1 /* 2 * QEMU access to the auxiliary vector 3 * 4 * Copyright (C) 2013 Red Hat, Inc 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 25 #include "qemu-common.h" 26 #include "qemu/osdep.h" 27 28 #ifdef CONFIG_GETAUXVAL 29 /* Don't inline this in qemu/osdep.h, because pulling in <sys/auxv.h> for 30 the system declaration of getauxval pulls in the system <elf.h>, which 31 conflicts with qemu's version. */ 32 33 #include <sys/auxv.h> 34 35 unsigned long qemu_getauxval(unsigned long key) 36 { 37 return getauxval(key); 38 } 39 #elif defined(__linux__) 40 #include "elf.h" 41 42 /* Our elf.h doesn't contain Elf32_auxv_t and Elf64_auxv_t, which is ok because 43 that just makes it easier to define it properly for the host here. */ 44 typedef struct { 45 unsigned long a_type; 46 unsigned long a_val; 47 } ElfW_auxv_t; 48 49 static const ElfW_auxv_t *auxv; 50 51 void qemu_init_auxval(char **envp) 52 { 53 /* The auxiliary vector is located just beyond the initial environment. */ 54 while (*envp++ != NULL) { 55 continue; 56 } 57 auxv = (const ElfW_auxv_t *)envp; 58 } 59 60 unsigned long qemu_getauxval(unsigned long type) 61 { 62 /* If we were able to find the auxiliary vector, use it. */ 63 if (auxv) { 64 const ElfW_auxv_t *a; 65 for (a = auxv; a->a_type != 0; a++) { 66 if (a->a_type == type) { 67 return a->a_val; 68 } 69 } 70 } 71 72 return 0; 73 } 74 #endif 75