Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2021-09-14

The following pull-request contains BPF updates for your *net* tree.

We've added 7 non-merge commits during the last 13 day(s) which contain
a total of 18 files changed, 334 insertions(+), 193 deletions(-).

The main changes are:

1) Fix mmap_lock lockdep splat in BPF stack map's build_id lookup, from Yonghong Song.

2) Fix BPF cgroup v2 program bypass upon net_cls/prio activation, from Daniel Borkmann.

3) Fix kvcalloc() BTF line info splat on oversized allocation attempts, from Bixuan Cui.

4) Fix BPF selftest build of task_pt_regs test for arm64/s390, from Jean-Philippe Brucker.

5) Fix BPF's disasm.{c,h} to dual-license so that it is aligned with bpftool given the former
   is a build dependency for the latter, from Daniel Borkmann with ACKs from contributors.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 40 deletions

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 881ce1470beb..8afa8690d288 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -6572,74 +6572,44 @@ int cgroup_parse_float(const char *input, unsigned dec_shift, s64 *v)
  */
 #ifdef CONFIG_SOCK_CGROUP_DATA
 
-#if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID)
-
-DEFINE_SPINLOCK(cgroup_sk_update_lock);
-static bool cgroup_sk_alloc_disabled __read_mostly;
-
-void cgroup_sk_alloc_disable(void)
-{
-	if (cgroup_sk_alloc_disabled)
-		return;
-	pr_info("cgroup: disabling cgroup2 socket matching due to net_prio or net_cls activation\n");
-	cgroup_sk_alloc_disabled = true;
-}
-
-#else
-
-#define cgroup_sk_alloc_disabled	false
-
-#endif
-
 void cgroup_sk_alloc(struct sock_cgroup_data *skcd)
 {
-	if (cgroup_sk_alloc_disabled) {
-		skcd->no_refcnt = 1;
-		return;
-	}
-
 	/* Don't associate the sock with unrelated interrupted task's cgroup. */
 	if (in_interrupt())
 		return;
 
 	rcu_read_lock();
-
 	while (true) {
 		struct css_set *cset;
 
 		cset = task_css_set(current);
 		if (likely(cgroup_tryget(cset->dfl_cgrp))) {
-			skcd->val = (unsigned long)cset->dfl_cgrp;
+			skcd->cgroup = cset->dfl_cgrp;
 			cgroup_bpf_get(cset->dfl_cgrp);
 			break;
 		}
 		cpu_relax();
 	}
-
 	rcu_read_unlock();
 }
 
 void cgroup_sk_clone(struct sock_cgroup_data *skcd)
 {
-	if (skcd->val) {
-		if (skcd->no_refcnt)
-			return;
-		/*
-		 * We might be cloning a socket which is left in an empty
-		 * cgroup and the cgroup might have already been rmdir'd.
-		 * Don't use cgroup_get_live().
-		 */
-		cgroup_get(sock_cgroup_ptr(skcd));
-		cgroup_bpf_get(sock_cgroup_ptr(skcd));
-	}
+	struct cgroup *cgrp = sock_cgroup_ptr(skcd);
+
+	/*
+	 * We might be cloning a socket which is left in an empty
+	 * cgroup and the cgroup might have already been rmdir'd.
+	 * Don't use cgroup_get_live().
+	 */
+	cgroup_get(cgrp);
+	cgroup_bpf_get(cgrp);
 }
 
 void cgroup_sk_free(struct sock_cgroup_data *skcd)
 {
 	struct cgroup *cgrp = sock_cgroup_ptr(skcd);
 
-	if (skcd->no_refcnt)
-		return;
 	cgroup_bpf_put(cgrp);
 	cgroup_put(cgrp);
 }