On Thu, 2013-09-12 at 01:19 +0100, Al Viro wrote: > On Wed, Sep 11, 2013 at 05:04:17PM -0700, Joe Perches wrote: > > On Thu, 2013-09-12 at 08:40 +0900, Tetsuo Handa wrote: > > > Joe Perches wrote: > > > > - seq_printf(m, "%s%d%n", con->name, con->index, &len); > > > > + len = seq_printf(m, "%s%d", con->name, con->index); > > > > > > Isn't len always 0 or -1 ? > > > > Right. Well you're no fun... > > > > These uses would seem broken anyway because the > > seq_printf isn't itself tested for correctness. > > > > Hmm. > > > > Also, there's a large amount of code that appears > > to do calculations with pos or len like: > > > > pos += seq_printf(handle, fmt. ...) > > ... and most of that code proceeds to ignore pos completely. > Note that ->show() is *NOT* supposed to return the number of > characters it has/would like to have produced. Just return > 0 and be done with that; overflows are dealt with just fine. > The large amount, BTW, is below 100 lines, AFAICS, in rather > few files. Unfortunately, when you count the uses of return seq_printf(...) it's rather higher and all the callers need to be chased down too. $ grep -rP --include=*.[ch] "^[ \t]*(\S[ \t\S]*=|return[\s\(]*)\s*\bseq_[v]?printf\b" * | wc -l 320 $ grep -rPl --include=*.[ch] "^[ \t]*(\S[ \t\S]*=|return[\s\(]*)\s*\bseq_[v]?printf\b" *|wc -l 81 > Just bury the cargo-culting crap. All those += seq_printf() should > be simply calling it. Most likely. > The *only* reason to look at the return > value is "if we'd already overflown the buffer, I'd rather skipped > the costly generation of the rest of the record". In that case > seq_printf() returning -1 means "skip it, nothing else will fit and > caller will be repeating with bigger buffer anyway". Perhaps changing the seq_vprintf return from 0 to len and testing for -1 would work. Still would need to change a few lines in netfilter and probably a few other places. _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
