[PATCH v10 0/5] drm/panthor: Display size of internal kernel BOs through fdinfo

[PATCH v10 0/5] drm/panthor: Display size of internal kernel BOs through fdinfo

[Adrián Larumbe]

This patch series enables display of the size of driver-owned shmem BO's that aren't
exposed to userspace through a DRM handle. Also fixes a use-after-free bug in the
existing fdinfo implementation for Panthor.

Discussion of previous revision can be found here [1].

Changelog:
v10:
 - Simplified locking scheme in panthor_vm_heaps_sizes
 - Fixed kernel test robot warning about documentation
 - Added some R-b tags to patches
v9:
 - Added proper locking around group pool xarray to prevent UAF errors.
 - Added proper locking around vms pool xarray loop for the same reason
 - Added new patch that fixes UAF error because no locking when accessing 
   fdinfo group stats.
 - Some minor cosmetic and naming changes.
v8:
 - Made print_size public and added prefix argument for drm_print_memory_stats
 - Updated documentation commit to reflect new name tags
 - Some minor polishing
v7:
 - Added new commit: mentions the formation rules for driver-specific fdinfo keys
 - Added new commit: adds a helper that lets driver print memory size key:value
   pairs with their driver name as a prefix.
 - Modified later commits to make use of the previous ones.
 - Deleted mentions of now unnecessary memory keys in the old revision.
v6:
 - Replace up_write witnh up_read, which was left out in the previous version
 - Fixed some minor comment and documentation issues reported by the kernel test robot
v5:
 - Replaced down_write semaphore with the read flavour
 - Fixed typo and added explicit description for drm-shared-internal in
 the fdinfo documentation file for Panthor.
v4:
 - Remove unrelated formating fix
 - Moved calculating overall size of a group's kernel BO's into
 its own static helper.
 - Renamed group kernel BO's size aggregation function to better
 reflect its actual responsibility.

[1] https://lore.kernel.org/dri-devel/20250123225325.3271764-1-adrian.larumbe@collabora.com/

Adrián Larumbe (5):
  Documentation/gpu: Clarify format of driver-specific fidnfo keys
  drm/file: Add fdinfo helper for printing regions with prefix
  drm/panthor: Expose size of driver internal BO's over fdinfo
  Documentation/gpu: Add fdinfo meanings of panthor-*-memory tags
  drm/panthor: Fix race condition when gathering fdinfo group samples

 Documentation/gpu/drm-usage-stats.rst   |  5 ++-
 Documentation/gpu/panthor.rst           | 10 +++++
 drivers/gpu/drm/drm_file.c              | 27 ++++++++----
 drivers/gpu/drm/panthor/panthor_drv.c   | 14 ++++++
 drivers/gpu/drm/panthor/panthor_heap.c  | 26 +++++++++++
 drivers/gpu/drm/panthor/panthor_heap.h  |  2 +
 drivers/gpu/drm/panthor/panthor_mmu.c   | 33 ++++++++++++++
 drivers/gpu/drm/panthor/panthor_mmu.h   |  3 ++
 drivers/gpu/drm/panthor/panthor_sched.c | 58 ++++++++++++++++++++++++-
 drivers/gpu/drm/panthor/panthor_sched.h |  3 ++
 include/drm/drm_file.h                  |  5 +++
 11 files changed, 176 insertions(+), 10 deletions(-)

-- 
2.47.1

[PATCH v10 1/5] Documentation/gpu: Clarify format of driver-specific fidnfo keys

[Adrián Larumbe]

This change reflects de facto usage by amdgpu, as exemplified by commit
d6530c33a978 ("drm/amdgpu: expose more memory stats in fdinfo").

