1 /* $NetBSD: linux_exec_powerpc.c,v 1.6 2001/11/13 02:08:45 lukem Exp $ */
2 
3 /*-
4  * Copyright (c) 2001 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Emmanuel Dreyfus.
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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *      This product includes software developed by the NetBSD
21  *      Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * From NetBSD's sys/compat/arch/alpha/linux_exec_alpha.c, with some
41  * powerpc add-ons (ifdef LINUX_SHIFT and LINUX_SP_WRAP).
42  *
43  * This code is to be common to alpha and powerpc. If it works on alpha, it
44  * should be moved to common/linux_exec_elf32.c. Beware that it needs
45  * LINUX_ELF_AUX_ENTRIES in arch/<arch>/linux_exec.h to also be moved to common
46  *
47  * Emmanuel Dreyfus <p99dreyf@criens.u-psud.fr>
48  */
49 
50 #include <sys/cdefs.h>
51 __KERNEL_RCSID(0, "$NetBSD: linux_exec_powerpc.c,v 1.6 2001/11/13 02:08:45 lukem Exp $");
52 
53 #if defined (__alpha__)
54 #define ELFSIZE 64
55 #elif defined (__powerpc__)
56 #define ELFSIZE 32
57 #else
58 #error Unified linux_elf_{32|64}copyargs not tested for this platform
59 #endif
60 
61 #include <sys/param.h>
62 #include <sys/systm.h>
63 #include <sys/kernel.h>
64 #include <sys/malloc.h>
65 #include <sys/proc.h>
66 #include <sys/exec.h>
67 #include <sys/exec_elf.h>
68 
69 #include <compat/linux/common/linux_exec.h>
70 
71 #ifdef LINUX_SP_WRAP
72 extern int linux_sp_wrap_start;
73 extern int linux_sp_wrap_end;
74 extern int linux_sp_wrap_entry;
75 #endif
76 /*
77  * Alpha and PowerPC specific linux copyargs function.
78  */
79 int
80 ELFNAME2(linux,copyargs)(pack, arginfo, stackp, argp)
81 	struct exec_package *pack;
82 	struct ps_strings *arginfo;
83 	char **stackp;
84 	void *argp;
85 {
86 	size_t len;
87 	LinuxAuxInfo ai[LINUX_ELF_AUX_ENTRIES], *a;
88 	struct elf_args *ap;
89 	struct proc *p = curproc;
90 #ifdef LINUX_SP_WRAP
91 	LinuxAuxInfo *prog_entry = NULL;
92 	char	linux_sp_wrap_code[LINUX_SP_WRAP];
93 	unsigned long*	cga;
94 #endif
95 	int error;
96 
97 #ifdef LINUX_SHIFT
98 	/*
99 	 * Seems that PowerPC Linux binaries expect argc to start on a 16 bytes
100 	 * aligned address. And we need one more 16 byte shift if it was already
101 	 * 16 bytes aligned,
102 	 */
103 	*stackp = (char *)(((unsigned long)*stackp - 1) & ~LINUX_SHIFT);
104 #endif
105 
106 	if ((error = copyargs(pack, arginfo, stackp, argp)) != 0)
107 		return error;
108 
109 #ifdef LINUX_SHIFT
110 	/*
111 	 * From Linux's arch/ppc/kernel/process.c:shove_aux_table(). GNU ld.so
112 	 * expects the ELF auxiliary table to start on a 16 bytes boundary on
113 	 * the PowerPC.
114 	 */
115 	*stackp = (char *)(((unsigned long)(*stackp) + LINUX_SHIFT)
116 	    & ~LINUX_SHIFT);
117 #endif
118 
119 	memset(ai, 0, sizeof(LinuxAuxInfo) * LINUX_ELF_AUX_ENTRIES);
120 
121 	a = ai;
122 
123 	/*
124 	 * Push extra arguments on the stack needed by dynamically
125 	 * linked binaries.
126 	 */
127 	if ((ap = (struct elf_args *)pack->ep_emul_arg)) {
128 #ifdef LINUX_SP_WRAP
129 		memset(linux_sp_wrap_code, 0, LINUX_SP_WRAP);
130 		bcopy(&linux_sp_wrap_start, linux_sp_wrap_code,
131 		    (unsigned long)(&linux_sp_wrap_end)
132 		    - (unsigned long)(&linux_sp_wrap_start));
133 		(unsigned long)cga = ((unsigned long)linux_sp_wrap_code)
134 		    + ((unsigned long)(&linux_sp_wrap_entry))
135 		    - ((unsigned long)(&linux_sp_wrap_start));
136 		(*cga) = (unsigned long)(ap->arg_entry);
137 #endif
138 #if 1
139 		/*
140 		 * The exec_package doesn't have a proc pointer and it's not
141 		 * exactly trivial to add one since the credentials are
142 		 * changing. XXX Linux uses curproc's credentials.
143 		 * Why can't we use them too?
144 		 */
145 		a->a_type = LINUX_AT_EGID;
146 		a->a_v = p->p_ucred->cr_gid;
147 		a++;
148 
149 		a->a_type = LINUX_AT_GID;
150 		a->a_v = p->p_cred->p_rgid;
151 		a++;
152 
153 		a->a_type = LINUX_AT_EUID;
154 		a->a_v = p->p_ucred->cr_uid;
155 		a++;
156 
157 		a->a_type = LINUX_AT_UID;
158 		a->a_v = p->p_cred->p_ruid;
159 		a++;
160 #endif
161 
162 		a->a_type = AT_ENTRY;
163 		a->a_v = ap->arg_entry;
164 #ifdef LINUX_SP_WRAP
165 		prog_entry = a;
166 #endif
167 		a++;
168 
169 		a->a_type = AT_FLAGS;
170 		a->a_v = 0;
171 		a++;
172 
173 		a->a_type = AT_BASE;
174 		a->a_v = ap->arg_interp;
175 		a++;
176 
177 		a->a_type = AT_PHNUM;
178 		a->a_v = ap->arg_phnum;
179 		a++;
180 
181 		a->a_type = AT_PHENT;
182 		a->a_v = ap->arg_phentsize;
183 		a++;
184 
185 		a->a_type = AT_PHDR;
186 		a->a_v = ap->arg_phaddr;
187 		a++;
188 
189 		a->a_type = LINUX_AT_CLKTCK;
190 		a->a_v = LINUX_CLOCKS_PER_SEC;
191 		a++;
192 
193 		a->a_type = AT_PAGESZ;
194 		a->a_v = NBPG;
195 		a++;
196 
197 		a->a_type = LINUX_AT_HWCAP;
198 		a->a_v = LINUX_ELF_HWCAP;
199 		a++;
200 
201 		free((char *)ap, M_TEMP);
202 		pack->ep_emul_arg = NULL;
203 	}
204 
205 	a->a_type = AT_NULL;
206 	a->a_v = 0;
207 	a++;
208 
209 	len = (a - ai) * sizeof(LinuxAuxInfo);
210 
211 #ifdef LINUX_SP_WRAP
212 	if (prog_entry != NULL)
213 		prog_entry->a_v = (unsigned long)(*stackp) + len;
214 #endif
215 
216 	if ((error = copyout(ai, *stackp, len)) != 0)
217 		return error;
218 	*stackp += len;
219 
220 #ifdef LINUX_SP_WRAP
221 	if (prog_entry != NULL) {
222 		if ((error = copyout(linux_sp_wrap_code, *stackp,
223 		    LINUX_SP_WRAP)) != 0)
224 			return error;
225 		*stackp += LINUX_SP_WRAP;
226 	}
227 #endif
228 
229 	return 0;
230 }
231