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

Andrii Nakryiko says:

====================
bpf-next 2022-08-17

We've added 45 non-merge commits during the last 14 day(s) which contain
a total of 61 files changed, 986 insertions(+), 372 deletions(-).

The main changes are:

1) New bpf_ktime_get_tai_ns() BPF helper to access CLOCK_TAI, from Kurt
   Kanzenbach and Jesper Dangaard Brouer.

2) Few clean ups and improvements for libbpf 1.0, from Andrii Nakryiko.

3) Expose crash_kexec() as kfunc for BPF programs, from Artem Savkov.

4) Add ability to define sleepable-only kfuncs, from Benjamin Tissoires.

5) Teach libbpf's bpf_prog_load() and bpf_map_create() to gracefully handle
   unsupported names on old kernels, from Hangbin Liu.

6) Allow opting out from auto-attaching BPF programs by libbpf's BPF skeleton,
   from Hao Luo.

7) Relax libbpf's requirement for shared libs to be marked executable, from
   Henqgi Chen.

8) Improve bpf_iter internals handling of error returns, from Hao Luo.

9) Few accommodations in libbpf to support GCC-BPF quirks, from James Hilliard.

10) Fix BPF verifier logic around tracking dynptr ref_obj_id, from Joanne Koong.

11) bpftool improvements to handle full BPF program names better, from Manu
    Bretelle.

12) bpftool fixes around libcap use, from Quentin Monnet.

13) BPF map internals clean ups and improvements around memory allocations,
    from Yafang Shao.

14) Allow to use cgroup_get_from_file() on cgroupv1, allowing BPF cgroup
    iterator to work on cgroupv1, from Yosry Ahmed.

15) BPF verifier internal clean ups, from Dave Marchevsky and Joanne Koong.

16) Various fixes and clean ups for selftests/bpf and vmtest.sh, from Daniel
    Xu, Artem Savkov, Joanne Koong, Andrii Nakryiko, Shibin Koikkara Reeny.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (45 commits)
  selftests/bpf: Few fixes for selftests/bpf built in release mode
  libbpf: Clean up deprecated and legacy aliases
  libbpf: Streamline bpf_attr and perf_event_attr initialization
  libbpf: Fix potential NULL dereference when parsing ELF
  selftests/bpf: Tests libbpf autoattach APIs
  libbpf: Allows disabling auto attach
  selftests/bpf: Fix attach point for non-x86 arches in test_progs/lsm
  libbpf: Making bpf_prog_load() ignore name if kernel doesn't support
  selftests/bpf: Update CI kconfig
  selftests/bpf: Add connmark read test
  selftests/bpf: Add existing connection bpf_*_ct_lookup() test
  bpftool: Clear errno after libcap's checks
  bpf: Clear up confusion in bpf_skb_adjust_room()'s documentation
  bpftool: Fix a typo in a comment
  libbpf: Add names for auxiliary maps
  bpf: Use bpf_map_area_alloc consistently on bpf map creation
  bpf: Make __GFP_NOWARN consistent in bpf map creation
  bpf: Use bpf_map_area_free instread of kvfree
  bpf: Remove unneeded memset in queue_stack_map creation
  libbpf: preserve errno across pr_warn/pr_info/pr_debug
  ...
====================

Link: https://lore.kernel.org/r/20220817215656.1180215-1-andrii@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 73 insertions, 31 deletions

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 50d41815f431..3ad139285fad 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -223,13 +223,18 @@ __printf(2, 3)
 void libbpf_print(enum libbpf_print_level level, const char *format, ...)
 {
 	va_list args;
+	int old_errno;
 
 	if (!__libbpf_pr)
 		return;
 
+	old_errno = errno;
+
 	va_start(args, format);
 	__libbpf_pr(level, format, args);
 	va_end(args);
+
+	errno = old_errno;
 }
 
 static void pr_perm_msg(int err)
@@ -412,6 +417,7 @@ struct bpf_program {
 
 	int fd;
 	bool autoload;
+	bool autoattach;
 	bool mark_btf_static;
 	enum bpf_prog_type type;
 	enum bpf_attach_type expected_attach_type;
@@ -591,7 +597,6 @@ struct elf_state {
 	size_t strtabidx;
 	struct elf_sec_desc *secs;
 	int sec_cnt;
-	int maps_shndx;
 	int btf_maps_shndx;
 	__u32 btf_maps_sec_btf_id;
 	int text_shndx;
@@ -751,6 +756,8 @@ bpf_object__init_prog(struct bpf_object *obj, struct bpf_program *prog,
 		prog->autoload = true;
 	}
 
