On 22-08-2007 19:03, Paul E. McKenney wrote: > On Wed, Aug 22, 2007 at 05:41:11PM +0200, Adrian Bunk wrote: >> On Wed, Aug 22, 2007 at 05:30:13PM +0200, Gabriel C wrote: >>> Got it with a randconfig ( >>> http://194.231.229.228/kernel/mm/2.6.23-rc3-mm1/r/randconfig-8 ) >>> >>> ... >>> >>> net/ipv4/fib_trie.c: In function 'trie_rebalance': >>> net/ipv4/fib_trie.c:969: error: lvalue required as unary '&' operand >>> net/ipv4/fib_trie.c:971: error: lvalue required as unary '&' operand >>> net/ipv4/fib_trie.c:977: error: lvalue required as unary '&' operand >>> net/ipv4/fib_trie.c:980: error: lvalue required as unary '&' operand >>> ... >> Side effect of the git-net removal, temporarily removing >> immunize-rcu_dereference-against-crazy-compiler-writers.patch should >> work around it. > > Alternatively, the following one-line patch to net/ipv4/fib_trie.c could > be used. > > Signed-off-by: Paul E. McKenney <[EMAIL PROTECTED]> > --- > > fib_trie.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff -urpNa -X dontdiff linux-2.6.23-rc3-mm1/net/ipv4/fib_trie.c > linux-2.6.23-rc3-mm1.compile/net/ipv4/fib_trie.c > --- linux-2.6.23-rc3-mm1/net/ipv4/fib_trie.c 2007-08-22 09:20:33.000000000 > -0700 > +++ linux-2.6.23-rc3-mm1.compile/net/ipv4/fib_trie.c 2007-08-22 > 09:47:33.000000000 -0700 > @@ -94,7 +94,7 @@ typedef unsigned int t_key; > #define T_LEAF 1 > #define NODE_TYPE_MASK 0x1UL > #define NODE_PARENT(node) \ > - ((struct tnode *)rcu_dereference(((node)->parent & ~NODE_TYPE_MASK))) > + ((struct tnode *)(rcu_dereference((node)->parent) & ~NODE_TYPE_MASK)) ...
After first reading of this thread I've had an impression it's about compiler's behavior, but now it seems to me this patch is not an alternative, but a 'must be' and only proper way of calling rcu_dereference (with a variable instead of an expression)? Am I right? Regards, Jarek P. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
