From 94c4aa266111262c96c98f822d1bccc494786fee Mon Sep 17 00:00:00 2001 From: Matthew Auld Date: Wed, 11 Sep 2024 16:55:28 +0100 Subject: drm/xe/client: add missing bo locking in show_meminfo() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit bo_meminfo() wants to inspect bo state like tt and the ttm resource, however this state can change at any point leading to stuff like NPD and UAF, if the bo lock is not held. Grab the bo lock when calling bo_meminfo(), ensuring we drop any spinlocks first. In the case of object_idr we now also need to hold a ref. v2 (MattB) - Also add xe_bo_assert_held() Fixes: 0845233388f8 ("drm/xe: Implement fdinfo memory stats printing") Signed-off-by: Matthew Auld Cc: Himal Prasad Ghimiray Cc: Tejas Upadhyay Cc: "Thomas Hellström" Cc: # v6.8+ Reviewed-by: Matthew Brost Reviewed-by: Tejas Upadhyay Link: https://patchwork.freedesktop.org/patch/msgid/20240911155527.178910-6-matthew.auld@intel.com (cherry picked from commit 4f63d712fa104c3ebefcb289d1e733e86d8698c7) Signed-off-by: Rodrigo Vivi --- drivers/gpu/drm/xe/xe_drm_client.c | 39 +++++++++++++++++++++++++++++++++++--- 1 file changed, 36 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/xe/xe_drm_client.c b/drivers/gpu/drm/xe/xe_drm_client.c index ec141357480f..1af95b9b9171 100644 --- a/drivers/gpu/drm/xe/xe_drm_client.c +++ b/drivers/gpu/drm/xe/xe_drm_client.c @@ -10,6 +10,7 @@ #include #include +#include "xe_assert.h" #include "xe_bo.h" #include "xe_bo_types.h" #include "xe_device_types.h" @@ -151,10 +152,13 @@ void xe_drm_client_add_bo(struct xe_drm_client *client, */ void xe_drm_client_remove_bo(struct xe_bo *bo) { + struct xe_device *xe = ttm_to_xe_device(bo->ttm.bdev); struct xe_drm_client *client = bo->client; + xe_assert(xe, !kref_read(&bo->ttm.base.refcount)); + spin_lock(&client->bos_lock); - list_del(&bo->client_link); + list_del_init(&bo->client_link); spin_unlock(&client->bos_lock); xe_drm_client_put(client); @@ -166,6 +170,8 @@ static void bo_meminfo(struct xe_bo *bo, u64 sz = bo->size; u32 mem_type; + xe_bo_assert_held(bo); + if (bo->placement.placement) mem_type = bo->placement.placement->mem_type; else @@ -207,7 +213,20 @@ static void show_meminfo(struct drm_printer *p, struct drm_file *file) idr_for_each_entry(&file->object_idr, obj, id) { struct xe_bo *bo = gem_to_xe_bo(obj); - bo_meminfo(bo, stats); + if (dma_resv_trylock(bo->ttm.base.resv)) { + bo_meminfo(bo, stats); + xe_bo_unlock(bo); + } else { + xe_bo_get(bo); + spin_unlock(&file->table_lock); + + xe_bo_lock(bo, false); + bo_meminfo(bo, stats); + xe_bo_unlock(bo); + + xe_bo_put(bo); + spin_lock(&file->table_lock); + } } spin_unlock(&file->table_lock); @@ -217,7 +236,21 @@ static void show_meminfo(struct drm_printer *p, struct drm_file *file) if (!kref_get_unless_zero(&bo->ttm.base.refcount)) continue; - bo_meminfo(bo, stats); + if (dma_resv_trylock(bo->ttm.base.resv)) { + bo_meminfo(bo, stats); + xe_bo_unlock(bo); + } else { + spin_unlock(&client->bos_lock); + + xe_bo_lock(bo, false); + bo_meminfo(bo, stats); + xe_bo_unlock(bo); + + spin_lock(&client->bos_lock); + /* The bo ref will prevent this bo from being removed from the list */ + xe_assert(xef->xe, !list_empty(&bo->client_link)); + } + xe_bo_put_deferred(bo, &deferred); } spin_unlock(&client->bos_lock); -- cgit v1.2.3-70-g09d2