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

Daniel Borkmann says:

====================
pull-request: bpf-next 2020-07-04

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

We've added 73 non-merge commits during the last 17 day(s) which contain
a total of 106 files changed, 5233 insertions(+), 1283 deletions(-).

The main changes are:

1) bpftool ability to show PIDs of processes having open file descriptors
   for BPF map/program/link/BTF objects, relying on BPF iterator progs
   to extract this info efficiently, from Andrii Nakryiko.

2) Addition of BPF iterator progs for dumping TCP and UDP sockets to
   seq_files, from Yonghong Song.

3) Support access to BPF map fields in struct bpf_map from programs
   through BTF struct access, from Andrey Ignatov.

4) Add a bpf_get_task_stack() helper to be able to dump /proc/*/stack
   via seq_file from BPF iterator progs, from Song Liu.

5) Make SO_KEEPALIVE and related options available to bpf_setsockopt()
   helper, from Dmitry Yakunin.

6) Optimize BPF sk_storage selection of its caching index, from Martin
   KaFai Lau.

7) Removal of redundant synchronize_rcu()s from BPF map destruction which
   has been a historic leftover, from Alexei Starovoitov.

8) Several improvements to test_progs to make it easier to create a shell
   loop that invokes each test individually which is useful for some CIs,
   from Jesper Dangaard Brouer.

9) Fix bpftool prog dump segfault when compiled without skeleton code on
   older clang versions, from John Fastabend.

10) Bunch of cleanups and minor improvements, from various others.
====================

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

71 files changed, 4078 insertions, 1003 deletions

diff --git a/tools/bpf/bpftool/.gitignore b/tools/bpf/bpftool/.gitignore
index 26cde83e1ca3..3e601bcfd461 100644
--- a/tools/bpf/bpftool/.gitignore
+++ b/tools/bpf/bpftool/.gitignore
@@ -1,10 +1,11 @@
 # SPDX-License-Identifier: GPL-2.0-only
 *.d
-/_bpftool
+/bpftool-bootstrap
 /bpftool
 bpftool*.8
 bpf-helpers.*
 FEATURE-DUMP.bpftool
 feature
 libbpf
-profiler.skel.h
+/*.skel.h
+/vmlinux.h
diff --git a/tools/bpf/bpftool/Documentation/bpftool-btf.rst b/tools/bpf/bpftool/Documentation/bpftool-btf.rst
index ce3a724f50c1..896f4c6c2870 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-btf.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-btf.rst
@@ -36,6 +36,11 @@ DESCRIPTION
 		  otherwise list all BTF objects currently loaded on the
 		  system.
 
+		  Since Linux 5.8 bpftool is able to discover information about
+		  processes that hold open file descriptors (FDs) against BTF
+		  objects. On such kernels bpftool will automatically emit this
+		  information as well.
+
 	**bpftool btf dump** *BTF_SRC*
 		  Dump BTF entries from a given *BTF_SRC*.
 
diff --git a/tools/bpf/bpftool/Documentation/bpftool-link.rst b/tools/bpf/bpftool/Documentation/bpftool-link.rst
index 0e43d7b06c11..38b0949a185b 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-link.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-link.rst
@@ -37,6 +37,11 @@ DESCRIPTION
 		  zero or more named attributes, some of which depend on type
 		  of link.
 
+		  Since Linux 5.8 bpftool is able to discover information about
+		  processes that hold open file descriptors (FDs) against BPF
+		  links. On such kernels bpftool will automatically emit this
+		  information as well.
+
 	**bpftool link pin** *LINK* *FILE*
 		  Pin link *LINK* as *FILE*.
 
@@ -82,6 +87,7 @@ EXAMPLES
 
     10: cgroup  prog 25
             cgroup_id 614  attach_type egress
+            pids test_progs(223)
 
 **# bpftool --json --pretty link show**
 
@@ -91,7 +97,12 @@ EXAMPLES
             "type": "cgroup",
             "prog_id": 25,
             "cgroup_id": 614,
-            "attach_type": "egress"
+            "attach_type": "egress",
+            "pids": [{
+                    "pid": 223,
+                    "comm": "test_progs"
+                }
+            ]
         }
     ]
 
diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst
index 70c78faa47ab..41e2a74252d0 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-map.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst
@@ -62,6 +62,11 @@ DESCRIPTION
 		  Output will start with map ID followed by map type and
 		  zero or more named attributes (depending on kernel version).
 
