uml: remove unused variables in the context switcher

This patch removes a variable which was not used in two functions.  Yet
another code cleanup, nothing really significant.

Please note that I could not test this on x86_64. I don't have the
hardware for it.

[ jdike - Bits of tidying around the affected code.  Also, it's fine on
x86_64 ]

Signed-off-by: Karol Swietlicki <magotari@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 13 insertions, 16 deletions

diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 91bd68eaba20..62a4e0e12c9c 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -81,12 +81,12 @@ static inline void set_current(struct task_struct *task)
 		{ external_pid(task), task });
 }
 
-extern void arch_switch_to(struct task_struct *from, struct task_struct *to);
+extern void arch_switch_to(struct task_struct *to);
 
 void *_switch_to(void *prev, void *next, void *last)
 {
 	struct task_struct *from = prev;
-	struct task_struct *to= next;
+	struct task_struct *to = next;
 
 	to->thread.prev_sched = from;
 	set_current(to);
@@ -94,16 +94,15 @@ void *_switch_to(void *prev, void *next, void *last)
 	do {
 		current->thread.saved_task = NULL;
 
-		switch_threads(&from->thread.switch_buf,
-			       &to->thread.switch_buf);
+		switch_threads(&from->thread.switch_buf, &to->thread.switch_buf);
 
-		arch_switch_to(current->thread.prev_sched, current);
+		arch_switch_to(current);
 
 		if (current->thread.saved_task)
 			show_regs(&(current->thread.regs));
-		next= current->thread.saved_task;
-		prev= current;
-	} while(current->thread.saved_task);
+		next = current->thread.saved_task;
+		prev = current;
+	} while (current->thread.saved_task);
 
 	return current->thread.prev_sched;
 
@@ -161,8 +160,6 @@ void new_thread_handler(void)
 void fork_handler(void)
 {
 	force_flush_all();
-	if (current->thread.prev_sched == NULL)
-		panic("blech");
 
 	schedule_tail(current->thread.prev_sched);
 
@@ -171,7 +168,7 @@ void fork_handler(void)
 	 * arch_switch_to isn't needed. We could want to apply this to
 	 * improve performance. -bb
 	 */
-	arch_switch_to(current->thread.prev_sched, current);
+	arch_switch_to(current);
 
 	current->thread.prev_sched = NULL;
 
diff --git a/arch/um/sys-i386/ptrace.c b/arch/um/sys-i386/ptrace.c
index bd3da8a61f64..6b4499906a6c 100644
--- a/arch/um/sys-i386/ptrace.c
+++ b/arch/um/sys-i386/ptrace.c
@@ -8,11 +8,11 @@
 #include "asm/uaccess.h"
 #include "skas.h"
 
-extern int arch_switch_tls(struct task_struct *from, struct task_struct *to);
+extern int arch_switch_tls(struct task_struct *to);
 
-void arch_switch_to(struct task_struct *from, struct task_struct *to)
+void arch_switch_to(struct task_struct *to)
 {
-	int err = arch_switch_tls(from, to);
+	int err = arch_switch_tls(to);
 	if (!err)
 		return;
 
diff --git a/arch/um/sys-i386/tls.c b/arch/um/sys-i386/tls.c
index 027e86ad9e5c..f29b8a8fc1e0 100644
--- a/arch/um/sys-i386/tls.c
+++ b/arch/um/sys-i386/tls.c
@@ -172,7 +172,7 @@ void clear_flushed_tls(struct task_struct *task)
  * SKAS patch.
  */
 
-int arch_switch_tls(struct task_struct *from, struct task_struct *to)
+int arch_switch_tls(struct task_struct *to)
 {
 	if (!host_supports_tls)
 		return 0;
diff --git a/arch/um/sys-x86_64/syscalls.c b/arch/um/sys-x86_64/syscalls.c
index 86f6b18410ee..e437ee2215c5 100644
--- a/arch/um/sys-x86_64/syscalls.c
+++ b/arch/um/sys-x86_64/syscalls.c
@@ -105,7 +105,7 @@ long sys_clone(unsigned long clone_flags, unsigned long newsp,
 	return ret;
 }
 
-void arch_switch_to(struct task_struct *from, struct task_struct *to)
+void arch_switch_to(struct task_struct *to)
 {
 	if ((to->thread.arch.fs == 0) || (to->mm == NULL))
 		return;