Daniel Borkmann says:

====================
bpf-next 2022-11-25

We've added 101 non-merge commits during the last 11 day(s) which contain
a total of 109 files changed, 8827 insertions(+), 1129 deletions(-).

The main changes are:

1) Support for user defined BPF objects: the use case is to allocate own
   objects, build own object hierarchies and use the building blocks to
   build own data structures flexibly, for example, linked lists in BPF,
   from Kumar Kartikeya Dwivedi.

2) Add bpf_rcu_read_{,un}lock() support for sleepable programs,
   from Yonghong Song.

3) Add support storing struct task_struct objects as kptrs in maps,
   from David Vernet.

4) Batch of BPF map documentation improvements, from Maryam Tahhan
   and Donald Hunter.

5) Improve BPF verifier to propagate nullness information for branches
   of register to register comparisons, from Eduard Zingerman.

6) Fix cgroup BPF iter infra to hold reference on the start cgroup,
   from Hou Tao.

7) Fix BPF verifier to not mark fentry/fexit program arguments as trusted
   given it is not the case for them, from Alexei Starovoitov.

8) Improve BPF verifier's realloc handling to better play along with dynamic
   runtime analysis tools like KASAN and friends, from Kees Cook.

9) Remove legacy libbpf mode support from bpftool,
   from Sahid Orentino Ferdjaoui.

10) Rework zero-len skb redirection checks to avoid potentially breaking
    existing BPF test infra users, from Stanislav Fomichev.

11) Two small refactorings which are independent and have been split out
    of the XDP queueing RFC series, from Toke Høiland-Jørgensen.

12) Fix a memory leak in LSM cgroup BPF selftest, from Wang Yufen.

13) Documentation on how to run BPF CI without patch submission,
    from Daniel Müller.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
====================

Link: https://lore.kernel.org/r/20221125012450.441-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

61 files changed, 4845 insertions, 195 deletions

diff --git a/tools/bpf/bpftool/Documentation/common_options.rst b/tools/bpf/bpftool/Documentation/common_options.rst
index 05350a1aadf9..30df7a707f02 100644
--- a/tools/bpf/bpftool/Documentation/common_options.rst
+++ b/tools/bpf/bpftool/Documentation/common_options.rst
@@ -23,12 +23,3 @@
 	  Print all logs available, even debug-level information. This includes
 	  logs from libbpf as well as from the verifier, when attempting to
 	  load programs.
-
--l, --legacy
-	  Use legacy libbpf mode which has more relaxed BPF program
-	  requirements. By default, bpftool has more strict requirements
-	  about section names, changes pinning logic and doesn't support
-	  some of the older non-BTF map declarations.
-
-	  See https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0
-	  for details.
diff --git a/tools/bpf/bpftool/Documentation/substitutions.rst b/tools/bpf/bpftool/Documentation/substitutions.rst
index ccf1ffa0686c..827e3ffb1766 100644
--- a/tools/bpf/bpftool/Documentation/substitutions.rst
+++ b/tools/bpf/bpftool/Documentation/substitutions.rst
@@ -1,3 +1,3 @@
 .. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
 
-.. |COMMON_OPTIONS| replace:: { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-d** | **--debug** } | { **-l** | **--legacy** }
+.. |COMMON_OPTIONS| replace:: { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-d** | **--debug** }
diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool
index 2957b42cab67..35f26f7c1124 100644
--- a/tools/bpf/bpftool/bash-completion/bpftool
+++ b/tools/bpf/bpftool/bash-completion/bpftool
@@ -261,7 +261,7 @@ _bpftool()
     # Deal with options
     if [[ ${words[cword]} == -* ]]; then
         local c='--version --json --pretty --bpffs --mapcompat --debug \
-	       --use-loader --base-btf --legacy'
+	       --use-loader --base-btf'
         COMPREPLY=( $( compgen -W "$c" -- "$cur" ) )
         return 0
     fi
diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c
index b87e4a7fd689..352290ba7b29 100644
--- a/tools/bpf/bpftool/btf.c
+++ b/tools/bpf/bpftool/btf.c
@@ -467,9 +467,8 @@ static int dump_btf_c(const struct btf *btf,
 	int err = 0, i;
 
