Re: [PATCH v2 0/3] Expose recovery/coredump configuration from sysfs

rishabhb
2020-09-02T23:14:30Z

On 2020-09-01 15:05, Mathieu Poirier wrote:
> Hi Rishabh,
>
> On Thu, Aug 27, 2020 at 12:48:48PM -0700, Rishabh Bhatnagar wrote:
>> From Android R onwards Google has restricted access to debugfs in user
>> and user-debug builds. This restricts access to most of the features
>> exposed through debugfs. This patch series adds a configurable option
>> to move the recovery/coredump interfaces to sysfs. If the feature
>> flag is selected it would move these interfaces to sysfs and remove
>> the equivalent debugfs interface.
>
> What I meant wast to move the coredump entry from debugfs to sysfs and
> from
> there make it available to user space using a kernel config. But
> thinking
> further on this it may be better to simply provide an API to set the
> coredump
> mode from the platform driver, the same way
> rproc_coredump_set_elf_info() works.
> That will prevent breaking a fair amount of user space code...
>
> Let me know if that can work for you.
>
> Thanks,
> Mathieu
>
Hi Mathieu,
That works for product configuration but that would still limit internal
testing. Since there is also restriction on accessing debugfs through
userspace code, automation won't be able to run recovery/coredump tests.
Only other way for us would be to provide these sysfs entries through
the
platform drivers locally but that would create a lot of mess/redundancy.

>> 'Coredump' and 'Recovery' are critical
>> interfaces that are required for remoteproc to work on Qualcomm
>> Chipsets.
>> Coredump configuration needs to be set to "inline" in debug/test build
>> and "disabled" in production builds. Whereas recovery needs to be
>> "disabled" for debugging purposes and "enabled" on production builds.
>>
>> Changelog:
>>
>> v1 -> v2:
>> - Correct the contact name in the sysfs documentation.
>> - Remove the redundant write documentation for coredump/recovery sysfs
>> - Add a feature flag to make this interface switch configurable.
>>
>> Rishabh Bhatnagar (3):
>> remoteproc: Expose remoteproc configuration through sysfs
>> remoteproc: Add coredump configuration to sysfs
>> remoteproc: Add recovery configuration to sysfs
>>
>> Documentation/ABI/testing/sysfs-class-remoteproc | 44 ++++++++
>> drivers/remoteproc/Kconfig | 12 +++
>> drivers/remoteproc/remoteproc_debugfs.c | 10 +-
>> drivers/remoteproc/remoteproc_sysfs.c | 126
>> +++++++++++++++++++++++
>> 4 files changed, 190 insertions(+), 2 deletions(-)
>>
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
>> Forum,
>> a Linux Foundation Collaborative Project
>>