1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * arch/um/kernel/elf_aux.c 4 * 5 * Scan the ELF auxiliary vector provided by the host to extract 6 * information about vsyscall-page, etc. 7 * 8 * Copyright (C) 2004 Fujitsu Siemens Computers GmbH 9 * Author: Bodo Stroesser (bodo.stroesser@fujitsu-siemens.com) 10 */ 11 #include <elf.h> 12 #include <stddef.h> 13 #include <init.h> 14 #include <elf_user.h> 15 #include <mem_user.h> 16 #include "internal.h" 17 #include <linux/swab.h> 18 19 #if __BITS_PER_LONG == 64 20 typedef Elf64_auxv_t elf_auxv_t; 21 #else 22 typedef Elf32_auxv_t elf_auxv_t; 23 #endif 24 25 /* These are initialized very early in boot and never changed */ 26 char * elf_aux_platform; 27 long elf_aux_hwcap; 28 29 __init void scan_elf_aux( char **envp) 30 { 31 elf_auxv_t * auxv; 32 33 while ( *envp++ != NULL) ; 34 35 for ( auxv = (elf_auxv_t *)envp; auxv->a_type != AT_NULL; auxv++) { 36 switch ( auxv->a_type ) { 37 case AT_HWCAP: 38 elf_aux_hwcap = auxv->a_un.a_val; 39 break; 40 case AT_PLATFORM: 41 /* elf.h removed the pointer elements from 42 * a_un, so we have to use a_val, which is 43 * all that's left. 44 */ 45 elf_aux_platform = 46 (char *) (long) auxv->a_un.a_val; 47 break; 48 } 49 } 50 } 51