Cc: Tvrtko Ursulin <tursulin@ursulin.net>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
---
 Documentation/gpu/drm-usage-stats.rst | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Documentation/gpu/drm-usage-stats.rst b/Documentation/gpu/drm-usage-stats.rst
index 2717cb2a597e..2b5393ed7692 100644
--- a/Documentation/gpu/drm-usage-stats.rst
+++ b/Documentation/gpu/drm-usage-stats.rst
@@ -21,7 +21,10 @@ File format specification
 
 - File shall contain one key value pair per one line of text.
 - Colon character (`:`) must be used to delimit keys and values.
-- All keys shall be prefixed with `drm-`.
+- All standardised keys shall be prefixed with `drm-`.
+- Driver-specific keys shall be prefixed with `driver_name-`, where
+  driver_name should ideally be the same as the `name` field in
+  `struct drm_driver`, although this is not mandatory.
 - Whitespace between the delimiter and first non-whitespace character shall be
   ignored when parsing.
 - Keys are not allowed to contain whitespace characters.
-- 
2.47.1

[PATCH v10 2/5] drm/file: Add fdinfo helper for printing regions with prefix

[Adrián Larumbe]

This is motivated by the desire of some drivers (eg. Panthor) to print the
size of internal memory regions with a prefix that reflects the driver
name, as suggested in the previous documentation commit.

That means adding a new argument to print_size and making it available for
DRM users.

Cc: Tvrtko Ursulin <tursulin@ursulin.net>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
---
 drivers/gpu/drm/drm_file.c | 27 +++++++++++++++++++--------
 include/drm/drm_file.h     |  5 +++++
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
index cb5f22f5bbb6..f584abcd13cb 100644
--- a/drivers/gpu/drm/drm_file.c
+++ b/drivers/gpu/drm/drm_file.c
@@ -830,8 +830,12 @@ void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
 }
 EXPORT_SYMBOL(drm_send_event);
 
-static void print_size(struct drm_printer *p, const char *stat,
-		       const char *region, u64 sz)
+
+void drm_fdinfo_print_size(struct drm_printer *p,
+			   const char *prefix,
+			   const char *stat,
+			   const char *region,
+			   u64 sz)
 {
 	const char *units[] = {"", " KiB", " MiB"};
 	unsigned u;
@@ -842,8 +846,10 @@ static void print_size(struct drm_printer *p, const char *stat,
 		sz = div_u64(sz, SZ_1K);
 	}
 
-	drm_printf(p, "drm-%s-%s:\t%llu%s\n", stat, region, sz, units[u]);
+	drm_printf(p, "%s-%s-%s:\t%llu%s\n",
+		   prefix, stat, region, sz, units[u]);
 }
+EXPORT_SYMBOL(drm_fdinfo_print_size);
 
 /**
  * drm_print_memory_stats - A helper to print memory stats
@@ -858,15 +864,20 @@ void drm_print_memory_stats(struct drm_printer *p,
 			    enum drm_gem_object_status supported_status,
 			    const char *region)
 {
-	print_size(p, "total", region, stats->private + stats->shared);
-	print_size(p, "shared", region, stats->shared);
-	print_size(p, "active", region, stats->active);
+	const char *prefix = "drm";
+
+	drm_fdinfo_print_size(p, prefix, "total", region,
+			      stats->private + stats->shared);
+	drm_fdinfo_print_size(p, prefix, "shared", region, stats->shared);
+	drm_fdinfo_print_size(p, prefix, "active", region, stats->active);
 
 	if (supported_status & DRM_GEM_OBJECT_RESIDENT)
-		print_size(p, "resident", region, stats->resident);
+		drm_fdinfo_print_size(p, prefix, "resident", region,
+				      stats->resident);
 
 	if (supported_status & DRM_GEM_OBJECT_PURGEABLE)
-		print_size(p, "purgeable", region, stats->purgeable);
+		drm_fdinfo_print_size(p, prefix, "purgeable", region,
+				      stats->purgeable);
 }
 EXPORT_SYMBOL(drm_print_memory_stats);
 
diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
index f0ef32e9fa5e..001ae553e8c3 100644
--- a/include/drm/drm_file.h
+++ b/include/drm/drm_file.h
@@ -494,6 +494,11 @@ struct drm_memory_stats {
 
 enum drm_gem_object_status;
 
+void drm_fdinfo_print_size(struct drm_printer *p,
+				  const char *prefix,
+				  const char *stat,
+				  const char *region,
+				  u64 sz);
 void drm_print_memory_stats(struct drm_printer *p,
 			    const struct drm_memory_stats *stats,
 			    enum drm_gem_object_status supported_status,
-- 
2.47.1

[PATCH v10 3/5] drm/panthor: Expose size of driver internal BO's over fdinfo

[Adrián Larumbe]

This will display the sizes of kenrel BO's bound to an open file, which are
otherwise not exposed to UM through a handle.

