usr/src/cmd/sgs/libconv/common/arch.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 #pragma ident   "%Z%%M% %I%     %E% SMI"
  27
  28 #include        <stdio.h>
  29 #include        <unistd.h>
  30 #include        <string.h>
  31 #include        <sys/systeminfo.h>
  32 #include        "_conv.h"
  33 #include        "arch_msg.h"
  34
  35 /*
  36  * Determine if the 32-bit or 64-bit kernel is running.
  37  * Return the corresponding EI_CLASS constant.
  38  */
  39 int
  40 conv_sys_eclass(void)
  41 {
  42         char buf[BUFSIZ];
  43
  44         /*
  45          * SI_ISALIST will return -1 on pre-2.6 machines,
  46          * which is fine - it can't be a 64-bit kernel.
  47          */
  48         if (sysinfo(SI_ISALIST, buf, BUFSIZ) == -1)
  49                 return (ELFCLASS32);
  50
  51         if ((strstr(buf, MSG_ORIG(MSG_ARCH_SPARCV9)) != NULL) ||
  52             (strstr(buf, MSG_ORIG(MSG_ARCH_AMD64)) != NULL))
  53                 return (ELFCLASS64);
  54
  55         return (ELFCLASS32);
  56 }
  57
  58 #if     defined(_LP64)
  59 /* ARGSUSED */
  60 uchar_t
  61 conv_check_native(char **argv, char **envp)
  62 {
  63         /* 64-bit version does nothing */
  64         return (ELFCLASS64);
  65 }
  66
  67 #else
  68
  69 /*
  70  * Wrapper for isaexec(3c) that allows disabling 64-bit counterpart execution
  71  * via setting LD_NOEXEC64=yes.
  72  *
  73  * The only callers are 32-bit sgs applications.  These applications determine
  74  * whether a 64-bit counterpart is available via this routine, and if not,
  75  * control is passed back to the caller, who will then complete execution.
  76  * Note, isaexec() will eventually fall through to looking for a 32-bit
  77  * counterpart (ie. sparcv7, or sparc), but as none of the callers provide these
  78  * counterparts, we simply return to the caller.
  79  */
  80 uchar_t
  81 conv_check_native(char **argv, char **envp)
  82 {
  83         const char      *str;
  84
  85         /*
  86          * LD_NOEXEC_64 defined in the environment prevents the isaexec() call.
  87          * This is used by the test suite to test 32-bit support libraries.
  88          */
  89         if (((str = getenv(MSG_ORIG(MSG_LD_NOEXEC64))) != NULL) && *str)
  90                 return (ELFCLASS32);
  91
  92         if ((str = getexecname()) != NULL)
  93                 (void) isaexec(str, argv, envp);
  94         return (ELFCLASS32);
  95 }
  96 #endif