linux_uselib.c revision 1.16
1 /* $NetBSD: linux_uselib.c,v 1.16 2006/07/23 22:06:09 ad Exp $ */ 2 3 /*- 4 * Copyright (c) 1995, 1998 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 and Eric Haszlakiewicz. 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 #include <sys/cdefs.h> 40 __KERNEL_RCSID(0, "$NetBSD: linux_uselib.c,v 1.16 2006/07/23 22:06:09 ad Exp $"); 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/kernel.h> 45 #include <sys/proc.h> 46 #include <sys/malloc.h> 47 #include <sys/namei.h> 48 #include <sys/vnode.h> 49 #include <sys/mount.h> 50 #include <sys/exec.h> 51 #include <sys/exec_elf.h> 52 53 #include <sys/mman.h> 54 #include <sys/sa.h> 55 #include <sys/syscallargs.h> 56 57 #include <machine/cpu.h> 58 #include <machine/reg.h> 59 60 #include <compat/linux/common/linux_types.h> 61 #include <compat/linux/common/linux_signal.h> 62 #include <compat/linux/common/linux_util.h> 63 #include <compat/linux/common/linux_exec.h> 64 #include <compat/linux/common/linux_machdep.h> 65 66 #ifndef EXEC_AOUT 67 /* define EXEC_AOUT to get prototype from linux_syscall.h */ 68 #define EXEC_AOUT 69 #endif 70 71 #include <compat/linux/linux_syscallargs.h> 72 #include <compat/linux/linux_syscall.h> 73 74 /* 75 * The Linux system call to load shared libraries, a.out version. The 76 * a.out shared libs are just files that are mapped onto a fixed 77 * address in the process' address space. The address is given in 78 * a_entry. Read in the header, set up some VM commands and run them. 79 * 80 * Yes, both text and data are mapped at once, so we're left with 81 * writable text for the shared libs. The Linux crt0 seemed to break 82 * sometimes when data was mapped separately. It munmapped a uselib() 83 * of ld.so by hand, which failed with shared text and data for ld.so 84 * Yuck. 85 * 86 * Because of the problem with ZMAGIC executables (text starts 87 * at 0x400 in the file, but needs to be mapped at 0), ZMAGIC 88 * shared libs are not handled very efficiently :-( 89 */ 90 91 int 92 linux_sys_uselib(l, v, retval) 93 struct lwp *l; 94 void *v; 95 register_t *retval; 96 { 97 struct linux_sys_uselib_args /* { 98 syscallarg(const char *) path; 99 } */ *uap = v; 100 caddr_t sg; 101 long bsize, dsize, tsize, taddr, baddr, daddr; 102 struct nameidata ni; 103 struct vnode *vp; 104 struct exec hdr; 105 struct exec_vmcmd_set vcset; 106 int i, magic, error; 107 size_t rem; 108 109 sg = stackgap_init(l->l_proc, 0); 110 CHECK_ALT_EXIST(l, &sg, SCARG(uap, path)); 111 112 NDINIT(&ni, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), l); 113 114 if ((error = namei(&ni))) 115 return error; 116 117 vp = ni.ni_vp; 118 119 if ((error = vn_rdwr(UIO_READ, vp, (caddr_t) &hdr, LINUX_AOUT_HDR_SIZE, 120 0, UIO_SYSSPACE, IO_NODELOCKED, l->l_cred, 121 &rem, NULL))) { 122 vrele(vp); 123 return error; 124 } 125 126 if (rem != 0) { 127 vrele(vp); 128 return ENOEXEC; 129 } 130 131 if (LINUX_N_MACHTYPE(&hdr) != LINUX_MID_MACHINE) 132 return ENOEXEC; 133 134 magic = LINUX_N_MAGIC(&hdr); 135 taddr = hdr.a_entry & (~(PAGE_SIZE - 1)); 136 tsize = hdr.a_text; 137 daddr = taddr + tsize; 138 dsize = hdr.a_data + hdr.a_bss; 139 140 error = vn_marktext(vp); 141 if (error) 142 return (error); 143 144 vcset.evs_cnt = 0; 145 vcset.evs_used = 0; 146 147 NEW_VMCMD(&vcset, 148 magic == ZMAGIC ? vmcmd_map_readvn : vmcmd_map_pagedvn, 149 hdr.a_text + hdr.a_data, taddr, 150 vp, LINUX_N_TXTOFF(hdr, magic), 151 VM_PROT_READ|VM_PROT_EXECUTE|VM_PROT_WRITE); 152 153 baddr = roundup(daddr + hdr.a_data, PAGE_SIZE); 154 bsize = daddr + dsize - baddr; 155 if (bsize > 0) { 156 NEW_VMCMD(&vcset, vmcmd_map_zero, bsize, baddr, 157 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 158 } 159 160 for (i = 0; i < vcset.evs_used && !error; i++) { 161 struct exec_vmcmd *vcp; 162 163 vcp = &vcset.evs_cmds[i]; 164 error = (*vcp->ev_proc)(l, vcp); 165 } 166 167 kill_vmcmds(&vcset); 168 169 vrele(vp); 170 171 return error; 172 } 173
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