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

From: kernelci.org bot
Date: Thu Aug 15 2019 - 17:47:15 EST


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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@xxxxxxxxxx>
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@xxxxxxxxxx>
Cc: Doug Anderson <dianders@xxxxxxxxxxxx>
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20190731193517.237136-10-sboyd@xxxxxxxxxx
Reviewed-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>

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()
-------------------------------------------------------------------------------