The sizes recorded are as follows:
 - Per group: suspend buffer, protm-suspend buffer, syncobjcs
 - Per queue: ringbuffer, profiling slots, firmware interface
 - For all heaps in all heap pools across all VM's bound to an open file,
 record size of all heap chuks, and for each pool the gpu_context BO too.

This does not record the size of FW regions, as these aren't bound to a
specific open file and remain active through the whole life of the driver.

Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Mihail Atanassov <mihail.atanassov@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
---
 drivers/gpu/drm/panthor/panthor_drv.c   | 14 +++++++
 drivers/gpu/drm/panthor/panthor_heap.c  | 26 ++++++++++++
 drivers/gpu/drm/panthor/panthor_heap.h  |  2 +
 drivers/gpu/drm/panthor/panthor_mmu.c   | 33 +++++++++++++++
 drivers/gpu/drm/panthor/panthor_mmu.h   |  3 ++
 drivers/gpu/drm/panthor/panthor_sched.c | 56 ++++++++++++++++++++++++-
 drivers/gpu/drm/panthor/panthor_sched.h |  3 ++
 7 files changed, 136 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
index ac7e53f6e3f0..d5f98598d8d7 100644
--- a/drivers/gpu/drm/panthor/panthor_drv.c
+++ b/drivers/gpu/drm/panthor/panthor_drv.c
@@ -1457,12 +1457,26 @@ static void panthor_gpu_show_fdinfo(struct panthor_device *ptdev,
 	drm_printf(p, "drm-curfreq-panthor:\t%lu Hz\n", ptdev->current_frequency);
 }
 
+static void panthor_show_internal_memory_stats(struct drm_printer *p, struct drm_file *file)
+{
+	char *drv_name = file->minor->dev->driver->name;
+	struct panthor_file *pfile = file->driver_priv;
+	struct drm_memory_stats stats = {0};
+
+	panthor_fdinfo_gather_group_mem_info(pfile, &stats);
+	panthor_vm_heaps_sizes(pfile, &stats);
+
+	drm_fdinfo_print_size(p, drv_name, "resident", "memory", stats.resident);
+	drm_fdinfo_print_size(p, drv_name, "active", "memory", stats.active);
+}
+
 static void panthor_show_fdinfo(struct drm_printer *p, struct drm_file *file)
 {
 	struct drm_device *dev = file->minor->dev;
 	struct panthor_device *ptdev = container_of(dev, struct panthor_device, base);
 
 	panthor_gpu_show_fdinfo(ptdev, file->driver_priv, p);
+	panthor_show_internal_memory_stats(p, file);
 
 	drm_show_memory_stats(p, file);
 }
diff --git a/drivers/gpu/drm/panthor/panthor_heap.c b/drivers/gpu/drm/panthor/panthor_heap.c
index 3796a9eb22af..db0285ce5812 100644
--- a/drivers/gpu/drm/panthor/panthor_heap.c
+++ b/drivers/gpu/drm/panthor/panthor_heap.c
@@ -603,3 +603,29 @@ void panthor_heap_pool_destroy(struct panthor_heap_pool *pool)
 
