[PATCH] x86: Some preparationary cleanup for stack trace

- Remove unused all_contexts parameter
No caller used it
- Move skip argument into the structure (needed for
followon patches)

Cc: mingo@elte.hu

Signed-off-by: Andi Kleen <ak@suse.de>

arch/i386/kernel/stacktrace.c

@@ -61,12 +61,8 @@ save_context_stack(struct stack_trace *trace, unsigned int skip,
 
 /*
  * Save stack-backtrace addresses into a stack_trace buffer.
- * If all_contexts is set, all contexts (hardirq, softirq and process)
- * are saved. If not set then only the current context is saved.
  */
-void save_stack_trace(struct stack_trace *trace,
-		      struct task_struct *task, int all_contexts,
-		      unsigned int skip)
+void save_stack_trace(struct stack_trace *trace, struct task_struct *task)
 {
 	unsigned long ebp;
 	unsigned long *stack = &ebp;
@@ -85,10 +81,9 @@ void save_stack_trace(struct stack_trace *trace,
 		struct thread_info *context = (struct thread_info *)
 				((unsigned long)stack & (~(THREAD_SIZE - 1)));
 
-		ebp = save_context_stack(trace, skip, context, stack, ebp);
+		ebp = save_context_stack(trace, trace->skip, context, stack, ebp);
 		stack = (unsigned long *)context->previous_esp;
-		if (!all_contexts || !stack ||
-				trace->nr_entries >= trace->max_entries)
+		if (!stack || trace->nr_entries >= trace->max_entries)
 			break;
 		trace->entries[trace->nr_entries++] = ULONG_MAX;
 		if (trace->nr_entries >= trace->max_entries)

arch/s390/kernel/stacktrace.c

@@ -59,9 +59,7 @@ static inline unsigned long save_context_stack(struct stack_trace *trace,
 	}
 }
 
-void save_stack_trace(struct stack_trace *trace,
-		      struct task_struct *task, int all_contexts,
-		      unsigned int skip)
+void save_stack_trace(struct stack_trace *trace, struct task_struct *task)
 {
 	register unsigned long sp asm ("15");
 	unsigned long orig_sp;
@@ -69,22 +67,23 @@ void save_stack_trace(struct stack_trace *trace,
 	sp &= PSW_ADDR_INSN;
 	orig_sp = sp;
 
-	sp = save_context_stack(trace, &skip, sp,
+	sp = save_context_stack(trace, &trace->skip, sp,
 				S390_lowcore.panic_stack - PAGE_SIZE,
 				S390_lowcore.panic_stack);
-	if ((sp != orig_sp) && !all_contexts)
+	if ((sp != orig_sp) && !trace->all_contexts)
 		return;
-	sp = save_context_stack(trace, &skip, sp,
+	sp = save_context_stack(trace, &trace->skip, sp,
 				S390_lowcore.async_stack - ASYNC_SIZE,
 				S390_lowcore.async_stack);
-	if ((sp != orig_sp) && !all_contexts)
+	if ((sp != orig_sp) && !trace->all_contexts)
 		return;
 	if (task)
-		save_context_stack(trace, &skip, sp,
+		save_context_stack(trace, &trace->skip, sp,
 				   (unsigned long) task_stack_page(task),
 				   (unsigned long) task_stack_page(task) + THREAD_SIZE);
 	else
-		save_context_stack(trace, &skip, sp, S390_lowcore.thread_info,
+		save_context_stack(trace, &trace->skip, sp,
+				   S390_lowcore.thread_info,
 				   S390_lowcore.thread_info + THREAD_SIZE);
 	return;
 }

arch/x86_64/kernel/stacktrace.c

@@ -109,9 +109,10 @@ out_restore:
  * Save stack-backtrace addresses into a stack_trace buffer:
  */
 static inline unsigned long
-save_context_stack(struct stack_trace *trace, unsigned int skip,
+save_context_stack(struct stack_trace *trace,
 		   unsigned long stack, unsigned long stack_end)
 {
+	int skip = trace->skip;
 	unsigned long addr;
 
 #ifdef CONFIG_FRAME_POINTER
@@ -159,12 +160,8 @@ save_context_stack(struct stack_trace *trace, unsigned int skip,
 
 /*
  * Save stack-backtrace addresses into a stack_trace buffer.
- * If all_contexts is set, all contexts (hardirq, softirq and process)
- * are saved. If not set then only the current context is saved.
  */
-void save_stack_trace(struct stack_trace *trace,
-		      struct task_struct *task, int all_contexts,
-		      unsigned int skip)
+void save_stack_trace(struct stack_trace *trace, struct task_struct *task)
 {
 	unsigned long stack = (unsigned long)&stack;
 	int i, nr_stacks = 0, stacks_done[MAX_STACKS];
@@ -207,9 +204,8 @@ void save_stack_trace(struct stack_trace *trace,
 				return;
 		stacks_done[nr_stacks] = stack_end;
 
-		stack = save_context_stack(trace, skip, stack, stack_end);
-		if (!all_contexts || !stack ||
-				trace->nr_entries >= trace->max_entries)
+		stack = save_context_stack(trace, stack, stack_end);
+		if (!stack || trace->nr_entries >= trace->max_entries)
 			return;
 		trace->entries[trace->nr_entries++] = ULONG_MAX;
 		if (trace->nr_entries >= trace->max_entries)

include/linux/stacktrace.h

@@ -5,15 +5,16 @@
 struct stack_trace {
 	unsigned int nr_entries, max_entries;
 	unsigned long *entries;
+	int skip;	/* input argument: How many entries to skip */
+	int all_contexts; /* input argument: if true do than one stack */
 };
 
 extern void save_stack_trace(struct stack_trace *trace,
-			     struct task_struct *task, int all_contexts,
-			     unsigned int skip);
+			     struct task_struct *task);
 
 extern void print_stack_trace(struct stack_trace *trace, int spaces);
 #else
-# define save_stack_trace(trace, task, all, skip)	do { } while (0)
+# define save_stack_trace(trace, task)			do { } while (0)
 # define print_stack_trace(trace)			do { } while (0)
 #endif
 

kernel/lockdep.c

@@ -224,7 +224,10 @@ static int save_trace(struct stack_trace *trace)
 	trace->max_entries = MAX_STACK_TRACE_ENTRIES - nr_stack_trace_entries;
 	trace->entries = stack_trace + nr_stack_trace_entries;
 
-	save_stack_trace(trace, NULL, 0, 3);
+	trace->skip = 3;
+	trace->all_contexts = 0;
+
+	save_stack_trace(trace, NULL);
 
 	trace->max_entries = trace->nr_entries;