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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2017-01-18 02:53:44 -0800
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2017-04-18 11:42:36 -0700
commit5f0d5a3ae7cff0d7fa943c199c3a2e44f23e1fac (patch)
treeb7ba2116923723e193dfe7c633ec10056c6b1b53 /net
parent4495c08e84729385774601b5146d51d9e5849f81 (diff)
mm: Rename SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU
A group of Linux kernel hackers reported chasing a bug that resulted from their assumption that SLAB_DESTROY_BY_RCU provided an existence guarantee, that is, that no block from such a slab would be reallocated during an RCU read-side critical section. Of course, that is not the case. Instead, SLAB_DESTROY_BY_RCU only prevents freeing of an entire slab of blocks. However, there is a phrase for this, namely "type safety". This commit therefore renames SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU in order to avoid future instances of this sort of confusion. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <linux-mm@kvack.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> [ paulmck: Add comments mentioning the old name, as requested by Eric Dumazet, in order to help people familiar with the old name find the new one. ] Acked-by: David Rientjes <rientjes@google.com>
Diffstat (limited to 'net')
-rw-r--r--net/dccp/ipv4.c2
-rw-r--r--net/dccp/ipv6.c2
-rw-r--r--net/ipv4/tcp_ipv4.c2
-rw-r--r--net/ipv6/tcp_ipv6.c2
-rw-r--r--net/llc/af_llc.c2
-rw-r--r--net/llc/llc_conn.c4
-rw-r--r--net/llc/llc_sap.c2
-rw-r--r--net/netfilter/nf_conntrack_core.c8
-rw-r--r--net/smc/af_smc.c2
9 files changed, 13 insertions, 13 deletions
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 409d0cfd3447..90210a0e3888 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -950,7 +950,7 @@ static struct proto dccp_v4_prot = {
.orphan_count = &dccp_orphan_count,
.max_header = MAX_DCCP_HEADER,
.obj_size = sizeof(struct dccp_sock),
- .slab_flags = SLAB_DESTROY_BY_RCU,
+ .slab_flags = SLAB_TYPESAFE_BY_RCU,
.rsk_prot = &dccp_request_sock_ops,
.twsk_prot = &dccp_timewait_sock_ops,
.h.hashinfo = &dccp_hashinfo,
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 233b57367758..b4019a5e4551 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -1012,7 +1012,7 @@ static struct proto dccp_v6_prot = {
.orphan_count = &dccp_orphan_count,
.max_header = MAX_DCCP_HEADER,
.obj_size = sizeof(struct dccp6_sock),
- .slab_flags = SLAB_DESTROY_BY_RCU,
+ .slab_flags = SLAB_TYPESAFE_BY_RCU,
.rsk_prot = &dccp6_request_sock_ops,
.twsk_prot = &dccp6_timewait_sock_ops,
.h.hashinfo = &dccp_hashinfo,
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 9a89b8deafae..82c89abeb989 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2398,7 +2398,7 @@ struct proto tcp_prot = {
.sysctl_rmem = sysctl_tcp_rmem,
.max_header = MAX_TCP_HEADER,
.obj_size = sizeof(struct tcp_sock),
- .slab_flags = SLAB_DESTROY_BY_RCU,
+ .slab_flags = SLAB_TYPESAFE_BY_RCU,
.twsk_prot = &tcp_timewait_sock_ops,
.rsk_prot = &tcp_request_sock_ops,
.h.hashinfo = &tcp_hashinfo,
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 60a5295a7de6..bdbc4327ebee 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1919,7 +1919,7 @@ struct proto tcpv6_prot = {
.sysctl_rmem = sysctl_tcp_rmem,
.max_header = MAX_TCP_HEADER,
.obj_size = sizeof(struct tcp6_sock),
- .slab_flags = SLAB_DESTROY_BY_RCU,
+ .slab_flags = SLAB_TYPESAFE_BY_RCU,
.twsk_prot = &tcp6_timewait_sock_ops,
.rsk_prot = &tcp6_request_sock_ops,
