Re: [RFC] tcp md5 use of alloc_percpu

From: Crestez Dan Leonard <redacted>
Date: Wed, 22 Oct 2014 21:55:46 +0300

 static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
 					__be32 daddr, __be32 saddr, int nbytes)
 {
-	struct tcp4_pseudohdr *bp;
+	struct tcp4_pseudohdr bp;

...

+	sg_init_one(&sg, &bp, sizeof(bp));
+	return crypto_hash_update(&hp->md5_desc, &sg, sizeof(bp));

As others have mentioned, you cannot do this.

On some architectures the kernel stack comes from vmalloc()
memory too.