 	panthor_heap_pool_put(pool);
 }
+
+/**
+ * panthor_heap_pool_size() - Calculate size of all chunks across all heaps in a pool
+ * @pool: Pool whose total chunk size to calculate.
+ *
+ * This function adds the size of all heap chunks across all heaps in the
+ * argument pool. It also adds the size of the gpu contexts kernel bo.
+ * It is meant to be used by fdinfo for displaying the size of internal
+ * driver BO's that aren't exposed to userspace through a GEM handle.
+ *
+ */
+size_t panthor_heap_pool_size(struct panthor_heap_pool *pool)
+{
+	struct panthor_heap *heap;
+	unsigned long i;
+	size_t size = 0;
+
+	down_read(&pool->lock);
+	xa_for_each(&pool->xa, i, heap)
+		size += heap->chunk_size * heap->chunk_count;
+	up_read(&pool->lock);
+
+	size += pool->gpu_contexts->obj->size;
+
+	return size;
+}
diff --git a/drivers/gpu/drm/panthor/panthor_heap.h b/drivers/gpu/drm/panthor/panthor_heap.h
index 25a5f2bba445..e3358d4e8edb 100644
--- a/drivers/gpu/drm/panthor/panthor_heap.h
+++ b/drivers/gpu/drm/panthor/panthor_heap.h
@@ -27,6 +27,8 @@ struct panthor_heap_pool *
 panthor_heap_pool_get(struct panthor_heap_pool *pool);
 void panthor_heap_pool_put(struct panthor_heap_pool *pool);
 
+size_t panthor_heap_pool_size(struct panthor_heap_pool *pool);
+
 int panthor_heap_grow(struct panthor_heap_pool *pool,
 		      u64 heap_gpu_va,
 		      u32 renderpasses_in_flight,
diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
index c3f0b0225cf9..064c40dc3bdf 100644
--- a/drivers/gpu/drm/panthor/panthor_mmu.c
+++ b/drivers/gpu/drm/panthor/panthor_mmu.c
@@ -1941,6 +1941,39 @@ struct panthor_heap_pool *panthor_vm_get_heap_pool(struct panthor_vm *vm, bool c
 	return pool;
 }
 
+/**
+ * panthor_vm_heaps_sizes() - Calculate size of all heap chunks across all
+ * heaps over all the heap pools in a VM
+ * @pfile: File.
+ * @stats: Memory stats to be updated.
+ *
+ * Calculate all heap chunk sizes in all heap pools bound to a VM. If the VM
+ * is active, record the size as active as well.
+ */
+void panthor_vm_heaps_sizes(struct panthor_file *pfile, struct drm_memory_stats *stats)
+{
+	struct panthor_vm *vm;
+	unsigned long i;
+
+	if (!pfile->vms)
+		return;
+
+	xa_lock(&pfile->vms->xa);
+	xa_for_each(&pfile->vms->xa, i, vm) {
+		size_t size = 0;
+
+		mutex_lock(&vm->heaps.lock);
+		if (vm->heaps.pool)
+			size = panthor_heap_pool_size(vm->heaps.pool);
+		mutex_unlock(&vm->heaps.lock);
+
+		stats->resident += size;
+		if (vm->as.id >= 0)
+			stats->active += size;
+	}
+	xa_unlock(&pfile->vms->xa);
+}
+
 static u64 mair_to_memattr(u64 mair, bool coherent)
 {
 	u64 memattr = 0;
diff --git a/drivers/gpu/drm/panthor/panthor_mmu.h b/drivers/gpu/drm/panthor/panthor_mmu.h
index 8d21e83d8aba..fc274637114e 100644
--- a/drivers/gpu/drm/panthor/panthor_mmu.h
+++ b/drivers/gpu/drm/panthor/panthor_mmu.h
@@ -9,6 +9,7 @@
 
 struct drm_exec;
 struct drm_sched_job;
+struct drm_memory_stats;
 struct panthor_gem_object;
 struct panthor_heap_pool;
 struct panthor_vm;
@@ -37,6 +38,8 @@ int panthor_vm_flush_all(struct panthor_vm *vm);
 struct panthor_heap_pool *
 panthor_vm_get_heap_pool(struct panthor_vm *vm, bool create);
 
