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

Daniel Borkmann says:

====================
pull-request: bpf-next 2022-09-05

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

We've added 106 non-merge commits during the last 18 day(s) which contain
a total of 159 files changed, 5225 insertions(+), 1358 deletions(-).

There are two small merge conflicts, resolve them as follows:

1) tools/testing/selftests/bpf/DENYLIST.s390x

  Commit 27e23836ce22 ("selftests/bpf: Add lru_bug to s390x deny list") in
  bpf tree was needed to get BPF CI green on s390x, but it conflicted with
  newly added tests on bpf-next. Resolve by adding both hunks, result:

  [...]
  lru_bug                                  # prog 'printk': failed to auto-attach: -524
  setget_sockopt                           # attach unexpected error: -524                                               (trampoline)
  cb_refs                                  # expected error message unexpected error: -524                               (trampoline)
  cgroup_hierarchical_stats                # JIT does not support calling kernel function                                (kfunc)
  htab_update                              # failed to attach: ERROR: strerror_r(-524)=22                                (trampoline)
  [...]

2) net/core/filter.c

  Commit 1227c1771dd2 ("net: Fix data-races around sysctl_[rw]mem_(max|default).")
  from net tree conflicts with commit 29003875bd5b ("bpf: Change bpf_setsockopt(SOL_SOCKET)
  to reuse sk_setsockopt()") from bpf-next tree. Take the code as it is from
  bpf-next tree, result:

  [...]
	if (getopt) {
		if (optname == SO_BINDTODEVICE)
			return -EINVAL;
		return sk_getsockopt(sk, SOL_SOCKET, optname,
				     KERNEL_SOCKPTR(optval),
				     KERNEL_SOCKPTR(optlen));
	}

	return sk_setsockopt(sk, SOL_SOCKET, optname,
			     KERNEL_SOCKPTR(optval), *optlen);
  [...]

The main changes are:

1) Add any-context BPF specific memory allocator which is useful in particular for BPF
   tracing with bonus of performance equal to full prealloc, from Alexei Starovoitov.

2) Big batch to remove duplicated code from bpf_{get,set}sockopt() helpers as an effort
   to reuse the existing core socket code as much as possible, from Martin KaFai Lau.

3) Extend BPF flow dissector for BPF programs to just augment the in-kernel dissector
   with custom logic. In other words, allow for partial replacement, from Shmulik Ladkani.

4) Add a new cgroup iterator to BPF with different traversal options, from Hao Luo.

5) Support for BPF to collect hierarchical cgroup statistics efficiently through BPF
   integration with the rstat framework, from Yosry Ahmed.

6) Support bpf_{g,s}et_retval() under more BPF cgroup hooks, from Stanislav Fomichev.

7) BPF hash table and local storages fixes under fully preemptible kernel, from Hou Tao.

8) Add various improvements to BPF selftests and libbpf for compilation with gcc BPF
   backend, from James Hilliard.

9) Fix verifier helper permissions and reference state management for synchronous
   callbacks, from Kumar Kartikeya Dwivedi.

10) Add support for BPF selftest's xskxceiver to also be used against real devices that
    support MAC loopback, from Maciej Fijalkowski.

11) Various fixes to the bpf-helpers(7) man page generation script, from Quentin Monnet.

12) Document BPF verifier's tnum_in(tnum_range(), ...) gotchas, from Shung-Hsi Yu.

13) Various minor misc improvements all over the place.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (106 commits)
  bpf: Optimize rcu_barrier usage between hash map and bpf_mem_alloc.
  bpf: Remove usage of kmem_cache from bpf_mem_cache.
  bpf: Remove prealloc-only restriction for sleepable bpf programs.
  bpf: Prepare bpf_mem_alloc to be used by sleepable bpf programs.
  bpf: Remove tracing program restriction on map types
  bpf: Convert percpu hash map to per-cpu bpf_mem_alloc.
  bpf: Add percpu allocation support to bpf_mem_alloc.
  bpf: Batch call_rcu callbacks instead of SLAB_TYPESAFE_BY_RCU.
  bpf: Adjust low/high watermarks in bpf_mem_cache
  bpf: Optimize call_rcu in non-preallocated hash map.
  bpf: Optimize element count in non-preallocated hash map.
  bpf: Relax the requirement to use preallocated hash maps in tracing progs.
  samples/bpf: Reduce syscall overhead in map_perf_test.
  selftests/bpf: Improve test coverage of test_maps
  bpf: Convert hash map to bpf_mem_alloc.
  bpf: Introduce any context BPF specific memory allocator.
  selftest/bpf: Add test for bpf_getsockopt()
  bpf: Change bpf_getsockopt(SOL_IPV6) to reuse do_ipv6_getsockopt()
  bpf: Change bpf_getsockopt(SOL_IP) to reuse do_ip_getsockopt()
  bpf: Change bpf_getsockopt(SOL_TCP) to reuse do_tcp_getsockopt()
  ...
====================

