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

Daniel Borkmann says:

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

We've added 10 non-merge commits during the last 8 day(s) which contain
a total of 7 files changed, 48 insertions(+), 30 deletions(-).

The main changes are:

1) Several libbpf ringbuf fixes related to probing for its availability,
   size overflows when mmaping a 2G ringbuf and rejection of invalid
   reservationsizes, from Hou Tao.

2) Fix a buggy return pointer in libbpf for attach_raw_tp function,
   from Jiri Olsa.

3) Fix a local storage BPF map bug where the value's spin lock field
   can get initialized incorrectly, from Xu Kuohai.

4) Two follow-up fixes in kprobe_multi BPF selftests for BPF CI,
   from Jiri Olsa.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests/bpf: Make test_bench_attach serial
  selftests/bpf: Filter out default_idle from kprobe_multi bench
  bpf: Set and check spin lock value in sk_storage_map_test
  bpf: Do not copy spin lock field from user in bpf_selem_alloc
  libbpf: Check the validity of size in user_ring_buffer__reserve()
  libbpf: Handle size overflow for user ringbuf mmap
  libbpf: Handle size overflow for ringbuf mmap
  libbpf: Use page size as max_entries when probing ring buffer map
  bpf, perf: Use subprog name when reporting subprog ksymbol
  libbpf: Use correct return pointer in attach_raw_tp
====================

Link: https://lore.kernel.org/r/20221125001034.29473-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

5 files changed, 46 insertions, 28 deletions

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 184ce1684dcd..91b7106a4a73 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -11169,7 +11169,7 @@ static int attach_raw_tp(const struct bpf_program *prog, long cookie, struct bpf
 	}
 
 	*link = bpf_program__attach_raw_tracepoint(prog, tp_name);
-	return libbpf_get_error(link);
+	return libbpf_get_error(*link);
 }
 
 /* Common logic for all BPF program types that attach to a btf_id */
diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c
index f3a8e8e74eb8..d504d96adc83 100644
--- a/tools/lib/bpf/libbpf_probes.c
+++ b/tools/lib/bpf/libbpf_probes.c
@@ -234,7 +234,7 @@ static int probe_map_create(enum bpf_map_type map_type)
 	case BPF_MAP_TYPE_USER_RINGBUF:
 		key_size = 0;
 		value_size = 0;
-		max_entries = 4096;
+		max_entries = sysconf(_SC_PAGE_SIZE);
 		break;
 	case BPF_MAP_TYPE_STRUCT_OPS:
 		/* we'll get -ENOTSUPP for invalid BTF type ID for struct_ops */
diff --git a/tools/lib/bpf/ringbuf.c b/tools/lib/bpf/ringbuf.c
index d285171d4b69..6af142953a94 100644
--- a/tools/lib/bpf/ringbuf.c
+++ b/tools/lib/bpf/ringbuf.c
@@ -77,6 +77,7 @@ int ring_buffer__add(struct ring_buffer *rb, int map_fd,
 	__u32 len = sizeof(info);
 	struct epoll_event *e;
 	struct ring *r;
+	__u64 mmap_sz;
 	void *tmp;
 	int err;
 
@@ -115,8 +116,7 @@ int ring_buffer__add(struct ring_buffer *rb, int map_fd,
 	r->mask = info.max_entries - 1;
 
