usr/src/cmd/sgs/libelf/common/newphdr.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #include <stdlib.h>
  33 #include <memory.h>
  34 #include <errno.h>
  35 #include "decl.h"
  36 #include "msg.h"
  37
  38 /*
  39  * This module is compiled twice, the second time having
  40  * -D_ELF64 defined.  The following set of macros, along
  41  * with machelf.h, represent the differences between the
  42  * two compilations.  Be careful *not* to add any class-
  43  * dependent code (anything that has elf32 or elf64 in the
  44  * name) to this code without hiding it behind a switch-
  45  * able macro like these.
  46  */
  47 #if     defined(_ELF64)
  48
  49 #define ELFCLASS        ELFCLASS64
  50 #define elf_newphdr     elf64_newphdr
  51 #define elf_getehdr     elf64_getehdr
  52 #define _elf_msize      _elf64_msize
  53 #define elf_fsize       elf64_fsize
  54
  55 #else   /* else ELF32 */
  56
  57 #define ELFCLASS        ELFCLASS32
  58 #define elf_newphdr     elf32_newphdr
  59 #define elf_getehdr     elf32_getehdr
  60 #define _elf_msize      _elf32_msize
  61 #define elf_fsize       elf32_fsize
  62
  63 #endif /* ELF64 */
  64
  65
  66 Phdr *
  67 elf_newphdr(Elf * elf, size_t count)
  68 {
  69         Elf_Void *      ph;
  70         size_t          sz;
  71         Phdr *          rc;
  72         unsigned        work;
  73
  74         if (elf == 0)
  75                 return (0);
  76         ELFRLOCK(elf)
  77         if (elf->ed_class != ELFCLASS) {
  78                 _elf_seterr(EREQ_CLASS, 0);
  79                 ELFUNLOCK(elf)
  80                 return (0);
  81         }
  82         ELFUNLOCK(elf)
  83         if (elf_getehdr(elf) == 0) {            /* this cooks if necessary */
  84                 _elf_seterr(ESEQ_EHDR, 0);
  85                 return (0);
  86         }
  87
  88         /*
  89          * Free the existing header if appropriate.  This could reuse
  90          * existing space if big enough, but that's unlikely, benefit
  91          * would be negligible, and code would be more complicated.
  92          */
  93
  94         ELFWLOCK(elf)
  95         if (elf->ed_myflags & EDF_PHALLOC) {
  96                 elf->ed_myflags &= ~EDF_PHALLOC;
  97                 rc = elf->ed_phdr;
  98                 free(rc);
  99         }
 100
 101         /*
 102          * Delete the header if count is zero.
 103          */
 104
 105         ELFACCESSDATA(work, _elf_work)
 106         if ((sz = count * _elf_msize(ELF_T_PHDR, work)) == 0) {
 107                 elf->ed_phflags &= ~ELF_F_DIRTY;
 108                 elf->ed_phdr = 0;
 109                 ((Ehdr*)elf->ed_ehdr)->e_phnum = 0;
 110                 ((Ehdr*)elf->ed_ehdr)->e_phentsize = 0;
 111                 elf->ed_phdrsz = 0;
 112                 ELFUNLOCK(elf)
 113                 return (0);
 114         }
 115
 116         if ((ph = malloc(sz)) == 0) {
 117                 _elf_seterr(EMEM_PHDR, errno);
 118                 elf->ed_phflags &= ~ELF_F_DIRTY;
 119                 elf->ed_phdr = 0;
 120                 ((Ehdr*)elf->ed_ehdr)->e_phnum = 0;
 121                 ((Ehdr*)elf->ed_ehdr)->e_phentsize = 0;
 122                 elf->ed_phdrsz = 0;
 123                 ELFUNLOCK(elf)
 124                 return (0);
 125         }
 126
 127         elf->ed_myflags |= EDF_PHALLOC;
 128         (void) memset(ph, 0, sz);
 129         elf->ed_phflags |= ELF_F_DIRTY;
 130         /* LINTED */
 131         ((Ehdr*)elf->ed_ehdr)->e_phnum = (Half)count;
 132         ((Ehdr*)elf->ed_ehdr)->e_phentsize
 133             /* LINTED */
 134             = (Half)elf_fsize(ELF_T_PHDR, 1, work);
 135         elf->ed_phdrsz = sz;
 136         elf->ed_phdr = rc = ph;
 137
 138         ELFUNLOCK(elf)
 139         return (rc);
 140 }