On Fri, Sep 2, 2022 at 2:57 AM Shuah Khan skhan@linuxfoundation.org wrote:
On 8/23/22 22:41, David Gow wrote:
On Wed, Aug 24, 2022 at 12:19 PM Joe Fradley joefradley@google.com wrote:
Commit c272612cb4a2 ("kunit: Taint the kernel when KUnit tests are run") added a new taint flag for when in-kernel tests run. This commit adds recognition of this new flag in kernel-chktaint.
What happens without this change? It isn't clear what this change is fixing.
Without this patch, running ./tools/debugging/kernel-chktaint against a kernel tainted due to loading/running an in-kernel test (KUnit, kselftest, etc) will not describe the reason for the taint:
Kernel is "tainted" for the following reasons: For a more detailed explanation of the various taint flags see Documentation/admin-guide/tainted-kernels.rst in the Linux kernel sources or https://kernel.org/doc/html/latest/admin-guide/tainted-kernels.html Raw taint value as int/string: 262144/'G '
With this change (which should've been introduced along with the new taint flag), the 'N' taint is printed correctly, along with an explanation:
Kernel is "tainted" for the following reasons: * an in-kernel test (such as a KUnit test) has been run (#18) For a more detailed explanation of the various taint flags see Documentation/admin-guide/tainted-kernels.rst in the Linux kernel sources or https://kernel.org/doc/html/latest/admin-guide/tainted-kernels.html Raw taint value as int/string: 262144/'G N'
Reviewed-by: David Gow davidgow@google.com Signed-off-by: Joe Fradley joefradley@google.com
Changes in v2:
- based off of kselftest/kunit branch
- Added David's Reviewed-by tag
This still looks good to me.
Unless anyone objects, I guess we'll take this through the KUnit branch (which, after all, is where the taint was originally added). I've added it to the list for 6.1, but it technically could be considered a fix for 6.0 as well.
I can definitely take this for Linux 6.0 with additional information on the problems seen without this change.
Yeah, basically the output from kernel-chktaint is incomplete (and, in the case of the taint string, I'd argue wrong).
Not a disaster if this doesn't land for 6.0, but given 6.0 c an generate the new taint flag, it makes sense to decode it correctly if possible.
Cheers, -- David