From f1bbacedb0af640a93e47799203e556be2825da3 Mon Sep 17 00:00:00 2001 From: Jens Wiklander Date: Thu, 7 Nov 2019 11:42:56 +0100 Subject: tee: don't assign shm id for private shms Private shared memory object must not be referenced from user space. To guarantee that, don't assign an id to shared memory objects which are driver private. Signed-off-by: Jens Wiklander --- drivers/tee/tee_private.h | 3 ++- drivers/tee/tee_shm.c | 31 ++++++++++++++++++------------- 2 files changed, 20 insertions(+), 14 deletions(-) (limited to 'drivers/tee') diff --git a/drivers/tee/tee_private.h b/drivers/tee/tee_private.h index f797171f0434..e55204df31ce 100644 --- a/drivers/tee/tee_private.h +++ b/drivers/tee/tee_private.h @@ -37,7 +37,8 @@ struct tee_shm_pool { * @num_users: number of active users of this device * @c_no_user: completion used when unregistering the device * @mutex: mutex protecting @num_users and @idr - * @idr: register of shared memory object allocated on this device + * @idr: register of user space shared memory objects allocated or + * registered on this device * @pool: shared memory pool */ struct tee_device { diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index b666854c2491..02210f179ae3 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -15,9 +15,11 @@ static void tee_shm_release(struct tee_shm *shm) { struct tee_device *teedev = shm->teedev; - mutex_lock(&teedev->mutex); - idr_remove(&teedev->idr, shm->id); - mutex_unlock(&teedev->mutex); + if (shm->flags & TEE_SHM_DMA_BUF) { + mutex_lock(&teedev->mutex); + idr_remove(&teedev->idr, shm->id); + mutex_unlock(&teedev->mutex); + } if (shm->flags & TEE_SHM_POOL) { struct tee_shm_pool_mgr *poolm; @@ -137,17 +139,18 @@ struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags) goto err_kfree; } - mutex_lock(&teedev->mutex); - shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL); - mutex_unlock(&teedev->mutex); - if (shm->id < 0) { - ret = ERR_PTR(shm->id); - goto err_pool_free; - } if (flags & TEE_SHM_DMA_BUF) { DEFINE_DMA_BUF_EXPORT_INFO(exp_info); + mutex_lock(&teedev->mutex); + shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL); + mutex_unlock(&teedev->mutex); + if (shm->id < 0) { + ret = ERR_PTR(shm->id); + goto err_pool_free; + } + exp_info.ops = &tee_shm_dma_buf_ops; exp_info.size = shm->size; exp_info.flags = O_RDWR; @@ -165,9 +168,11 @@ struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags) return shm; err_rem: - mutex_lock(&teedev->mutex); - idr_remove(&teedev->idr, shm->id); - mutex_unlock(&teedev->mutex); + if (flags & TEE_SHM_DMA_BUF) { + mutex_lock(&teedev->mutex); + idr_remove(&teedev->idr, shm->id); + mutex_unlock(&teedev->mutex); + } err_pool_free: poolm->ops->free(poolm, shm); err_kfree: -- cgit v1.2.3