clk/clk-next boot bisection: v5.3-rc1-84-g2ced74113e7f on panda

clk/clk-next boot bisection: v5.3-rc1-84-g2ced74113e7f on panda

[kernelci.org bot]

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* This automated bisection report was sent to you on the basis  *
* that you may be involved with the breaking commit it has      *
* found.  No manual investigation has been done to verify it,   *
* and the root cause of the problem may be somewhere else.      *
*                                                               *
* If you do send a fix, please include this trailer:            *
*   Reported-by: "kernelci.org bot" <bot@kernelci.org>          *
*                                                               *
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* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

clk/clk-next boot bisection: v5.3-rc1-84-g2ced74113e7f on panda

Summary:
  Start:      2ced74113e7f Merge branch 'clk-init-destroy' into clk-next
  Details:    https://kernelci.org/boot/id/5d55b8e459b514d41bf122b4
  Plain log:  https://storage.kernelci.org//clk/clk-next/v5.3-rc1-84-g2ced74113e7f/arm/omap2plus_defconfig/gcc-8/lab-collabora/boot-omap4-panda.txt
  HTML log:   https://storage.kernelci.org//clk/clk-next/v5.3-rc1-84-g2ced74113e7f/arm/omap2plus_defconfig/gcc-8/lab-collabora/boot-omap4-panda.html
  Result:     c82987e740d1 clk: Overwrite clk_hw::init with NULL during clk_register()

Checks:
  revert:     PASS
  verify:     PASS

Parameters:
  Tree:       clk
  URL:        https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git
  Branch:     clk-next
  Target:     panda
  CPU arch:   arm
  Lab:        lab-collabora
  Compiler:   gcc-8
  Config:     omap2plus_defconfig
  Test suite: boot

Breaking commit found:

-------------------------------------------------------------------------------
commit c82987e740d12be98b8ae8aa9221b8b9e2541271
Author: Stephen Boyd <sboyd@kernel.org>
Date:   Wed Jul 31 12:35:17 2019 -0700

    clk: Overwrite clk_hw::init with NULL during clk_register()
    
    We don't want clk provider drivers to use the init structure after clk
    registration time, but we leave a dangling reference to it by means of
    clk_hw::init. Let's overwrite the member with NULL during clk_register()
    so that this can't be used anymore after registration time.
    
    Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
    Cc: Doug Anderson <dianders@chromium.org>
    Signed-off-by: Stephen Boyd <sboyd@kernel.org>
    Link: https://lkml.kernel.org/r/20190731193517.237136-10-sboyd@kernel.org
    Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index c0990703ce54..efac620264a2 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -3484,9 +3484,9 @@ static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
 	return 0;
 }
 
-static int clk_core_populate_parent_map(struct clk_core *core)
+static int clk_core_populate_parent_map(struct clk_core *core,
+					const struct clk_init_data *init)
 {
-	const struct clk_init_data *init = core->hw->init;
 	u8 num_parents = init->num_parents;
 	const char * const *parent_names = init->parent_names;
 	const struct clk_hw **parent_hws = init->parent_hws;
@@ -3566,6 +3566,14 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
 {
 	int ret;
 	struct clk_core *core;
+	const struct clk_init_data *init = hw->init;
+
+	/*
+	 * The init data is not supposed to be used outside of registration path.
+	 * Set it to NULL so that provider drivers can't use it either and so that
+	 * we catch use of hw->init early on in the core.
+	 */
+	hw->init = NULL;
 
 	core = kzalloc(sizeof(*core), GFP_KERNEL);
 	if (!core) {
@@ -3573,17 +3581,17 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
 		goto fail_out;
 	}
 
-	core->name = kstrdup_const(hw->init->name, GFP_KERNEL);
+	core->name = kstrdup_const(init->name, GFP_KERNEL);
 	if (!core->name) {
 		ret = -ENOMEM;
 		goto fail_name;
 	}
 
-	if (WARN_ON(!hw->init->ops)) {
+	if (WARN_ON(!init->ops)) {
 		ret = -EINVAL;
 		goto fail_ops;
 	}
-	core->ops = hw->init->ops;
+	core->ops = init->ops;
 
 	if (dev && pm_runtime_enabled(dev))
 		core->rpm_enabled = true;
@@ -3592,13 +3600,13 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
 	if (dev && dev->driver)
 		core->owner = dev->driver->owner;
 	core->hw = hw;
-	core->flags = hw->init->flags;
-	core->num_parents = hw->init->num_parents;
+	core->flags = init->flags;
+	core->num_parents = init->num_parents;
 	core->min_rate = 0;
 	core->max_rate = ULONG_MAX;
 	hw->core = core;
 
-	ret = clk_core_populate_parent_map(core);
+	ret = clk_core_populate_parent_map(core, init);
 	if (ret)
 		goto fail_parents;
 
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 2ae7604783dd..214c75ed62ae 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -299,7 +299,8 @@ struct clk_init_data {
  * into the clk API
  *
  * @init: pointer to struct clk_init_data that contains the init data shared
- * with the common clock framework.
+ * with the common clock framework. This pointer will be set to NULL once
+ * a clk_register() variant is called on this clk_hw pointer.
  */
 struct clk_hw {
 	struct clk_core *core;
-------------------------------------------------------------------------------


Git bisection log:

-------------------------------------------------------------------------------
git bisect start
# good: [21a2f76849f16d5a48d205b68e923694bc93aaf3] Merge branch 'clk-fixes' into clk-next
git bisect good 21a2f76849f16d5a48d205b68e923694bc93aaf3
# bad: [2ced74113e7f0e2e7dd4c1b4c09b4020cc75fa23] Merge branch 'clk-init-destroy' into clk-next
git bisect bad 2ced74113e7f0e2e7dd4c1b4c09b4020cc75fa23
# good: [7c9dc000bd199f1f90c4e9f1b2814c0dd0ebaa2c] Merge tag 'clk-meson-v5.4-1' of https://github.com/BayLibre/clk-meson into clk-meson
git bisect good 7c9dc000bd199f1f90c4e9f1b2814c0dd0ebaa2c
# bad: [47add07b00b64d8e698e5a6fb50bf900d1e89167] clk: milbeaut: Don't reference clk_init_data after registration
git bisect bad 47add07b00b64d8e698e5a6fb50bf900d1e89167
# good: [f4bfe4fff7ecb7aea391120608cfe1d9bc1a1f49] clk: sirf: Don't reference clk_init_data after registration
git bisect good f4bfe4fff7ecb7aea391120608cfe1d9bc1a1f49
# good: [735822a8b114f73289679178ff075b73facd4571] phy: ti: am654-serdes: Don't reference clk_init_data after registration
git bisect good 735822a8b114f73289679178ff075b73facd4571
# bad: [ad8bb39501bc50ec04c88f123273f3e7ea8394ca] clk: socfpga: deindent code to proper indentation
git bisect bad ad8bb39501bc50ec04c88f123273f3e7ea8394ca
# bad: [c82987e740d12be98b8ae8aa9221b8b9e2541271] clk: Overwrite clk_hw::init with NULL during clk_register()
git bisect bad c82987e740d12be98b8ae8aa9221b8b9e2541271
# first bad commit: [c82987e740d12be98b8ae8aa9221b8b9e2541271] clk: Overwrite clk_hw::init with NULL during clk_register()
-------------------------------------------------------------------------------