 	d = btf_dump__new(btf, btf_dump_printf, NULL, NULL);
-	err = libbpf_get_error(d);
-	if (err)
-		return err;
+	if (!d)
+		return -errno;
 
 	printf("#ifndef __VMLINUX_H__\n");
 	printf("#define __VMLINUX_H__\n");
@@ -512,11 +511,9 @@ static struct btf *get_vmlinux_btf_from_sysfs(void)
 	struct btf *base;
 
 	base = btf__parse(sysfs_vmlinux, NULL);
-	if (libbpf_get_error(base)) {
-		p_err("failed to parse vmlinux BTF at '%s': %ld\n",
-		      sysfs_vmlinux, libbpf_get_error(base));
-		base = NULL;
-	}
+	if (!base)
+		p_err("failed to parse vmlinux BTF at '%s': %d\n",
+		      sysfs_vmlinux, -errno);
 
 	return base;
 }
@@ -559,7 +556,7 @@ static int do_dump(int argc, char **argv)
 	__u32 btf_id = -1;
 	const char *src;
 	int fd = -1;
-	int err;
+	int err = 0;
 
 	if (!REQ_ARGS(2)) {
 		usage();
@@ -634,8 +631,8 @@ static int do_dump(int argc, char **argv)
 			base = get_vmlinux_btf_from_sysfs();
 
 		btf = btf__parse_split(*argv, base ?: base_btf);
-		err = libbpf_get_error(btf);
 		if (!btf) {
+			err = -errno;
 			p_err("failed to load BTF from %s: %s",
 			      *argv, strerror(errno));
 			goto done;
@@ -681,8 +678,8 @@ static int do_dump(int argc, char **argv)
 		}
 
 		btf = btf__load_from_kernel_by_id_split(btf_id, base_btf);
-		err = libbpf_get_error(btf);
 		if (!btf) {
+			err = -errno;
 			p_err("get btf by id (%u): %s", btf_id, strerror(errno));
 			goto done;
 		}
diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c
index 19924b6ce796..eda71fdfe95a 100644
--- a/tools/bpf/bpftool/btf_dumper.c
+++ b/tools/bpf/bpftool/btf_dumper.c
@@ -75,7 +75,7 @@ static int dump_prog_id_as_func_ptr(const struct btf_dumper *d,
 		goto print;
 
 	prog_btf = btf__load_from_kernel_by_id(info.btf_id);
-	if (libbpf_get_error(prog_btf))
+	if (!prog_btf)
 		goto print;
 	func_type = btf__type_by_id(prog_btf, finfo.type_id);
 	if (!func_type || !btf_is_func(func_type))
diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index 01bb8d8f5568..2883660d6b67 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -252,9 +252,8 @@ static int codegen_datasecs(struct bpf_object *obj, const char *obj_name)
 	int err = 0;
 
 	d = btf_dump__new(btf, codegen_btf_dump_printf, NULL, NULL);
-	err = libbpf_get_error(d);
-	if (err)
-		return err;
+	if (!d)
+		return -errno;
 
 	bpf_object__for_each_map(map, obj) {
 		/* only generate definitions for memory-mapped internal maps */
@@ -976,13 +975,12 @@ static int do_skeleton(int argc, char **argv)
 		/* log_level1 + log_level2 + stats, but not stable UAPI */
 		opts.kernel_log_level = 1 + 2 + 4;
 	obj = bpf_object__open_mem(obj_data, file_sz, &opts);
-	err = libbpf_get_error(obj);
-	if (err) {
+	if (!obj) {
 		char err_buf[256];
 
+		err = -errno;
 		libbpf_strerror(err, err_buf, sizeof(err_buf));
 		p_err("failed to open BPF object file: %s", err_buf);
-		obj = NULL;
 		goto out;
 	}
 
diff --git a/tools/bpf/bpftool/iter.c b/tools/bpf/bpftool/iter.c
index a3e6b167153d..9a1d2365a297 100644
--- a/tools/bpf/bpftool/iter.c
+++ b/tools/bpf/bpftool/iter.c
@@ -4,6 +4,7 @@
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE
 #endif
+#include <errno.h>
 #include <unistd.h>
 #include <linux/err.h>
 #include <bpf/libbpf.h>
@@ -48,8 +49,8 @@ static int do_pin(int argc, char **argv)
 	}
 
