Re: [PATCH] perf: Incorrect use of snprintf results in SEGV

From: Peter Seebach
Date: Wed Mar 07 2012 - 16:29:21 EST


On Wed, 7 Mar 2012 21:59:24 +0100
Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> On Wed, 2012-03-07 at 21:37 +0100, Ingo Molnar wrote:
> > size_needed = snprintf_size(...);
>
> This would require 3 passes over the fmt+args, first to find the
> allocated size is insufficient, 2nd to compute the size, 3rd to fill
> buffer.
>
> Whereas with the current "creative" API only 2 passes are needed.
>
> I can imagine that back in the day of small memory and small CPU this
> was deemed important enough.

It occurs to me that I have seen this discussion, or a variant, before:

http://coding.derkeiler.com/Archive/C_CPP/comp.lang.c/2004-11/2332.html

In which people discuss the possible alternative return values at some
length.

-s
--
Listen, get this. Nobody with a good compiler needs to be justified.
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