diff options
| author | Tejun Heo <tj@kernel.org> | 2009-02-09 14:17:40 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-02-10 00:41:58 +0100 |
| commit | d9a89a26e02ef9ed03f74a755a8b4d8f3a066622 (patch) | |
| tree | 35f3713bca4e6b815f6b9db92dc9d812ec7213ff /arch/x86/include | |
| parent | x86: use asm .macro instead of cpp #define in entry_32.S (diff) | |
| download | linux-d9a89a26e02ef9ed03f74a755a8b4d8f3a066622.tar.xz 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')
| -rw-r--r-- | arch/x86/include/asm/a.out-core.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/elf.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/mmu_context.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/system.h | 9 |
4 files changed, 12 insertions, 3 deletions
diff --git a/arch/x86/include/asm/a.out-core.h b/arch/x86/include/asm/a.out-core.h index 3c601f8224be..bb70e397aa84 100644 --- a/arch/x86/include/asm/a.out-core.h +++ b/arch/x86/include/asm/a.out-core.h @@ -55,7 +55,7 @@ static inline void aout_dump_thread(struct pt_regs *regs, struct user *dump) dump->regs.ds = (u16)regs->ds; dump->regs.es = (u16)regs->es; dump->regs.fs = (u16)regs->fs; - savesegment(gs, dump->regs.gs); + dump->regs.gs = get_user_gs(regs); dump->regs.orig_ax = regs->orig_ax; dump->regs.ip = regs->ip; dump->regs.cs = (u16)regs->cs; diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index f51a3ddde01a..39b0aac1675c 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -124,7 +124,7 @@ do { \ pr_reg[7] = regs->ds & 0xffff; \ pr_reg[8] = regs->es & 0xffff; \ pr_reg[9] = regs->fs & 0xffff; \ - savesegment(gs, pr_reg[10]); \ + pr_reg[10] = get_user_gs(regs); \ pr_reg[11] = regs->orig_ax; \ pr_reg[12] = regs->ip; \ pr_reg[13] = regs->cs & 0xffff; \ diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h index 52948df9cd1d..4955165682c5 100644 --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -79,7 +79,7 @@ do { \ #ifdef CONFIG_X86_32 #define deactivate_mm(tsk, mm) \ do { \ - loadsegment(gs, 0); \ + set_user_gs(task_pt_regs(tsk), 0); \ } while (0) #else #define deactivate_mm(tsk, mm) \ 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; |