1 /* $NetBSD: linux_exec_powerpc.c,v 1.14 2004/06/18 17:06:15 manu 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 1.14 2004/06/18 17:06:15 manu 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 #include <sys/resourcevar.h> 69 70 #include <uvm/uvm_extern.h> 71 72 #include <compat/linux/common/linux_exec.h> 73 74 #ifdef LINUX_SP_WRAP 75 extern int linux_sp_wrap_start; 76 extern int linux_sp_wrap_end; 77 extern int linux_sp_wrap_entry; 78 #endif 79 /* 80 * Alpha and PowerPC specific linux copyargs function. 81 */ 82 int 83 ELFNAME2(linux,copyargs)(p, pack, arginfo, stackp, argp) 84 struct proc *p; 85 struct exec_package *pack; 86 struct ps_strings *arginfo; 87 char **stackp; 88 void *argp; 89 { 90 size_t len; 91 AuxInfo ai[LINUX_ELF_AUX_ENTRIES], *a; 92 struct elf_args *ap; 93 #ifdef LINUX_SP_WRAP 94 AuxInfo *prog_entry = NULL; 95 char linux_sp_wrap_code[LINUX_SP_WRAP]; 96 unsigned long* cga; 97 #endif 98 int error; 99 100 #ifdef LINUX_SHIFT 101 /* 102 * Seems that PowerPC Linux binaries expect argc to start on a 16 bytes 103 * aligned address. And we need one more 16 byte shift if it was already 104 * 16 bytes aligned, 105 */ 106 *stackp = (char *)(((unsigned long)*stackp - 1) & ~LINUX_SHIFT); 107 #endif 108 109 if ((error = copyargs(p, pack, arginfo, stackp, argp)) != 0) 110 return error; 111 112 #ifdef LINUX_SHIFT 113 /* 114 * From Linux's arch/ppc/kernel/process.c:shove_aux_table(). GNU ld.so 115 * expects the ELF auxiliary table to start on a 16 bytes boundary on 116 * the PowerPC. 117 */ 118 *stackp = (char *)(((unsigned long)(*stackp) + LINUX_SHIFT) 119 & ~LINUX_SHIFT); 120 #endif 121 122 memset(ai, 0, sizeof(AuxInfo) * LINUX_ELF_AUX_ENTRIES); 123 124 a = ai; 125 126 /* 127 * Push extra arguments on the stack needed by dynamically 128 * linked binaries. 129 */ 130 if ((ap = (struct elf_args *)pack->ep_emul_arg)) { 131 #ifdef LINUX_SP_WRAP 132 memset(linux_sp_wrap_code, 0, LINUX_SP_WRAP); 133 bcopy(&linux_sp_wrap_start, linux_sp_wrap_code, 134 (unsigned long)(&linux_sp_wrap_end) 135 - (unsigned long)(&linux_sp_wrap_start)); 136 (unsigned long)cga = ((unsigned long)linux_sp_wrap_code) 137 + ((unsigned long)(&linux_sp_wrap_entry)) 138 - ((unsigned long)(&linux_sp_wrap_start)); 139 (*cga) = (unsigned long)(ap->arg_entry); 140 #endif 141 #if 1 142 /* 143 * The exec_package doesn't have a proc pointer and it's not 144 * exactly trivial to add one since the credentials are 145 * changing. XXX Linux uses curlwp's credentials. 146 * Why can't we use them too? 147 */ 148 a->a_type = LINUX_AT_EGID; 149 a->a_v = p->p_ucred->cr_gid; 150 a++; 151 152 a->a_type = LINUX_AT_GID; 153 a->a_v = p->p_cred->p_rgid; 154 a++; 155 156 a->a_type = LINUX_AT_EUID; 157 a->a_v = p->p_ucred->cr_uid; 158 a++; 159 160 a->a_type = LINUX_AT_UID; 161 a->a_v = p->p_cred->p_ruid; 162 a++; 163 #endif 164 165 a->a_type = AT_ENTRY; 166 a->a_v = ap->arg_entry; 167 #ifdef LINUX_SP_WRAP 168 prog_entry = a; 169 #endif 170 a++; 171 172 a->a_type = AT_FLAGS; 173 