On 6/17/25 14:49, André Almeida wrote:
> When a device get wedged, it might be caused by a guilty application.
> For userspace, knowing which task was involved can be useful for some
> situations, like for implementing a policy, logs or for giving a chance
> for the compositor to let the user know what task was involved in the
> problem. This is an optional argument, when the task info is not
> available, the PID and TASK string won't appear in the event string.
>
> Sometimes just the PID isn't enough giving that the task might be already
> dead by the time userspace will try to check what was this PID's name,
> so to make the life easier also notify what's the task's name in the user
> event.
>
> Acked-by: Rodrigo Vivi <rodrigo.v...@intel.com> (for i915 and xe)
> Reviewed-by: Krzysztof Karas <krzysztof.ka...@intel.com>
> Reviewed-by: Raag Jadav <raag.ja...@intel.com>
> Signed-off-by: André Almeida <andrealm...@igalia.com>
Acked-by: Christian König <christian.koe...@amd.com>
> ---
> v8: Code style changes (Raag)
> v7:
> - Change `char *comm` to `char comm[TASK_COMM_LEN]`
> v6:
> - s/cause/involved
> - drop string initialization
> v5:
> - s/app/task for struct and commit message as well
> - move defines to drm_drv.c
> - validates if comm is not NULL and it's not empty
> v4: s/APP/TASK
> v3: Make comm_string and pid_string empty when there's no app info
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 +-
> drivers/gpu/drm/amd/amdgpu/amdgpu_job.c | 2 +-
> drivers/gpu/drm/drm_drv.c | 21 +++++++++++++++++----
> drivers/gpu/drm/i915/gt/intel_reset.c | 3 ++-
> drivers/gpu/drm/xe/xe_device.c | 3 ++-
> include/drm/drm_device.h | 9 +++++++++
> include/drm/drm_drv.h | 3 ++-
> 7 files changed, 34 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index e1bab6a96cb6..8a0f36f33f13 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -6364,7 +6364,7 @@ int amdgpu_device_gpu_recover(struct amdgpu_device
> *adev,
> atomic_set(&adev->reset_domain->reset_res, r);
>
> if (!r)
> - drm_dev_wedged_event(adev_to_drm(adev),
> DRM_WEDGE_RECOVERY_NONE);
> + drm_dev_wedged_event(adev_to_drm(adev),
> DRM_WEDGE_RECOVERY_NONE, NULL);
>
> return r;
> }
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
> index 3d887428ca2b..0c1381b527fe 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
> @@ -164,7 +164,7 @@ static enum drm_gpu_sched_stat amdgpu_job_timedout(struct
> drm_sched_job *s_job)
> if (amdgpu_ring_sched_ready(ring))
> drm_sched_start(&ring->sched, 0);
> dev_err(adev->dev, "Ring %s reset succeeded\n",
> ring->sched.name);
> - drm_dev_wedged_event(adev_to_drm(adev),
> DRM_WEDGE_RECOVERY_NONE);
> + drm_dev_wedged_event(adev_to_drm(adev),
> DRM_WEDGE_RECOVERY_NONE, NULL);
> goto exit;
> }
> dev_err(adev->dev, "Ring %s reset failure\n", ring->sched.name);
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 56dd61f8e05a..a994da9d9233 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -34,6 +34,7 @@
> #include <linux/moduleparam.h>
> #include <linux/mount.h>
> #include <linux/pseudo_fs.h>
> +#include <linux/sched.h>
> #include <linux/slab.h>
> #include <linux/sprintf.h>
> #include <linux/srcu.h>
> @@ -538,10 +539,15 @@ static const char *drm_get_wedge_recovery(unsigned int
> opt)
> }
> }
>
> +#define WEDGE_STR_LEN 32
> +#define PID_STR_LEN 15
> +#define COMM_STR_LEN (TASK_COMM_LEN + 5)
> +
> /**
> * drm_dev_wedged_event - generate a device wedged uevent
> * @dev: DRM device
> * @method: method(s) to be used for recovery
> + * @info: optional information about the guilty task
> *
> * This generates a device wedged uevent for the DRM device specified by
> @dev.
> * Recovery @method\(s) of choice will be sent in the uevent environment as
> @@ -554,13 +560,13 @@ static const char *drm_get_wedge_recovery(unsigned int
> opt)
> *
> * Returns: 0 on success, negative error code otherwise.
