From: Leo Yan <leo.yan@linaro.org>
To: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>,
Mike Leach <mike.leach@linaro.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
James Clark <james.clark@arm.com>,
coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 2/4] coresight: etm4x: Don't use virtual contextID for non-root PID namespace
Date: Thu, 4 Nov 2021 23:24:26 +0800 [thread overview]
Message-ID: <20211104152426.GD743063@leoy-ThinkPad-X240s> (raw)
In-Reply-To: <2cd79645-2f1f-1e59-1a26-5540aa7b6f3b@arm.com>
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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next prev parent reply other threads:[~2021-11-04 15:26 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-31 14:42 [PATCH v1 0/4] coresight: etm: Correct (virtual) contextID tracing for namespace Leo Yan
2021-10-31 14:42 ` [PATCH v1 1/4] coresight: etm4x: Add lock for reading virtual context ID comparator Leo Yan
2021-11-01 9:49 ` Suzuki K Poulose
2021-11-01 10:59 ` Leo Yan
2021-10-31 14:42 ` [PATCH v1 2/4] coresight: etm4x: Don't use virtual contextID for non-root PID namespace Leo Yan
2021-11-04 15:07 ` Suzuki K Poulose
2021-11-04 15:24 ` Leo Yan [this message]
2021-10-31 14:42 ` [PATCH v1 3/4] coresight: etm4x: Don't trace contextID for non-root namespace in perf mode Leo Yan
2021-11-16 9:46 ` Suzuki K Poulose
2021-11-17 13:53 ` Leo Yan
2021-10-31 14:42 ` [PATCH v1 4/4] coresight: etm3x: " Leo Yan
2021-11-16 13:52 ` [PATCH v1 0/4] coresight: etm: Correct (virtual) contextID tracing for namespace Suzuki K Poulose
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