Merge branch 'bpf: remove the cgroup -> bpf header dependecy'

Jakub Kicinski says:

====================

Changes to bpf.h tend to clog up our build systems. The netdev/bpf
build bot does incremental builds to save time (reusing the build
directory to only rebuild changed objects).

This is the rough breakdown of how many objects needs to be rebuilt
based on file touched:

kernel.h      40633
bpf.h         17881
bpf-cgroup.h  17875
skbuff.h      10696
bpf-netns.h    7604
netdevice.h    7452
filter.h       5003
sock.h         4959
tcp.h          4048

As the stats show touching bpf.h is _very_ expensive.

Bulk of the objects get rebuilt because MM includes cgroup headers.
Luckily bpf-cgroup.h does not fundamentally depend on bpf.h so we
can break that dependency and reduce the number of objects.

With the patches applied touching bpf.h causes 5019 objects to be rebuilt
(17881 / 5019 = 3.56x). That's pretty much down to filter.h plus noise.

v2:
Try to make the new headers wider in scope. Collapse bpf-link and
bpf-cgroup-types into one header, which may serve as "BPF kernel
API" header in the future if needed. Rename bpf-cgroup-storage.h
to bpf-inlines.h.

Add a fix for the s390 build issue.

v3: https://lore.kernel.org/all/20211215061916.715513-1-kuba@kernel.org/
Merge bpf-includes.h into bpf.h.

v4: https://lore.kernel.org/all/20211215181231.1053479-1-kuba@kernel.org/
Change course - break off cgroup instead of breaking off bpf.

v5:
Add forward declaration of struct bpf_prog to perf_event.h
when !CONFIG_BPF_SYSCALL (kbuild bot).
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

15 files changed, 84 insertions, 57 deletions

diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
index da36d13ffc16..082793d497ec 100644
--- a/arch/s390/mm/hugetlbpage.c
+++ b/arch/s390/mm/hugetlbpage.c
@@ -9,6 +9,7 @@
 #define KMSG_COMPONENT "hugetlb"
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
+#include <asm/pgalloc.h>
 #include <linux/mm.h>
 #include <linux/hugetlb.h>
 #include <linux/mman.h>
diff --git a/include/linux/bpf-cgroup-defs.h b/include/linux/bpf-cgroup-defs.h
new file mode 100644
index 000000000000..695d1224a71b
--- /dev/null
+++ b/include/linux/bpf-cgroup-defs.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BPF_CGROUP_DEFS_H
+#define _BPF_CGROUP_DEFS_H
+
+#ifdef CONFIG_CGROUP_BPF
+
+#include <linux/list.h>
+#include <linux/percpu-refcount.h>
+#include <linux/workqueue.h>
+
+struct bpf_prog_array;
+
+enum cgroup_bpf_attach_type {
+	CGROUP_BPF_ATTACH_TYPE_INVALID = -1,
+	CGROUP_INET_INGRESS = 0,
+	CGROUP_INET_EGRESS,
+	CGROUP_INET_SOCK_CREATE,
+	CGROUP_SOCK_OPS,
+	CGROUP_DEVICE,
+	CGROUP_INET4_BIND,
+	CGROUP_INET6_BIND,
+	CGROUP_INET4_CONNECT,
+	CGROUP_INET6_CONNECT,
+	CGROUP_INET4_POST_BIND,
+	CGROUP_INET6_POST_BIND,
+	CGROUP_UDP4_SENDMSG,
+	CGROUP_UDP6_SENDMSG,
+	CGROUP_SYSCTL,
+	CGROUP_UDP4_RECVMSG,
+	CGROUP_UDP6_RECVMSG,
+	CGROUP_GETSOCKOPT,
+	CGROUP_SETSOCKOPT,
+	CGROUP_INET4_GETPEERNAME,
+	CGROUP_INET6_GETPEERNAME,
+	CGROUP_INET4_GETSOCKNAME,
+	CGROUP_INET6_GETSOCKNAME,
+	CGROUP_INET_SOCK_RELEASE,
+	MAX_CGROUP_BPF_ATTACH_TYPE
+};
+
+struct cgroup_bpf {
+	/* array of effective progs in this cgroup */
+	struct bpf_prog_array __rcu *effective[MAX_CGROUP_BPF_ATTACH_TYPE];
+
+	/* attached progs to this cgroup and attach flags
+	 * when flags == 0 or BPF_F_ALLOW_OVERRIDE the progs list will
+	 * have either zero or one element
+	 * when BPF_F_ALLOW_MULTI the list can have up to BPF_CGROUP_MAX_PROGS
+	 */
+	struct list_head progs[MAX_CGROUP_BPF_ATTACH_TYPE];
+	u32 flags[MAX_CGROUP_BPF_ATTACH_TYPE];
+
+	/* list of cgroup shared storages */
+	struct list_head storages;
+
+	/* temp storage for effective prog array used by prog_attach/detach */
+	struct bpf_prog_array *inactive;
+
+	/* reference counter used to detach bpf programs after cgroup removal */
+	struct percpu_ref refcnt;
+
+	/* cgroup_bpf is released using a work queue */
+	struct work_struct release_work;
+};
+
+#else /* CONFIG_CGROUP_BPF */
+struct cgroup_bpf {};
+#endif /* CONFIG_CGROUP_BPF */
+
+#endif
diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index 11820a430d6c..b525d8cdc25b 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -3,10 +3,10 @@
 #define _BPF_CGROUP_H
 
