Re: Subject: [PATCH] net/ipv6: Use GFP_ATOMIC when a lock is held
From: Eric Dumazet <hidden>
Date: 2010-05-30 20:11:37
Also in:
kernel-janitors, lkml
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Le dimanche 30 mai 2010 à 21:48 +0200, Julia Lawall a écrit :
quoted hunk ↗ jump to hunk
From: Julia Lawall <redacted> A spin lock is taken near the beginning of the enclosing function. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ @@ spin_lock(...) ... when != spin_unlock(...) -GFP_KERNEL +GFP_ATOMIC // </smpl> Signed-off-by: Julia Lawall <redacted> --- net/ipv6/sit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -u -p a/net/ipv6/sit.c b/net/ipv6/sit.c--- a/net/ipv6/sit.c +++ b/net/ipv6/sit.c@@ -358,7 +358,7 @@ ipip6_tunnel_add_prl(struct ip_tunnel *t goto out; } - p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL); + p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_ATOMIC); if (!p) { err = -ENOBUFS; goto out;
Nice catch, but what about allocating this outside of the locked section ?
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index e51e650..ff3dd84 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c@@ -340,6 +340,10 @@ ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg) if (a->addr == htonl(INADDR_ANY)) return -EINVAL; + p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL); + if (!p) + return -ENOBUFS; + spin_lock(&ipip6_prl_lock); for (p = t->prl; p; p = p->next) {
@@ -358,19 +362,16 @@ ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg) goto out; } - p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL); - if (!p) { - err = -ENOBUFS; - goto out; - } p->next = t->prl; p->addr = a->addr; p->flags = a->flags; t->prl_count++; rcu_assign_pointer(t->prl, p); + p = NULL; out: spin_unlock(&ipip6_prl_lock); + kfree(p); return err; }