 	/* Map writable consumer page */
-	tmp = mmap(NULL, rb->page_size, PROT_READ | PROT_WRITE, MAP_SHARED,
-		   map_fd, 0);
+	tmp = mmap(NULL, rb->page_size, PROT_READ | PROT_WRITE, MAP_SHARED, map_fd, 0);
 	if (tmp == MAP_FAILED) {
 		err = -errno;
 		pr_warn("ringbuf: failed to mmap consumer page for map fd=%d: %d\n",
@@ -129,8 +129,12 @@ int ring_buffer__add(struct ring_buffer *rb, int map_fd,
 	 * data size to allow simple reading of samples that wrap around the
 	 * end of a ring buffer. See kernel implementation for details.
 	 * */
-	tmp = mmap(NULL, rb->page_size + 2 * info.max_entries, PROT_READ,
-		   MAP_SHARED, map_fd, rb->page_size);
+	mmap_sz = rb->page_size + 2 * (__u64)info.max_entries;
+	if (mmap_sz != (__u64)(size_t)mmap_sz) {
+		pr_warn("ringbuf: ring buffer size (%u) is too big\n", info.max_entries);
+		return libbpf_err(-E2BIG);
+	}
+	tmp = mmap(NULL, (size_t)mmap_sz, PROT_READ, MAP_SHARED, map_fd, rb->page_size);
 	if (tmp == MAP_FAILED) {
 		err = -errno;
 		ringbuf_unmap_ring(rb, r);
@@ -348,6 +352,7 @@ static int user_ringbuf_map(struct user_ring_buffer *rb, int map_fd)
 {
 	struct bpf_map_info info;
 	__u32 len = sizeof(info);
+	__u64 mmap_sz;
 	void *tmp;
 	struct epoll_event *rb_epoll;
 	int err;
@@ -384,8 +389,13 @@ static int user_ringbuf_map(struct user_ring_buffer *rb, int map_fd)
 	 * simple reading and writing of samples that wrap around the end of
 	 * the buffer.  See the kernel implementation for details.
 	 */
-	tmp = mmap(NULL, rb->page_size + 2 * info.max_entries,
-		   PROT_READ | PROT_WRITE, MAP_SHARED, map_fd, rb->page_size);
+	mmap_sz = rb->page_size + 2 * (__u64)info.max_entries;
+	if (mmap_sz != (__u64)(size_t)mmap_sz) {
+		pr_warn("user ringbuf: ring buf size (%u) is too big\n", info.max_entries);
+		return -E2BIG;
+	}
+	tmp = mmap(NULL, (size_t)mmap_sz, PROT_READ | PROT_WRITE, MAP_SHARED,
+		   map_fd, rb->page_size);
 	if (tmp == MAP_FAILED) {
 		err = -errno;
 		pr_warn("user ringbuf: failed to mmap data pages for map fd=%d: %d\n",
@@ -476,6 +486,10 @@ void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size)
 	__u64 cons_pos, prod_pos;
 	struct ringbuf_hdr *hdr;
 
+	/* The top two bits are used as special flags */
+	if (size & (BPF_RINGBUF_BUSY_BIT | BPF_RINGBUF_DISCARD_BIT))
+		return errno = E2BIG, NULL;
+
 	/* Synchronizes with smp_store_release() in __bpf_user_ringbuf_peek() in
 	 * the kernel.
 	 */
diff --git a/tools/testing/selftests/bpf/map_tests/sk_storage_map.c b/tools/testing/selftests/bpf/map_tests/sk_storage_map.c
index 099eb4dfd4f7..18405c3b7cee 100644
--- a/tools/testing/selftests/bpf/map_tests/sk_storage_map.c
+++ b/tools/testing/selftests/bpf/map_tests/sk_storage_map.c
@@ -458,7 +458,7 @@ static void test_sk_storage_map_basic(void)
 	struct {
 		int cnt;
 		int lock;
-	} value = { .cnt = 0xeB9f, .lock = 0, }, lookup_value;
+	} value = { .cnt = 0xeB9f, .lock = 1, }, lookup_value;
 	struct bpf_map_create_opts bad_xattr;
 	int btf_fd, map_fd, sk_fd, err;
 
@@ -483,38 +483,41 @@ static void test_sk_storage_map_basic(void)
 	      "err:%d errno:%d\n", err, errno);
 	err = bpf_map_lookup_elem_flags(map_fd, &sk_fd, &lookup_value,
 					BPF_F_LOCK);
-	CHECK(err || lookup_value.cnt != value.cnt,
+	CHECK(err || lookup_value.lock || lookup_value.cnt != value.cnt,
 	      "bpf_map_lookup_elem_flags(BPF_F_LOCK)",
-	      "err:%d errno:%d cnt:%x(%x)\n",
-	      err, errno, lookup_value.cnt, value.cnt);
+	      "err:%d errno:%d lock:%x cnt:%x(%x)\n",
+	      err, errno, lookup_value.lock, lookup_value.cnt, value.cnt);
 
 	/* Bump the cnt and update with BPF_EXIST | BPF_F_LOCK */
 	value.cnt += 1;
+	value.lock = 2;
 	err = bpf_map_update_elem(map_fd, &sk_fd, &value,
 				  BPF_EXIST | BPF_F_LOCK);
 	CHECK(err, "bpf_map_update_elem(BPF_EXIST|BPF_F_LOCK)",
 	      "err:%d errno:%d\n", err, errno);
 	err = bpf_map_lookup_elem_flags(map_fd, &sk_fd, &lookup_value,
 					BPF_F_LOCK);
-	CHECK(err || lookup_value.cnt != value.cnt,
+	CHECK(err || lookup_value.lock || lookup_value.cnt != value.cnt,
 	      "bpf_map_lookup_elem_flags(BPF_F_LOCK)",
-	      "err:%d errno:%d cnt:%x(%x)\n",
-	      err, errno, lookup_value.cnt, value.cnt);
+	      "err:%d errno:%d lock:%x cnt:%x(%x)\n",
+	      err, errno, lookup_value.lock, lookup_value.cnt, value.cnt);
 
