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      1 /*	$NetBSD: reloc_x86_64.c,v 1.2 2021/10/08 23:08:06 jmcneill Exp $	*/
      2 
      3 /* reloc_x86_64.c - position independent x86_64 ELF shared object relocator
      4    Copyright (C) 1999 Hewlett-Packard Co.
      5 	Contributed by David Mosberger <davidm (at) hpl.hp.com>.
      6    Copyright (C) 2005 Intel Co.
      7 	Contributed by Fenghua Yu <fenghua.yu (at) intel.com>.
      8 
      9     All rights reserved.
     10 
     11     Redistribution and use in source and binary forms, with or without
     12     modification, are permitted provided that the following conditions
     13     are met:
     14 
     15     * Redistributions of source code must retain the above copyright
     16       notice, this list of conditions and the following disclaimer.
     17     * Redistributions in binary form must reproduce the above
     18       copyright notice, this list of conditions and the following
     19       disclaimer in the documentation and/or other materials
     20       provided with the distribution.
     21     * Neither the name of Hewlett-Packard Co. nor the names of its
     22       contributors may be used to endorse or promote products derived
     23       from this software without specific prior written permission.
     24 
     25     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
     26     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
     27     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     28     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     29     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
     30     BE LIABLE FOR ANYDIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
     31     OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     32     PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     33     PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     34     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
     35     TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
     36     THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     37     SUCH DAMAGE.
     38 */
     39 
     40 #include <efi.h>
     41 #include <efilib.h>
     42 
     43 #ifdef __NetBSD__
     44 #include <sys/types.h>
     45 #include <sys/exec_elf.h>
     46 #else
     47 #include <elf.h>
     48 #endif
     49 
     50 EFI_STATUS _relocate (long, Elf64_Dyn *, EFI_HANDLE, EFI_SYSTEM_TABLE *);
     51 
     52 EFI_STATUS _relocate (long ldbase, Elf64_Dyn *dyn,
     53 		      EFI_HANDLE image EFI_UNUSED,
     54 		      EFI_SYSTEM_TABLE *systab EFI_UNUSED)
     55 {
     56 	long relsz = 0, relent = 0;
     57 	Elf64_Rel *rel = 0;
     58 	unsigned long *addr;
     59 	int i;
     60 
     61 	for (i = 0; dyn[i].d_tag != DT_NULL; ++i) {
     62 		switch (dyn[i].d_tag) {
     63 			case DT_RELA:
     64 				rel = (Elf64_Rel*)
     65 					((unsigned long)dyn[i].d_un.d_ptr
     66 					 + ldbase);
     67 				break;
     68 
     69 			case DT_RELASZ:
     70 				relsz = dyn[i].d_un.d_val;
     71 				break;
     72 
     73 			case DT_RELAENT:
     74 				relent = dyn[i].d_un.d_val;
     75 				break;
     76 
     77 			default:
     78 				break;
     79 		}
     80 	}
     81 
     82         if (!rel && relent == 0)
     83                 return EFI_SUCCESS;
     84 
     85 	if (!rel || relent == 0)
     86 		return EFI_LOAD_ERROR;
     87 
     88 	while (relsz > 0) {
     89 		/* apply the relocs */
     90 		switch (ELF64_R_TYPE (rel->r_info)) {
     91 			case R_X86_64_NONE:
     92 				break;
     93 
     94 			case R_X86_64_RELATIVE:
     95 				addr = (unsigned long *)
     96 					(ldbase + rel->r_offset);
     97 				*addr += ldbase;
     98 				break;
     99 
    100 			default:
    101 				break;
    102 		}
    103 		rel = (Elf64_Rel*) ((char *) rel + relent);
    104 		relsz -= relent;
    105 	}
    106 	return EFI_SUCCESS;
    107 }
    108