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linux32_exec_elf32.c revision 1.10
      1 /*	$NetBSD: linux32_exec_elf32.c,v 1.10 2010/04/18 23:47:52 jym 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 1.10 2010/04/18 23:47:52 jym 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/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;
     96 	epp->ep_vm_minaddr = VM_MIN_ADDRESS;
     97 	epp->ep_vm_maxaddr = USRSTACK32;
     98 
     99 	return 0;
    100 }
    101 
    102 /* round up and down to page boundaries. */
    103 #define	ELF_ROUND(a, b)		(((a) + (b) - 1) & ~((b) - 1))
    104 #define	ELF_TRUNC(a, b)		((a) & ~((b) - 1))
    105 
    106 /*
    107  * Copy arguments onto the stack in the normal way, but add some
    108  * extra information in case of dynamic binding.
    109  */
    110 int
    111 linux32_elf32_copyargs(struct lwp *l, struct exec_package *pack,
    112     struct ps_strings *arginfo, char **stackp, void *argp)
    113 {
    114 	struct linux32_extra_stack_data *esdp, esd;
    115 	struct elf_args *ap;
    116 	struct vattr *vap;
    117 	Elf_Ehdr *eh;
    118 	Elf_Phdr *ph;
    119 	Elf_Addr phdr = 0;
    120 	u_long phsize;
    121 	int error;
    122 	int i;
    123 
    124 	if ((error = netbsd32_copyargs(l, pack, arginfo, stackp, argp)) != 0)
    125 		return error;
    126 
    127 	/*
    128 	 * Push extra arguments on the stack needed by dynamically
    129 	 * linked binaries and static binaries as well.
    130 	 */
    131 	memset(&esd, 0, sizeof(esd));
    132 	esdp = (struct linux32_extra_stack_data *)(*stackp);
    133 	ap = (struct elf_args *)pack->ep_emul_arg;
    134 	vap = pack->ep_vap;
    135 	eh = (Elf_Ehdr *)pack->ep_hdr;
    136 
    137 	/*
    138 	 * We forgot this, so we ned to reload it now. XXX keep track of it?
    139 	 */
    140 	if (ap == NULL) {
    141 		phsize = eh->e_phnum * sizeof(Elf_Phdr);
    142 		ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
    143 		error = exec_read_from(l, pack->ep_vp, eh->e_phoff, ph, phsize);
    144 		if (error != 0) {
    145 			for (i = 0; i < eh->e_phnum; i++) {
    146 				if (ph[i].p_type == PT_PHDR) {
    147 					phdr = ph[i].p_vaddr;
    148 					break;
    149 				}
    150 			}
    151 		}
    152 		free(ph, M_TEMP);
    153 	}
    154 
    155 
    156 	/*
    157 	 * The exec_package doesn't have a proc pointer and it's not
    158 	 * exactly trivial to add one since the credentials are
    159 	 * changing. XXX Linux uses curlwp's credentials.
    160 	 * Why can't we use them too? XXXad we do now; what's different
    161 	 * about Linux's LWP creds?
    162 	 */
    163 
    164 	i = 0;
    165 	esd.ai[i].a_type = LINUX_AT_SYSINFO;
    166 	esd.ai[i++].a_v = NETBSD32PTR32I(&esdp->kernel_vsyscall[0]);
    167 
    168 	esd.ai[i].a_type = LINUX_AT_SYSINFO_EHDR;
    169 	esd.ai[i++].a_v = NETBSD32PTR32I(&esdp->elfhdr);
    170 
    171 	esd.ai[i].a_type = LINUX_AT_HWCAP;
    172 	esd.ai[i++].a_v = LINUX32_CPUCAP;
    173 
    174 	esd.ai[i].a_type = AT_PAGESZ;
    175 	esd.ai[i++].a_v = PAGE_SIZE;
    176 
    177 	esd.ai[i].a_type = LINUX_AT_CLKTCK;
    178 	esd.ai[i++].a_v = hz;
    179 
    180 	esd.ai[i].a_type = AT_PHDR;
    181 	esd.ai[i++].a_v = (ap ? ap->arg_phaddr: phdr);
    182 
    183 	esd.ai[i].a_type = AT_PHENT;
    184 	esd.ai[i++].a_v = (ap ? ap->arg_phentsize : eh->e_phentsize);
    185 
    186 	esd.ai[i].a_type = AT_PHNUM;
    187 	esd.ai[i++].a_v = (ap ? ap->arg_phnum : eh->e_phnum);
    188 
    189 	esd.ai[i].a_type = AT_BASE;
    190 	esd.ai[i++].a_v = (ap ? ap->arg_interp : 0);
    191 
    192 	esd.ai[i].a_type = AT_FLAGS;
    193 	esd.ai[i++].a_v = 0;
    194 
    195 	esd.ai[i].a_type = AT_ENTRY;
    196 	esd.ai[i++].a_v = (ap ? ap->arg_entry : eh->e_entry);
    197 
    198 	esd.ai[i].a_type = LINUX_AT_EGID;
    199 	esd.ai[i++].a_v = ((vap->va_mode & S_ISGID) ?
    200 	    vap->va_gid : kauth_cred_getegid(l->l_cred));
    201 
    202 	esd.ai[i].a_type = LINUX_AT_GID;
    203 	esd.ai[i++].a_v = kauth_cred_getgid(l->l_cred);
    204 
    205 	esd.ai[i].a_type = LINUX_AT_EUID;
    206 	esd.ai[i++].a_v = ((vap->va_mode & S_ISUID) ?
    207 	    vap->va_uid : kauth_cred_geteuid(l->l_cred));
    208 
    209 	esd.ai[i].a_type = LINUX_AT_UID;
    210 	esd.ai[i++].a_v = kauth_cred_getuid(l->l_cred);
    211 
    212 	esd.ai[i].a_type = LINUX_AT_SECURE;
    213 	esd.ai[i++].a_v = 0;
    214 
    215 	esd.ai[i].a_type = LINUX_AT_PLATFORM;
    216 	esd.ai[i++].a_v = NETBSD32PTR32I(&esdp->hw_platform[0]);
    217 
    218 	esd.ai[i].a_type = AT_NULL;
    219 	esd.ai[i++].a_v = 0;
    220 
    221 #ifdef DEBUG_LINUX
    222 	if (i != LINUX32_ELF_AUX_ENTRIES) {
    223 		printf("linux32_elf32_copyargs: %d Aux entries\n", i);
    224 		return EINVAL;
    225 	}
    226 #endif
    227 
    228 	memcpy(esd.kernel_vsyscall, linux32_kernel_vsyscall,
    229 	    sizeof(linux32_kernel_vsyscall));
    230 
    231 	memcpy(&esd.elfhdr, eh, sizeof(*eh));
    232 
    233 	strcpy(esd.hw_platform, LINUX32_PLATFORM);
    234 
    235 	if (ap) {
    236 		free((char *)ap, M_TEMP);
    237 		pack->ep_emul_arg = NULL;
    238 	}
    239 
    240 	/*
    241 	 * Copy out the ELF auxiliary table and hw platform name
    242 	 */
    243 	if ((error = copyout(&esd, esdp, sizeof(esd))) != 0)
    244 		return error;
    245 	*stackp += sizeof(esd);
    246 	return 0;
    247 }
    248 
    249