Re: [PATCH v1 2/4] x86/mce: dump error msg from severities

[Shuai Xue]

在 2025/2/12 00:44, Luck, Tony 写道:
> > The message in severities is useful for identifying the type of MCE that
> > has occurred; dump it if it is valid.
> >
> > Signed-off-by: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx>
> > ---
> >   arch/x86/kernel/cpu/mce/core.c | 2 ++
> >   1 file changed, 2 insertions(+)
> >
> > diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
> > index 2919a077cd66..c1319db45b0a 100644
> > --- a/arch/x86/kernel/cpu/mce/core.c
> > +++ b/arch/x86/kernel/cpu/mce/core.c
> > @@ -1456,6 +1456,8 @@ static void queue_task_work(struct mce_hw_err *err, char *msg, void (*func)(stru
> >        if (count > 1)
> >                return;
> >
> > +     if (msg)
> > +             pr_err("%s\n", msg);
> >        task_work_add(current, &current->mce_kill_me, TWA_RESUME);
> >   }
>
> This is called from the #MC handler. Is that a safe context to print a console
> message? It wasn't in the past, but maybe changes to how console messages
> are handled have changed this.
>
> -Tony

#MC is a kind of NMI context, as far as I know, since

commit 42a0bb3f71383b457a7db362f1c69e7afb96732b
printk/nmi: generic solution for safe printk in NMI

print a console message is safe.

Please correct me if I missed anything.

Thanks.
Shuai