Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-06-06

We've added 54 non-merge commits during the last 10 day(s) which contain
a total of 50 files changed, 1887 insertions(+), 527 deletions(-).

The main changes are:

1) Add a user space notification mechanism via epoll when a struct_ops
   object is getting detached/unregistered, from Kui-Feng Lee.

2) Big batch of BPF selftest refactoring for sockmap and BPF congctl
   tests, from Geliang Tang.

3) Add BTF field (type and string fields, right now) iterator support
   to libbpf instead of using existing callback-based approaches,
   from Andrii Nakryiko.

4) Extend BPF selftests for the latter with a new btf_field_iter
   selftest, from Alan Maguire.

5) Add new kfuncs for a generic, open-coded bits iterator,
   from Yafang Shao.

6) Fix BPF selftests' kallsyms_find() helper under kernels configured
   with CONFIG_LTO_CLANG_THIN, from Yonghong Song.

7) Remove a bunch of unused structs in BPF selftests,
   from David Alan Gilbert.

8) Convert test_sockmap section names into names understood by libbpf
   so it can deduce program type and attach type, from Jakub Sitnicki.

9) Extend libbpf with the ability to configure log verbosity
   via LIBBPF_LOG_LEVEL environment variable, from Mykyta Yatsenko.

10) Fix BPF selftests with regards to bpf_cookie and find_vma flakiness
    in nested VMs, from Song Liu.

11) Extend riscv32/64 JITs to introduce shift/add helpers to generate Zba
    optimization, from Xiao Wang.

12) Enable BPF programs to declare arrays and struct fields with kptr,
    bpf_rb_root, and bpf_list_head, from Kui-Feng Lee.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (54 commits)
  selftests/bpf: Drop useless arguments of do_test in bpf_tcp_ca
  selftests/bpf: Use start_test in test_dctcp in bpf_tcp_ca
  selftests/bpf: Use start_test in test_dctcp_fallback in bpf_tcp_ca
  selftests/bpf: Add start_test helper in bpf_tcp_ca
  selftests/bpf: Use connect_to_fd_opts in do_test in bpf_tcp_ca
  libbpf: Auto-attach struct_ops BPF maps in BPF skeleton
  selftests/bpf: Add btf_field_iter selftests
  selftests/bpf: Fix send_signal test with nested CONFIG_PARAVIRT
  libbpf: Remove callback-based type/string BTF field visitor helpers
  bpftool: Use BTF field iterator in btfgen
  libbpf: Make use of BTF field iterator in BTF handling code
  libbpf: Make use of BTF field iterator in BPF linker code
  libbpf: Add BTF field iterator
  selftests/bpf: Ignore .llvm.<hash> suffix in kallsyms_find()
  selftests/bpf: Fix bpf_cookie and find_vma in nested VM
  selftests/bpf: Test global bpf_list_head arrays.
  selftests/bpf: Test global bpf_rb_root arrays and fields in nested struct types.
  selftests/bpf: Test kptr arrays and kptrs in nested struct fields.
  bpf: limit the number of levels of a nested struct type.
  bpf: look into the types of the fields of a struct type recursively.
  ...
====================

Link: https://lore.kernel.org/r/20240606223146.23020-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 51 insertions, 22 deletions

diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index b3979ddc0189..4a4eedfcd479 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -848,7 +848,7 @@ out:
 }
 
