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

[rishabhb]

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