Messages in this thread Patch in this message | | | Date | Thu, 4 Nov 2021 23:24:26 +0800 | From | Leo Yan <> | Subject | Re: [PATCH v1 2/4] coresight: etm4x: Don't use virtual contextID for non-root PID namespace |
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On Thu, Nov 04, 2021 at 03:07:45PM +0000, Suzuki Kuruppassery Poulose wrote:
[...]
> > @@ -2111,6 +2111,13 @@ static ssize_t vmid_val_show(struct device *dev, > > struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent); > > struct etmv4_config *config = &drvdata->config; > > + /* > > + * Don't use virtual contextID tracing if coming from a PID namespace. > > + * See comment in ctxid_pid_store(). > > + */ > > + if (task_active_pid_ns(current) != &init_pid_ns) > > + return -EINVAL; > > + > > spin_lock(&drvdata->spinlock); > > val = (unsigned long)config->vmid_val[config->vmid_idx]; > > spin_unlock(&drvdata->spinlock); > > @@ -2125,6 +2132,13 @@ static ssize_t vmid_val_store(struct device *dev, > > struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent); > > struct etmv4_config *config = &drvdata->config; > > + /* > > + * Don't use virtual contextID tracing if coming from a PID namespace. > > + * See comment in ctxid_pid_store(). > > + */ > > + if (task_active_pid_ns(current) != &init_pid_ns) > > Please could we add a helper function to make this obvious ? > > e.g: task_is_in_root_ns(task) ?
Yeah, I will use a separate patch set to add this helper function and polish relevant codes in the kernel. Thanks for suggestion.
Leo
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