+		  Since Linux 5.8 bpftool is able to discover information about
+		  processes that hold open file descriptors (FDs) against BPF
+		  maps. On such kernels bpftool will automatically emit this
+		  information as well.
+
 	**bpftool map create** *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE*  **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**dev** *NAME*]
 		  Create a new map with given parameters and pin it to *bpffs*
 		  as *FILE*.
@@ -180,7 +185,8 @@ EXAMPLES
 ::
 
   10: hash  name some_map  flags 0x0
-	key 4B  value 8B  max_entries 2048  memlock 167936B
+        key 4B  value 8B  max_entries 2048  memlock 167936B
+        pids systemd(1)
 
 The following three commands are equivalent:
 
diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
index 2b254959d488..412ea3d9bf7f 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
@@ -75,6 +75,11 @@ DESCRIPTION
 		  program run. Activation or deactivation of the feature is
 		  performed via the **kernel.bpf_stats_enabled** sysctl knob.
 
+		  Since Linux 5.8 bpftool is able to discover information about
+		  processes that hold open file descriptors (FDs) against BPF
+		  programs. On such kernels bpftool will automatically emit this
+		  information as well.
+
 	**bpftool prog dump xlated** *PROG* [{ **file** *FILE* | **opcodes** | **visual** | **linum** }]
 		  Dump eBPF instructions of the programs from the kernel. By
 		  default, eBPF will be disassembled and printed to standard
@@ -243,6 +248,7 @@ EXAMPLES
     10: xdp  name some_prog  tag 005a3d2123620c8b  gpl run_time_ns 81632 run_cnt 10
             loaded_at 2017-09-29T20:11:00+0000  uid 0
             xlated 528B  jited 370B  memlock 4096B  map_ids 10
+            pids systemd(1)
 
 **# bpftool --json --pretty prog show**
 
@@ -262,6 +268,11 @@ EXAMPLES
             "bytes_jited": 370,
             "bytes_memlock": 4096,
             "map_ids": [10
+            ],
+            "pids": [{
+                    "pid": 1,
+                    "comm": "systemd"
+                }
             ]
         }
     ]
diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index 9e85f101be85..51bd520ed437 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -40,8 +40,9 @@ bash_compdir ?= /usr/share/bash-completion/completions
 
 CFLAGS += -O2
 CFLAGS += -W -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers
-CFLAGS += $(filter-out -Wswitch-enum,$(EXTRA_WARNINGS))
+CFLAGS += $(filter-out -Wswitch-enum -Wnested-externs,$(EXTRA_WARNINGS))
 CFLAGS += -DPACKAGE='"bpftool"' -D__EXPORTED_HEADERS__ \
+	-I$(if $(OUTPUT),$(OUTPUT),.) \
 	-I$(srctree)/kernel/bpf/ \
 	-I$(srctree)/tools/include \
 	-I$(srctree)/tools/include/uapi \
@@ -61,9 +62,9 @@ CLANG ?= clang
 
 FEATURE_USER = .bpftool
 FEATURE_TESTS = libbfd disassembler-four-args reallocarray zlib libcap \
-	clang-bpf-global-var
+	clang-bpf-co-re
 FEATURE_DISPLAY = libbfd disassembler-four-args zlib libcap \
-	clang-bpf-global-var
+	clang-bpf-co-re
 
 check_feat := 1
 NON_CHECK_FEAT_TARGETS := clean uninstall doc doc-clean doc-install doc-uninstall
@@ -116,40 +117,60 @@ CFLAGS += -DHAVE_LIBBFD_SUPPORT
 SRCS += $(BFD_SRCS)
 endif
 
+BPFTOOL_BOOTSTRAP := $(if $(OUTPUT),$(OUTPUT)bpftool-bootstrap,./bpftool-bootstrap)
+
+BOOTSTRAP_OBJS = $(addprefix $(OUTPUT),main.o common.o json_writer.o gen.o btf.o)
 OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o
-_OBJS = $(filter-out $(OUTPUT)prog.o,$(OBJS)) $(OUTPUT)_prog.o
 
-ifeq ($(feature-clang-bpf-global-var),1)
-	__OBJS = $(OBJS)
-else
-	__OBJS = $(_OBJS)
-endif
+VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux)				\
+		     $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux)	\
+		     ../../../vmlinux					\
+		     /sys/kernel/btf/vmlinux				\
+		     /boot/vmlinux-$(shell uname -r)
+VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
 
-$(OUTPUT)_prog.o: prog.c
-	$(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -DBPFTOOL_WITHOUT_SKELETONS -o $@ $<
+ifneq ($(VMLINUX_BTF)$(VMLINUX_H),)
+ifeq ($(feature-clang-bpf-co-re),1)
 
