| Message ID | 20190731193517.237136-10-sboyd@kernel.org (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
| Series | Make clk_hw::init NULL after clk registration | expand |
On 7/31/19 21:35, Stephen Boyd wrote: > 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> Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com> > drivers/clk/clk.c | 24 ++++++++++++++++-------- > include/linux/clk-provider.h | 3 ++- > 2 files changed, 18 insertions(+), 9 deletions(-) > > 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. > + */ nit: This comment could be re-edited to not exceed 80 columns limit. > + hw->init = NULL;
Quoting Stephen Boyd (2019-07-31 12:35:17) > 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> > --- Applied to clk-next
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;
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> --- Please ack so I can take this through clk tree drivers/clk/clk.c | 24 ++++++++++++++++-------- include/linux/clk-provider.h | 3 ++- 2 files changed, 18 insertions(+), 9 deletions(-)