 	/* Bump the cnt and update with BPF_EXIST */
 	value.cnt += 1;
+	value.lock = 2;
 	err = bpf_map_update_elem(map_fd, &sk_fd, &value, BPF_EXIST);
 	CHECK(err, "bpf_map_update_elem(BPF_EXIST)",
 	      "err:%d errno:%d\n", err, errno);
 	err = bpf_map_lookup_elem_flags(map_fd, &sk_fd, &lookup_value,
 					BPF_F_LOCK);
-	CHECK(err || lookup_value.cnt != value.cnt,
+	CHECK(err || lookup_value.lock || lookup_value.cnt != value.cnt,
 	      "bpf_map_lookup_elem_flags(BPF_F_LOCK)",
-	      "err:%d errno:%d cnt:%x(%x)\n",
-	      err, errno, lookup_value.cnt, value.cnt);
+	      "err:%d errno:%d lock:%x cnt:%x(%x)\n",
+	      err, errno, lookup_value.lock, lookup_value.cnt, value.cnt);
 
 	/* Update with BPF_NOEXIST */
 	value.cnt += 1;
+	value.lock = 2;
 	err = bpf_map_update_elem(map_fd, &sk_fd, &value,
 				  BPF_NOEXIST | BPF_F_LOCK);
 	CHECK(!err || errno != EEXIST,
@@ -526,22 +529,23 @@ static void test_sk_storage_map_basic(void)
 	value.cnt -= 1;
 	err = bpf_map_lookup_elem_flags(map_fd, &sk_fd, &lookup_value,
 					BPF_F_LOCK);
-	CHECK(err || lookup_value.cnt != value.cnt,
+	CHECK(err || lookup_value.lock || lookup_value.cnt != value.cnt,
 	      "bpf_map_lookup_elem_flags(BPF_F_LOCK)",
-	      "err:%d errno:%d cnt:%x(%x)\n",
-	      err, errno, lookup_value.cnt, value.cnt);
+	      "err:%d errno:%d lock:%x cnt:%x(%x)\n",
+	      err, errno, lookup_value.lock, lookup_value.cnt, value.cnt);
 
 	/* Bump the cnt again and update with map_flags == 0 */
 	value.cnt += 1;
+	value.lock = 2;
 	err = bpf_map_update_elem(map_fd, &sk_fd, &value, 0);
 	CHECK(err, "bpf_map_update_elem()", "err:%d errno:%d\n",
 	      err, errno);
 	err = bpf_map_lookup_elem_flags(map_fd, &sk_fd, &lookup_value,
 					BPF_F_LOCK);
-	CHECK(err || lookup_value.cnt != value.cnt,
+	CHECK(err || lookup_value.lock || lookup_value.cnt != value.cnt,
 	      "bpf_map_lookup_elem_flags(BPF_F_LOCK)",
-	      "err:%d errno:%d cnt:%x(%x)\n",
-	      err, errno, lookup_value.cnt, value.cnt);
+	      "err:%d errno:%d lock:%x cnt:%x(%x)\n",
+	      err, errno, lookup_value.lock, lookup_value.cnt, value.cnt);
 
 	/* Test delete elem */
 	err = bpf_map_delete_elem(map_fd, &sk_fd);
diff --git a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c
index d457a55ff408..a4b4133d39e9 100644
--- a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c
@@ -358,10 +358,12 @@ static int get_syms(char ***symsp, size_t *cntp)
 		 * We attach to almost all kernel functions and some of them
 		 * will cause 'suspicious RCU usage' when fprobe is attached
 		 * to them. Filter out the current culprits - arch_cpu_idle
-		 * and rcu_* functions.
+		 * default_idle and rcu_* functions.
 		 */
 		if (!strcmp(name, "arch_cpu_idle"))
 			continue;
+		if (!strcmp(name, "default_idle"))
+			continue;
 		if (!strncmp(name, "rcu_", 4))
 			continue;
 		if (!strcmp(name, "bpf_dispatcher_xdp_func"))
@@ -400,7 +402,7 @@ error:
 	return err;
 }
 
-static void test_bench_attach(void)
+void serial_test_kprobe_multi_bench_attach(void)
 {
 	LIBBPF_OPTS(bpf_kprobe_multi_opts, opts);
 	struct kprobe_multi_empty *skel = NULL;
@@ -468,6 +470,4 @@ void test_kprobe_multi_test(void)
 		test_attach_api_syms();
 	if (test__start_subtest("attach_api_fails"))
 		test_attach_api_fails();
-	if (test__start_subtest("bench_attach"))
-		test_bench_attach();
 }