 #include <linux/bpf.h>
+#include <linux/bpf-cgroup-defs.h>
 #include <linux/errno.h>
 #include <linux/jump_label.h>
 #include <linux/percpu.h>
-#include <linux/percpu-refcount.h>
 #include <linux/rbtree.h>
 #include <uapi/linux/bpf.h>
 
@@ -23,33 +23,6 @@ struct ctl_table_header;
 struct task_struct;
 
 #ifdef CONFIG_CGROUP_BPF
-enum cgroup_bpf_attach_type {
-	CGROUP_BPF_ATTACH_TYPE_INVALID = -1,
-	CGROUP_INET_INGRESS = 0,
-	CGROUP_INET_EGRESS,
-	CGROUP_INET_SOCK_CREATE,
-	CGROUP_SOCK_OPS,
-	CGROUP_DEVICE,
-	CGROUP_INET4_BIND,
-	CGROUP_INET6_BIND,
-	CGROUP_INET4_CONNECT,
-	CGROUP_INET6_CONNECT,
-	CGROUP_INET4_POST_BIND,
-	CGROUP_INET6_POST_BIND,
-	CGROUP_UDP4_SENDMSG,
-	CGROUP_UDP6_SENDMSG,
-	CGROUP_SYSCTL,
-	CGROUP_UDP4_RECVMSG,
-	CGROUP_UDP6_RECVMSG,
-	CGROUP_GETSOCKOPT,
-	CGROUP_SETSOCKOPT,
-	CGROUP_INET4_GETPEERNAME,
-	CGROUP_INET6_GETPEERNAME,
-	CGROUP_INET4_GETSOCKNAME,
-	CGROUP_INET6_GETSOCKNAME,
-	CGROUP_INET_SOCK_RELEASE,
-	MAX_CGROUP_BPF_ATTACH_TYPE
-};
 
 #define CGROUP_ATYPE(type) \
 	case BPF_##type: return type
@@ -127,33 +100,6 @@ struct bpf_prog_list {
 	struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE];
 };
 
-struct bpf_prog_array;
-
-struct cgroup_bpf {
-	/* array of effective progs in this cgroup */
-	struct bpf_prog_array __rcu *effective[MAX_CGROUP_BPF_ATTACH_TYPE];
-
-	/* attached progs to this cgroup and attach flags
-	 * when flags == 0 or BPF_F_ALLOW_OVERRIDE the progs list will
-	 * have either zero or one element
-	 * when BPF_F_ALLOW_MULTI the list can have up to BPF_CGROUP_MAX_PROGS
-	 */
-	struct list_head progs[MAX_CGROUP_BPF_ATTACH_TYPE];
-	u32 flags[MAX_CGROUP_BPF_ATTACH_TYPE];
-
-	/* list of cgroup shared storages */
-	struct list_head storages;
-
-	/* temp storage for effective prog array used by prog_attach/detach */
-	struct bpf_prog_array *inactive;
-
-	/* reference counter used to detach bpf programs after cgroup removal */
-	struct percpu_ref refcnt;
-
-	/* cgroup_bpf is released using a work queue */
-	struct work_struct release_work;
-};
-
 int cgroup_bpf_inherit(struct cgroup *cgrp);
 void cgroup_bpf_offline(struct cgroup *cgrp);
 