+	prog->autoattach = true;
+
 	/* inherit object's log_level */
 	prog->log_level = obj->log_level;
 
@@ -1272,7 +1279,6 @@ static struct bpf_object *bpf_object__new(const char *path,
 	 */
 	obj->efile.obj_buf = obj_buf;
 	obj->efile.obj_buf_sz = obj_buf_sz;
-	obj->efile.maps_shndx = -1;
 	obj->efile.btf_maps_shndx = -1;
 	obj->efile.st_ops_shndx = -1;
 	obj->kconfig_map_idx = -1;
@@ -1642,6 +1648,10 @@ static int bpf_object__init_global_data_maps(struct bpf_object *obj)
 	for (sec_idx = 1; sec_idx < obj->efile.sec_cnt; sec_idx++) {
 		sec_desc = &obj->efile.secs[sec_idx];
 
+		/* Skip recognized sections with size 0. */
+		if (!sec_desc->data || sec_desc->data->d_size == 0)
+			continue;
+
 		switch (sec_desc->sec_type) {
 		case SEC_DATA:
 			sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx));
@@ -3359,7 +3369,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 			if (err)
 				return err;
 		} else if (strcmp(name, "maps") == 0) {
-			obj->efile.maps_shndx = idx;
+			pr_warn("elf: legacy map definitions in 'maps' section are not supported by libbpf v1.0+\n");
+			return -ENOTSUP;
 		} else if (strcmp(name, MAPS_ELF_SEC) == 0) {
 			obj->efile.btf_maps_shndx = idx;
 		} else if (strcmp(name, BTF_ELF_SEC) == 0) {
@@ -3891,8 +3902,7 @@ static bool bpf_object__shndx_is_data(const struct bpf_object *obj,
 static bool bpf_object__shndx_is_maps(const struct bpf_object *obj,
 				      int shndx)
 {
-	return shndx == obj->efile.maps_shndx ||
-	       shndx == obj->efile.btf_maps_shndx;
+	return shndx == obj->efile.btf_maps_shndx;
 }
 
 static enum libbpf_map_type
@@ -4277,11 +4287,12 @@ int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate)
 
 int bpf_map__reuse_fd(struct bpf_map *map, int fd)
 {
-	struct bpf_map_info info = {};
+	struct bpf_map_info info;
 	__u32 len = sizeof(info), name_len;
 	int new_fd, err;
 	char *new_name;
 
+	memset(&info, 0, len);
 	err = bpf_obj_get_info_by_fd(fd, &info, &len);
 	if (err && errno == EINVAL)
 		err = bpf_get_map_info_from_fdinfo(fd, &info);
@@ -4408,14 +4419,23 @@ static int probe_fd(int fd)
 
 static int probe_kern_prog_name(void)
 {
+	const size_t attr_sz = offsetofend(union bpf_attr, prog_name);
 	struct bpf_insn insns[] = {
 		BPF_MOV64_IMM(BPF_REG_0, 0),
 		BPF_EXIT_INSN(),
 	};
-	int ret, insn_cnt = ARRAY_SIZE(insns);
+	union bpf_attr attr;
+	int ret;
+
+	memset(&attr, 0, attr_sz);
+	attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
+	attr.license = ptr_to_u64("GPL");
+	attr.insns = ptr_to_u64(insns);
+	attr.insn_cnt = (__u32)ARRAY_SIZE(insns);
+	libbpf_strlcpy(attr.prog_name, "libbpf_nametest", sizeof(attr.prog_name));
 
 	/* make sure loading with name works */
-	ret = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, "test", "GPL", insns, insn_cnt, NULL);
+	ret = sys_bpf_prog_load(&attr, attr_sz, PROG_LOAD_ATTEMPTS);
 	return probe_fd(ret);
 }
 
@@ -4430,7 +4450,7 @@ static int probe_kern_global_data(void)
 	};
 	int ret, map, insn_cnt = ARRAY_SIZE(insns);
 
-	map = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, sizeof(int), 32, 1, NULL);
+	map = bpf_map_create(BPF_MAP_TYPE_ARRAY, "libbpf_global", sizeof(int), 32, 1, NULL);
 	if (map < 0) {
 		ret = -errno;
 		cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg));
@@ -4563,7 +4583,7 @@ static int probe_kern_array_mmap(void)
 	LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_MMAPABLE);
 	int fd;
 
-	fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, sizeof(int), sizeof(int), 1, &opts);
+	fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, "libbpf_mmap", sizeof(int), sizeof(int), 1, &opts);
 	return probe_fd(fd);
 }
 
