/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright 2008 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ /* Copyright (c) 1988 AT&T */ /* All Rights Reserved */ #include <string.h> #include <ar.h> #include <stdlib.h> #include <sys/mman.h> #include <errno.h> #include <libelf.h> #include "decl.h" #include "member.h" #include "msg.h" #include <sys/mman.h> /* * Cook the input file. * These functions take the input file buffer and extract * the Ehdr, Phdr table, and the Shdr table. They keep track * of the buffer status as "fresh," "cooked," or "frozen." * * fresh The file buffer is in its original state and * nothing has yet referenced it. * * cooked The application asked for translated data first * and caused the library to return a pointer into * the file buffer. After this happens, all "raw" * operations must go back to the disk. * * frozen The application first did a "raw" operation that * prohibits reusing the file buffer. This effectively * freezes the buffer, and all "normal" operations must * duplicate their data. * * For archive handling, these functions conspire to align the * file buffer to the host memory format. Archive members * are guaranteed only even byte alignment, but the file uses * objects at least 4 bytes long. If an archive member is about * to be cooked and is not aligned in memory, these functions * "slide" the buffer up into the archive member header. * This sliding never occurs for frozen files. * * Some processors might not need sliding at all, if they have * no alignment constraints on memory references. This code * ignores that possibility for two reasons. First, even machines * that have no constraints usually handle aligned objects faster * than unaligned. Forcing alignment here probably leads to better * performance. Second, there's no way to test at run time whether * alignment is required or not. The safe thing is to align in * all cases. * * This sliding relies on the archive header being disposable. * Only archive members that are object files ever slide. * They're also the only ones that ever need to. Archives never * freeze to make headers disposable. Any program peculiar enough * to want a frozen archive pays the penalty. * * The library itself inspects the Ehdr and the Shdr table * from the file. Consequently, it converts the file's data * to EV_CURRENT version, not the working version. This is * transparent to the user. The library never looks at the * Phdr table; so that's kept in the working version. */ Dnode * _elf_dnode() { register Dnode *d; if ((d = (Dnode *)malloc(sizeof (Dnode))) == 0) { _elf_seterr(EMEM_DNODE, errno); return (0); } *d = _elf_dnode_init; d->db_myflags = DBF_ALLOC; return (d); } int _elf_slide(Elf * elf) { Elf *par = elf->ed_parent; size_t sz, szof; register char *dst; register char *src = elf->ed_ident; if (par == 0 || par->ed_kind != ELF_K_AR) return (0); /* * This code relies on other code to ensure * the ar_hdr is big enough to move into. */ if (elf->ed_ident[EI_CLASS] == ELFCLASS64) szof = sizeof (Elf64); else szof = sizeof (Elf32); if ((sz = (size_t)(src - (char *)elf->ed_image) % szof) == 0) return (0); dst = src - sz; elf->ed_ident -= sz; elf->ed_memoff -= sz; elf->ed_armem->m_slide = sz; if (_elf_vm(par, elf->ed_memoff, sz + elf->ed_fsz) != OK_YES) return (-1); /* * If the archive has been mmaped in, and we're going to slide it, * and it wasn't open for write in the first place, and we've never * done the mprotect() operation before, then do it now. */ if ((elf->ed_vm == 0) && ((elf->ed_myflags & EDF_WRITE) == 0) && ((elf->ed_myflags & EDF_MPROTECT) == 0)) { if (mprotect((char *)elf->ed_image, elf->ed_imagesz, PROT_READ|PROT_WRITE) == -1) { _elf_seterr(EIO_VM, errno); return (-1); } elf->ed_myflags |= EDF_MPROTECT; } if (memmove((void *)dst, (const void *)src, elf->ed_fsz) != (void *)dst) return (-1); else return (0); } Okay _elf_cook(Elf * elf) { register int inplace = 1; if (elf->ed_kind != ELF_K_ELF) return (OK_YES); if ((elf->ed_status == ES_COOKED) || ((elf->ed_myflags & EDF_READ) == 0)) return (OK_YES); /* * Here's where the unaligned archive member gets fixed. */ if (elf->ed_status == ES_FRESH && _elf_slide(elf) != 0) return (OK_NO); if (elf->ed_status == ES_FROZEN) inplace = 0; /* * This is the first time we've actually looked at the file * contents. We need to know whether or not this is an * Elf32 or Elf64 file before we can decode the header. * But it's the header that tells us which is which. * * Resolve the chicken-and-egg problem by peeking at the * 'class' byte in the ident string. */ if (elf->ed_ident[EI_CLASS] == ELFCLASS32) { if (_elf32_ehdr(elf, inplace) != 0) return (OK_NO); if (_elf32_phdr(elf, inplace) != 0) goto xehdr; if (_elf32_shdr(elf, inplace) != 0) goto xphdr; elf->ed_class = ELFCLASS32; } else if (elf->ed_ident[EI_CLASS] == ELFCLASS64) { if (_elf64_ehdr(elf, inplace) != 0) return (OK_NO); if (_elf64_phdr(elf, inplace) != 0) goto xehdr; if (_elf64_shdr(elf, inplace) != 0) goto xphdr; elf->ed_class = ELFCLASS64; } else return (OK_NO); return (OK_YES); xphdr: if (elf->ed_myflags & EDF_PHALLOC) { elf->ed_myflags &= ~EDF_PHALLOC; free(elf->ed_phdr); } elf->ed_phdr = 0; xehdr: if (elf->ed_myflags & EDF_EHALLOC) { elf->ed_myflags &= ~EDF_EHALLOC; free(elf->ed_ehdr); } elf->ed_ehdr = 0; return (OK_NO); } Okay _elf_cookscn(Elf_Scn * s) { Elf * elf = s->s_elf; if (elf->ed_class == ELFCLASS32) { return (_elf32_cookscn(s)); } else if (elf->ed_class == ELFCLASS64) { return (_elf64_cookscn(s)); } _elf_seterr(EREQ_CLASS, 0); return (OK_NO); }