 	obj = bpf_object__open(objfile);
-	err = libbpf_get_error(obj);
-	if (err) {
+	if (!obj) {
+		err = -errno;
 		p_err("can't open objfile %s", objfile);
 		goto close_map_fd;
 	}
@@ -62,13 +63,14 @@ static int do_pin(int argc, char **argv)
 
 	prog = bpf_object__next_program(obj, NULL);
 	if (!prog) {
+		err = -errno;
 		p_err("can't find bpf program in objfile %s", objfile);
 		goto close_obj;
 	}
 
 	link = bpf_program__attach_iter(prog, &iter_opts);
-	err = libbpf_get_error(link);
-	if (err) {
+	if (!link) {
+		err = -errno;
 		p_err("attach_iter failed for program %s",
 		      bpf_program__name(prog));
 		goto close_obj;
diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c
index 741e50ee0b6c..08d0ac543c67 100644
--- a/tools/bpf/bpftool/main.c
+++ b/tools/bpf/bpftool/main.c
@@ -31,7 +31,6 @@ bool block_mount;
 bool verifier_logs;
 bool relaxed_maps;
 bool use_loader;
-bool legacy_libbpf;
 struct btf *base_btf;
 struct hashmap *refs_table;
 
@@ -160,7 +159,6 @@ static int do_version(int argc, char **argv)
 		jsonw_start_object(json_wtr);	/* features */
 		jsonw_bool_field(json_wtr, "libbfd", has_libbfd);
 		jsonw_bool_field(json_wtr, "llvm", has_llvm);
-		jsonw_bool_field(json_wtr, "libbpf_strict", !legacy_libbpf);
 		jsonw_bool_field(json_wtr, "skeletons", has_skeletons);
 		jsonw_bool_field(json_wtr, "bootstrap", bootstrap);
 		jsonw_end_object(json_wtr);	/* features */
@@ -179,7 +177,6 @@ static int do_version(int argc, char **argv)
 		printf("features:");
 		print_feature("libbfd", has_libbfd, &nb_features);
 		print_feature("llvm", has_llvm, &nb_features);
-		print_feature("libbpf_strict", !legacy_libbpf, &nb_features);
 		print_feature("skeletons", has_skeletons, &nb_features);
 		print_feature("bootstrap", bootstrap, &nb_features);
 		printf("\n");
@@ -337,12 +334,12 @@ static int do_batch(int argc, char **argv)
 	if (argc < 2) {
 		p_err("too few parameters for batch");
 		return -1;
-	} else if (!is_prefix(*argv, "file")) {
-		p_err("expected 'file', got: %s", *argv);
-		return -1;
 	} else if (argc > 2) {
 		p_err("too many parameters for batch");
 		return -1;
+	} else if (!is_prefix(*argv, "file")) {
+		p_err("expected 'file', got: %s", *argv);
+		return -1;
 	}
 	NEXT_ARG();
 
@@ -451,7 +448,6 @@ int main(int argc, char **argv)
 		{ "debug",	no_argument,	NULL,	'd' },
 		{ "use-loader",	no_argument,	NULL,	'L' },
 		{ "base-btf",	required_argument, NULL, 'B' },
-		{ "legacy",	no_argument,	NULL,	'l' },
 		{ 0 }
 	};
 	bool version_requested = false;
@@ -514,19 +510,15 @@ int main(int argc, char **argv)
 			break;
 		case 'B':
 			base_btf = btf__parse(optarg, NULL);
-			if (libbpf_get_error(base_btf)) {
-				p_err("failed to parse base BTF at '%s': %ld\n",
-				      optarg, libbpf_get_error(base_btf));
-				base_btf = NULL;
+			if (!base_btf) {
+				p_err("failed to parse base BTF at '%s': %d\n",
+				      optarg, -errno);
 				return -1;
 			}
 			break;
 		case 'L':
 			use_loader = true;
 			break;
-		case 'l':
-			legacy_libbpf = true;
-			break;
 		default:
 			p_err("unrecognized option '%s'", argv[optind - 1]);
 			if (json_output)
@@ -536,14 +528,6 @@ int main(int argc, char **argv)
 		}
 	}
 
