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 <[email protected]> --- Note, I have not found any offenders, but a mistake can easily be made. The following example shows what can go wrong if little intention is paid to the definition of the DBG() macro. Example: if something_went_wrong() DBG("oh no, something went wrong!\n"); else printk("all went fine\n"); Old result where the else is placed inside the first if-statment: if something_went_wrong() { if (omapfb_debug) { printk(KERN_DEBUG "oh no, something went wrong!\n"); } else { printk("all went fine\n"); } } New result where the else is an alternative to the first if-statement: if something_went_wrong() { do { if (omapfb_debug) printk(KERN_DEBUG "oh no, something went wrong!\n"); } while (0); } else { printk("all went fine\n"); } --- drivers/video/omap2/omapfb/omapfb.h | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/video/omap2/omapfb/omapfb.h b/drivers/video/omap2/omapfb/omapfb.h index 1305fc9..a01b0bb 100644 --- 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) #else #define DBG(format, ...) #endif -- 1.7.4.4 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