@@ -4610,7 +4630,7 @@ static int probe_prog_bind_map(void)
 	};
 	int ret, map, prog, insn_cnt = ARRAY_SIZE(insns);
 
-	map = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, sizeof(int), 32, 1, NULL);
+	map = bpf_map_create(BPF_MAP_TYPE_ARRAY, "libbpf_det_bind", sizeof(int), 32, 1, NULL);
 	if (map < 0) {
 		ret = -errno;
 		cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg));
@@ -4814,13 +4834,12 @@ bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id)
 
 static bool map_is_reuse_compat(const struct bpf_map *map, int map_fd)
 {
-	struct bpf_map_info map_info = {};
+	struct bpf_map_info map_info;
 	char msg[STRERR_BUFSIZE];
-	__u32 map_info_len;
+	__u32 map_info_len = sizeof(map_info);
 	int err;
 
-	map_info_len = sizeof(map_info);
-
+	memset(&map_info, 0, map_info_len);
 	err = bpf_obj_get_info_by_fd(map_fd, &map_info, &map_info_len);
 	if (err && errno == EINVAL)
 		err = bpf_get_map_info_from_fdinfo(map_fd, &map_info);
@@ -7244,8 +7263,6 @@ static int bpf_object_unload(struct bpf_object *obj)
 	return 0;
 }
 
-int bpf_object__unload(struct bpf_object *obj) __attribute__((alias("bpf_object_unload")));
-
 static int bpf_object__sanitize_maps(struct bpf_object *obj)
 {
 	struct bpf_map *m;
@@ -8298,6 +8315,16 @@ int bpf_program__set_autoload(struct bpf_program *prog, bool autoload)
 	return 0;
 }
 
+bool bpf_program__autoattach(const struct bpf_program *prog)
+{
+	return prog->autoattach;
+}
+
+void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach)
+{
+	prog->autoattach = autoattach;
+}
+
 const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog)
 {
 	return prog->insns;
@@ -8978,11 +9005,12 @@ int libbpf_find_vmlinux_btf_id(const char *name,
 
 static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd)
 {
-	struct bpf_prog_info info = {};
+	struct bpf_prog_info info;
 	__u32 info_len = sizeof(info);
 	struct btf *btf;
 	int err;
 
+	memset(&info, 0, info_len);
 	err = bpf_obj_get_info_by_fd(attach_prog_fd, &info, &info_len);
 	if (err) {
 		pr_warn("failed bpf_obj_get_info_by_fd for FD %d: %d\n",
@@ -9810,13 +9838,16 @@ static int determine_uprobe_retprobe_bit(void)
 static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name,
 				 uint64_t offset, int pid, size_t ref_ctr_off)
 {
-	struct perf_event_attr attr = {};
+	const size_t attr_sz = sizeof(struct perf_event_attr);
+	struct perf_event_attr attr;
 	char errmsg[STRERR_BUFSIZE];
 	int type, pfd;
 
 	if (ref_ctr_off >= (1ULL << PERF_UPROBE_REF_CTR_OFFSET_BITS))
 		return -EINVAL;
 
+	memset(&attr, 0, attr_sz);
+
 	type = uprobe ? determine_uprobe_perf_type()
 		      : determine_kprobe_perf_type();
 	if (type < 0) {
@@ -9837,7 +9868,7 @@ static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name,
 		}
 		attr.config |= 1 << bit;
 	}
-	attr.size = sizeof(attr);
+	attr.size = attr_sz;
 	attr.type = type;
 	attr.config |= (__u64)ref_ctr_off << PERF_UPROBE_REF_CTR_OFFSET_SHIFT;
 	attr.config1 = ptr_to_u64(name); /* kprobe_func or uprobe_path */
@@ -9936,7 +9967,8 @@ static int determine_kprobe_perf_type_legacy(const char *probe_name, bool retpro
 static int perf_event_kprobe_open_legacy(const char *probe_name, bool retprobe,
 					 const char *kfunc_name, size_t offset, int pid)
 {
-	struct perf_event_attr attr = {};
+	const size_t attr_sz = sizeof(struct perf_event_attr);
+	struct perf_event_attr attr;
 	char errmsg[STRERR_BUFSIZE];
 	int type, pfd, err;
 