+void panthor_vm_heaps_sizes(struct panthor_file *pfile, struct drm_memory_stats *stats);
+
 struct panthor_vm *panthor_vm_get(struct panthor_vm *vm);
 void panthor_vm_put(struct panthor_vm *vm);
 struct panthor_vm *panthor_vm_create(struct panthor_device *ptdev, bool for_mcu,
diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
index ef4bec7ff9c7..f3c6ca4dc11c 100644
--- a/drivers/gpu/drm/panthor/panthor_sched.c
+++ b/drivers/gpu/drm/panthor/panthor_sched.c
@@ -618,7 +618,7 @@ struct panthor_group {
 	 */
 	struct panthor_kernel_bo *syncobjs;
 
-	/** @fdinfo: Per-file total cycle and timestamp values reference. */
+	/** @fdinfo: Per-file info exposed through /proc/<process>/fdinfo */
 	struct {
 		/** @data: Total sampled values for jobs in queues from this group. */
 		struct panthor_gpu_usage data;
@@ -628,6 +628,9 @@ struct panthor_group {
 		 * and job post-completion processing function
 		 */
 		struct mutex lock;
+
+		/** @fdinfo.kbo_sizes: Aggregate size of private kernel BO's held by the group. */
+		size_t kbo_sizes;
 	} fdinfo;
 
 	/** @state: Group state. */
@@ -3365,6 +3368,29 @@ group_create_queue(struct panthor_group *group,
 	return ERR_PTR(ret);
 }
 
+static void add_group_kbo_sizes(struct panthor_device *ptdev,
+				struct panthor_group *group)
+{
+	struct panthor_queue *queue;
+	int i;
+
+	if (drm_WARN_ON(&ptdev->base, IS_ERR_OR_NULL(group)))
+		return;
+	if (drm_WARN_ON(&ptdev->base, ptdev != group->ptdev))
+		return;
+
+	group->fdinfo.kbo_sizes += group->suspend_buf->obj->size;
+	group->fdinfo.kbo_sizes += group->protm_suspend_buf->obj->size;
+	group->fdinfo.kbo_sizes += group->syncobjs->obj->size;
+
+	for (i = 0; i < group->queue_count; i++) {
+		queue =	group->queues[i];
+		group->fdinfo.kbo_sizes += queue->ringbuf->obj->size;
+		group->fdinfo.kbo_sizes += queue->iface.mem->obj->size;
+		group->fdinfo.kbo_sizes += queue->profiling.slots->obj->size;
+	}
+}
+
 #define MAX_GROUPS_PER_POOL		128
 
 int panthor_group_create(struct panthor_file *pfile,
@@ -3489,6 +3515,7 @@ int panthor_group_create(struct panthor_file *pfile,
 	}
 	mutex_unlock(&sched->reset.lock);
 
+	add_group_kbo_sizes(group->ptdev, group);
 	mutex_init(&group->fdinfo.lock);
 
 	return gid;
@@ -3606,6 +3633,33 @@ void panthor_group_pool_destroy(struct panthor_file *pfile)
 	pfile->groups = NULL;
 }
 
+/**
+ * panthor_fdinfo_gather_group_mem_info() - Retrieve aggregate size of all private kernel BO's
+ * belonging to all the groups owned by an open Panthor file
+ * @pfile: File.
+ * @stats: Memory statistics to be updated.
+ *
+ */
+void
+panthor_fdinfo_gather_group_mem_info(struct panthor_file *pfile,
+				     struct drm_memory_stats *stats)
+{
+	struct panthor_group_pool *gpool = pfile->groups;
+	struct panthor_group *group;
+	unsigned long i;
+
+	if (IS_ERR_OR_NULL(gpool))
+		return;
+
+	xa_lock(&gpool->xa);
+	xa_for_each(&gpool->xa, i, group) {
+		stats->resident += group->fdinfo.kbo_sizes;
+		if (group->csg_id >= 0)
+			stats->active += group->fdinfo.kbo_sizes;
+	}
+	xa_unlock(&gpool->xa);
+}
+
 static void job_release(struct kref *ref)
 {
 	struct panthor_job *job = container_of(ref, struct panthor_job, refcount);
diff --git a/drivers/gpu/drm/panthor/panthor_sched.h b/drivers/gpu/drm/panthor/panthor_sched.h
index 5ae6b4bde7c5..e650a445cf50 100644
--- a/drivers/gpu/drm/panthor/panthor_sched.h
+++ b/drivers/gpu/drm/panthor/panthor_sched.h
@@ -9,6 +9,7 @@ struct dma_fence;
 struct drm_file;
 struct drm_gem_object;
 struct drm_sched_job;
+struct drm_memory_stats;
 struct drm_panthor_group_create;
 struct drm_panthor_queue_create;
 struct drm_panthor_group_get_state;
@@ -36,6 +37,8 @@ void panthor_job_update_resvs(struct drm_exec *exec, struct drm_sched_job *job);
 
