Re: [PATCH v2] init: Do not warn on non-zero initcall return

[Steven Rostedt]

On Thu, 2013-05-02 at 09:43 +0200, Geert Uytterhoeven wrote:
> On Wed, May 1, 2013 at 7:35 PM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> > Commit f91eb62f71 "init: scream bloody murder if interrupts are enabled
> > too early" added three new warnings. The first two seemed reasonable,
> > but the third included a warning when an initcall returned non-zero.
> > Although, the third WARN() does include an imbalanced preempt disabled,
> > or irqs disable, it shouldn't warn if it only had an initcall that just
> > returns non-zero.
> >
> > In fact, according to Linus, it shouldn't print at all. As it only
> > prints with initcall_debug set, and that already shows enough
> > information to fix things.
> >
> > Link: http://lkml.kernel.org/r/CA+55aFzaBC5SFi7=F2mfm+KWY5qTsBmOqgbbs8E+LUS8JK-sBg@xxxxxxxxxxxxxx
> >
> > Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> > Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> > Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
> >
> > diff --git a/init/main.c b/init/main.c
> > index bea1287..ceed17a 100644
> > --- a/init/main.c
> > +++ b/init/main.c
> > @@ -686,11 +686,8 @@ int __init_or_module do_one_initcall(initcall_t fn)
> >
> >         msgbuf[0] = 0;
> >
> > -       if (ret && ret != -ENODEV && initcall_debug)
> > -               sprintf(msgbuf, "error code %d ", ret);
> > -
> >         if (preempt_count() != count) {
> > -               strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
> > +               sprintf(msgbuf, "preemption imbalance ");
> 
> snprintf(), please?

Why? The msgbuf is 64 bytes, this is the first occurrence and
"preemption imbalance " is much less than 64 bytes.

> 
> JFYI, the v3.9 version already used up all of msgbuf[] in the
> worst-case scenario,
> and it did have the strlcat() as a parachute:

Right, the other users had strlcat as they were not the first user and
add onto the string.

-- Steve

> 
> $ echo -n "error code 1234567890 preemption imbalance disabled
> interrupts " | wc -c
> 63
> $


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