linux_uselib.c revision 1.13.12.2
1 /* $NetBSD: linux_uselib.c,v 1.13.12.2 2006/12/30 20:47:38 yamt 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 1.13.12.2 2006/12/30 20:47:38 yamt 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(struct lwp *l, void *v, register_t *retval) 93 { 94 struct linux_sys_uselib_args /* { 95 syscallarg(const char *) path; 96 } */ *uap = v; 97 caddr_t sg; 98 long bsize, dsize, tsize, taddr, baddr, daddr; 99 struct nameidata ni; 100 struct vnode *vp; 101 struct exec hdr; 102 struct exec_vmcmd_set vcset; 103 int i, magic, error; 104 size_t rem; 105 106 sg = stackgap_init(l->l_proc, 0); 107 CHECK_ALT_EXIST(l, &sg, SCARG(uap, path)); 108 109 NDINIT(&ni, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), l); 110 111 if ((error = namei(&ni))) 112 return error; 113 114 vp = ni.ni_vp; 115 116 if ((error = vn_rdwr(UIO_READ, vp, (caddr_t) &hdr, LINUX_AOUT_HDR_SIZE, 117 0, UIO_SYSSPACE, IO_NODELOCKED, l->l_cred, 118 &rem, NULL))) { 119 vrele(vp); 120 return error; 121 } 122 123 if (rem != 0) { 124 vrele(vp); 125 return ENOEXEC; 126 } 127 128 if (LINUX_N_MACHTYPE(&hdr) != LINUX_MID_MACHINE) 129 return ENOEXEC; 130 131 magic = LINUX_N_MAGIC(&hdr); 132 taddr = hdr.a_entry & (~(PAGE_SIZE - 1)); 133 tsize = hdr.a_text; 134 daddr = taddr + tsize; 135 dsize = hdr.a_data + hdr.a_bss; 136 137 error = vn_marktext(vp); 138 if (error) 139 return (error); 140 141 vcset.evs_cnt = 0; 142 vcset.evs_used = 0; 143 144 NEW_VMCMD(&vcset, 145 magic == ZMAGIC ? vmcmd_map_readvn : vmcmd_map_pagedvn, 146 hdr.a_text + hdr.a_data, taddr, 147 vp, LINUX_N_TXTOFF(hdr, magic), 148 VM_PROT_READ|VM_PROT_EXECUTE|VM_PROT_WRITE); 149 150 baddr = roundup(daddr + hdr.a_data, PAGE_SIZE); 151 bsize = daddr + dsize - baddr; 152 if (bsize > 0) { 153 NEW_VMCMD(&vcset, vmcmd_map_zero, bsize, baddr, 154 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 155 } 156 157 for (i = 0; i < vcset.evs_used && !error; i++) { 158 struct exec_vmcmd *vcp; 159 160 vcp = &vcset.evs_cmds[i]; 161 error = (*vcp->ev_proc)(l, vcp); 162 } 163 164 kill_vmcmds(&vcset); 165 166 vrele(vp); 167 168 return error; 169 } 170
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