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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 04/10] keys: Change keyring_serialise_link_sem to a mutex [ver #2] From: David Howells To: keyrings@vger.kernel.org Cc: dhowells@redhat.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, ebiggers@kernel.org Date: Thu, 30 May 2019 18:25:41 +0100 Message-ID: <155923714140.949.13143637354252349694.stgit@warthog.procyon.org.uk> In-Reply-To: <155923711088.949.14909672457214372214.stgit@warthog.procyon.org.uk> References: <155923711088.949.14909672457214372214.stgit@warthog.procyon.org.uk> User-Agent: StGit/unknown-version MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Thu, 30 May 2019 17:25:43 +0000 (UTC) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP Change keyring_serialise_link_sem to a mutex as it's only ever write-locked. Signed-off-by: David Howells --- security/keys/keyring.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/security/keys/keyring.c b/security/keys/keyring.c index 5b218b270598..ca6694ba1773 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -100,7 +100,7 @@ EXPORT_SYMBOL(key_type_keyring); * Semaphore to serialise link/link calls to prevent two link calls in parallel * introducing a cycle. */ -static DECLARE_RWSEM(keyring_serialise_link_sem); +static DEFINE_MUTEX(keyring_serialise_link_lock); /* * Publish the name of a keyring so that it can be found by name (if it has @@ -1206,7 +1206,7 @@ int __key_link_begin(struct key *keyring, const struct keyring_index_key *index_key, struct assoc_array_edit **_edit) __acquires(&keyring->sem) - __acquires(&keyring_serialise_link_sem) + __acquires(&keyring_serialise_link_lock) { struct assoc_array_edit *edit; int ret; @@ -1228,7 +1228,7 @@ int __key_link_begin(struct key *keyring, /* serialise link/link calls to prevent parallel calls causing a cycle * when linking two keyring in opposite orders */ if (index_key->type == &key_type_keyring) - down_write(&keyring_serialise_link_sem); + mutex_lock(&keyring_serialise_link_lock); /* Create an edit script that will insert/replace the key in the * keyring tree. @@ -1260,7 +1260,7 @@ int __key_link_begin(struct key *keyring, assoc_array_cancel_edit(edit); error_sem: if (index_key->type == &key_type_keyring) - up_write(&keyring_serialise_link_sem); + mutex_unlock(&keyring_serialise_link_lock); error_krsem: up_write(&keyring->sem); kleave(" = %d", ret); @@ -1307,13 +1307,13 @@ void __key_link_end(struct key *keyring, const struct keyring_index_key *index_key, struct assoc_array_edit *edit) __releases(&keyring->sem) - __releases(&keyring_serialise_link_sem) + __releases(&keyring_serialise_link_lock) { BUG_ON(index_key->type == NULL); kenter("%d,%s,", keyring->serial, index_key->type->name); if (index_key->type == &key_type_keyring) - up_write(&keyring_serialise_link_sem); + mutex_unlock(&keyring_serialise_link_lock); if (edit) { if (!edit->dead_leaf) {