| /* |
| * QEMU access to the auxiliary vector |
| * |
| * Copyright (C) 2013 Red Hat, Inc |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this software and associated documentation files (the "Software"), to deal |
| * in the Software without restriction, including without limitation the rights |
| * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| * copies of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| * THE SOFTWARE. |
| */ |
| |
| #include "qemu/osdep.h" |
| |
| #ifdef CONFIG_GETAUXVAL |
| /* Don't inline this in qemu/osdep.h, because pulling in <sys/auxv.h> for |
| the system declaration of getauxval pulls in the system <elf.h>, which |
| conflicts with qemu's version. */ |
| |
| #include <sys/auxv.h> |
| |
| unsigned long qemu_getauxval(unsigned long key) |
| { |
| return getauxval(key); |
| } |
| #elif defined(__linux__) |
| #include "elf.h" |
| |
| /* Our elf.h doesn't contain Elf32_auxv_t and Elf64_auxv_t, which is ok because |
| that just makes it easier to define it properly for the host here. */ |
| typedef struct { |
| unsigned long a_type; |
| unsigned long a_val; |
| } ElfW_auxv_t; |
| |
| static const ElfW_auxv_t *auxv; |
| |
| static const ElfW_auxv_t *qemu_init_auxval(void) |
| { |
| ElfW_auxv_t *a; |
| ssize_t size = 512, r, ofs; |
| int fd; |
| |
| /* Allocate some initial storage. Make sure the first entry is set |
| to end-of-list, so that we've got a valid list in case of error. */ |
| auxv = a = g_malloc(size); |
| a[0].a_type = 0; |
| a[0].a_val = 0; |
| |
| fd = open("/proc/self/auxv", O_RDONLY); |
| if (fd < 0) { |
| return a; |
| } |
| |
| /* Read the first SIZE bytes. Hopefully, this covers everything. */ |
| r = read(fd, a, size); |
| |
| if (r == size) { |
| /* Continue to expand until we do get a partial read. */ |
| do { |
| ofs = size; |
| size *= 2; |
| auxv = a = g_realloc(a, size); |
| r = read(fd, (char *)a + ofs, ofs); |
| } while (r == ofs); |
| } |
| |
| close(fd); |
| return a; |
| } |
| |
| unsigned long qemu_getauxval(unsigned long type) |
| { |
| const ElfW_auxv_t *a = auxv; |
| |
| if (unlikely(a == NULL)) { |
| a = qemu_init_auxval(); |
| } |
| |
| for (; a->a_type != 0; a++) { |
| if (a->a_type == type) { |
| return a->a_val; |
| } |
| } |
| |
| return 0; |
| } |
| |
| #else |
| |
| unsigned long qemu_getauxval(unsigned long type) |
| { |
| return 0; |
| } |
| |
| #endif |