Messages in this thread | | | Date | Tue, 10 May 2011 11:57:18 +0100 | Subject | Re: [PATCH] omap2/omapfb: make DBG() more resistant in if-else constructions | From | Niels de Vos <> |
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On Tue, May 10, 2011 at 10:42 AM, Geert Uytterhoeven <geert@linux-m68k.org> wrote: > On Tue, May 10, 2011 at 11:20, Niels de Vos <ndevos@redhat.com> wrote: >> When DBG() is used in a simple if-else, the resulting code path >> currently depends on the definition of DBG(). Inserting the statement in >> a "do { ... } while (0)" prevents this possible misuse. >> >> Signed-off-by: Niels de Vos <ndevos@redhat.com> > >> --- a/drivers/video/omap2/omapfb/omapfb.h >> +++ b/drivers/video/omap2/omapfb/omapfb.h >> @@ -34,8 +34,10 @@ >> #ifdef DEBUG >> extern unsigned int omapfb_debug; >> #define DBG(format, ...) \ >> - if (omapfb_debug) \ >> - printk(KERN_DEBUG "OMAPFB: " format, ## __VA_ARGS__) >> + do { \ >> + if (omapfb_debug) \ >> + printk(KERN_DEBUG "OMAPFB: " format, ## __VA_ARGS__); \ >> + while (0) > > Where's the closing '}'?
Good catch! That's in a "fixup!" that I forgot to squash :-/ I'll post an update version in a bit.
>> #else >> #define DBG(format, ...) > > BTW, no printf()-style format checking here. > >> #endif > > What about using the standard pr_debug()/dev_dbg() instead? > With dynamic debug, it can be enabled at run time. > As a bonus, you get printf()-style format checking if debugging is disabled.
I think removing DBG() and the omapfb_debug module-parameter is surely a good thing. Unfortunately DBG() is used quite a bit in the code and replacing them 'll take some more time. I don't know yet when I find some time to do and test that.
Thanks for the pointers, Niels
> Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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