Re: [Qemu-devel] [PATCH v2 1/2] qemu-error: introduce {error|warn}_report_once

[Peter Xu]

On Wed, May 23, 2018 at 10:47:29AM -0500, Eric Blake wrote:
> On 05/21/2018 10:56 PM, Peter Xu wrote:
> > I stole the printk_once() macro.
> > 
> > I always wanted to be able to print some error directly if there is a
> > buffer to dump, however we can't use error_report() where the code path
> > can be triggered by DDOS attack.  To avoid that, we can introduce a
> > print-once-like function for it.  Meanwhile, we also introduce the
> > corresponding helper for warn_report().
> > 
> > CC: Markus Armbruster <address@hidden>
> > Signed-off-by: Peter Xu <address@hidden>
> > ---
> >   include/qemu/error-report.h | 26 ++++++++++++++++++++++++++
> >   1 file changed, 26 insertions(+)
> > 
> > diff --git a/include/qemu/error-report.h b/include/qemu/error-report.h
> > index e1c8ae1a52..3e6e84801f 100644
> > --- a/include/qemu/error-report.h
> > +++ b/include/qemu/error-report.h
> > @@ -44,6 +44,32 @@ void error_report(const char *fmt, ...) GCC_FMT_ATTR(1, 
> > 2);
> >   void warn_report(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
> >   void info_report(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
> > +/* Similar to error_report(), but it only prints the message once. */
> > +#define error_report_once(fmt, ...)             \
> > +    ({                                          \
> > +        static bool __print_once;               \
> 
> You're still using the reserved namespace.  I asked you to fix that on v1;
> it's disappointing when a later revision doesn't make changes requested by a
> reviewers, without also offering a counter-argument for why the request does
> not need to be considered.

I am sorry.  It's totally because I forgot that one!  (It rarely
happens since I note them down in most cases, but there must be
something that even interrupted the procedure when I took notes...)

I will repost with another one soon.  Sorry again.

-- 
Peter Xu