1 /* $NetBSD: linux_uselib.c,v 1.6 2002/03/16 20:43:54 christos 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 1.6 2002/03/16 20:43:54 christos 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/syscallargs.h> 55 56 #include <machine/cpu.h> 57 #include <machine/reg.h> 58 59 #include <compat/linux/common/linux_types.h> 60 #include <compat/linux/common/linux_signal.h> 61 #include <compat/linux/common/linux_util.h> 62 #include <compat/linux/common/linux_exec.h> 63 #include <compat/linux/common/linux_machdep.h> 64 65 #ifndef EXEC_AOUT 66 /* define EXEC_AOUT to get prototype from linux_syscall.h */ 67 #define EXEC_AOUT 68 #endif 69 70 #include <compat/linux/linux_syscallargs.h> 71 #include <compat/linux/linux_syscall.h> 72 73 /* 74 * The Linux system call to load shared libraries, a.out version. The 75 * a.out shared libs are just files that are mapped onto a fixed 76 * address in the process' address space. The address is given in 77 * a_entry. Read in the header, set up some VM commands and run them. 78 * 79 * Yes, both text and data are mapped at once, so we're left with 80 * writeable text for the shared libs. The Linux crt0 seemed to break 81 * sometimes when data was mapped separately. It munmapped a uselib() 82 * of ld.so by hand, which failed with shared text and data for ld.so 83 * Yuck. 84 * 85 * Because of the problem with ZMAGIC executables (text starts 86 * at 0x400 in the file, but needs to be mapped at 0), ZMAGIC 87 * shared libs are not handled very efficiently :-( 88 */ 89 90 int 91 linux_sys_uselib(p, v, retval) 92 struct proc *p; 93 void *v; 94 register_t *retval; 95 { 96 struct linux_sys_uselib_args /* { 97 syscallarg(const char *) path; 98 } */ *uap = v; 99 caddr_t sg; 100 long bsize, dsize, tsize, taddr, baddr, daddr; 101 struct nameidata ni; 102 struct vnode *vp; 103 struct exec hdr; 104 struct exec_vmcmd_set vcset; 105 int i, magic, error; 106 size_t rem; 107 108 sg = stackgap_init(p, 0); 109 CHECK_ALT_EXIST(p, &sg, SCARG(uap, path)); 110 111 NDINIT(&ni, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 112 113 if ((error = namei(&ni))) 114 return error; 115 116 vp = ni.ni_vp; 117 118 if ((error = vn_rdwr(UIO_READ, vp, (caddr_t) &hdr, LINUX_AOUT_HDR_SIZE, 119 0, UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, 120 &rem, p))) { 121 vrele(vp); 122 return error; 123 } 124 125 if (rem != 0) { 126 vrele(vp); 127 return ENOEXEC; 128 } 129 130 if (LINUX_N_MACHTYPE(&hdr) != LINUX_MID_MACHINE) 131 return ENOEXEC; 132 133 magic = LINUX_N_MAGIC(&hdr); 134 taddr = hdr.a_entry & (~(NBPG - 1)); 135 tsize = hdr.a_text; 136 daddr = taddr + tsize; 137 dsize = hdr.a_data + hdr.a_bss; 138 139 if ((hdr.a_text != 0 || hdr.a_data != 0) && vp->v_writecount != 0) { 140 vrele(vp); 141 return ETXTBSY; 142 } 143 vp->v_flag |= VTEXT; 144 145 vcset.evs_cnt = 0; 146 vcset.evs_used = 0; 147 148 NEW_VMCMD(&vcset, 149 magic == ZMAGIC ? vmcmd_map_readvn : vmcmd_map_pagedvn, 150 hdr.a_text + hdr.a_data, taddr, 151 vp, LINUX_N_TXTOFF(hdr, magic), 152 VM_PROT_READ|VM_PROT_EXECUTE|VM_PROT_WRITE); 153 154 baddr = roundup(daddr + hdr.a_data, NBPG); 155 bsize = daddr + dsize - baddr; 156 if (bsize > 0) { 157 NEW_VMCMD(&vcset, vmcmd_map_zero, bsize, baddr, 158 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 159 } 160 161 for (i = 0; i < vcset.evs_used && !error; i++) { 162 struct exec_vmcmd *vcp; 163 164 vcp = &vcset.evs_cmds[i]; 165 error = (*vcp->ev_proc)(p, vcp); 166 } 167 168 kill_vmcmds(&vcset); 169 170 vrele(vp); 171 172 return error; 173 } 174