Re: [PATCH v2] lockdep: Add header and footer to surround warning reports

[Waiman Long]

On 12/16/25 7:31 PM, Tzung-Bi Shih wrote:
> On Tue, Dec 16, 2025 at 11:20:45AM -0500, Waiman Long wrote:
> > On 12/15/25 2:26 AM, Tzung-Bi Shih wrote:
> > > Add header and footer to improve log parsing and automated analysis.
> > > This makes lockdep output easier to interpret.
> > >
> > > Signed-off-by: Tzung-Bi Shih <tzungbi@xxxxxxxxxx>
> > > ---
> > > v2:
> > > - asm/bugs.h -> linux/bug.h.
> > >
> > > v1: https://lore.kernel.org/all/20251114062730.1828416-1-tzungbi@xxxxxxxxxx/
> > >
> > >    kernel/locking/lockdep.c | 34 ++++++++++++++++++++++++++++++++++
> > >    1 file changed, 34 insertions(+)
> > >
> > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
> > > index 2d4c5bab5af8..adbc44c3808d 100644
> > > --- a/kernel/locking/lockdep.c
> > > +++ b/kernel/locking/lockdep.c
> > > @@ -58,6 +58,7 @@
> > >    #include <linux/context_tracking.h>
> > >    #include <linux/console.h>
> > >    #include <linux/kasan.h>
> > > +#include <linux/bug.h>
> > >    #include <asm/sections.h>
> > > @@ -110,6 +111,11 @@ static __init int kernel_lockdep_sysctls_init(void)
> > >    late_initcall(kernel_lockdep_sysctls_init);
> > >    #endif /* CONFIG_SYSCTL */
> > > +static void print_footer(void)
> > > +{
> > > +	pr_warn("---[ end trace %016llx ]---\n", 0ULL);
> > What is the purpose of putting 16 '0' in this "end trace" line? Is it
> > related to how your parsing script works?
> Mostly wanted to align to print_oops_end_marker() in kernel/panic.c.  Before
> e83a4472bf9f ("panic: remove oops_id"), it was an oops ID.  My parsing script
> doesn't rely on the 16 '0's but existing parsers might.
>
> I have no strong opinion.  Should we just remove the 16 '0's here?

These are warning messages, not panic. So I would prefer not to have 
them if they serve no useful purpose and can cause confusion.

Cheers,
Longman

>