Commit 0c868627e617e43a295d8 (cpufreq: dt: Allow platform specific
intermediate callbacks) added two function pointers to the
struct cpufreq_dt_platform_data. However, armada37xx_cpufreq_driver_init()
has this struct (pdata) located on the stack and uses only "suspend"
and "resume" fields. So these newly added "get_intermediate" and
"target_intermediate" pointers are uninitialized and contain arbitrary
non-null values, causing all kinds of trouble.
For instance, here is an oops on espressobin after an attempt to change
the cpefreq governor:
[ 29.174554] Unable to handle kernel execute from non-executable memory at virtual address ffff00003f87bdc0
...
[ 29.269373] pc : 0xffff00003f87bdc0
[ 29.272957] lr : __cpufreq_driver_target+0x138/0x580
...
Fixed by zeroing out pdata before use.
Signed-off-by: Ivan Kokshaysky <[email protected]>
---
drivers/cpufreq/armada-37xx-cpufreq.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/cpufreq/armada-37xx-cpufreq.c b/drivers/cpufreq/armada-37xx-cpufreq.c
index aa0f06dec959..df1c941260d1 100644
--- a/drivers/cpufreq/armada-37xx-cpufreq.c
+++ b/drivers/cpufreq/armada-37xx-cpufreq.c
@@ -456,6 +456,7 @@ static int __init armada37xx_cpufreq_driver_init(void)
/* Now that everything is setup, enable the DVFS at hardware level */
armada37xx_cpufreq_enable_dvfs(nb_pm_base);
+ memset(&pdata, 0, sizeof(pdata));
pdata.suspend = armada37xx_cpufreq_suspend;
pdata.resume = armada37xx_cpufreq_resume;
--
2.20.1
On Sat, Jun 20, 2020 at 05:44:49PM +0100, Ivan Kokshaysky wrote:
> Commit 0c868627e617e43a295d8 (cpufreq: dt: Allow platform specific
> intermediate callbacks) added two function pointers to the
> struct cpufreq_dt_platform_data. However, armada37xx_cpufreq_driver_init()
> has this struct (pdata) located on the stack and uses only "suspend"
> and "resume" fields. So these newly added "get_intermediate" and
> "target_intermediate" pointers are uninitialized and contain arbitrary
> non-null values, causing all kinds of trouble.
>
> For instance, here is an oops on espressobin after an attempt to change
> the cpefreq governor:
>
> [ 29.174554] Unable to handle kernel execute from non-executable memory at virtual address ffff00003f87bdc0
> ...
> [ 29.269373] pc : 0xffff00003f87bdc0
> [ 29.272957] lr : __cpufreq_driver_target+0x138/0x580
> ...
>
> Fixed by zeroing out pdata before use.
>
> Signed-off-by: Ivan Kokshaysky <[email protected]>
Hi Ivan
A Fixes: tag would be good.
Reviewed-by: Andrew Lunn <[email protected]>
Andrew
On Sat, Jun 20, 2020 at 07:54:38PM +0200, Andrew Lunn wrote:
> On Sat, Jun 20, 2020 at 05:44:49PM +0100, Ivan Kokshaysky wrote:
> > Commit 0c868627e617e43a295d8 (cpufreq: dt: Allow platform specific
> > intermediate callbacks) added two function pointers to the
> > struct cpufreq_dt_platform_data. However, armada37xx_cpufreq_driver_init()
> > has this struct (pdata) located on the stack and uses only "suspend"
> > and "resume" fields. So these newly added "get_intermediate" and
> > "target_intermediate" pointers are uninitialized and contain arbitrary
> > non-null values, causing all kinds of trouble.
> >
> > For instance, here is an oops on espressobin after an attempt to change
> > the cpefreq governor:
> >
> > [ 29.174554] Unable to handle kernel execute from non-executable memory at virtual address ffff00003f87bdc0
> > ...
> > [ 29.269373] pc : 0xffff00003f87bdc0
> > [ 29.272957] lr : __cpufreq_driver_target+0x138/0x580
> > ...
> >
> > Fixed by zeroing out pdata before use.
> >
> > Signed-off-by: Ivan Kokshaysky <[email protected]>
>
> Hi Ivan
>
> A Fixes: tag would be good.
Hi Andrew,
I'm not sure that "Fixes:" would be appropriate here - commit 0c868627e617
is fine by itself, it just revealed a bug in older code.
Thanks for reviewing,
Ivan.
> Reviewed-by: Andrew Lunn <[email protected]>
>
> Andrew
On 20-06-20, 17:44, Ivan Kokshaysky wrote:
> Commit 0c868627e617e43a295d8 (cpufreq: dt: Allow platform specific
> intermediate callbacks) added two function pointers to the
> struct cpufreq_dt_platform_data. However, armada37xx_cpufreq_driver_init()
> has this struct (pdata) located on the stack and uses only "suspend"
> and "resume" fields. So these newly added "get_intermediate" and
> "target_intermediate" pointers are uninitialized and contain arbitrary
> non-null values, causing all kinds of trouble.
>
> For instance, here is an oops on espressobin after an attempt to change
> the cpefreq governor:
>
> [ 29.174554] Unable to handle kernel execute from non-executable memory at virtual address ffff00003f87bdc0
> ...
> [ 29.269373] pc : 0xffff00003f87bdc0
> [ 29.272957] lr : __cpufreq_driver_target+0x138/0x580
> ...
>
> Fixed by zeroing out pdata before use.
>
> Signed-off-by: Ivan Kokshaysky <[email protected]>
> ---
> drivers/cpufreq/armada-37xx-cpufreq.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/cpufreq/armada-37xx-cpufreq.c b/drivers/cpufreq/armada-37xx-cpufreq.c
> index aa0f06dec959..df1c941260d1 100644
> --- a/drivers/cpufreq/armada-37xx-cpufreq.c
> +++ b/drivers/cpufreq/armada-37xx-cpufreq.c
> @@ -456,6 +456,7 @@ static int __init armada37xx_cpufreq_driver_init(void)
> /* Now that everything is setup, enable the DVFS at hardware level */
> armada37xx_cpufreq_enable_dvfs(nb_pm_base);
>
> + memset(&pdata, 0, sizeof(pdata));
> pdata.suspend = armada37xx_cpufreq_suspend;
> pdata.resume = armada37xx_cpufreq_resume;
Applied. Thanks.
--
viresh