.h.hashinfo = &tcp_hashinfo,
diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c
index 06186d608a27..d096ca563054 100644
--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -142,7 +142,7 @@ static struct proto llc_proto = {
.name = "LLC",
.owner = THIS_MODULE,
.obj_size = sizeof(struct llc_sock),
- .slab_flags = SLAB_DESTROY_BY_RCU,
+ .slab_flags = SLAB_TYPESAFE_BY_RCU,
};
/**
diff --git a/net/llc/llc_conn.c b/net/llc/llc_conn.c
index 8bc5a1bd2d45..9b02c13d258b 100644
--- a/net/llc/llc_conn.c
+++ b/net/llc/llc_conn.c
@@ -506,7 +506,7 @@ static struct sock *__llc_lookup_established(struct llc_sap *sap,
again:
sk_nulls_for_each_rcu(rc, node, laddr_hb) {
if (llc_estab_match(sap, daddr, laddr, rc)) {
- /* Extra checks required by SLAB_DESTROY_BY_RCU */
+ /* Extra checks required by SLAB_TYPESAFE_BY_RCU */
if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
goto again;
if (unlikely(llc_sk(rc)->sap != sap ||
@@ -565,7 +565,7 @@ static struct sock *__llc_lookup_listener(struct llc_sap *sap,
again:
sk_nulls_for_each_rcu(rc, node, laddr_hb) {
if (llc_listener_match(sap, laddr, rc)) {
- /* Extra checks required by SLAB_DESTROY_BY_RCU */
+ /* Extra checks required by SLAB_TYPESAFE_BY_RCU */
if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
goto again;
if (unlikely(llc_sk(rc)->sap != sap ||
diff --git a/net/llc/llc_sap.c b/net/llc/llc_sap.c
index 5404d0d195cc..63b6ab056370 100644
--- a/net/llc/llc_sap.c
+++ b/net/llc/llc_sap.c
@@ -328,7 +328,7 @@ static struct sock *llc_lookup_dgram(struct llc_sap *sap,
again:
sk_nulls_for_each_rcu(rc, node, laddr_hb) {
if (llc_dgram_match(sap, laddr, rc)) {
- /* Extra checks required by SLAB_DESTROY_BY_RCU */
+ /* Extra checks required by SLAB_TYPESAFE_BY_RCU */
if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
goto again;
if (unlikely(llc_sk(rc)->sap != sap ||
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 071b97fcbefb..fdcdac7916b2 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -914,7 +914,7 @@ static unsigned int early_drop_list(struct net *net,
continue;
/* kill only if still in same netns -- might have moved due to
- * SLAB_DESTROY_BY_RCU rules.
+ * SLAB_TYPESAFE_BY_RCU rules.
*
* We steal the timer reference. If that fails timer has
* already fired or someone else deleted it. Just drop ref
@@ -1069,7 +1069,7 @@ __nf_conntrack_alloc(struct net *net,
/*
* Do not use kmem_cache_zalloc(), as this cache uses
- * SLAB_DESTROY_BY_RCU.
+ * SLAB_TYPESAFE_BY_RCU.
*/
ct = kmem_cache_alloc(nf_conntrack_cachep, gfp);
if (ct == NULL)
@@ -1114,7 +1114,7 @@ void nf_conntrack_free(struct nf_conn *ct)
struct net *net = nf_ct_net(ct);
/* A freed object has refcnt == 0, that's
- * the golden rule for SLAB_DESTROY_BY_RCU
+ * the golden rule for SLAB_TYPESAFE_BY_RCU
*/
NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 0);
@@ -1878,7 +1878,7 @@ int nf_conntrack_init_start(void)
nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
sizeof(struct nf_conn),
NFCT_INFOMASK + 1,
- SLAB_DESTROY_BY_RCU | SLAB_HWCACHE_ALIGN, NULL);
+ SLAB_TYPESAFE_BY_RCU | SLAB_HWCACHE_ALIGN, NULL);
if (!nf_conntrack_cachep)
goto err_cachep;
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 85837ab90e89..d34bbd6d8f38 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -101,7 +101,7 @@ struct proto smc_proto = {
.unhash = smc_unhash_sk,
.obj_size = sizeof(struct smc_sock),
.h.smc_hash = &smc_v4_hashinfo,
- .slab_flags = SLAB_DESTROY_BY_RCU,
+ .slab_flags = SLAB_TYPESAFE_BY_RCU,
};
EXPORT_SYMBOL_GPL(smc_proto);