2016-12-16 18:41:04

by Boris Ostrovsky

Subject: [PATCH] ACPI/CPC: Don't try to clean up uninitialized CPC data

If acpi_cppc_processor_probe() had not executed successfully (for
example, if _CPC object was not found) then cpc_desc_ptr for that
processor will be invalid.

Signed-off-by: Boris Ostrovsky <[email protected]>
---
drivers/acpi/cppc_acpi.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index d0d0504..5bba26e 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -824,6 +824,8 @@ void acpi_cppc_processor_exit(struct acpi_processor *pr)
void __iomem *addr;

cpc_ptr = per_cpu(cpc_desc_ptr, pr->id);
+ if (!cpc_ptr)
+ return;

/* Free all the mapped sys mem areas for this CPU */
for (i = 2; i < cpc_ptr->num_entries; i++) {
--
1.8.3.1

2016-12-16 21:52:46

by Prakash, Prashanth

Subject: Re: [PATCH] ACPI/CPC: Don't try to clean up uninitialized CPC data

Hi Boris,

On 12/16/2016 11:35 AM, Boris Ostrovsky wrote:
> If acpi_cppc_processor_probe() had not executed successfully (for
> example, if _CPC object was not found) then cpc_desc_ptr for that
> processor will be invalid.
>
> Signed-off-by: Boris Ostrovsky <[email protected]>
> ---
> drivers/acpi/cppc_acpi.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
> index d0d0504..5bba26e 100644
> --- a/drivers/acpi/cppc_acpi.c
> +++ b/drivers/acpi/cppc_acpi.c
> @@ -824,6 +824,8 @@ void acpi_cppc_processor_exit(struct acpi_processor *pr)
> void __iomem *addr;
>
> cpc_ptr = per_cpu(cpc_desc_ptr, pr->id);
> + if (!cpc_ptr)
> + return;
>
> /* Free all the mapped sys mem areas for this CPU */
> for (i = 2; i < cpc_ptr->num_entries; i++) {
I think a recent patch from Sebastian fixed the same issue.
https://git.kernel.org/cgit/linux/kernel/git/rafael/linux-pm.git/commit/?h=bleeding-edge&id=9e9d68dad58c70f40f50adfeabd2fdaa39a743fd

--
Thanks,
Prashanth

2016-12-16 22:00:11

by Boris Ostrovsky

Subject: Re: [PATCH] ACPI/CPC: Don't try to clean up uninitialized CPC data

On 12/16/2016 04:52 PM, Prakash, Prashanth wrote:
> Hi Boris,
>
> On 12/16/2016 11:35 AM, Boris Ostrovsky wrote:
>> If acpi_cppc_processor_probe() had not executed successfully (for
>> example, if _CPC object was not found) then cpc_desc_ptr for that
>> processor will be invalid.
>>
>> Signed-off-by: Boris Ostrovsky <[email protected]>
>> ---
>> drivers/acpi/cppc_acpi.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
>> index d0d0504..5bba26e 100644
>> --- a/drivers/acpi/cppc_acpi.c
>> +++ b/drivers/acpi/cppc_acpi.c
>> @@ -824,6 +824,8 @@ void acpi_cppc_processor_exit(struct acpi_processor *pr)
>> void __iomem *addr;
>>
>> cpc_ptr = per_cpu(cpc_desc_ptr, pr->id);
>> + if (!cpc_ptr)
>> + return;
>>
>> /* Free all the mapped sys mem areas for this CPU */
>> for (i = 2; i < cpc_ptr->num_entries; i++) {
> I think a recent patch from Sebastian fixed the same issue.
> https://git.kernel.org/cgit/linux/kernel/git/rafael/linux-pm.git/commit/?h=bleeding-edge&id=9e9d68dad58c70f40f50adfeabd2fdaa39a743fd

Ah, excellent! Thanks.

-boris