1 /*
   2  * Copyright (c) 2016, 2019 SAP SE. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <sys/ldr.h>
  28 
  29 #include "java_md_aix.h"
  30 
  31 static unsigned char dladdr_buffer[0x8000];
  32 
  33 static int fill_dll_info(void) {
  34     return loadquery(L_GETINFO, dladdr_buffer, sizeof(dladdr_buffer));
  35 }
  36 
  37 static int dladdr_dont_reload(void *addr, Dl_info *info) {
  38     const struct ld_info *p = (struct ld_info *)dladdr_buffer;
  39     memset((void *)info, 0, sizeof(Dl_info));
  40     for (;;) {
  41         if (addr >= p->ldinfo_textorg &&
  42             addr < (((char*)p->ldinfo_textorg) + p->ldinfo_textsize))
  43         {
  44             info->dli_fname = p->ldinfo_filename;
  45             return 1;
  46         }
  47         if (!p->ldinfo_next) {
  48             break;
  49         }
  50         p = (struct ld_info *)(((char *)p) + p->ldinfo_next);
  51     }
  52     return 0;
  53 }
  54 
  55 int dladdr(void *addr, Dl_info *info) {
  56     static int loaded = 0;
  57     int rc = 0;
  58     void *addr0;
  59     if (!addr) {
  60         return rc;
  61     }
  62     if (!loaded) {
  63         if (fill_dll_info() == -1)
  64             return rc;
  65         loaded = 1;
  66     }
  67 
  68     // first try with addr on cached data
  69     rc = dladdr_dont_reload(addr, info);
  70 
  71     // addr could be an AIX function descriptor, so try dereferenced version
  72     if (rc == 0) {
  73         addr0 = *((void **)addr);
  74         rc = dladdr_dont_reload(addr0, info);
  75     }
  76 
  77     // if we had no success until now, maybe loadquery info is outdated.
  78     // refresh and retry
  79     if (rc == 0) {
  80         if (fill_dll_info() == -1)
  81             return rc;
  82         rc = dladdr_dont_reload(addr, info);
  83         if (rc == 0) {
  84             rc = dladdr_dont_reload(addr0, info);
  85         }
  86     }
  87     return rc;
  88 }