++].a_v = 0;
193 
194 	esd.ai[i].a_type = AT_ENTRY;
195 	esd.ai[i++].a_v = (ap ? ap->arg_entry : eh->e_entry);
196 
197 	esd.ai[i].a_type = LINUX_AT_EGID;
198 	esd.ai[i++].a_v = ((vap->va_mode & S_ISGID) ?
199 	    vap->va_gid : kauth_cred_getegid(l->l_cred));
200 
201 	esd.ai[i].a_type = LINUX_AT_GID;
202 	esd.ai[i++].a_v = kauth_cred_getgid(l->l_cred);
203 
204 	esd.ai[i].a_type = LINUX_AT_EUID;
205 	esd.ai[i++].a_v = ((vap->va_mode & S_ISUID) ?
206 	    vap->va_uid : kauth_cred_geteuid(l->l_cred));
207 
208 	esd.ai[i].a_type = LINUX_AT_UID;
209 	esd.ai[i++].a_v = kauth_cred_getuid(l->l_cred);
210 
211 	esd.ai[i].a_type = LINUX_AT_SECURE;
212 	esd.ai[i++].a_v = 0;
213 
214 	esd.ai[i].a_type = LINUX_AT_PLATFORM;
215 	esd.ai[i++].a_v = NETBSD32PTR32I(&esdp->hw_platform[0]);
216 
217 	esd.ai[i].a_type = AT_NULL;
218 	esd.ai[i++].a_v = 0;
219 
220 #ifdef DEBUG_LINUX
221 	if (i != LINUX32_ELF_AUX_ENTRIES) {
222 		printf("linux32_elf32_copyargs: %d Aux entries\n", i);
223 		return EINVAL;
224 	}
225 #endif
226 
227 	memcpy(esd.kernel_vsyscall, linux32_kernel_vsyscall,
228 	    sizeof(linux32_kernel_vsyscall));
229 
230 	memcpy(&esd.elfhdr, eh, sizeof(*eh));
231 
232 	strcpy(esd.hw_platform, LINUX32_PLATFORM);
233 
234 	if (ap) {
235 		free((char *)ap, M_TEMP);
236 		pack->ep_emul_arg = NULL;
237 	}
238 
239 	/*
240 	 * Copy out the ELF auxiliary table and hw platform name
241 	 */
242 	if ((error = copyout(&esd, esdp, sizeof(esd))) != 0)
243 		return error;
244 	*stackp += sizeof(esd);
245 	return 0;
246 }
247 
248