From 0ad41b244ca0ca07af2a652014bc929cbdf91e87 Mon Sep 17 00:00:00 2001 From: Lukas Bulwahn Date: Wed, 28 Oct 2020 12:35:33 +0100 Subject: net: cls_api: remove unneeded local variable in tc_dump_chain() make clang-analyzer on x86_64 defconfig caught my attention with: net/sched/cls_api.c:2964:3: warning: Value stored to 'parent' is never read [clang-analyzer-deadcode.DeadStores] parent = 0; ^ net/sched/cls_api.c:2977:4: warning: Value stored to 'parent' is never read [clang-analyzer-deadcode.DeadStores] parent = q->handle; ^ Commit 32a4f5ecd738 ("net: sched: introduce chain object to uapi") introduced tc_dump_chain() and this initial implementation already contained these unneeded dead stores. Simplify the code to make clang-analyzer happy. As compilers will detect these unneeded assignments and optimize this anyway, the resulting binary is identical before and after this change. No functional change. No change in object code. Signed-off-by: Lukas Bulwahn Link: https://lore.kernel.org/r/20201028113533.26160-1-lukas.bulwahn@gmail.com Signed-off-by: Jakub Kicinski --- net/sched/cls_api.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) (limited to 'net/sched/cls_api.c') diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index 838b3fd94d77..ba0715ee9eac 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -2940,7 +2940,6 @@ static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb) struct tcf_chain *chain; long index_start; long index; - u32 parent; int err; if (nlmsg_len(cb->nlh) < sizeof(*tcm)) @@ -2955,13 +2954,6 @@ static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb) block = tcf_block_refcnt_get(net, tcm->tcm_block_index); if (!block) goto out; - /* If we work with block index, q is NULL and parent value - * will never be used in the following code. The check - * in tcf_fill_node prevents it. However, compiler does not - * see that far, so set parent to zero to silence the warning - * about parent being uninitialized. - */ - parent = 0; } else { const struct Qdisc_class_ops *cops; struct net_device *dev; @@ -2971,13 +2963,11 @@ static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb) if (!dev) return skb->len; - parent = tcm->tcm_parent; - if (!parent) { + if (!tcm->tcm_parent) q = dev->qdisc; - parent = q->handle; - } else { + else q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent)); - } + if (!q) goto out; cops = q->ops->cl_ops; -- cgit From 9ca718743ad8402958637bfc196d7b62371a1b9f Mon Sep 17 00:00:00 2001 From: Francis Laniel Date: Sun, 15 Nov 2020 18:08:05 +0100 Subject: Modify return value of nla_strlcpy to match that of strscpy. nla_strlcpy now returns -E2BIG if src was truncated when written to dst. It also returns this error value if dstsize is 0 or higher than INT_MAX. For example, if src is "foo\0" and dst is 3 bytes long, the result will be: 1. "foG" after memcpy (G means garbage). 2. "fo\0" after memset. 3. -E2BIG is returned because src was not completely written into dst. The callers of nla_strlcpy were modified to take into account this modification. Signed-off-by: Francis Laniel Reviewed-by: Kees Cook Signed-off-by: Jakub Kicinski --- net/sched/cls_api.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/sched/cls_api.c') diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index ba0715ee9eac..c2e9661e20d3 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -223,7 +223,7 @@ static inline u32 tcf_auto_prio(struct tcf_proto *tp) static bool tcf_proto_check_kind(struct nlattr *kind, char *name) { if (kind) - return nla_strlcpy(name, kind, IFNAMSIZ) >= IFNAMSIZ; + return nla_strlcpy(name, kind, IFNAMSIZ) < 0; memset(name, 0, IFNAMSIZ); return false; } -- cgit From 872f690341948b502c93318f806d821c56772c42 Mon Sep 17 00:00:00 2001 From: Francis Laniel Date: Sun, 15 Nov 2020 18:08:06 +0100 Subject: treewide: rename nla_strlcpy to nla_strscpy. Calls to nla_strlcpy are now replaced by calls to nla_strscpy which is the new name of this function. Signed-off-by: Francis Laniel Reviewed-by: Kees Cook Signed-off-by: Jakub Kicinski --- net/sched/cls_api.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/sched/cls_api.c') diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index c2e9661e20d3..ff3e943febaa 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -223,7 +223,7 @@ static inline u32 tcf_auto_prio(struct tcf_proto *tp) static bool tcf_proto_check_kind(struct nlattr *kind, char *name) { if (kind) - return nla_strlcpy(name, kind, IFNAMSIZ) < 0; + return nla_strscpy(name, kind, IFNAMSIZ) < 0; memset(name, 0, IFNAMSIZ); return false; } -- cgit From 0fca55ed988a694f5896f36de2a8f18715a78279 Mon Sep 17 00:00:00 2001 From: Vlad Buslov Date: Fri, 27 Nov 2020 17:12:05 +0200 Subject: net: sched: remove redundant 'rtnl_held' argument Functions tfilter_notify_chain() and tcf_get_next_proto() are always called with rtnl lock held in current implementation. Moreover, attempting to call them without rtnl lock would cause a warning down the call chain in function __tcf_get_next_proto() that requires the lock to be held by callers. Remove the 'rtnl_held' argument in order to simplify the code and make rtnl lock requirement explicit. Signed-off-by: Vlad Buslov Link: https://lore.kernel.org/r/20201127151205.23492-1-vladbu@nvidia.com Signed-off-by: Jakub Kicinski --- net/sched/cls_api.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) (limited to 'net/sched/cls_api.c') diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index ff3e943febaa..37b77bd30974 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -991,13 +991,12 @@ __tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp) */ struct tcf_proto * -tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp, - bool rtnl_held) +tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp) { struct tcf_proto *tp_next = __tcf_get_next_proto(chain, tp); if (tp) - tcf_proto_put(tp, rtnl_held, NULL); + tcf_proto_put(tp, true, NULL); return tp_next; } @@ -1924,15 +1923,14 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb, static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb, struct tcf_block *block, struct Qdisc *q, u32 parent, struct nlmsghdr *n, - struct tcf_chain *chain, int event, - bool rtnl_held) + struct tcf_chain *chain, int event) { struct tcf_proto *tp; - for (tp = tcf_get_next_proto(chain, NULL, rtnl_held); - tp; tp = tcf_get_next_proto(chain, tp, rtnl_held)) + for (tp = tcf_get_next_proto(chain, NULL); + tp; tp = tcf_get_next_proto(chain, tp)) tfilter_notify(net, oskb, n, tp, block, - q, parent, NULL, event, false, rtnl_held); + q, parent, NULL, event, false, true); } static void tfilter_put(struct tcf_proto *tp, void *fh) @@ -2262,7 +2260,7 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n, if (prio == 0) { tfilter_notify_chain(net, skb, block, q, parent, n, - chain, RTM_DELTFILTER, rtnl_held); + chain, RTM_DELTFILTER); tcf_chain_flush(chain, rtnl_held); err = 0; goto errout; @@ -2895,7 +2893,7 @@ replay: break; case RTM_DELCHAIN: tfilter_notify_chain(net, skb, block, q, parent, n, - chain, RTM_DELTFILTER, true); + chain, RTM_DELTFILTER); /* Flush the chain first as the user requested chain removal. */ tcf_chain_flush(chain, true); /* In case the chain was successfully deleted, put a reference -- cgit