[PATCH V8 1/5] drm: add drm_file_err function to add process info

[Khatri, Sunil]

On 4/22/2025 2:33 PM, Christian König wrote:
> Am 17.04.25 um 18:10 schrieb Sunil Khatri:
>> Add a drm helper function which appends the process information for
>> the drm_file over drm_err formatted output.
>>
>> v5: change to macro from function (Christian Koenig)
>>      add helper functions for lock/unlock (Christian Koenig)
>>
>> v6: remove __maybe_unused and make function inline (Jani Nikula)
>>      remove drm_print.h
>>
>> v7: Use va_format and %pV to concatenate fmt and vargs (Jani Nikula)
>>
>> v8: Code formatting and typos (Ursulin tvrtko)
>>
>> Signed-off-by: Sunil Khatri <sunil.khatri at amd.com>
>> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at igalia.com>
> Any objections to merge this through amd-staging-drm-next?
Gentle reminder here folks ??
> The follow up amdgpu patches all depend on stuff in there which is not yet merged to drm-misc-next.
>
> Thanks,
> Christian.
>
>> ---
>>   drivers/gpu/drm/drm_file.c | 34 ++++++++++++++++++++++++++++++++++
>>   include/drm/drm_file.h     |  3 +++
>>   2 files changed, 37 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
>> index c299cd94d3f7..dd351f601acd 100644
>> --- a/drivers/gpu/drm/drm_file.c
>> +++ b/drivers/gpu/drm/drm_file.c
>> @@ -986,6 +986,40 @@ void drm_show_fdinfo(struct seq_file *m, struct file *f)
>>   }
>>   EXPORT_SYMBOL(drm_show_fdinfo);
>>   
>> +/**
>> + * drm_file_err - log process name, pid and client_name associated with a drm_file
>> + * @file_priv: context of interest for process name and pid
>> + * @fmt: printf() like format string
>> + *
>> + * Helper function for clients which needs to log process details such
>> + * as name and pid etc along with user logs.
>> + */
>> +void drm_file_err(struct drm_file *file_priv, const char *fmt, ...)
>> +{
>> +	va_list args;
>> +	struct va_format vaf;
>> +	struct pid *pid;
>> +	struct task_struct *task;
>> +	struct drm_device *dev = file_priv->minor->dev;
>> +
>> +	va_start(args, fmt);
>> +	vaf.fmt = fmt;
>> +	vaf.va = &args;
>> +
>> +	mutex_lock(&file_priv->client_name_lock);
>> +	rcu_read_lock();
>> +	pid = rcu_dereference(file_priv->pid);
>> +	task = pid_task(pid, PIDTYPE_TGID);
>> +
>> +	drm_err(dev, "comm: %s pid: %d client: %s ... %pV", task ? task->comm : "Unset",
>> +		task ? task->pid : 0, file_priv->client_name ?: "Unset", &vaf);
>> +
>> +	va_end(args);
>> +	rcu_read_unlock();
>> +	mutex_unlock(&file_priv->client_name_lock);
>> +}
>> +EXPORT_SYMBOL(drm_file_err);
>> +
>>   /**
>>    * mock_drm_getfile - Create a new struct file for the drm device
>>    * @minor: drm minor to wrap (e.g. #drm_device.primary)
>> diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
>> index 94d365b22505..5c3b2aa3e69d 100644
>> --- a/include/drm/drm_file.h
>> +++ b/include/drm/drm_file.h
>> @@ -446,6 +446,9 @@ static inline bool drm_is_accel_client(const struct drm_file *file_priv)
>>   	return file_priv->minor->type == DRM_MINOR_ACCEL;
>>   }
>>   
>> +__printf(2, 3)
>> +void drm_file_err(struct drm_file *file_priv, const char *fmt, ...);
>> +
>>   void drm_file_update_pid(struct drm_file *);
>>   
>>   struct drm_minor *drm_minor_acquire(struct xarray *minors_xa, unsigned int minor_id);