linux-kernel - [PATCH 1/2] clk: Introduce kunit wrapper around clk_hw_init_rate

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230721-clk-fix-kunit-lockdep-v1-1-32cdba4c8fc1@kernel.org>
Date:   Fri, 21 Jul 2023 09:09:32 +0200
From:   Maxime Ripard <mripard@...nel.org>
To:     Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>
Cc:     linux-clk@...r.kernel.org, linux-kernel@...r.kernel.org,
        Maxime Ripard <mripard@...nel.org>,
        Guenter Roeck <linux@...ck-us.net>,
        kernel test robot <yujie.liu@...el.com>
Subject: [PATCH 1/2] clk: Introduce kunit wrapper around
 clk_hw_init_rate_request

Some kunit tests are meant to test the behaviour of providers (and
most notably __clk_determine_rate()), but don't run those functions with
the clk prepare_lock held which results in lockdep warning.

clk_hw_init_rate_request is one of the functions being executed from a
test which should have the lock held. Let's introduce a wrapper around
it meant to be used only by kunit tests.

Reported-by: Guenter Roeck <linux@...ck-us.net>
Link: https://lore.kernel.org/linux-clk/2b594e50-2bbf-4a2d-88e6-49fc39f3957a@roeck-us.net/
Reported-by: kernel test robot <yujie.liu@...el.com>
Link: https://lore.kernel.org/oe-lkp/202301310919.b9d56ee3-yujie.liu@intel.com
Fixes: 262ca38f4b6e ("clk: Stop forwarding clk_rate_requests to the parent")
Signed-off-by: Maxime Ripard <mripard@...nel.org>
---
 drivers/clk/clk.c            | 26 ++++++++++++++++++++++++++
 drivers/clk/clk_test.c       |  2 +-
 include/linux/clk-provider.h | 11 +++++++++++
 3 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index c249f9791ae8..8ee9bd02af76 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -6,6 +6,7 @@
  * Standard functionality for the common clock API.  See Documentation/driver-api/clk.rst
  */
 
+#include <kunit/test-bug.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
 #include <linux/clk/clk-conf.h>
@@ -1556,6 +1557,31 @@ void clk_hw_init_rate_request(const struct clk_hw *hw,
 }
 EXPORT_SYMBOL_GPL(clk_hw_init_rate_request);
 
+#if IS_ENABLED(CONFIG_KUNIT)
+/**
+ * clk_kunit_init_rate_request - Initializes a clk_rate_request
+ * @hw: the clk for which we want to submit a rate request
+ * @req: the clk_rate_request structure we want to initialise
+ * @rate: the rate which is to be requested
+ *
+ * Initializes a clk_rate_request structure to submit to
+ * __clk_determine_rate() or similar functions. Only usable in kunit
+ * test contexts, use clk_hw_init_rate_request() otherwise.
+ */
+void clk_kunit_init_rate_request(const struct clk_hw *hw,
+				 struct clk_rate_request *req,
+				 unsigned long rate)
+{
+	if (!kunit_get_current_test())
+		return;
+
+	clk_prepare_lock();
+	clk_hw_init_rate_request(hw, req, rate);
+	clk_prepare_unlock();
+}
+EXPORT_SYMBOL_GPL(clk_kunit_init_rate_request);
+#endif
+
 /**
  * clk_hw_forward_rate_request - Forwards a clk_rate_request to a clock's parent
  * @hw: the original clock that got the rate request
diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c
index a154ec9d0111..a64f7036baa3 100644
--- a/drivers/clk/clk_test.c
+++ b/drivers/clk/clk_test.c
@@ -2230,7 +2230,7 @@ static void clk_leaf_mux_set_rate_parent_determine_rate(struct kunit *test)
 	rate = clk_get_rate(clk);
 	KUNIT_ASSERT_EQ(test, rate, DUMMY_CLOCK_RATE_1);
 
-	clk_hw_init_rate_request(hw, &req, DUMMY_CLOCK_RATE_2);
+	clk_kunit_init_rate_request(hw, &req, DUMMY_CLOCK_RATE_2);
 
 	ret = __clk_determine_rate(hw, &req);
 	KUNIT_ASSERT_EQ(test, ret, 0);
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 0f0cd01906b4..efdebfa3fce9 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -67,6 +67,17 @@ struct clk_rate_request {
 void clk_hw_init_rate_request(const struct clk_hw *hw,
 			      struct clk_rate_request *req,
 			      unsigned long rate);
+#if IS_ENABLED(CONFIG_KUNIT)
+void clk_kunit_init_rate_request(const struct clk_hw *hw,
+				 struct clk_rate_request *req,
+				 unsigned long rate);
+#else
+static inline void clk_kunit_init_rate_request(const struct clk_hw *hw,
+					       struct clk_rate_request *req,
+					       unsigned long rate)
+{
+}
+#endif
 void clk_hw_forward_rate_request(const struct clk_hw *core,
 				 const struct clk_rate_request *old_req,
 				 const struct clk_hw *parent,

-- 
2.41.0