/arch/um/os-Linux/sys-i386/tls.c
https://bitbucket.org/thekraven/iscream_thunderc-2.6.35 · C · 36 lines · 26 code · 6 blank · 4 comment · 9 complexity · d2230df0e4862d4ed728503f86474121 MD5 · raw file
- #include <errno.h>
- #include <linux/unistd.h>
- #include <sys/syscall.h>
- #include <unistd.h>
- #include "sysdep/tls.h"
- #include "user.h"
- /* Checks whether host supports TLS, and sets *tls_min according to the value
- * valid on the host.
- * i386 host have it == 6; x86_64 host have it == 12, for i386 emulation. */
- void check_host_supports_tls(int *supports_tls, int *tls_min) {
- /* Values for x86 and x86_64.*/
- int val[] = {GDT_ENTRY_TLS_MIN_I386, GDT_ENTRY_TLS_MIN_X86_64};
- int i;
- for (i = 0; i < ARRAY_SIZE(val); i++) {
- user_desc_t info;
- info.entry_number = val[i];
- if (syscall(__NR_get_thread_area, &info) == 0) {
- *tls_min = val[i];
- *supports_tls = 1;
- return;
- } else {
- if (errno == EINVAL)
- continue;
- else if (errno == ENOSYS)
- *supports_tls = 0;
- return;
- }
- }
- *supports_tls = 0;
- }