Re: [PATCH v3] kdb: Simplify kdb commands registration

[Daniel Thompson]

On Mon, Feb 08, 2021 at 03:18:19PM +0530, Sumit Garg wrote:
> On Mon, 8 Feb 2021 at 15:13, Daniel Thompson <daniel.thompson@xxxxxxxxxx> wrote:
> >
> > On Fri, Jan 29, 2021 at 03:47:07PM +0530, Sumit Garg wrote:
> > > @@ -1011,25 +1005,17 @@ int kdb_parse(const char *cmdstr)
> > >               ++argv[0];
> > >       }
> > >
> > > -     for_each_kdbcmd(tp, i) {
> > > -             if (tp->cmd_name) {
> > > -                     /*
> > > -                      * If this command is allowed to be abbreviated,
> > > -                      * check to see if this is it.
> > > -                      */
> > > -
> > > -                     if (tp->cmd_minlen
> > > -                      && (strlen(argv[0]) <= tp->cmd_minlen)) {
> > > -                             if (strncmp(argv[0],
> > > -                                         tp->cmd_name,
> > > -                                         tp->cmd_minlen) == 0) {
> > > -                                     break;
> > > -                             }
> > > -                     }
> > > -
> > > -                     if (strcmp(argv[0], tp->cmd_name) == 0)
> > > +     list_for_each_entry(tp, &kdb_cmds_head, list_node) {
> > > +             /*
> > > +              * If this command is allowed to be abbreviated,
> > > +              * check to see if this is it.
> > > +              */
> > > +             if (tp->cmd_minlen && (strlen(argv[0]) <= tp->cmd_minlen) &&
> > > +                 (strncmp(argv[0], tp->cmd_name, tp->cmd_minlen) == 0))
> > >                               break;
> >
> > Looks like you forgot to unindent this line.
> >
> > I will fix it up but... checkpatch would have found this.
> >
> 
> Ah, I missed to run checkpatch on v3. Thanks for fixing this up.

Unfortunately, it's not just checkpatch. This patch also causes a
large number of test suite regressions. In particular it looks like
kgdbwait does not work with this patch applied.

The problem occurs on multiple architectures all with
close-to-defconfig kernels. However to share one specific
failure, x86_64_defconfig plus the following is not bootable:

    ../scripts/config --enable DEBUG_INFO --enable DEBUG_FS \
      --enable KALLSYMS_ALL --enable MAGIC_SYSRQ --enable KGDB \
      --enable KGDB_TESTS --enable KGDB_KDB --enable KDB_KEYBOARD \
      --enable LKDTM

Try:

    qemu-system-x86_64 \
      -enable-kvm -m 1G -smp 2 -nographic
      -kernel arch/x86/boot/bzImage \
      -append "console=ttyS0,115200 kgdboc=ttyS0 kgdbwait"


Daniel.