On Tue, Sep 17, 2019 at 09:02:54AM -0400, Steven Rostedt wrote:
> On Tue, 17 Sep 2019 09:52:16 +0200
> Petr Mladek <pmla...@suse.com> wrote:
>
> > Heh, I did some grepping and the return value is actually used on
> > three locations:
> >
> > $> git grep "= printk("
> > drivers/scsi/aic7xxx/aic79xx_core.c: printed = printk("%s[0x%x]",
> > name, value);
> > drivers/scsi/aic7xxx/aic79xx_core.c: printed += printk(" ");
> > drivers/scsi/aic7xxx/aic79xx_core.c: printed +=
> > printk("%s%s",
> > drivers/scsi/aic7xxx/aic79xx_core.c: printed += printk(") ");
> > drivers/scsi/aic7xxx/aic79xx_core.c: printed += printk(" ");
> > drivers/scsi/aic7xxx/aic79xx_core.c: cur_col = printk("\n%3d
> > FIFO_USE[0x%x] ", SCB_GET_TAG(scb),
> > drivers/scsi/aic7xxx/aic79xx_core.c: cur_col +=
> > printk("SHADDR = 0x%x%x, SHCNT = 0x%x ",
> > drivers/scsi/aic7xxx/aic79xx_core.c: cur_col +=
> > printk("HADDR = 0x%x%x, HCNT = 0x%x ",
> > drivers/scsi/aic7xxx/aic7xxx_core.c: printed = printk("%s[0x%x]",
> > name, value);
> > drivers/scsi/aic7xxx/aic7xxx_core.c: printed += printk(" ");
> > drivers/scsi/aic7xxx/aic7xxx_core.c: printed +=
> > printk("%s%s",
> > drivers/scsi/aic7xxx/aic7xxx_core.c: printed += printk(") ");
> > drivers/scsi/aic7xxx/aic7xxx_core.c: printed += printk(" ");
> > drivers/scsi/aic7xxx/aic7xxx_core.c: cur_col =
> > printk("\n%3d ", i);
> > drivers/scsi/aic7xxx/aic7xxx_core.c: cur_col =
> > printk("\n%3d ", scb->hscb->tag);
All of those can be removed as none of the returned values are used.
What a mess.
> > drivers/scsi/libsas/sas_ata.c: r = printk("%s" SAS_FMT "ata%u: %s:
> > %pV",
return value is also ignored, this can be fixed.
> > kernel/locking/lockdep.c: len += printk("%*s %s",
> > depth, "", usage_str[bit]);
> > kernel/locking/lockdep.c: len += printk(KERN_CONT "
> > at:\n");
That seems to be the only semi-legitimate use, but if it _really_ needs
it, it can just create the string ahead of time, and use the length then
after it printks it out.
> > It is probably not a big deal. For example, lockdep uses the value
> > just for formatting (extra spaces) when printing backtrace.
> >
> > I agree that it does not make sense to return the value if it
> > complicates the code too much. Well, we will need to count
> > the string length also from another reason (reservation).
>
> Well, it's being used. I was thinking of dropping it if it was not.
> Let's keep it then.
I think it should be dropped, only one user of the kernel is using it in
a legitimate way, which kind of implies it isn't needed.
thanks,
greg k-h
