[PATCH 1/2] optee: fix tee out of memory failure seen during kexec reboot

Allen Pais
2021-02-17T09:28:28Z

From: Allen Pais <apais@linux.microsoft.com>

The following out of memory errors are seen on kexec reboot
from the optee core.

[ 0.368428] tee_bnxt_fw optee-clnt0: tee_shm_alloc failed
[ 0.368461] tee_bnxt_fw: probe of optee-clnt0 failed with error -22

tee_shm_release() is not invoked on dma shm buffer.

Implement .shutdown() method to handle the release of the buffers
correctly.

More info:
https://github.com/OP-TEE/optee_os/issues/3637

Signed-off-by: Allen Pais <apais@linux.microsoft.com>
---
drivers/tee/optee/core.c | 69 ++++++++++++++++++++++++++++------------
1 file changed, 49 insertions(+), 20 deletions(-)

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
index cf4718c6d35d..b402e5eace7b 100644
--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c
@@ -582,36 +582,64 @@ static optee_invoke_fn *get_invoke_func(struct device *dev)
return ERR_PTR(-EINVAL);
}

-static int optee_remove(struct platform_device *pdev)
+static int __optee_shutoff(struct platform_device *pdev, bool shutdown)
{
struct optee *optee = platform_get_drvdata(pdev);

- /*
- * Ask OP-TEE to free all cached shared memory objects to decrease
- * reference counters and also avoid wild pointers in secure world
- * into the old shared memory range.
- */
- optee_disable_shm_cache(optee);
+ if (shutdown) {
+ optee_disable_shm_cache(optee);
+ } else {
+ /*
+ * Ask OP-TEE to free all cached shared memory
+ * objects to decrease reference counters and
+ * also avoid wild pointers in secure world
+ * into the old shared memory range.
+ */
+ optee_disable_shm_cache(optee);

- /*
- * The two devices have to be unregistered before we can free the
- * other resources.
- */
- tee_device_unregister(optee->supp_teedev);
- tee_device_unregister(optee->teedev);
+ /*
+ * The two devices have to be unregistered before
+ * we can free the other resources.
+ */
+ tee_device_unregister(optee->supp_teedev);
+ tee_device_unregister(optee->teedev);

- tee_shm_pool_free(optee->pool);
- if (optee->memremaped_shm)
- memunmap(optee->memremaped_shm);
- optee_wait_queue_exit(&optee->wait_queue);
- optee_supp_uninit(&optee->supp);
- mutex_destroy(&optee->call_queue.mutex);
+ tee_shm_pool_free(optee->pool);
+ if (optee->memremaped_shm)
+ memunmap(optee->memremaped_shm);
+ optee_wait_queue_exit(&optee->wait_queue);
+ optee_supp_uninit(&optee->supp);
+ mutex_destroy(&optee->call_queue.mutex);

- kfree(optee);
+ kfree(optee);
+ }

return 0;
}

+/* optee_remove - Device Removal Routine
+ * @pdev: platform device information struct
+ *
+ * optee_remove is called by platform subsystem to alter the driver
+ * that it should release the device
+ */
+static int optee_remove(struct platform_device *pdev)
+{
+ return __optee_shutoff(pdev, false);
+}
+
+/* optee_shutdown - Device Removal Routine
+ * @pdev: platform device information struct
+ *
+ * platform_shutdown is called by the platform subsystem to alter
+ * the driver that a shutdown/reboot(or kexec) is happening and
+ * device must be disabled.
+ */
+static void optee_shutdown(struct platform_device *pdev)
+{
+ __optee_shutoff(pdev, true);
+}
+
static int optee_probe(struct platform_device *pdev)
{
optee_invoke_fn *invoke_fn;
@@ -738,6 +766,7 @@ MODULE_DEVICE_TABLE(of, optee_dt_match);
static struct platform_driver optee_driver = {
.probe = optee_probe,
.remove = optee_remove,
+ .shutdown = optee_shutdown,
.driver = {
.name = "optee",
.of_match_table = optee_dt_match,
--
2.25.1