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| author | Tejun Heo <tj@kernel.org> | 2009-02-09 22:17:40 +0900 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-02-10 00:41:58 +0100 |
| commit | d9a89a26e02ef9ed03f74a755a8b4d8f3a066622 (patch) | |
| tree | 35f3713bca4e6b815f6b9db92dc9d812ec7213ff /arch/x86/include/asm/system.h | |
| parent | f0d96110f9fd98a1a22e03b8adba69508843d910 (diff) | |
| download | talos-obmc-linux-d9a89a26e02ef9ed03f74a755a8b4d8f3a066622.tar.gz talos-obmc-linux-d9a89a26e02ef9ed03f74a755a8b4d8f3a066622.zip | |
x86: add %gs accessors for x86_32
Impact: cleanup
On x86_32, %gs is handled lazily. It's not saved and restored on
kernel entry/exit but only when necessary which usually is during task
switch but there are few other places. Currently, it's done by
calling savesegment() and loadsegment() explicitly. Define
get_user_gs(), set_user_gs() and task_user_gs() and use them instead.
While at it, clean up register access macros in signal.c.
This cleans up code a bit and will help future changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/include/asm/system.h')
| -rw-r--r-- | arch/x86/include/asm/system.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/include/asm/system.h b/arch/x86/include/asm/system.h index 2fcc70bc85f3..70c74b8db875 100644 --- a/arch/x86/include/asm/system.h +++ b/arch/x86/include/asm/system.h @@ -182,6 +182,15 @@ extern void native_load_gs_index(unsigned); #define savesegment(seg, value) \ asm("mov %%" #seg ",%0":"=r" (value) : : "memory") +/* + * x86_32 user gs accessors. + */ +#ifdef CONFIG_X86_32 +#define get_user_gs(regs) (u16)({unsigned long v; savesegment(gs, v); v;}) +#define set_user_gs(regs, v) loadsegment(gs, (unsigned long)(v)) +#define task_user_gs(tsk) ((tsk)->thread.gs) +#endif + static inline unsigned long get_limit(unsigned long segment) { unsigned long __limit; |
