Subject: Re: [PATCH v20 3/5] binder: introduce transaction reports via netlink

From: Greg Kroah-Hartman <[email-masked]>
Date: Thu, 21 Aug 2025 15:25:59 +0200

On Thu, Aug 21, 2025 at 03:00:50PM +0200, Thorsten Leemhuis wrote:
> On 21.08.25 14:19, Greg Kroah-Hartman wrote:
> > On Thu, Aug 21, 2025 at 10:49:09AM +0200, Thorsten Leemhuis wrote:
> >> On 27.07.25 20:29, Carlos Llamas wrote:
> >>> From: Li Li <[email-masked]>
> >>>
> >>> Introduce a generic netlink multicast event to report binder transaction
> >>> failures to userspace. This allows subscribers to monitor these events
> >>> and take appropriate actions, such as stopping a misbehaving application
> >>> that is spamming a service with huge amount of transactions.
> >>>
> >>> The multicast event contains full details of the failed transactions,
> >>> including the sender/target PIDs, payload size and specific error code.
> >>> This interface is defined using a YAML spec, from which the UAPI and
> >>> kernel headers and source are auto-generated.
> >>
> >> It seems to me like this patch (which showed up in -next today after
> >> Greg merged it) caused a build error for me in my daily -next builds
> >> for Fedora when building tools/net/ynl:
> >>
> >> """
> >> make[1]: Entering directory '/home/kbuilder/ark-vanilla/linux-knurd42/tools/net/ynl/lib'
> >> gcc -std=gnu11 -O2 -W -Wall -Wextra -Wno-unused-parameter -Wshadow   -c -MMD -c -o ynl.o ynl.c
> >>         AR ynl.a
> >> make[1]: Leaving directory '/home/kbuilder/ark-vanilla/linux-knurd42/tools/net/ynl/lib'
> >> make[1]: Entering directory '/home/kbuilder/ark-vanilla/linux-knurd42/tools/net/ynl/generated'
> >>         GEN binder-user.c
> >> Traceback (most recent call last):
> >>   File "/home/kbuilder/ark-vanilla/linux-knurd42/tools/net/ynl/generated/../pyynl/ynl_gen_c.py", line 3673, in <module>
> >>     main()
> >>     ~~~~^^
> >>   File "/home/kbuilder/ark-vanilla/linux-knurd42/tools/net/ynl/generated/../pyynl/ynl_gen_c.py", line 3382, in main
> >>     parsed = Family(args.spec, exclude_ops)
> >>   File "/home/kbuilder/ark-vanilla/linux-knurd42/tools/net/ynl/generated/../pyynl/ynl_gen_c.py", line 1205, in __init__
> >>     super().__init__(file_name, exclude_ops=exclude_ops)
> >>     ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> >>   File "/home/kbuilder/ark-vanilla/linux-knurd42/tools/net/ynl/pyynl/lib/nlspec.py", line 462, in __init__
> >>     jsonschema.validate(self.yaml, schema)
> >>     ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^
> >>   File "/usr/lib/python3.13/site-packages/jsonschema/validators.py", line 1307, in validate
> >>     raise error
> >> jsonschema.exceptions.ValidationError: 'from_pid' does not match '^[0-9a-z-]+$'
> >>
> >> Failed validating 'pattern' in schema['properties']['attribute-sets']['items']['properties']['attributes']['items']['properties']['name']:
> >>     {'pattern': '^[0-9a-z-]+$', 'type': 'string'}
> >>
> >> On instance['attribute-sets'][0]['attributes'][2]['name']:
> >>     'from_pid'
> >> make[1]: *** [Makefile:48: binder-user.c] Error 1
> >> make[1]: Leaving directory '/home/kbuilder/ark-vanilla/linux-knurd42/tools/net/ynl/generated'
> >> make: *** [Makefile:25: generated] Error 2
> >> """
> > 
> > Odd, this works for me.
> 
> Hmmm, happened on various Fedora releases and archs in Fedora's coprs
> buildsys for me today. And with a local Fedora 41 x86_64 install, too;
> in the latter case (just verified) both when checking out next-20250821
> and 63740349eba78f ("binder: introduce transaction reports via netlink")
> from -next.
> 
> > How exactly are you building this?
> 
> Just "cd tools/net/ynl; make".

Odd, this works for me in the driver-core-next branch, but in linux-next
it blows up like this.  Is it a merge issue somewhere?  I don't know
what this tool is doing to attempt to debug it myself, sorry.

greg k-h