On 4/16/2025 12:37 PM, Tvrtko Ursulin wrote:
On 15/04/2025 19:43, Sunil Khatri wrote:
Add a drm helper function which get the process information for
the drm_file and append the process information using the existing
drm_err.
Signed-off-by: Sunil Khatri <sunil.kha...@amd.com>
---
include/drm/drm_file.h | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
index 94d365b22505..e329299a2b2c 100644
--- a/include/drm/drm_file.h
+++ b/include/drm/drm_file.h
@@ -37,6 +37,7 @@
#include <uapi/drm/drm.h>
#include <drm/drm_prime.h>
+#include <drm/drm_print.h>
struct dma_fence;
struct drm_file;
@@ -446,6 +447,45 @@ static inline bool drm_is_accel_client(const
struct drm_file *file_priv)
return file_priv->minor->type == DRM_MINOR_ACCEL;
}
+/**
+ * drm_file_err - Fill info string with process name and pid
+ * @file_priv: context of interest for process name and pid
+ * @fmt: prinf() like format string
+ *
+ * This update the user provided buffer with process
+ * name and pid information for @file_priv
+ */
+__printf(2, 3)
+static inline void drm_file_err(struct drm_file *file_priv, const
char *fmt, ...)
+{
+ struct task_struct *task;
+ struct pid *pid;
+ struct drm_device *dev = file_priv->minor->dev;
+ char new_fmt[256];
+ char final_fmt[512];
+ va_list args;
+
+ mutex_lock(&file_priv->client_name_lock);
+ rcu_read_lock();
+ pid = rcu_dereference(file_priv->pid);
+ task = pid_task(pid, PIDTYPE_TGID);
+
+ if (drm_WARN_ON_ONCE(dev, !task))
+ return;
+
+ snprintf(new_fmt, sizeof(new_fmt), "proc:%s pid:%d
client_name:%s %s",
+ task->comm, task->pid, file_priv->client_name ?: "Unset", fmt);
+
+ va_start(args, fmt);
+ vsnprintf(final_fmt, sizeof(final_fmt), new_fmt, args);
+
+ drm_err(dev, "%s", final_fmt);
+ va_end(args);
+
+ rcu_read_unlock();
+ mutex_unlock(&file_priv->client_name_lock);
+}
+
I was hoping something primitive could be enough. With no temporary
stack space required. Primitive on the level of (but simplified for
illustration purpose):
#define some_err(_file, _fmt, ...) \
drm_err(dev, "client-%s: " _fmt, (_this)->client_name, ##__VA_ARGS__)
I also thought of doing it similarly but that dint work. There was lot
of code to get the process name and pid along with client_name too. So
##__VA_ARGS__ dont work as soon as its a function and not macro.
Also drm_err gave me errors and this is the way i find it not
complaining. new_fmt is a string directly anymore and hence need to %s
to pass but then the drm_err complain too many args for args to pass. So
i have to combine new_fmt and args in one to get final_fmt and atleast
functionally it worked.
Yesterday even i though that i would be as simple as adding a macro.
Am I missing something or that would work?
Regards,
Tvrtko
void drm_file_update_pid(struct drm_file *);
struct drm_minor *drm_minor_acquire(struct xarray *minors_xa,
unsigned int minor_id);
