We don't want imported/exported BOs to be purges, as those are shared with other processes that might still use them. We should also refuse to export a BO if it's been marked purgeable or has already been purged.
Fixes: 013b65101315 ("drm/panfrost: Add madvise and shrinker support") Cc: stable@vger.kernel.org Signed-off-by: Boris Brezillon boris.brezillon@collabora.com --- drivers/gpu/drm/panfrost/panfrost_drv.c | 19 ++++++++++++++++- drivers/gpu/drm/panfrost/panfrost_gem.c | 27 +++++++++++++++++++++++++ 2 files changed, 45 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c index 1c67ac434e10..751df975534f 100644 --- a/drivers/gpu/drm/panfrost/panfrost_drv.c +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c @@ -343,6 +343,7 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data, struct drm_panfrost_madvise *args = data; struct panfrost_device *pfdev = dev->dev_private; struct drm_gem_object *gem_obj; + int ret;
gem_obj = drm_gem_object_lookup(file_priv, args->handle); if (!gem_obj) { @@ -350,6 +351,19 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data, return -ENOENT; }
+ /* + * We don't want to mark exported/imported BOs as purgeable: we're not + * the only owner in that case. + */ + mutex_lock(&dev->object_name_lock); + if (gem_obj->dma_buf) + ret = -EINVAL; + else + ret = 0; + + if (ret) + goto out_unlock_object_name; + mutex_lock(&pfdev->shrinker_lock); args->retained = drm_gem_shmem_madvise(gem_obj, args->madv);
@@ -364,8 +378,11 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data, } mutex_unlock(&pfdev->shrinker_lock);
+out_unlock_object_name: + mutex_unlock(&dev->object_name_lock); + drm_gem_object_put_unlocked(gem_obj); - return 0; + return ret; }
int panfrost_unstable_ioctl_check(void) diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c index 92a95210a899..31d6417dd21c 100644 --- a/drivers/gpu/drm/panfrost/panfrost_gem.c +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c @@ -99,6 +99,32 @@ void panfrost_gem_close(struct drm_gem_object *obj, struct drm_file *file_priv) spin_unlock(&priv->mm_lock); }
+static struct dma_buf * +panfrost_gem_export(struct drm_gem_object *obj, int flags) +{ + struct panfrost_gem_object *bo = to_panfrost_bo(obj); + int ret; + + /* + * We must make sure the BO has not been marked purgeable/purged before + * adding the mapping. + * Note that we don't need to protect this test with a lock because + * &drm_gem_object_funcs.export() is called with + * &drm_device.object_lock held, and panfrost_ioctl_madvise() takes + * this lock before calling drm_gem_shmem_madvise() (the function that + * modifies bo->base.madv). + */ + if (bo->base.madv == PANFROST_MADV_WILLNEED) + ret = -EINVAL; + else + ret = 0; + + if (ret) + return ERR_PTR(ret); + + return drm_gem_prime_export(obj, flags); +} + static int panfrost_gem_pin(struct drm_gem_object *obj) { if (to_panfrost_bo(obj)->is_heap) @@ -112,6 +138,7 @@ static const struct drm_gem_object_funcs panfrost_gem_funcs = { .open = panfrost_gem_open, .close = panfrost_gem_close, .print_info = drm_gem_shmem_print_info, + .export = panfrost_gem_export, .pin = panfrost_gem_pin, .unpin = drm_gem_shmem_unpin, .get_sg_table = drm_gem_shmem_get_sg_table,