-	if (!legacy_libbpf) {
-		/* Allow legacy map definitions for skeleton generation.
-		 * It will still be rejected if users use LIBBPF_STRICT_ALL
-		 * mode for loading generated skeleton.
-		 */
-		libbpf_set_strict_mode(LIBBPF_STRICT_ALL & ~LIBBPF_STRICT_MAP_DEFINITIONS);
-	}
-
 	argc -= optind;
 	argv += optind;
 	if (argc < 0)
diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index d4e8a1aef787..a84224b6a604 100644
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -57,7 +57,7 @@ static inline void *u64_to_ptr(__u64 ptr)
 #define HELP_SPEC_PROGRAM						\
 	"PROG := { id PROG_ID | pinned FILE | tag PROG_TAG | name PROG_NAME }"
 #define HELP_SPEC_OPTIONS						\
-	"OPTIONS := { {-j|--json} [{-p|--pretty}] | {-d|--debug} | {-l|--legacy}"
+	"OPTIONS := { {-j|--json} [{-p|--pretty}] | {-d|--debug}"
 #define HELP_SPEC_MAP							\
 	"MAP := { id MAP_ID | pinned FILE | name MAP_NAME }"
 #define HELP_SPEC_LINK							\
@@ -82,7 +82,6 @@ extern bool block_mount;
 extern bool verifier_logs;
 extern bool relaxed_maps;
 extern bool use_loader;
-extern bool legacy_libbpf;
 extern struct btf *base_btf;
 extern struct hashmap *refs_table;
 
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index d884070a2314..88911d3aa2d9 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -786,18 +786,18 @@ static int get_map_kv_btf(const struct bpf_map_info *info, struct btf **btf)
 	if (info->btf_vmlinux_value_type_id) {
 		if (!btf_vmlinux) {
 			btf_vmlinux = libbpf_find_kernel_btf();
-			err = libbpf_get_error(btf_vmlinux);
-			if (err) {
+			if (!btf_vmlinux) {
 				p_err("failed to get kernel btf");
-				return err;
+				return -errno;
 			}
 		}
 		*btf = btf_vmlinux;
 	} else if (info->btf_value_type_id) {
 		*btf = btf__load_from_kernel_by_id(info->btf_id);
-		err = libbpf_get_error(*btf);
-		if (err)
+		if (!*btf) {
+			err = -errno;
 			p_err("failed to get btf");
+		}
 	} else {
 		*btf = NULL;
 	}
@@ -807,16 +807,10 @@ static int get_map_kv_btf(const struct bpf_map_info *info, struct btf **btf)
 
 static void free_map_kv_btf(struct btf *btf)
 {
-	if (!libbpf_get_error(btf) && btf != btf_vmlinux)
+	if (btf != btf_vmlinux)
 		btf__free(btf);
 }
 
-static void free_btf_vmlinux(void)
-{
-	if (!libbpf_get_error(btf_vmlinux))
-		btf__free(btf_vmlinux);
-}
-
 static int
 map_dump(int fd, struct bpf_map_info *info, json_writer_t *wtr,
 	 bool show_header)
@@ -953,7 +947,7 @@ exit_close:
 		close(fds[i]);
 exit_free:
 	free(fds);
-	free_btf_vmlinux();
+	btf__free(btf_vmlinux);
 	return err;
 }
 
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 9d32ffb9f22e..cfc9fdc1e863 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -322,7 +322,7 @@ static void show_prog_metadata(int fd, __u32 num_maps)
 		return;
 
 	btf = btf__load_from_kernel_by_id(map_info.btf_id);
-	if (libbpf_get_error(btf))
+	if (!btf)
 		goto out_free;
 
 	t_datasec = btf__type_by_id(btf, map_info.btf_value_type_id);
@@ -726,7 +726,7 @@ prog_dump(struct bpf_prog_info *info, enum dump_mode mode,
 
 	if (info->btf_id) {
 		btf = btf__load_from_kernel_by_id(info->btf_id);
-		if (libbpf_get_error(btf)) {
+		if (!btf) {
 			p_err("failed to get btf");
 			return -1;
 		}
@@ -1663,7 +1663,7 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
 		open_opts.kernel_log_level = 1 + 2 + 4;
 
