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authorTejun Heo <tj@kernel.org>2009-02-09 22:17:40 +0900
committerIngo Molnar <mingo@elte.hu>2009-02-10 00:41:58 +0100
commitd9a89a26e02ef9ed03f74a755a8b4d8f3a066622 (patch)
tree35f3713bca4e6b815f6b9db92dc9d812ec7213ff /arch/x86/kernel/signal.c
parentf0d96110f9fd98a1a22e03b8adba69508843d910 (diff)
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/kernel/signal.c')
-rw-r--r--arch/x86/kernel/signal.c41
1 files changed, 16 insertions, 25 deletions
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);