diff options
author | Yang Zhang <yang.z.zhang@intel.com> | 2015-08-28 09:58:54 +0800 |
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committer | Yang Zhang <yang.z.zhang@intel.com> | 2015-09-01 12:44:00 +0800 |
commit | e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb (patch) | |
tree | 66b09f592c55df2878107a468a91d21506104d3f /qemu/util/getauxval.c | |
parent | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (diff) |
Add qemu 2.4.0
Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Diffstat (limited to 'qemu/util/getauxval.c')
-rw-r--r-- | qemu/util/getauxval.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/qemu/util/getauxval.c b/qemu/util/getauxval.c new file mode 100644 index 000000000..1732ace2b --- /dev/null +++ b/qemu/util/getauxval.c @@ -0,0 +1,109 @@ +/* + * 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-common.h" +#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 |