On Thu, Jun 24, 2021 at 2:57 PM HAGIO KAZUHITO(萩尾 一仁)
<k-hagio-ab@xxxxxxx> wrote:
>
> -----Original Message-----
> > On Thu, Jun 24, 2021 at 12:51 PM HAGIO KAZUHITO(萩尾 一仁)
> > <k-hagio-ab@xxxxxxx> wrote:
> > >
> > > -----Original Message-----
> > > > > > } else {
> > > > > > - return;
> > > > > > + error(FATAL, "cannot determine wait queue structure\n");
> > > > >
> > > > > oh, I should have checked the replacement.. this emits compilation warnings:
> > > > >
> > > > > $ make clean ; make warn
> > > > > ...
> > > > > cc -c -g -DX86_64 -DLZO -DSNAPPY -DGDB_7_6 kernel.c -Wall -O2 -Wstrict-prototypes
> > -Wmissing-prototypes
> > > > -fstack-protector -Wformat-security
> > > > > kernel.c: In function 'cmd_waitq':
> > > > > kernel.c:9380:6: warning: 'start_index' may be used uninitialized in this function
> > > > [-Wmaybe-uninitialized]
> > > > > int start_index; /* where to start in wq array */
> > > > > ^~~~~~~~~~~
> > > > > kernel.c:9454:22: warning: 'task_offset' may be used uninitialized in this function
> > > > [-Wmaybe-uninitialized]
> > > > > readmem(wq_list[i] + task_offset, KVADDR, &task,
> > > > > ~~~~~~~~~~~^~~~~~~~~~~~~
> > > > > kernel.c:9378:8: note: 'task_offset' was declared here
> > > > > ulong task_offset; /* offset of task in wq element */
> > > > > ^~~~~~~~~~~
> > > > >
> > > > > Hmm, in this case, I'd like to put the return back when merging.
> > > > > Lianbo, is this ok?
> > > > >
> > > > > } else {
> > > > > error(FATAL, "cannot determine wait queue structure\n");
> > > >
> > > > After the log level is set to FATAL, it will exit, and the "return"
> > > > has no chance to execute . So it could be good
> > > > to use the log level "WARNING or INFO" for error()?
> > >
> > > I thought this is actually a fatal level error for the waitq command,
> > > so we should use FATAL normally, and put return with the comment to
> > > avoid confusion. It's a little rough but lesser effort.
> > >
> > > + return; /* just to suppress compilation warings */
> > >
> > > And the outputs are below respectively, I think "WARNING" in a message
> > > implies that there is a problem but the command can continue somehow.
> > > I don't want to use it in this case.
> > >
> > > crash> waitq kauditd_wait
> > > waitq: cannot determine wait queue structure // INFO
> > > waitq: WARNING: cannot determine wait queue structure // WARNING
> > > waitq: cannot determine wait queue structure // FATAL
> > >
> > > So I would prefer FATAL. INFO is better?
> >
> > Maybe we should keep the original changes:
> > - return;
> > + error(FATAL, "cannot determine wait queue structure\n");
> >
> > And fix the warnings directly in the kernel.c(dump_waitq()) as below:
> >
> > - ulong task_offset; /* offset of task in wq element */
> > + ulong task_offset = 0; /* offset of task in wq element */
> > int cnt; /* # elems on Queue */
> > - int start_index; /* where to start in wq array */
> > + int start_index = -1; /* where to start in wq array */
>
> OK, I see. Let's go with this reasonable fix.
>
Thanks, Kazu.
For v2 with the warning fix: Acked-by: Lianbo Jiang <lijang@xxxxxxxxxx>
> Thanks,
> Kazu
>
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