Preparing for the next release: call for testing

[Mike Frysinger]

On 03 Mar 2015 21:01, Dmitry V. Levin wrote:
> On Tue, Mar 03, 2015 at 12:47:19PM -0500, Mike Frysinger wrote:
> > build warnings:
> > there's still random -Wsign-compare warnings, but i guess we don't care
> > about those
> 
> There are exactly 3 different -Wsign-compare warning messages:
> socketutils.c:145: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
> netlink_inet_diag.c:67: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
> netlink_unix_diag.c:75: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
> 
> The only way to fix them is to fix NLMSG_OK macro defined
> in <linux/netlink.h>.

hmm, i'm not so sure.  the kernel headers declare:
struct nlmsghdr {
	__u32		nlmsg_len;	/* Length of message including header */
...
#define NLMSG_OK(nlh,len) ((len) >= (int)sizeof(struct nlmsghdr) && \
			   (nlh)->nlmsg_len >= sizeof(struct nlmsghdr) && \
			   (nlh)->nlmsg_len <= (len))

and the strace code does:
		ssize_t ret;
		struct nlmsghdr *h;
		...
		     NLMSG_OK(h, ret);

if the kernel headers provided a function instead of a macro, it'd be:
static bool NLMSG_OK(const struct nlmsghdr *nlh, __u32 len) {...}

which is to say, the API of this macro is that it takes a u32 len, but we're 
passing it a ssize_t (as that is what recvmsg/etc... returns).  it is annoying 
that there's a type mismatch here, but i think the problem is still on our side 
to sort out:
	NLMSG_OK(h, (size_t)ret)

we've already verified earlier in the code that it's not negative, so the cast 
by itself should be safe:
		ret = recvmsg(fd, &msg, 0);
		if (ret < 0) {
			if (errno == EINTR)
				continue;
			return false;
		}
-mike
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