Date: Fri, 14 Apr 2017 09:53:26 -0600 From: Ian Lepore <ian@freebsd.org> To: cem@freebsd.org, "Andrey V. Elsukov" <ae@freebsd.org> Cc: src-committers <src-committers@freebsd.org>, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r316826 - head/sys/netpfil/ipfw/nat64 Message-ID: <1492185206.73883.126.camel@freebsd.org> In-Reply-To: <CAG6CVpVJ%2BJ_dy%2BNV=SFXSN6O7OOBQOAW6gZvRBJDsQNxNyHy2A@mail.gmail.com> References: <201704141158.v3EBwfLm003147@repo.freebsd.org> <CAG6CVpVJ%2BJ_dy%2BNV=SFXSN6O7OOBQOAW6gZvRBJDsQNxNyHy2A@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, 2017-04-14 at 08:32 -0700, Conrad Meyer wrote: > On Fri, Apr 14, 2017 at 4:58 AM, Andrey V. Elsukov <ae@freebsd.org> > wrote: > > > > Author: ae > > Date: Fri Apr 14 11:58:41 2017 > > New Revision: 316826 > > URL: https://svnweb.freebsd.org/changeset/base/316826 > > > > Log: > > Avoid undefined behavior. > > > > The 'pktid' variable is modified while being used twice between > > sequence points, probably due to htonl() is macro. > FYI — there are a ton of similar reports in sys/rpc due to the XDR > macros (which read a network value off a pointer and increment it). > See e.g., IXDR_GET_UINT32() macro. > > Best, > Conrad Aren't they all false positives, since the macros involved are g'teed not to evaluate their arguments more than once as written (because __builtin_constant_p always evaluates at compile time)? Do we really want to churn our source code to eliminate false positives from some tool that appears to still be in its alpha-testing state? -- Ian
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?1492185206.73883.126.camel>