-$(OUTPUT)_bpftool: $(_OBJS) $(LIBBPF)
-	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(_OBJS) $(LIBS)
+BUILD_BPF_SKELS := 1
 
-skeleton/profiler.bpf.o: skeleton/profiler.bpf.c $(LIBBPF)
+$(OUTPUT)vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL_BOOTSTRAP)
+ifeq ($(VMLINUX_H),)
+	$(QUIET_GEN)$(BPFTOOL_BOOTSTRAP) btf dump file $< format c > $@
+else
+	$(Q)cp "$(VMLINUX_H)" $@
+endif
+
+$(OUTPUT)%.bpf.o: skeleton/%.bpf.c $(OUTPUT)vmlinux.h $(LIBBPF)
 	$(QUIET_CLANG)$(CLANG) \
+		-I$(if $(OUTPUT),$(OUTPUT),.) \
 		-I$(srctree)/tools/include/uapi/ \
-		-I$(LIBBPF_PATH) -I$(srctree)/tools/lib \
+		-I$(LIBBPF_PATH) \
+		-I$(srctree)/tools/lib \
 		-g -O2 -target bpf -c $< -o $@
 
-profiler.skel.h: $(OUTPUT)_bpftool skeleton/profiler.bpf.o
-	$(QUIET_GEN)$(OUTPUT)./_bpftool gen skeleton skeleton/profiler.bpf.o > $@
+$(OUTPUT)%.skel.h: $(OUTPUT)%.bpf.o $(BPFTOOL_BOOTSTRAP)
+	$(QUIET_GEN)$(BPFTOOL_BOOTSTRAP) gen skeleton $< > $@
 
-$(OUTPUT)prog.o: prog.c profiler.skel.h
-	$(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -o $@ $<
+$(OUTPUT)prog.o: $(OUTPUT)profiler.skel.h
+
+$(OUTPUT)pids.o: $(OUTPUT)pid_iter.skel.h
+
+endif
+endif
+
+CFLAGS += $(if $(BUILD_BPF_SKELS),,-DBPFTOOL_WITHOUT_SKELETONS)
 
 $(OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c
 	$(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -o $@ $<
 
 $(OUTPUT)feature.o: | zdep
 
-$(OUTPUT)bpftool: $(__OBJS) $(LIBBPF)
-	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(__OBJS) $(LIBS)
+$(BPFTOOL_BOOTSTRAP): $(BOOTSTRAP_OBJS) $(LIBBPF)
+	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(BOOTSTRAP_OBJS) $(LIBS)
+
+$(OUTPUT)bpftool: $(OBJS) $(LIBBPF)
+	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(OBJS) $(LIBS)
 
 $(OUTPUT)%.o: %.c
 	$(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -o $@ $<
@@ -157,7 +178,7 @@ $(OUTPUT)%.o: %.c
 clean: $(LIBBPF)-clean
 	$(call QUIET_CLEAN, bpftool)
 	$(Q)$(RM) -- $(OUTPUT)bpftool $(OUTPUT)*.o $(OUTPUT)*.d
-	$(Q)$(RM) -- $(OUTPUT)_bpftool profiler.skel.h skeleton/profiler.bpf.o
+	$(Q)$(RM) -- $(BPFTOOL_BOOTSTRAP) $(OUTPUT)*.skel.h $(OUTPUT)vmlinux.h
 	$(Q)$(RM) -r -- $(OUTPUT)libbpf/
 	$(call QUIET_CLEAN, core-gen)
 	$(Q)$(RM) -- $(OUTPUT)FEATURE-DUMP.bpftool
@@ -192,6 +213,7 @@ FORCE:
 zdep:
 	@if [ "$(feature-zlib)" != "1" ]; then echo "No zlib found"; exit 1 ; fi
 
+.SECONDARY:
 .PHONY: all FORCE clean install uninstall zdep
 .PHONY: doc doc-clean doc-install doc-uninstall
 .DEFAULT_GOAL := all
diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c
index faac8189b285..fc9bc7a23db6 100644
--- a/tools/bpf/bpftool/btf.c
+++ b/tools/bpf/bpftool/btf.c
@@ -809,6 +809,7 @@ show_btf_plain(struct bpf_btf_info *info, int fd,
 			printf("%s%u", n++ == 0 ? "  map_ids " : ",",
 			       obj->obj_id);
 	}
+	emit_obj_refs_plain(&refs_table, info->id, "\n\tpids ");
 
 	printf("\n");
 }
@@ -841,6 +842,9 @@ show_btf_json(struct bpf_btf_info *info, int fd,
 			jsonw_uint(json_wtr, obj->obj_id);
 	}
 	jsonw_end_array(json_wtr);	/* map_ids */
+
+	emit_obj_refs_json(&refs_table, info->id, json_wtr); /* pids */
+
 	jsonw_end_object(json_wtr);	/* btf object */
 }
 