a->a_v = 0; 174 a++; 175 176 a->a_type = AT_BASE; 177 a->a_v = ap->arg_interp; 178 a++; 179 180 a->a_type = AT_PHNUM; 181 a->a_v = ap->arg_phnum; 182 a++; 183 184 a->a_type = AT_PHENT; 185 a->a_v = ap->arg_phentsize; 186 a++; 187 188 a->a_type = AT_PHDR; 189 a->a_v = ap->arg_phaddr; 190 a++; 191 192 a->a_type = LINUX_AT_CLKTCK; 193 a->a_v = LINUX_CLOCKS_PER_SEC; 194 a++; 195 196 a->a_type = AT_PAGESZ; 197 a->a_v = PAGE_SIZE; 198 a++; 199 200 a->a_type = LINUX_AT_HWCAP; 201 a->a_v = LINUX_ELF_HWCAP; 202 a++; 203 204 free((char *)ap, M_TEMP); 205 pack->ep_emul_arg = NULL; 206 } 207 208 a->a_type = AT_NULL; 209 a->a_v = 0; 210 a++; 211 212 len = (a - ai) * sizeof(AuxInfo); 213 214 #ifdef LINUX_SP_WRAP 215 if (prog_entry != NULL) 216 prog_entry->a_v = (unsigned long)(*stackp) + len; 217 #endif 218 219 if ((error = copyout(ai, *stackp, len)) != 0) 220 return error; 221 *stackp += len; 222 223 #ifdef LINUX_SP_WRAP 224 if (prog_entry != NULL) { 225 if ((error = copyout(linux_sp_wrap_code, *stackp, 226 LINUX_SP_WRAP)) != 0) 227 return error; 228 *stackp += LINUX_SP_WRAP; 229 } 230 #endif 231 232 return 0; 233 } 234 235 /* 236 * This is copied from sys/kern/exec_subr.c:exec_setup_stack() 237 * We need a Linux version only to avoid the non executable 238 * mappings. They will probably break signal delivery on Linux, 239 * and they surely break the stack fixup hack. 240 */ 241 int 242 linux_exec_setup_stack(p, epp) 243 struct proc *p; 244 struct exec_package *epp; 245 { 246 u_long max_stack_size; 247 u_long access_linear_min, access_size; 248 u_long noaccess_linear_min, noaccess_size; 249 250 #ifndef USRSTACK32 251 #define USRSTACK32 (0x00000000ffffffffL&~PGOFSET) 252 #endif 253 254 if (epp->ep_flags & EXEC_32) { 255 epp->ep_minsaddr = USRSTACK32; 256 max_stack_size = MAXSSIZ; 257 } else { 258 epp->ep_minsaddr = USRSTACK; 259 max_stack_size = MAXSSIZ; 260 } 261 epp->ep_maxsaddr = (u_long)STACK_GROW(epp->ep_minsaddr, 262 max_stack_size); 263 epp->ep_ssize = p->p_rlimit[RLIMIT_STACK].rlim_cur; 264 265 /* 266 * set up commands for stack. note that this takes *two*, one to 267 * map the part of the stack which we can access, and one to map 268 * the part which we can't. 269 * 270 * arguably, it could be made into one, but that would require the 271 * addition of another mapping proc, which is unnecessary 272 */ 273 access_size = epp->ep_ssize; 274 access_linear_min = (u_long)STACK_ALLOC(epp->ep_minsaddr, access_size); 275 noaccess_size = max_stack_size - access_size; 276 noaccess_linear_min = (u_long)STACK_ALLOC(STACK_GROW(epp->ep_minsaddr, 277 access_size), noaccess_size); 278 if (noaccess_size > 0) { 279 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, noaccess_size, 280 noaccess_linear_min, NULL, 0, VM_PROT_NONE); 281 } 282 KASSERT(access_size > 0); 283 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, access_size, 284 access_linear_min, NULL, 0, 285 VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE); 286 287 return 0; 288 } 289