diff options
Diffstat (limited to 'arch/x86/kernel/ds.c')
| -rw-r--r-- | arch/x86/kernel/ds.c | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/arch/x86/kernel/ds.c b/arch/x86/kernel/ds.c index c730155bf54..5cd137ab267 100644 --- a/arch/x86/kernel/ds.c +++ b/arch/x86/kernel/ds.c @@ -299,6 +299,7 @@ static inline struct ds_context *ds_get_context(struct task_struct *task) static inline void ds_put_context(struct ds_context *context) { + struct task_struct *task; unsigned long irq; if (!context) @@ -313,14 +314,20 @@ static inline void ds_put_context(struct ds_context *context) *(context->this) = NULL; - if (context->task) - clear_tsk_thread_flag(context->task, TIF_DS_AREA_MSR); + task = context->task; + + if (task) + clear_tsk_thread_flag(task, TIF_DS_AREA_MSR); - if (!context->task || (context->task == current)) + if (!task || (task == current)) wrmsrl(MSR_IA32_DS_AREA, 0); spin_unlock_irqrestore(&ds_lock, irq); + /* The context might still be in use for context switching. */ + if (task && (task != current)) + wait_task_context_switch(task); + kfree(context); } @@ -781,15 +788,23 @@ struct pebs_tracer *ds_request_pebs(struct task_struct *task, void ds_release_bts(struct bts_tracer *tracer) { + struct task_struct *task; + if (!tracer) return; + task = tracer->ds.context->task; + ds_suspend_bts(tracer); WARN_ON_ONCE(tracer->ds.context->bts_master != tracer); tracer->ds.context->bts_master = NULL; - put_tracer(tracer->ds.context->task); + /* Make sure tracing stopped and the tracer is not in use. */ + if (task && (task != current)) + wait_task_context_switch(task); + + put_tracer(task); ds_put_context(tracer->ds.context); kfree(tracer); |