@@ -893,6 +897,7 @@ static int do_show(int argc, char **argv)
 			close(fd);
 		return err;
 	}
+	build_obj_refs_table(&refs_table, BPF_OBJ_BTF);
 
 	if (fd >= 0) {
 		err = show_btf(fd, &btf_prog_table, &btf_map_table);
@@ -939,6 +944,7 @@ static int do_show(int argc, char **argv)
 exit_free:
 	delete_btf_table(&btf_prog_table);
 	delete_btf_table(&btf_map_table);
+	delete_obj_refs_table(&refs_table);
 
 	return err;
 }
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
index c47bdc65de8e..18e5604fe260 100644
--- a/tools/bpf/bpftool/common.c
+++ b/tools/bpf/bpftool/common.c
@@ -29,6 +29,42 @@
 #define BPF_FS_MAGIC		0xcafe4a11
 #endif
 
+const char * const attach_type_name[__MAX_BPF_ATTACH_TYPE] = {
+	[BPF_CGROUP_INET_INGRESS]	= "ingress",
+	[BPF_CGROUP_INET_EGRESS]	= "egress",
+	[BPF_CGROUP_INET_SOCK_CREATE]	= "sock_create",
+	[BPF_CGROUP_SOCK_OPS]		= "sock_ops",
+	[BPF_CGROUP_DEVICE]		= "device",
+	[BPF_CGROUP_INET4_BIND]		= "bind4",
+	[BPF_CGROUP_INET6_BIND]		= "bind6",
+	[BPF_CGROUP_INET4_CONNECT]	= "connect4",
+	[BPF_CGROUP_INET6_CONNECT]	= "connect6",
+	[BPF_CGROUP_INET4_POST_BIND]	= "post_bind4",
+	[BPF_CGROUP_INET6_POST_BIND]	= "post_bind6",
+	[BPF_CGROUP_INET4_GETPEERNAME]	= "getpeername4",
+	[BPF_CGROUP_INET6_GETPEERNAME]	= "getpeername6",
+	[BPF_CGROUP_INET4_GETSOCKNAME]	= "getsockname4",
+	[BPF_CGROUP_INET6_GETSOCKNAME]	= "getsockname6",
+	[BPF_CGROUP_UDP4_SENDMSG]	= "sendmsg4",
+	[BPF_CGROUP_UDP6_SENDMSG]	= "sendmsg6",
+	[BPF_CGROUP_SYSCTL]		= "sysctl",
+	[BPF_CGROUP_UDP4_RECVMSG]	= "recvmsg4",
+	[BPF_CGROUP_UDP6_RECVMSG]	= "recvmsg6",
+	[BPF_CGROUP_GETSOCKOPT]		= "getsockopt",
+	[BPF_CGROUP_SETSOCKOPT]		= "setsockopt",
+
+	[BPF_SK_SKB_STREAM_PARSER]	= "sk_skb_stream_parser",
+	[BPF_SK_SKB_STREAM_VERDICT]	= "sk_skb_stream_verdict",
+	[BPF_SK_MSG_VERDICT]		= "sk_msg_verdict",
+	[BPF_LIRC_MODE2]		= "lirc_mode2",
+	[BPF_FLOW_DISSECTOR]		= "flow_dissector",
+	[BPF_TRACE_RAW_TP]		= "raw_tp",
+	[BPF_TRACE_FENTRY]		= "fentry",
+	[BPF_TRACE_FEXIT]		= "fexit",
+	[BPF_MODIFY_RETURN]		= "mod_ret",
+	[BPF_LSM_MAC]			= "lsm_mac",
+};
+
 void p_err(const char *fmt, ...)
 {
 	va_list ap;
@@ -581,3 +617,311 @@ print_all_levels(__maybe_unused enum libbpf_print_level level,
 {
 	return vfprintf(stderr, format, args);
 }
+
+static int prog_fd_by_nametag(void *nametag, int **fds, bool tag)
+{
+	unsigned int id = 0;
+	int fd, nb_fds = 0;
+	void *tmp;
+	int e