blk-throttle: check for overflow in calculate_bytes_allowed

[platform/kernel/linux-starfive.git] / block / blk-crypto-profile.c

diff --git a/block/blk-crypto-profile.c b/block/blk-crypto-profile.c
index 96c5119..aa7fc14 100644 (file)
--- a/block/blk-crypto-profile.c
+++ b/block/blk-crypto-profile.c
@@ -32,6 +32,7 @@
 #include <linux/wait.h>
 #include <linux/blkdev.h>
 #include <linux/blk-integrity.h>
+#include "blk-crypto-internal.h"
 
 struct blk_crypto_keyslot {
        atomic_t slot_refs;
@@ -78,7 +79,14 @@ int blk_crypto_profile_init(struct blk_crypto_profile *profile,
        unsigned int slot_hashtable_size;
 
        memset(profile, 0, sizeof(*profile));
-       init_rwsem(&profile->lock);
+
+       /*
+        * profile->lock of an underlying device can nest inside profile->lock
+        * of a device-mapper device, so use a dynamic lock class to avoid
+        * false-positive lockdep reports.
+        */
+       lockdep_register_key(&profile->lockdep_key);
+       __init_rwsem(&profile->lock, "&profile->lock", &profile->lockdep_key);
 
        if (num_slots == 0)
                return 0;
@@ -88,7 +96,7 @@ int blk_crypto_profile_init(struct blk_crypto_profile *profile,
        profile->slots = kvcalloc(num_slots, sizeof(profile->slots[0]),
                                  GFP_KERNEL);
        if (!profile->slots)
-               return -ENOMEM;
+               goto err_destroy;
 
        profile->num_slots = num_slots;
 
@@ -353,28 +361,16 @@ bool __blk_crypto_cfg_supported(struct blk_crypto_profile *profile,
        return true;
 }
 
-/**
- * __blk_crypto_evict_key() - Evict a key from a device.
- * @profile: the crypto profile of the device
- * @key: the key to evict.  It must not still be used in any I/O.
- *
- * If the device has keyslots, this finds the keyslot (if any) that contains the
- * specified key and calls the driver's keyslot_evict function to evict it.
- *
- * Otherwise, this just calls the driver's keyslot_evict function if it is
- * implemented, passing just the key (without any particular keyslot).  This
- * allows layered devices to evict the key from their underlying devices.
- *
- * Context: Process context. Takes and releases profile->lock.
- * Return: 0 on success or if there's no keyslot with the specified key, -EBUSY
- *        if the keyslot is still in use, or another -errno value on other
- *        error.
+/*
+ * This is an internal function that evicts a key from an inline encryption
+ * device that can be either a real device or the blk-crypto-fallback "device".
+ * It is used only by blk_crypto_evict_key(); see that function for details.
  */
 int __blk_crypto_evict_key(struct blk_crypto_profile *profile,
                           const struct blk_crypto_key *key)
 {
        struct blk_crypto_keyslot *slot;
-       int err = 0;
+       int err;
 
        if (profile->num_slots == 0) {
                if (profile->ll_ops.keyslot_evict) {
@@ -388,22 +384,30 @@ int __blk_crypto_evict_key(struct blk_crypto_profile *profile,
 
        blk_crypto_hw_enter(profile);
        slot = blk_crypto_find_keyslot(profile, key);
-       if (!slot)
-               goto out_unlock;
+       if (!slot) {
+               /*
+                * Not an error, since a key not in use by I/O is not guaranteed
+                * to be in a keyslot.  There can be more keys than keyslots.
+                */
+               err = 0;
+               goto out;
+       }
 
        if (WARN_ON_ONCE(atomic_read(&slot->slot_refs) != 0)) {
+               /* BUG: key is still in use by I/O */
                err = -EBUSY;
-               goto out_unlock;
+               goto out_remove;
        }
        err = profile->ll_ops.keyslot_evict(profile, key,
                                            blk_crypto_keyslot_index(slot));
-       if (err)
-               goto out_unlock;
-
+out_remove:
+       /*
+        * Callers free the key even on error, so unlink the key from the hash
+        * table and clear slot->key even on error.
+        */
        hlist_del(&slot->hash_node);
        slot->key = NULL;
-       err = 0;
-out_unlock:
+out:
        blk_crypto_hw_exit(profile);
        return err;
 }
@@ -444,6 +448,7 @@ void blk_crypto_profile_destroy(struct blk_crypto_profile *profile)
 {
        if (!profile)
                return;
+       lockdep_unregister_key(&profile->lockdep_key);
        kvfree(profile->slot_hashtable);
        kvfree_sensitive(profile->slots,
                         sizeof(profile->slots[0]) * profile->num_slots);