1 /* $NetBSD: linux_uselib.c,v 1.29 2009/08/15 23:39:35 matt 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: linux_uselib.c,v 1.29 2009/08/15 23:39:35 matt Exp $"); 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/kernel.h> 38 #include <sys/proc.h> 39 #include <sys/malloc.h> 40 #include <sys/namei.h> 41 #include <sys/vnode.h> 42 #include <sys/mount.h> 43 #include <sys/exec.h> 44 45 #include <sys/mman.h> 46 #include <sys/syscallargs.h> 47 48 #include <sys/cpu.h> 49 #include <machine/reg.h> 50 51 #ifndef EXEC_AOUT 52 /* define EXEC_AOUT to get prototype from linux_syscall.h */ 53 #define EXEC_AOUT 54 #endif 55 56 #include <compat/linux/common/linux_types.h> 57 #include <compat/linux/common/linux_signal.h> 58 #include <compat/linux/common/linux_util.h> 59 #include <compat/linux/common/linux_exec.h> 60 #include <compat/linux/common/linux_machdep.h> 61 #include <compat/linux/common/linux_ipc.h> 62 #include <compat/linux/common/linux_sem.h> 63 64 #include <compat/linux/linux_syscallargs.h> 65 #include <compat/linux/linux_syscall.h> 66 67 /* 68 * The Linux system call to load shared libraries, a.out version. The 69 * a.out shared libs are just files that are mapped onto a fixed 70 * address in the process' address space. The address is given in 71 * a_entry. Read in the header, set up some VM commands and run them. 72 * 73 * Yes, both text and data are mapped at once, so we're left with 74 * writable text for the shared libs. The Linux crt0 seemed to break 75 * sometimes when data was mapped separately. It munmapped a uselib() 76 * of ld.so by hand, which failed with shared text and data for ld.so 77 * Yuck. 78 * 79 * Because of the problem with ZMAGIC executables (text starts 80 * at 0x400 in the file, but needs to be mapped at 0), ZMAGIC 81 * shared libs are not handled very efficiently :-( 82 */ 83 84 int 85 linux_sys_uselib(struct lwp *l, const struct linux_sys_uselib_args *uap, register_t *retval) 86 { 87 /* { 88 syscallarg(const char *) path; 89 } */ 90 long bsize, dsize, tsize, taddr, baddr, daddr; 91 struct vnode *vp; 92 struct exec hdr; 93 struct exec_vmcmd_set vcset; 94 int i, magic, error; 95 size_t rem; 96 97 error = namei_simple_user(SCARG(uap, path), 98 NSM_FOLLOW_TRYEMULROOT, &vp); 99 if (error != 0) 100 return error; 101 102 if ((error = vn_rdwr(UIO_READ, vp, (void *) &hdr, LINUX_AOUT_HDR_SIZE, 103 0, UIO_SYSSPACE, IO_NODELOCKED, l->l_cred, 104 &rem, NULL))) { 105 vrele(vp); 106 return error; 107 } 108 109 if (rem != 0) { 110 vrele(vp); 111 return ENOEXEC; 112 } 113 114 if (LINUX_N_MACHTYPE(&hdr) != LINUX_MID_MACHINE) 115 return ENOEXEC; 116 117 magic = LINUX_N_MAGIC(&hdr); 118 taddr = hdr.a_entry & (~(PAGE_SIZE - 1)); 119 tsize = hdr.a_text; 120 daddr = taddr + tsize; 121 dsize = hdr.a_data + hdr.a_bss; 122 123 error = vn_marktext(vp); 124 if (error) 125 return (error); 126 127 vcset.evs_cnt = 0; 128 vcset.evs_used = 0; 129 130 NEW_VMCMD(&vcset, 131 magic == ZMAGIC ? vmcmd_map_readvn : vmcmd_map_pagedvn, 132 hdr.a_text + hdr.a_data, taddr, 133 vp, LINUX_N_TXTOFF(hdr, magic), 134 VM_PROT_READ|VM_PROT_EXECUTE|VM_PROT_WRITE); 135 136 baddr = roundup(daddr + hdr.a_data, PAGE_SIZE); 137 bsize = daddr + dsize - baddr; 138 if (bsize > 0) { 139 NEW_VMCMD(&vcset, vmcmd_map_zero, bsize, baddr, 140 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 141 } 142 143 for (i = 0; i < vcset.evs_used && !error; i++) { 144 struct exec_vmcmd *vcp; 145 146 vcp = &vcset.evs_cmds[i]; 147 error = (*vcp->ev_proc)(l, vcp); 148 } 149 150 kill_vmcmds(&vcset); 151 152 vrele(vp); 153 154 return error; 155 } 156