@@ -451,7 +397,6 @@ int cgroup_bpf_prog_query(const union bpf_attr *attr,
 			  union bpf_attr __user *uattr);
 #else
 
-struct cgroup_bpf {};
 static inline int cgroup_bpf_inherit(struct cgroup *cgrp) { return 0; }
 static inline void cgroup_bpf_offline(struct cgroup *cgrp) {}
 
diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
index db2e147e069f..411684c80cf3 100644
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -19,7 +19,7 @@
 #include <linux/percpu-rwsem.h>
 #include <linux/u64_stats_sync.h>
 #include <linux/workqueue.h>
-#include <linux/bpf-cgroup.h>
+#include <linux/bpf-cgroup-defs.h>
 #include <linux/psi_types.h>
 
 #ifdef CONFIG_CGROUPS
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 0dcfd265beed..4a021149eaf0 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -611,6 +611,7 @@ struct swevent_hlist {
 #define PERF_ATTACH_SCHED_CB	0x20
 #define PERF_ATTACH_CHILD	0x40
 
+struct bpf_prog;
 struct perf_cgroup;
 struct perf_buffer;
 
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 8babae03d30a..34d6f91dec1c 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -2,6 +2,7 @@
 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
  */
 #include <linux/bpf.h>
+#include <linux/bpf-cgroup.h>
 #include <linux/rcupdate.h>
 #include <linux/random.h>
 #include <linux/smp.h>
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index ddd81d543203..da07bdf71697 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2,6 +2,7 @@
 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
  */
 #include <linux/bpf.h>
+#include <linux/bpf-cgroup.h>
 #include <linux/bpf_trace.h>
 #include <linux/bpf_lirc.h>
 #include <linux/bpf_verifier.h>
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d74e8a99412e..f0604796132f 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -4,6 +4,7 @@
  * Copyright (c) 2018 Covalent IO, Inc. http://covalent.io
  */
 #include <uapi/linux/btf.h>
+#include <linux/bpf-cgroup.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/slab.h>
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 919194de39c8..cd4c23f7e3df 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -30,6 +30,7 @@
 
 #include "cgroup-internal.h"
 
+#include <linux/bpf-cgroup.h>
 #include <linux/cred.h>
 #include <linux/errno.h>
 #include <linux/init_task.h>
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 33272a7b6912..4e1257f50aa3 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -7,6 +7,7 @@
  */
 #define pr_fmt(fmt)	"trace_kprobe: " fmt
 
+#include <linux/bpf-cgroup.h>
 #include <linux/security.h>
 #include <linux/module.h>
 #include <linux/uaccess.h>
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index f5f0039d31e5..4f35514a48f3 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -7,6 +7,7 @@
  */
 #define pr_fmt(fmt)	"trace_uprobe: " fmt
 
+#include <linux/bpf-cgroup.h>
 #include <linux/security.h>
 #include <linux/ctype.h>
 #include <linux/module.h>
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 69d30053fed9..99536127650b 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -74,6 +74,7 @@
 
 #define pr_fmt(fmt) "UDP: " fmt
 
+#include <linux/bpf-cgroup.h>
 #include <linux/uaccess.h>
 #include <asm/ioctls.h>
 #include <linux/memblock.h>
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 6a0e569f0bb8..ba8986d12413 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -17,6 +17,7 @@
  *      YOSHIFUJI Hideaki @USAGI:	convert /proc/net/udp6 to seq_file.
  */
 
+#include <linux/bpf-cgroup.h>
 #include <linux/errno.h>
 #include <linux/types.h>
 #include <linux/socket.h>
diff --git a/net/socket.c b/net/socket.c
index 7f64a6eccf63..721a5a1b1106 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -52,6 +52,7 @@
  *	Based upon Swansea University Computer Society NET3.039
  */
 
+#include <linux/bpf-cgroup.h>
 #include <linux/ethtool.h>
 #include <linux/mm.h>
 #include <linux/socket.h>
diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index 04375df52fc9..842889f3dcb7 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -5,6 +5,7 @@
  * Copyright 2007 IBM Corp
  */
 
+#include <linux/bpf-cgroup.h>
 #include <linux/device_cgroup.h>
 #include <linux/cgroup.h>
 #include <linux/ctype.h>