> */
> -int drm_dev_wedged_event(struct drm_device *dev, unsigned long method)
> +int drm_dev_wedged_event(struct drm_device *dev, unsigned long method,
> + struct drm_wedge_task_info *info)
> {
> + char event_string[WEDGE_STR_LEN], pid_string[PID_STR_LEN],
> comm_string[COMM_STR_LEN];
> + char *envp[] = { event_string, NULL, NULL, NULL };
> const char *recovery = NULL;
> unsigned int len, opt;
> - /* Event string length up to 28+ characters with available methods */
> - char event_string[32];
> - char *envp[] = { event_string, NULL };
>
> len = scnprintf(event_string, sizeof(event_string), "%s", "WEDGED=");
>
> @@ -582,6 +588,13 @@ int drm_dev_wedged_event(struct drm_device *dev,
> unsigned long method)
> drm_info(dev, "device wedged, %s\n", method == DRM_WEDGE_RECOVERY_NONE ?
> "but recovered through reset" : "needs recovery");
>
> + if (info && (info->comm[0] != '\0') && (info->pid >= 0)) {
> + snprintf(pid_string, sizeof(pid_string), "PID=%u", info->pid);
> + snprintf(comm_string, sizeof(comm_string), "TASK=%s",
> info->comm);
> + envp[1] = pid_string;
> + envp[2] = comm_string;
> + }
> +
> return kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
> }
> EXPORT_SYMBOL(drm_dev_wedged_event);
> diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c
> b/drivers/gpu/drm/i915/gt/intel_reset.c
> index dbdcfe130ad4..ba1d8fdc3c7b 100644
> --- a/drivers/gpu/drm/i915/gt/intel_reset.c
> +++ b/drivers/gpu/drm/i915/gt/intel_reset.c
> @@ -1448,7 +1448,8 @@ static void intel_gt_reset_global(struct intel_gt *gt,
> kobject_uevent_env(kobj, KOBJ_CHANGE, reset_done_event);
> else
> drm_dev_wedged_event(>->i915->drm,
> - DRM_WEDGE_RECOVERY_REBIND |
> DRM_WEDGE_RECOVERY_BUS_RESET);
> + DRM_WEDGE_RECOVERY_REBIND |
> DRM_WEDGE_RECOVERY_BUS_RESET,
> + NULL);
> }
>
> /**
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index c02c4c4e9412..f329613e061f 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -1168,7 +1168,8 @@ void xe_device_declare_wedged(struct xe_device *xe)
>
> /* Notify userspace of wedged device */
> drm_dev_wedged_event(&xe->drm,
> - DRM_WEDGE_RECOVERY_REBIND |
> DRM_WEDGE_RECOVERY_BUS_RESET);
> + DRM_WEDGE_RECOVERY_REBIND |
> DRM_WEDGE_RECOVERY_BUS_RESET,
> + NULL);
> }
>
> for_each_gt(gt, xe, id)
> diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
> index e2f894f1b90a..08b3b2467c4c 100644
> --- a/include/drm/drm_device.h
> +++ b/include/drm/drm_device.h
> @@ -5,6 +5,7 @@
> #include <linux/kref.h>
> #include <linux/mutex.h>
> #include <linux/idr.h>
> +#include <linux/sched.h>
>
> #include <drm/drm_mode_config.h>
>
> @@ -30,6 +31,14 @@ struct pci_controller;
> #define DRM_WEDGE_RECOVERY_REBIND BIT(1) /* unbind + bind driver */
> #define DRM_WEDGE_RECOVERY_BUS_RESET BIT(2) /* unbind + reset bus device +
> bind */
>
> +/**
> + * struct drm_wedge_task_info - information about the guilty task of a wedge
> dev
> + */
> +struct drm_wedge_task_info {
> + pid_t pid;
> + char comm[TASK_COMM_LEN];
> +};
> +
> /**
> * enum switch_power_state - power state of drm device
> */
> diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
> index 63b51942d606..3f76a32d6b84 100644
> --- a/include/drm/drm_drv.h
> +++ b/include/drm/drm_drv.h
> @@ -487,7 +487,8 @@ void drm_put_dev(struct drm_device *dev);
> bool drm_dev_enter(struct drm_device *dev, int *idx);
> void drm_dev_exit(int idx);
> void drm_dev_unplug(struct drm_device *dev);
> -int drm_dev_wedged_event(struct drm_device *dev, unsigned long method);
> +int drm_dev_wedged_event(struct drm_device *dev, unsigned long method,
> + struct drm_wedge_task_info *info);
>
> /**
> * drm_dev_is_unplugged - is a DRM device unplugged
