diff options
Diffstat (limited to 'util')
| -rw-r--r-- | util/getauxval.c | 51 |
1 files changed, 39 insertions, 12 deletions
diff --git a/util/getauxval.c b/util/getauxval.c index 476c883b32..25f48e5456 100644 --- a/util/getauxval.c +++ b/util/getauxval.c @@ -48,24 +48,51 @@ typedef struct { static const ElfW_auxv_t *auxv; -void qemu_init_auxval(char **envp) +static const ElfW_auxv_t *qemu_init_auxval(void) { - /* The auxiliary vector is located just beyond the initial environment. */ - while (*envp++ != NULL) { - continue; + 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); } - auxv = (const ElfW_auxv_t *)envp; + + close(fd); + return a; } unsigned long qemu_getauxval(unsigned long type) { - /* If we were able to find the auxiliary vector, use it. */ - if (auxv) { - const ElfW_auxv_t *a; - for (a = auxv; a->a_type != 0; a++) { - if (a->a_type == type) { - return a->a_val; - } + 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; } } |