From d9a89a26e02ef9ed03f74a755a8b4d8f3a066622 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 9 Feb 2009 22:17:40 +0900 Subject: 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 Signed-off-by: Ingo Molnar --- arch/x86/kernel/ptrace.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) (limited to 'arch/x86/kernel/ptrace.c') diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 0a5df5f82fb9..508b6b57d0c3 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -90,9 +90,10 @@ static u16 get_segment_reg(struct task_struct *task, unsigned long offset) if (offset != offsetof(struct user_regs_struct, gs)) retval = *pt_regs_access(task_pt_regs(task), offset); else { - retval = task->thread.gs; if (task == current) - savesegment(gs, retval); + retval = get_user_gs(task_pt_regs(task)); + else + retval = task_user_gs(task); } return retval; } @@ -126,13 +127,10 @@ static int set_segment_reg(struct task_struct *task, break; case offsetof(struct user_regs_struct, gs): - task->thread.gs = value; if (task == current) - /* - * The user-mode %gs is not affected by - * kernel entry, so we must update the CPU. - */ - loadsegment(gs, value); + set_user_gs(task_pt_regs(task), value); + else + task_user_gs(task) = value; } return 0; -- cgit v1.2.3