netdev - RE: [PATCH 2/3] ipv6, route: remove BACKTRACK() macro

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <AE90C24D6B3A694183C094C60CF0A2F6026B6FE6@saturn3.aculab.com>
Date:	Mon, 10 Sep 2012 14:54:45 +0100
From:	"David Laight" <David.Laight@...LAB.COM>
To:	"Cong Wang" <amwang@...hat.com>, <netdev@...r.kernel.org>
Cc:	"David S. Miller" <davem@...emloft.net>
Subject: RE: [PATCH 2/3] ipv6, route: remove BACKTRACK() macro

> Subject: [PATCH 2/3] ipv6, route: remove BACKTRACK() macro
> 
> It doesn't save any code, nor it helps readability.
> 
> Signed-off-by: Cong Wang <amwang@...hat.com>
> ---
>  net/ipv6/route.c |   48 ++++++++++++++++++++++++++++--------------------
>  1 files changed, 28 insertions(+), 20 deletions(-)
> 
> diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> index b130bf2..71267e9 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -675,24 +675,6 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
>  }
>  #endif
> 
> -#define BACKTRACK(__net, saddr)			\
> -do { \
> -	if (rt == __net->ipv6.ip6_null_entry) {	\
> -		struct fib6_node *pn; \
> -		while (1) { \
> -			if (fn->fn_flags & RTN_TL_ROOT) \
> -				goto out; \
> -			pn = fn->parent; \
> -			if (FIB6_SUBTREE(pn) && FIB6_SUBTREE(pn) != fn) \
> -				fn = fib6_lookup(FIB6_SUBTREE(pn), NULL, saddr); \
> -			else \
> -				fn = pn; \
> -			if (fn->fn_flags & RTN_RTINFO) \
> -				goto restart; \
> -		} \
> -	} \
> -} while (0)
> -

It does, however, seem to avoid replicating some relatively complex logic.
OTOH goto out of a #define and hidden parameters (rt, fn ...) are not nice.

Maybe the 'while (1)' part can be an inline function?

	David

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html