From: Horia GeantA <horia.geanta@xxxxxxx>
Current implementations is not being able to gracefully unregister
crypto algorithms from crypto API while there are users / allocated
tfms (cra_refcnt > 1).
When unloading the caam_jr module, the .remove callback for the last JR
device exits with -EBUSY and doesn't perform the clean-up
(crypto algorithms unregistering etc.).
One side effect of this is leading to an oops, which occurs due to a
corruption in the linked list of "misc devices"
(drivers/char/misc.c - misc_list)
Signed-off-by: Horia GeantA <horia.geanta@xxxxxxx>
---
drivers/crypto/caam/jr.c | 39 +++++++++++++++++++++++++++++++++------
1 file changed, 33 insertions(+), 6 deletions(-)
diff --git a/drivers/crypto/caam/jr.c b/drivers/crypto/caam/jr.c
index 724fdec18bf9..9918ae0a33a7 100644
--- a/drivers/crypto/caam/jr.c
+++ b/drivers/crypto/caam/jr.c
@@ -27,8 +27,36 @@ static struct jr_driver_data driver_data;
static DEFINE_MUTEX(algs_lock);
static unsigned int active_devs;
-static void register_algs(struct caam_drv_private_jr *jrpriv,
- struct device *dev)
+static void init_misc_func(struct caam_drv_private_jr *jrpriv,
+ struct device *dev)
+{
+ mutex_lock(&algs_lock);
+
+ if (active_devs != 1)
+ goto algs_unlock;
+
+ jrpriv->hwrng = !caam_rng_init(dev);
+
+algs_unlock:
+ mutex_unlock(&algs_lock);
+}
+
+static void exit_misc_func(struct caam_drv_private_jr *jrpriv,
+ struct device *dev)
+{
+ mutex_lock(&algs_lock);
+
+ if (active_devs != 1)
+ goto algs_unlock;
+
+ if (jrpriv->hwrng)
+ caam_rng_exit(dev);
+
+algs_unlock:
+ mutex_unlock(&algs_lock);
+}
+
+static void register_algs(struct device *dev)
{
mutex_lock(&algs_lock);
@@ -38,7 +66,6 @@ static void register_algs(struct caam_drv_private_jr *jrpriv,
caam_algapi_init(dev);
caam_algapi_hash_init(dev);
caam_pkc_init(dev);
- jrpriv->hwrng = !caam_rng_init(dev);
caam_prng_register(dev);
caam_qi_algapi_init(dev);
@@ -136,8 +163,7 @@ static int caam_jr_remove(struct platform_device *pdev)
jrdev = &pdev->dev;
jrpriv = dev_get_drvdata(jrdev);
- if (jrpriv->hwrng)
- caam_rng_exit(jrdev->parent);
+ exit_misc_func(jrpriv, jrdev->parent);
/*
* Return EBUSY if job ring already allocated.
@@ -595,7 +621,8 @@ static int caam_jr_probe(struct platform_device *pdev)
atomic_set(&jrpriv->tfm_count, 0);
- register_algs(jrpriv, jrdev->parent);
+ register_algs(jrdev->parent);
+ init_misc_func(jrpriv, jrdev->parent);
return 0;
}
--
2.25.1