 static void
-codegen_maps_skeleton(struct bpf_object *obj, size_t map_cnt, bool mmaped)
+codegen_maps_skeleton(struct bpf_object *obj, size_t map_cnt, bool mmaped, bool populate_links)
 {
 	struct bpf_map *map;
 	char ident[256];
@@ -888,6 +888,14 @@ codegen_maps_skeleton(struct bpf_object *obj, size_t map_cnt, bool mmaped)
 			printf("\ts->maps[%zu].mmaped = (void **)&obj->%s;\n",
 				i, ident);
 		}
+
+		if (populate_links && bpf_map__type(map) == BPF_MAP_TYPE_STRUCT_OPS) {
+			codegen("\
+				\n\
+					s->maps[%zu].link = &obj->links.%s;\n\
+				",
+				i, ident);
+		}
 		i++;
 	}
 }
@@ -1141,7 +1149,7 @@ static void gen_st_ops_shadow_init(struct btf *btf, struct bpf_object *obj)
 static int do_skeleton(int argc, char **argv)
 {
 	char header_guard[MAX_OBJ_NAME_LEN + sizeof("__SKEL_H__")];
-	size_t map_cnt = 0, prog_cnt = 0, file_sz, mmap_sz;
+	size_t map_cnt = 0, prog_cnt = 0, attach_map_cnt = 0, file_sz, mmap_sz;
 	DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts);
 	char obj_name[MAX_OBJ_NAME_LEN] = "", *obj_data;
 	struct bpf_object *obj = NULL;
@@ -1225,6 +1233,10 @@ static int do_skeleton(int argc, char **argv)
 			      bpf_map__name(map));
 			continue;
 		}
+
+		if (bpf_map__type(map) == BPF_MAP_TYPE_STRUCT_OPS)
+			attach_map_cnt++;
+
 		map_cnt++;
 	}
 	bpf_object__for_each_program(prog, obj) {
@@ -1297,6 +1309,9 @@ static int do_skeleton(int argc, char **argv)
 				       bpf_program__name(prog));
 		}
 		printf("\t} progs;\n");
+	}
+
+	if (prog_cnt + attach_map_cnt) {
 		printf("\tstruct {\n");
 		bpf_object__for_each_program(prog, obj) {
 			if (use_loader)
@@ -1306,6 +1321,19 @@ static int do_skeleton(int argc, char **argv)
 				printf("\t\tstruct bpf_link *%s;\n",
 				       bpf_program__name(prog));
 		}
+
+		bpf_object__for_each_map(map, obj) {
+			if (!get_map_ident(map, ident, sizeof(ident)))
+				continue;
+			if (bpf_map__type(map) != BPF_MAP_TYPE_STRUCT_OPS)
+				continue;
+
+			if (use_loader)
+				printf("t\tint %s_fd;\n", ident);
+			else
+				printf("\t\tstruct bpf_link *%s;\n", ident);
+		}
+
 		printf("\t} links;\n");
 	}
 
@@ -1448,7 +1476,7 @@ static int do_skeleton(int argc, char **argv)
 		obj_name
 	);
 
-	codegen_maps_skeleton(obj, map_cnt, true /*mmaped*/);
+	codegen_maps_skeleton(obj, map_cnt, true /*mmaped*/, true /*links*/);
 	codegen_progs_skeleton(obj, prog_cnt, true /*populate_links*/);
 
 	codegen("\
@@ -1786,7 +1814,7 @@ static int do_subskeleton(int argc, char **argv)
 		}
 	}
 
-	codegen_maps_skeleton(obj, map_cnt, false /*mmaped*/);
+	codegen_maps_skeleton(obj, map_cnt, false /*mmaped*/, false /*links*/);
 	codegen_progs_skeleton(obj, prog_cnt, false /*links*/);
 
 	codegen("\
@@ -2379,15 +2407,6 @@ out:
 	return err;
 }
 
-static int btfgen_remap_id(__u32 *type_id, void *ctx)
-{
-	unsigned int *ids = ctx;
-
-	*type_id = ids[*type_id];
-
-	return 0;
-}
-
 /* Generate BTF from relocation information previously recorded */
 static struct btf *btfgen_get_btf(struct btfgen_info *info)
 {
@@ -2467,10 +2486,15 @@ static struct btf *btfgen_get_btf(struct btfgen_info *info)
 	/* second pass: fix up type ids */
 	for (i = 1; i < btf__type_cnt(btf_new); i++) {
 		struct btf_type *btf_type = (struct btf_type *) btf__type_by_id(btf_new, i);
+		struct btf_field_iter it;
+		__u32 *type_id;
 