 int panthor_group_pool_create(struct panthor_file *pfile);
 void panthor_group_pool_destroy(struct panthor_file *pfile);
+void panthor_fdinfo_gather_group_mem_info(struct panthor_file *pfile,
+					  struct drm_memory_stats *stats);
 
 int panthor_sched_init(struct panthor_device *ptdev);
 void panthor_sched_unplug(struct panthor_device *ptdev);
-- 
2.47.1

[PATCH v10 4/5] Documentation/gpu: Add fdinfo meanings of panthor-*-memory tags

[Adrián Larumbe]

A previous commit enabled display of driver-internal kernel BO sizes
through the device file's fdinfo interface.

Expand the description of the relevant driver-specific key:value pairs
with the definitions of the new panthor-*-memory ones.

Reviewed-by: Mihail Atanassov <mihail.atanassov@arm.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
---
 Documentation/gpu/panthor.rst | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Documentation/gpu/panthor.rst b/Documentation/gpu/panthor.rst
index 3f8979fa2b86..7a841741278f 100644
--- a/Documentation/gpu/panthor.rst
+++ b/Documentation/gpu/panthor.rst
@@ -26,6 +26,8 @@ the currently possible format options:
      drm-cycles-panthor:     94439687187
      drm-maxfreq-panthor:    1000000000 Hz
      drm-curfreq-panthor:    1000000000 Hz
+     panthor-resident-memory:        10396 KiB
+     panthor-active-memory:  10396 KiB
      drm-total-memory:       16480 KiB
      drm-shared-memory:      0
      drm-active-memory:      16200 KiB
@@ -44,3 +46,11 @@ driver by writing into the appropriate sysfs node::
 
 Where `N` is a bit mask where cycle and timestamp sampling are respectively
 enabled by the first and second bits.
+
+Possible `panthor-*-memory` keys are: `active` and `resident`.
+These values convey the sizes of the internal driver-owned shmem BO's that
+aren't exposed to user-space through a DRM handle, like queue ring buffers,
+sync object arrays and heap chunks. Because they are all allocated and pinned
+at creation time, only `panthor-resident-memory` is necessary to tell us their
+size. `panthor-active-memory` shows the size of kernel BO's associated with
+VM's and groups currently being scheduled for execution by the GPU.
-- 
2.47.1

[PATCH v10 5/5] drm/panthor: Fix race condition when gathering fdinfo group samples

[Adrián Larumbe]

Commit e16635d88fa0 ("drm/panthor: add DRM fdinfo support") failed to
protect access to groups with an xarray lock, which could lead to
use-after-free errors.

Fixes: e16635d88fa0 ("drm/panthor: add DRM fdinfo support")
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
---
 drivers/gpu/drm/panthor/panthor_sched.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
index f3c6ca4dc11c..6d49b4f40f58 100644
--- a/drivers/gpu/drm/panthor/panthor_sched.c
+++ b/drivers/gpu/drm/panthor/panthor_sched.c
@@ -2865,6 +2865,7 @@ void panthor_fdinfo_gather_group_samples(struct panthor_file *pfile)
 	if (IS_ERR_OR_NULL(gpool))
 		return;
 
