diff options
| author | Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> | 2006-03-31 12:30:25 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-31 22:18:52 +0200 |
| commit | 3feb88562d149f078319e5a1b2f7acaa10251a5c (patch) | |
| tree | 73fb00f0ecb9ed0c4cf8eec24c84253ce9620464 /arch/um/os-Linux | |
| parent | [PATCH] uml: add arch_switch_to for newly forked thread (diff) | |
| download | linux-3feb88562d149f078319e5a1b2f7acaa10251a5c.tar.xz linux-3feb88562d149f078319e5a1b2f7acaa10251a5c.zip | |
[PATCH] uml: check for differences in host support
If running on a host not supporting TLS (for instance 2.4) we should report
that cleanly to the user, instead of printing not comprehensible "error 5" for
that.
Additionally, i386 and x86_64 support different ranges for
user_desc->entry_number, and we must account for that; we couldn't pass
ourselves -1 because we need to override previously existing TLS descriptors
which glibc has possibly set, so test at startup the range to use.
x86 and x86_64 existing ranges are hardcoded.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/um/os-Linux')
| -rw-r--r-- | arch/um/os-Linux/sys-i386/Makefile | 2 | ||||
| -rw-r--r-- | arch/um/os-Linux/sys-i386/tls.c | 33 | ||||
| -rw-r--r-- | arch/um/os-Linux/tls.c | 4 |
3 files changed, 36 insertions, 3 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; +} diff --git a/arch/um/os-Linux/tls.c b/arch/um/os-Linux/tls.c index 642db553ab60..9cb09a45546b 100644 --- a/arch/um/os-Linux/tls.c +++ b/arch/um/os-Linux/tls.c @@ -48,8 +48,8 @@ int os_get_thread_area(user_desc_t *info, int pid) #ifdef UML_CONFIG_MODE_TT #include "linux/unistd.h" -_syscall1(int, get_thread_area, user_desc_t *, u_info); -_syscall1(int, set_thread_area, user_desc_t *, u_info); +static _syscall1(int, get_thread_area, user_desc_t *, u_info); +static _syscall1(int, set_thread_area, user_desc_t *, u_info); int do_set_thread_area_tt(user_desc_t *info) { |