@@ -9955,7 +9987,9 @@ static int perf_event_kprobe_open_legacy(const char *probe_name, bool retprobe,
 			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
 		goto err_clean_legacy;
 	}
-	attr.size = sizeof(attr);
+
+	memset(&attr, 0, attr_sz);
+	attr.size = attr_sz;
 	attr.config = type;
 	attr.type = PERF_TYPE_TRACEPOINT;
 
@@ -10412,6 +10446,7 @@ static int determine_uprobe_perf_type_legacy(const char *probe_name, bool retpro
 static int perf_event_uprobe_open_legacy(const char *probe_name, bool retprobe,
 					 const char *binary_path, size_t offset, int pid)
 {
+	const size_t attr_sz = sizeof(struct perf_event_attr);
 	struct perf_event_attr attr;
 	int type, pfd, err;
 
@@ -10429,8 +10464,8 @@ static int perf_event_uprobe_open_legacy(const char *probe_name, bool retprobe,
 		goto err_clean_legacy;
 	}
 
-	memset(&attr, 0, sizeof(attr));
-	attr.size = sizeof(attr);
+	memset(&attr, 0, attr_sz);
+	attr.size = attr_sz;
 	attr.config = type;
 	attr.type = PERF_TYPE_TRACEPOINT;
 
@@ -10662,15 +10697,17 @@ static const char *arch_specific_lib_paths(void)
 static int resolve_full_path(const char *file, char *result, size_t result_sz)
 {
 	const char *search_paths[3] = {};
-	int i;
+	int i, perm;
 
 	if (str_has_sfx(file, ".so") || strstr(file, ".so.")) {
 		search_paths[0] = getenv("LD_LIBRARY_PATH");
 		search_paths[1] = "/usr/lib64:/usr/lib";
 		search_paths[2] = arch_specific_lib_paths();
+		perm = R_OK;
 	} else {
 		search_paths[0] = getenv("PATH");
 		search_paths[1] = "/usr/bin:/usr/sbin";
+		perm = R_OK | X_OK;
 	}
 
 	for (i = 0; i < ARRAY_SIZE(search_paths); i++) {
@@ -10689,8 +10726,8 @@ static int resolve_full_path(const char *file, char *result, size_t result_sz)
 			if (!seg_len)
 				continue;
 			snprintf(result, result_sz, "%.*s/%s", seg_len, s, file);
-			/* ensure it is an executable file/link */
-			if (access(result, R_OK | X_OK) < 0)
+			/* ensure it has required permissions */
+			if (access(result, perm) < 0)
 				continue;
 			pr_debug("resolved '%s' to '%s'\n", file, result);
 			return 0;
@@ -10967,7 +11004,8 @@ static int determine_tracepoint_id(const char *tp_category,
 static int perf_event_open_tracepoint(const char *tp_category,
 				      const char *tp_name)
 {
-	struct perf_event_attr attr = {};
+	const size_t attr_sz = sizeof(struct perf_event_attr);
+	struct perf_event_attr attr;
 	char errmsg[STRERR_BUFSIZE];
 	int tp_id, pfd, err;
 
@@ -10979,8 +11017,9 @@ static int perf_event_open_tracepoint(const char *tp_category,
 		return tp_id;
 	}
 
+	memset(&attr, 0, attr_sz);
 	attr.type = PERF_TYPE_TRACEPOINT;
-	attr.size = sizeof(attr);
+	attr.size = attr_sz;
 	attr.config = tp_id;
 
 	pfd = syscall(__NR_perf_event_open, &attr, -1 /* pid */, 0 /* cpu */,
@@ -11600,12 +11639,15 @@ struct perf_buffer *perf_buffer__new(int map_fd, size_t page_cnt,
 				     void *ctx,
 				     const struct perf_buffer_opts *opts)
 {
+	const size_t attr_sz = sizeof(struct perf_event_attr);
 	struct perf_buffer_params p = {};
-	struct perf_event_attr attr = {};
+	struct perf_event_attr attr;
 
 	if (!OPTS_VALID(opts, perf_buffer_opts))
 		return libbpf_err_ptr(-EINVAL);
 
+	memset(&attr, 0, attr_sz);
+	attr.size = attr_sz;
 	attr.config = PERF_COUNT_SW_BPF_OUTPUT;
 	attr.type = PERF_TYPE_SOFTWARE;
 	attr.sample_type = PERF_SAMPLE_RAW;
@@ -12328,7 +12370,7 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
 		struct bpf_program *prog = *s->progs[i].prog;
 		struct bpf_link **link = s->progs[i].link;
 
-		if (!prog->autoload)
+		if (!prog->autoload || !prog->autoattach)
 			continue;
 
 		/* auto-attaching not supported for this program */