+	xa_lock(&gpool->xa);
 	xa_for_each(&gpool->xa, i, group) {
 		mutex_lock(&group->fdinfo.lock);
 		pfile->stats.cycles += group->fdinfo.data.cycles;
@@ -2873,6 +2874,7 @@ void panthor_fdinfo_gather_group_samples(struct panthor_file *pfile)
 		group->fdinfo.data.time = 0;
 		mutex_unlock(&group->fdinfo.lock);
 	}
+	xa_unlock(&gpool->xa);
 }
 
 static void group_sync_upd_work(struct work_struct *work)
-- 
2.47.1

Re: [PATCH v10 0/5] drm/panthor: Display size of internal kernel BOs through fdinfo

[Boris Brezillon]

On Thu, 30 Jan 2025 17:28:08 +0000
Adrián Larumbe <adrian.larumbe@collabora.com> wrote:

> This patch series enables display of the size of driver-owned shmem BO's that aren't
> exposed to userspace through a DRM handle. Also fixes a use-after-free bug in the
> existing fdinfo implementation for Panthor.
> 
> Discussion of previous revision can be found here [1].
> 
> Changelog:
> v10:
>  - Simplified locking scheme in panthor_vm_heaps_sizes
>  - Fixed kernel test robot warning about documentation
>  - Added some R-b tags to patches
> v9:
>  - Added proper locking around group pool xarray to prevent UAF errors.
>  - Added proper locking around vms pool xarray loop for the same reason
>  - Added new patch that fixes UAF error because no locking when accessing 
>    fdinfo group stats.
>  - Some minor cosmetic and naming changes.
> v8:
>  - Made print_size public and added prefix argument for drm_print_memory_stats
>  - Updated documentation commit to reflect new name tags
>  - Some minor polishing
> v7:
>  - Added new commit: mentions the formation rules for driver-specific fdinfo keys
>  - Added new commit: adds a helper that lets driver print memory size key:value
>    pairs with their driver name as a prefix.
>  - Modified later commits to make use of the previous ones.
>  - Deleted mentions of now unnecessary memory keys in the old revision.
> v6:
>  - Replace up_write witnh up_read, which was left out in the previous version
>  - Fixed some minor comment and documentation issues reported by the kernel test robot
> v5:
>  - Replaced down_write semaphore with the read flavour
>  - Fixed typo and added explicit description for drm-shared-internal in
>  the fdinfo documentation file for Panthor.
> v4:
>  - Remove unrelated formating fix
>  - Moved calculating overall size of a group's kernel BO's into
>  its own static helper.
>  - Renamed group kernel BO's size aggregation function to better
>  reflect its actual responsibility.
> 
> [1] https://lore.kernel.org/dri-devel/20250123225325.3271764-1-adrian.larumbe@collabora.com/
> 
> Adrián Larumbe (5):
>   Documentation/gpu: Clarify format of driver-specific fidnfo keys
>   drm/file: Add fdinfo helper for printing regions with prefix
>   drm/panthor: Expose size of driver internal BO's over fdinfo
>   Documentation/gpu: Add fdinfo meanings of panthor-*-memory tags
>   drm/panthor: Fix race condition when gathering fdinfo group samples

Queued to drm-misc-next.

> 
>  Documentation/gpu/drm-usage-stats.rst   |  5 ++-
>  Documentation/gpu/panthor.rst           | 10 +++++
>  drivers/gpu/drm/drm_file.c              | 27 ++++++++----
>  drivers/gpu/drm/panthor/panthor_drv.c   | 14 ++++++
>  drivers/gpu/drm/panthor/panthor_heap.c  | 26 +++++++++++
>  drivers/gpu/drm/panthor/panthor_heap.h  |  2 +
>  drivers/gpu/drm/panthor/panthor_mmu.c   | 33 ++++++++++++++
>  drivers/gpu/drm/panthor/panthor_mmu.h   |  3 ++
>  drivers/gpu/drm/panthor/panthor_sched.c | 58 ++++++++++++++++++++++++-
>  drivers/gpu/drm/panthor/panthor_sched.h |  3 ++
>  include/drm/drm_file.h                  |  5 +++
>  11 files changed, 176 insertions(+), 10 deletions(-)
>