From: Ingo Molnar <mingo@elte.hu>
Date: Tue, 25 Nov 2008 16:30:25 +0000 (+0100)
Subject: Merge branches 'tracing/core', 'x86/urgent' and 'x86/ptrace' into tracing/hw-branch... 
X-Git-Tag: v2.6.29-rc1~586^2~48
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=7d55718b0c19ba611241c330f688ee824e9bab79;p=linux-2.6-omap-h63xx.git

Merge branches 'tracing/core', 'x86/urgent' and 'x86/ptrace' into tracing/hw-branch-tracing

This pulls together all the topic branches that are needed
for the DS/BTS/PEBS tracing work.
---

7d55718b0c19ba611241c330f688ee824e9bab79
diff --cc arch/x86/kernel/ds.c
index d1a121443bd,a2d1176c38e,c570252905a..d6938d9351c
--- a/arch/x86/kernel/ds.c
+++ b/arch/x86/kernel/ds.c
@@@@ -234,16 -231,12 -234,12 +231,12 @@@@ static inline struct ds_context *ds_all
   	struct ds_context **p_context =
   		(task ? &task->thread.ds_ctx : &this_system_context);
   	struct ds_context *context = *p_context;
+ +	unsigned long irq;
   
   	if (!context) {
-  		spin_unlock(&ds_lock);
-  
   		context = kzalloc(sizeof(*context), GFP_KERNEL);
- -
-  		if (!context) {
-  			spin_lock(&ds_lock);
+  		if (!context)
   			return NULL;
-  		}
   
   		context->ds = kzalloc(ds_cfg.sizeof_ds, GFP_KERNEL);
   		if (!context->ds) {
@@@@ -251,30 -244,27 -247,18 +244,27 @@@@
   			return NULL;
   		}
   
-  		spin_lock(&ds_lock);
-  		/*
-  		 * Check for race - another CPU could have allocated
-  		 * it meanwhile:
-  		 */
  -		*p_context = context;
+ +		spin_lock_irqsave(&ds_lock, irq);
+  
  -		context->this = p_context;
  -		context->task = task;
  +		if (*p_context) {
  +			kfree(context->ds);
  +			kfree(context);
-  			return *p_context;
-  		}
  +
-  		*p_context = context;
+ +			context = *p_context;
+ +		} else {
+ +			*p_context = context;
   
-  		context->this = p_context;
-  		context->task = task;
  -		if (task)
  -			set_tsk_thread_flag(task, TIF_DS_AREA_MSR);
+ +			context->this = p_context;
+ +			context->task = task;
   
-  		if (task)
-  			set_tsk_thread_flag(task, TIF_DS_AREA_MSR);
  -		if (!task || (task == current))
  -			wrmsr(MSR_IA32_DS_AREA, (unsigned long)context->ds, 0);
+ +			if (task)
+ +				set_tsk_thread_flag(task, TIF_DS_AREA_MSR);
   
-  		if (!task || (task == current))
-  			wrmsr(MSR_IA32_DS_AREA, (unsigned long)context->ds, 0);
-  
- -		get_tracer(task);
+ +			if (!task || (task == current))
+ +				wrmsrl(MSR_IA32_DS_AREA,
+ +				       (unsigned long)context->ds);
+ +		}
+ +		spin_unlock_irqrestore(&ds_lock, irq);
   	}
   
   	context->count++;
@@@@ -398,26 -391,27 -382,25 +391,27 @@@@ static int ds_request(struct task_struc
   		return -EOPNOTSUPP;
   
   
- -	spin_lock(&ds_lock);
  -
  -	if (!check_tracer(task))
  -		return -EPERM;
- -
- -	error = -ENOMEM;
   	context = ds_alloc_context(task);
   	if (!context)
-  		goto out_unlock;
+ +		return -ENOMEM;
+ +
+ +	spin_lock_irqsave(&ds_lock, irq);
  +
  +	error = -EPERM;
  +	if (!check_tracer(task))
   		goto out_unlock;
   
+ +	get_tracer(task);
+ +
   	error = -EALREADY;
   	if (context->owner[qual] == current)
- -		goto out_unlock;
+ +		goto out_put_tracer;
   	error = -EPERM;
   	if (context->owner[qual] != NULL)
- -		goto out_unlock;
+ +		goto out_put_tracer;
   	context->owner[qual] = current;
   
- -	spin_unlock(&ds_lock);
+ +	spin_unlock_irqrestore(&ds_lock, irq);
   
   
   	error = -ENOMEM;