Re: [PATCH v2 1/2] Provide in-kernel headers for making it easy to extend the kernel

From: Manoj
Date: Sat Feb 16 2019 - 14:12:49 EST

Joel Fernandes writes:

> On Thu, Feb 14, 2019 at 07:19:29PM -0800, Alexei Starovoitov wrote:
>> On Mon, Feb 11, 2019 at 09:35:59AM -0500, Joel Fernandes (Google) wrote:
>> > Introduce in-kernel headers and other artifacts which are made available
>> > as an archive through proc (/proc/kheaders.txz file). This archive makes
>> > it possible to build kernel modules, run eBPF programs, and other
>> > tracing programs that need to extend the kernel for tracing purposes
>> > without any dependency on the file system having headers and build
>> > artifacts.
>> >
>> > On Android and embedded systems, it is common to switch kernels but not
>> > have kernel headers available on the file system. Raw kernel headers
>> > also cannot be copied into the filesystem like they can be on other
>> > distros, due to licensing and other issues. There's no linux-headers
>> > package on Android. Further once a different kernel is booted, any
>> > headers stored on the file system will no longer be useful. By storing
>> > the headers as a compressed archive within the kernel, we can avoid these
>> > issues that have been a hindrance for a long time.
>> The set looks good to me and since the main use case is building bpf progs
>> I can route it via bpf-next tree if there are no objections.
>> Masahiro, could you please ack it?
> Yes, eBPF is one of the usecases. After this, I am also planning to send
> patches to BCC so that it can use this feature when compiling C to eBPF.

Tested-by: Manoj Rao <linux@xxxxxxxxxxxxxxxx>

I think this can definitely make it easier to use eBPF on
Android. Thanks for initiating this.

> Thanks!
> - Joel