lkml.org 
[lkml]   [2023]   [Feb]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    SubjectRe: [PATCH] drivers/core: Replace lockdep_set_novalidate_class() with unique class keys
    From
    On 2023/02/09 11:26, Alan Stern wrote:
    > On Thu, Feb 09, 2023 at 09:22:39AM +0900, Tetsuo Handa wrote:
    >> On 2023/02/09 0:07, Alan Stern wrote:
    >>> I'm happy to have people test this patch, but I do not want anybody
    >>> think that it is ready to be merged into the kernel.
    >>
    >> People (and build/test bots) won't test changes that are not proposed as
    >> a formal patch with Signed-off-by: tag. As far as I am aware, bot is not
    >> testing plain diff.
    >
    > People _do_ test changes without a Signed-off-by: tag. This happens
    > with my patches all the time; I don't put Signed-off-by: on a patch
    > until I think it is ready to be merged. If you search through the email
    > archives, you'll find examples where people deliberately put a
    > "Not-yet-signed-off-by:" tag on a suggested patch.

    That's a cultural difference. I know there are developers who use
    "Not-yet-signed-off-by:" tag. But I'm not subscribed to mailing lists
    which you are subscribed to. I'm subscribed to linux-security-module, but
    I feel that it is quite rare that developers post changes as plain diff
    without Signed-off-by: tag, for people prefer to see formal patches than
    plain diff. I can see that only David Howells was using Not-yet-signed-off-by:
    tag (like https://marc.info/?l=linux-security-module&m=130455572927447 ).

    But even with Not-yet-signed-off-by: tag, his patches are formal patches
    with description rather than plain diff. Unlike networking subsystem where
    patches sometimes get merged before people have time to review/test,
    developers in my subscribed mailing lists tend to propose v2, v3, v4...
    patches with "Signed-off-by:" tag instead of posting plain diff.

    > Syzbot also tests patches without a Signed-off-by: tag. Here's a recent
    > example:
    >
    > https://lore.kernel.org/linux-usb/Y9wh8dGK6oHSjJQl@rowland.harvard.edu/

    That's completely different. syzbot is designed to test plain diff via
    explict "#syz test:" directive. If "#syz test:" directive is not included,
    syzbot does not test your diff.

    Do you know any bot which automatically does testing plain diff? I don't know
    when bots (or automated systems) test changes, but my guess is that a formal
    patch with "Signed-off-by:" tag serves as the directive for bots to test
    changes. Maybe we want a directive (e.g. "Test-requested-by:" tag) which
    encourages/asks bots (or automated systems) to test patches but does not
    want patches to get merged into permanent git trees.

    >> I can update the patch if lockdep developers prefer rename over add.
    >> What I worry is that lockdep developers do not permit static_obj() being
    >> used by non-lockdep code.
    >
    > I worry about that too, and I hoped that Peter Z. would comment on it.
    > But if they don't want the function to be exported, they ought to be
    > able to suggest an alternative.

    Then, at least we can start without "EXPORT_SYMBOL_GPL(lockdep_static_obj);"
    line, for drivers/base/core.c cannot be built as a module.

    Since there are already several locations which directly use e.g. _stext symbol,
    we would simply duplicate static_obj() into drivers/base/core.c if Peter does
    not want to make static_obj() visible to built-in code.



    Anyway, despite being posted as a formal patch, it seems that nobody was
    interested in manual testing. As far as I tried "#syz test" this patch against
    https://syzkaller.appspot.com/bug?extid=9ef743bba3a17c756174 , syzbot kernel
    was able to boot. Therefore, I think it is OK to stay for a week whether
    this patch causes too frequent crashes to continue using linux-next.git .

    Please propose a formal patch to Peter with your "Signed-off-by:" tag...

    \
     
     \ /
      Last update: 2023-03-27 00:18    [W:4.300 / U:0.072 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site