Hi Am 15.01.21 um 15:11 schrieb Daniel Vetter:
On Fri, Jan 15, 2021 at 09:57:24AM +0000, Kieran Bingham wrote:Hi Thomas, On 15/01/2021 09:30, Thomas Zimmermann wrote:The GEM mmap code relies on the GEM object's mmap callback to set the VMA's vm_ops field. This is easily forgotten and already led to a memory leak in the CMA helpers. Instead set the vm_ops field in the DRM core code to the GEM object's value. Drivers with different needs can override this in their mmap callback. v2: * support (vm_ops == NULL) if mmap is given; required by VRAM helpersI guess vram helpers need this because ttm has it's own vm_ops struct? Might be another thing worth unifying (eventually).
I've been working on converting drivers to struct drm_gem_object_funcs.mmap and using DRM helpers for the other mmap callbacks. Part of this would include some unifying of the vm_ops handling. TTM drivers are kind of special here.
Best regards Thomas
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx> Fixes: f5ca8eb6f9bd ("drm/cma-helper: Implement mmap as GEM CMA object functions") Reported-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx> Tested-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>Re-tested just fine this side ;-) - https://paste.ubuntu.com/p/Jgz6xMKNJX/Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>Thanks KieranCc: Maxime Ripard <mripard@xxxxxxxxxx> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> Cc: David Airlie <airlied@xxxxxxxx> Cc: Daniel Vetter <daniel@xxxxxxxx> Cc: Eric Anholt <eric@xxxxxxxxxx> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx --- drivers/gpu/drm/drm_gem.c | 19 ++++++++++--------- drivers/gpu/drm/drm_prime.c | 2 ++ 2 files changed, 12 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index 34b2f111c01c..c2ce78c4edc3 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -1068,20 +1068,17 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size, drm_gem_object_get(obj);vma->vm_private_data = obj;+ vma->vm_ops = obj->funcs->vm_ops;if (obj->funcs->mmap) {ret = obj->funcs->mmap(obj, vma); - if (ret) { - drm_gem_object_put(obj); - return ret; - } + if (ret) + goto err_drm_gem_object_put; WARN_ON(!(vma->vm_flags & VM_DONTEXPAND)); } else { - if (obj->funcs->vm_ops) - vma->vm_ops = obj->funcs->vm_ops; - else { - drm_gem_object_put(obj); - return -EINVAL; + if (!vma->vm_ops) { + ret = -EINVAL; + goto err_drm_gem_object_put; }vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;@@ -1090,6 +1087,10 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size, }return 0;+ +err_drm_gem_object_put: + drm_gem_object_put(obj); + return ret; } EXPORT_SYMBOL(drm_gem_mmap_obj);diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.cindex 683aa29ecd3b..2a54f86856af 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -717,6 +717,8 @@ int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) vma->vm_pgoff += drm_vma_node_start(&obj->vma_node);if (obj->funcs && obj->funcs->mmap) {+ vma->vm_ops = obj->funcs->vm_ops; +Do you know how much we still need the non-obj->funcs path here? Maybe time to detele it and wrape the obj->funcs check in a WARN_ON? -Danielret = obj->funcs->mmap(obj, vma); if (ret) return ret;
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 Nürnberg, Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Felix Imendörffer
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