diff options
Diffstat (limited to 'arch/um/os-Linux/sys-i386')
| -rw-r--r-- | arch/um/os-Linux/sys-i386/Makefile | 2 | ||||
| -rw-r--r-- | arch/um/os-Linux/sys-i386/tls.c | 33 |
2 files changed, 34 insertions, 1 deletions
diff --git a/arch/um/os-Linux/sys-i386/Makefile b/arch/um/os-Linux/sys-i386/Makefile index 340ef26f5944..b3213613c41c 100644 --- a/arch/um/os-Linux/sys-i386/Makefile +++ b/arch/um/os-Linux/sys-i386/Makefile @@ -3,7 +3,7 @@ # Licensed under the GPL # -obj-$(CONFIG_MODE_SKAS) = registers.o +obj-$(CONFIG_MODE_SKAS) = registers.o tls.o USER_OBJS := $(obj-y) diff --git a/arch/um/os-Linux/sys-i386/tls.c b/arch/um/os-Linux/sys-i386/tls.c new file mode 100644 index 000000000000..ba21f0e04a2f --- /dev/null +++ b/arch/um/os-Linux/sys-i386/tls.c @@ -0,0 +1,33 @@ +#include <linux/unistd.h> +#include "sysdep/tls.h" +#include "user_util.h" + +static _syscall1(int, get_thread_area, user_desc_t *, u_info); + +/* 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 (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; +} |