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/signal.c | 41 ++++++++++++++++------------------------- 1 file changed, 16 insertions(+), 25 deletions(-) (limited to 'arch/x86/kernel/signal.c') diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 7fc78b019815..8562387c75a7 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -50,27 +50,23 @@ # define FIX_EFLAGS __FIX_EFLAGS #endif -#define COPY(x) { \ - get_user_ex(regs->x, &sc->x); \ -} +#define COPY(x) do { \ + get_user_ex(regs->x, &sc->x); \ +} while (0) -#define COPY_SEG(seg) { \ - unsigned short tmp; \ - get_user_ex(tmp, &sc->seg); \ - regs->seg = tmp; \ -} +#define GET_SEG(seg) ({ \ + unsigned short tmp; \ + get_user_ex(tmp, &sc->seg); \ + tmp; \ +}) -#define COPY_SEG_CPL3(seg) { \ - unsigned short tmp; \ - get_user_ex(tmp, &sc->seg); \ - regs->seg = tmp | 3; \ -} +#define COPY_SEG(seg) do { \ + regs->seg = GET_SEG(seg); \ +} while (0) -#define GET_SEG(seg) { \ - unsigned short tmp; \ - get_user_ex(tmp, &sc->seg); \ - loadsegment(seg, tmp); \ -} +#define COPY_SEG_CPL3(seg) do { \ + regs->seg = GET_SEG(seg) | 3; \ +} while (0) static int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, @@ -86,7 +82,7 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, get_user_try { #ifdef CONFIG_X86_32 - GET_SEG(gs); + set_user_gs(regs, GET_SEG(gs)); COPY_SEG(fs); COPY_SEG(es); COPY_SEG(ds); @@ -138,12 +134,7 @@ setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate, put_user_try { #ifdef CONFIG_X86_32 - { - unsigned int tmp; - - savesegment(gs, tmp); - put_user_ex(tmp, (unsigned int __user *)&sc->gs); - } + put_user_ex(get_user_gs(regs), (unsigned int __user *)&sc->gs); put_user_ex(regs->fs, (unsigned int __user *)&sc->fs); put_user_ex(regs->es, (unsigned int __user *)&sc->es); put_user_ex(regs->ds, (unsigned int __user *)&sc->ds); -- cgit v1.2.3