 	obj = bpf_object__open_file(file, &open_opts);
-	if (libbpf_get_error(obj)) {
+	if (!obj) {
 		p_err("failed to open object file");
 		goto err_free_reuse_maps;
 	}
@@ -1802,11 +1802,6 @@ err_unpin:
 	else
 		bpf_object__unpin_programs(obj, pinfile);
 err_close_obj:
-	if (!legacy_libbpf) {
-		p_info("Warning: bpftool is now running in libbpf strict mode and has more stringent requirements about BPF programs.\n"
-		       "If it used to work for this object file but now doesn't, see --legacy option for more details.\n");
-	}
-
 	bpf_object__close(obj);
 err_free_reuse_maps:
 	for (i = 0; i < old_map_fds; i++)
@@ -1887,7 +1882,7 @@ static int do_loader(int argc, char **argv)
 		open_opts.kernel_log_level = 1 + 2 + 4;
 
 	obj = bpf_object__open_file(file, &open_opts);
-	if (libbpf_get_error(obj)) {
+	if (!obj) {
 		p_err("failed to open object file");
 		goto err_close_obj;
 	}
@@ -2204,7 +2199,7 @@ static char *profile_target_name(int tgt_fd)
 	}
 
 	btf = btf__load_from_kernel_by_id(info.btf_id);
-	if (libbpf_get_error(btf)) {
+	if (!btf) {
 		p_err("failed to load btf for prog FD %d", tgt_fd);
 		goto out;
 	}
diff --git a/tools/bpf/bpftool/struct_ops.c b/tools/bpf/bpftool/struct_ops.c
index e08a6ff2866c..903b80ff4e9a 100644
--- a/tools/bpf/bpftool/struct_ops.c
+++ b/tools/bpf/bpftool/struct_ops.c
@@ -32,7 +32,7 @@ static const struct btf *get_btf_vmlinux(void)
 		return btf_vmlinux;
 
 	btf_vmlinux = libbpf_find_kernel_btf();
-	if (libbpf_get_error(btf_vmlinux))
+	if (!btf_vmlinux)
 		p_err("struct_ops requires kernel CONFIG_DEBUG_INFO_BTF=y");
 
 	return btf_vmlinux;
@@ -45,7 +45,7 @@ static const char *get_kern_struct_ops_name(const struct bpf_map_info *info)
 	const char *st_ops_name;
 
 	kern_btf = get_btf_vmlinux();
-	if (libbpf_get_error(kern_btf))
+	if (!kern_btf)
 		return "<btf_vmlinux_not_found>";
 
 	t = btf__type_by_id(kern_btf, info->btf_vmlinux_value_type_id);
@@ -63,10 +63,8 @@ static __s32 get_map_info_type_id(void)
 		return map_info_type_id;
 
 	kern_btf = get_btf_vmlinux();
-	if (libbpf_get_error(kern_btf)) {
-		map_info_type_id = PTR_ERR(kern_btf);
-		return map_info_type_id;
-	}
+	if (!kern_btf)
+		return 0;
 
 	map_info_type_id = btf__find_by_name_kind(kern_btf, "bpf_map_info",
 						  BTF_KIND_STRUCT);
@@ -415,7 +413,7 @@ static int do_dump(int argc, char **argv)
 	}
 
 	kern_btf = get_btf_vmlinux();
-	if (libbpf_get_error(kern_btf))
+	if (!kern_btf)
 		return -1;
 
 	if (!json_output) {
@@ -498,7 +496,7 @@ static int do_register(int argc, char **argv)
 		open_opts.kernel_log_level = 1 + 2 + 4;
 
 	obj = bpf_object__open_file(file, &open_opts);
-	if (libbpf_get_error(obj))
+	if (!obj)
 		return -1;
 
 	set_max_rlimit();
@@ -513,10 +511,9 @@ static int do_register(int argc, char **argv)
 			continue;
 
 		link = bpf_map__attach_struct_ops(map);
-		if (libbpf_get_error(link)) {
+		if (!link) {
 			p_err("can't register struct_ops %s: %s",
-			      bpf_map__name(map),
-			      strerror(-PTR_ERR(link)));
+			      bpf_map__name(map), strerror(errno));
 			nr_errs++;
 			continue;
 		}
@@ -593,8 +590,7 @@ int do_struct_ops(int argc, char **argv)
 
 	err = cmd_select(cmds, argc, argv, do_help);
 
-	if (!libbpf_get_error(btf_vmlinux))