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From:   Brendan Higgins <brendanhiggins@google.com>
Date:   Thu, 18 Mar 2021 14:27:24 -0700
Message-ID: <CAFd5g47uR=HxjVET3uygeND8tFsZtfkgsS-PjMagbcagPMTBEg@mail.gmail.com>
Subject: Re: [PATCH 4/6] um: split up CONFIG_GCOV
To:     Johannes Berg <johannes@sipsolutions.net>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-um <linux-um@lists.infradead.org>,
        Jessica Yu <jeyu@kernel.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Johannes Berg <johannes.berg@intel.com>
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On Fri, Mar 12, 2021 at 1:56 AM Johannes Berg <johannes@sipsolutions.net> wrote:
>
> From: Johannes Berg <johannes.berg@intel.com>
>
> It's not always desirable to collect coverage data for the
> entire kernel, so split off CONFIG_GCOV_BASE. This option
> only enables linking with coverage options, and compiles a
> single file (reboot.c) with them as well to force gcov to
> be linked into the kernel binary. That way, modules also
> work.
>
> To use this new option properly, one needs to manually add
> '-fprofile-arcs -ftest-coverage' to the compiler options
> of some object(s) or subdir(s) to collect coverage data at
> the desired places.
>
> Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Hey, thanks for doing this! I was looking into this a few weeks ago
and root caused part of the issue in GCC and in the kernel, but I did
not have a fix put together.

Anyway, most of the patches make sense to me, but I am not able to
apply this patch on torvalds/master. Do you mind sending a rebase so I
can test it?

Thanks!