-		err = btf_type_visit_type_ids(btf_type, btfgen_remap_id, ids);
+		err = btf_field_iter_init(&it, btf_type, BTF_FIELD_ITER_IDS);
 		if (err)
 			goto err_out;
+
+		while ((type_id = btf_field_iter_next(&it)))
+			*type_id = ids[*type_id];
 	}
 
 	free(ids);
diff --git a/tools/bpf/bpftool/skeleton/pid_iter.bpf.c b/tools/bpf/bpftool/skeleton/pid_iter.bpf.c
index 7bdbcac3cf62..948dde25034e 100644
--- a/tools/bpf/bpftool/skeleton/pid_iter.bpf.c
+++ b/tools/bpf/bpftool/skeleton/pid_iter.bpf.c
@@ -29,6 +29,7 @@ enum bpf_link_type___local {
 };
 
 extern const void bpf_link_fops __ksym;
+extern const void bpf_link_fops_poll __ksym __weak;
 extern const void bpf_map_fops __ksym;
 extern const void bpf_prog_fops __ksym;
 extern const void btf_fops __ksym;
@@ -84,7 +85,11 @@ int iter(struct bpf_iter__task_file *ctx)
 		fops = &btf_fops;
 		break;
 	case BPF_OBJ_LINK:
-		fops = &bpf_link_fops;
+		if (&bpf_link_fops_poll &&
+		    file->f_op == &bpf_link_fops_poll)
+			fops = &bpf_link_fops_poll;
+		else
+			fops = &bpf_link_fops;
 		break;
 	default:
 		return 0;
diff --git a/tools/bpf/bpftool/skeleton/profiler.bpf.c b/tools/bpf/bpftool/skeleton/profiler.bpf.c
index 2f80edc682f1..f48c783cb9f7 100644
--- a/tools/bpf/bpftool/skeleton/profiler.bpf.c
+++ b/tools/bpf/bpftool/skeleton/profiler.bpf.c
@@ -40,17 +40,17 @@ struct {
 
 const volatile __u32 num_cpu = 1;
 const volatile __u32 num_metric = 1;
-#define MAX_NUM_MATRICS 4
+#define MAX_NUM_METRICS 4
 
 SEC("fentry/XXX")
 int BPF_PROG(fentry_XXX)
 {
-	struct bpf_perf_event_value___local *ptrs[MAX_NUM_MATRICS];
+	struct bpf_perf_event_value___local *ptrs[MAX_NUM_METRICS];
 	u32 key = bpf_get_smp_processor_id();
 	u32 i;
 
 	/* look up before reading, to reduce error */
-	for (i = 0; i < num_metric && i < MAX_NUM_MATRICS; i++) {
+	for (i = 0; i < num_metric && i < MAX_NUM_METRICS; i++) {
 		u32 flag = i;
 
 		ptrs[i] = bpf_map_lookup_elem(&fentry_readings, &flag);
@@ -58,7 +58,7 @@ int BPF_PROG(fentry_XXX)
 			return 0;
 	}
 
-	for (i = 0; i < num_metric && i < MAX_NUM_MATRICS; i++) {
+	for (i = 0; i < num_metric && i < MAX_NUM_METRICS; i++) {
 		struct bpf_perf_event_value___local reading;
 		int err;
 
@@ -99,14 +99,14 @@ fexit_update_maps(u32 id, struct bpf_perf_event_value___local *after)
 SEC("fexit/XXX")
 int BPF_PROG(fexit_XXX)
 {
-	struct bpf_perf_event_value___local readings[MAX_NUM_MATRICS];
+	struct bpf_perf_event_value___local readings[MAX_NUM_METRICS];
 	u32 cpu = bpf_get_smp_processor_id();
 	u32 i, zero = 0;
 	int err;
 	u64 *count;
 
 	/* read all events before updating the maps, to reduce error */
-	for (i = 0; i < num_metric && i < MAX_NUM_MATRICS; i++) {
+	for (i = 0; i < num_metric && i < MAX_NUM_METRICS; i++) {
 		err = bpf_perf_event_read_value(&events, cpu + i * num_cpu,
 						(void *)(readings + i),
 						sizeof(*readings));
@@ -116,7 +116,7 @@ int BPF_PROG(fexit_XXX)
 	count = bpf_map_lookup_elem(&counts, &zero);
 	if (count) {
 		*count += 1;
-		for (i = 0; i < num_metric && i < MAX_NUM_MATRICS; i++)
+		for (i = 0; i < num_metric && i < MAX_NUM_METRICS; i++)
 			fexit_update_maps(i, &readings[i]);
 	}
 	return 0;