Link: https://lore.kernel.org/r/20220905161136.9150-1-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 224 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_iter.c b/tools/testing/selftests/bpf/prog_tests/cgroup_iter.c
new file mode 100644
index 000000000000..c4a2adb38da1
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/cgroup_iter.c
@@ -0,0 +1,224 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Google */
+
+#include <test_progs.h>
+#include <bpf/libbpf.h>
+#include <bpf/btf.h>
+#include "cgroup_iter.skel.h"
+#include "cgroup_helpers.h"
+
+#define ROOT           0
+#define PARENT         1
+#define CHILD1         2
+#define CHILD2         3
+#define NUM_CGROUPS    4
+
+#define PROLOGUE       "prologue\n"
+#define EPILOGUE       "epilogue\n"
+
+static const char *cg_path[] = {
+	"/", "/parent", "/parent/child1", "/parent/child2"
+};
+
+static int cg_fd[] = {-1, -1, -1, -1};
+static unsigned long long cg_id[] = {0, 0, 0, 0};
+static char expected_output[64];
+
+static int setup_cgroups(void)
+{
+	int fd, i = 0;
+
+	for (i = 0; i < NUM_CGROUPS; i++) {
+		fd = create_and_get_cgroup(cg_path[i]);
+		if (fd < 0)
+			return fd;
+
+		cg_fd[i] = fd;
+		cg_id[i] = get_cgroup_id(cg_path[i]);
+	}
+	return 0;
+}
+
+static void cleanup_cgroups(void)
+{
+	int i;
+
+	for (i = 0; i < NUM_CGROUPS; i++)
+		close(cg_fd[i]);
+}
+
+static void read_from_cgroup_iter(struct bpf_program *prog, int cgroup_fd,
+				  int order, const char *testname)
+{
+	DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts);
+	union bpf_iter_link_info linfo;
+	struct bpf_link *link;
+	int len, iter_fd;
+	static char buf[128];
+	size_t left;
+	char *p;
+
+	memset(&linfo, 0, sizeof(linfo));
+	linfo.cgroup.cgroup_fd = cgroup_fd;
+	linfo.cgroup.order = order;
+	opts.link_info = &linfo;
+	opts.link_info_len = sizeof(linfo);
+
+	link = bpf_program__attach_iter(prog, &opts);
+	if (!ASSERT_OK_PTR(link, "attach_iter"))
+		return;
+
+	iter_fd = bpf_iter_create(bpf_link__fd(link));
+	if (iter_fd < 0)
+		goto free_link;
+
+	memset(buf, 0, sizeof(buf));
+	left = ARRAY_SIZE(buf);
+	p = buf;
+	while ((len = read(iter_fd, p, left)) > 0) {
+		p += len;
+		left -= len;
+	}
+
+	ASSERT_STREQ(buf, expected_output, testname);
+
+	/* read() after iter finishes should be ok. */
+	if (len == 0)
+		ASSERT_OK(read(iter_fd, buf, sizeof(buf)), "second_read");
+
+	close(iter_fd);
+free_link:
+	bpf_link__destroy(link);
+}
+
+/* Invalid cgroup. */
+static void test_invalid_cgroup(struct cgroup_iter *skel)
+{
+	DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts);
+	union bpf_iter_link_info linfo;
+	struct bpf_link *link;
+
+	memset(&linfo, 0, sizeof(linfo));
+	linfo.cgroup.cgroup_fd = (__u32)-1;
+	opts.link_info = &linfo;
+	opts.link_info_len = sizeof(linfo);
+
+	link = bpf_program__attach_iter(skel->progs.cgroup_id_printer, &opts);
+	ASSERT_ERR_PTR(link, "attach_iter");
+	bpf_link__destroy(link);
+}
+
+/* Specifying both cgroup_fd and cgroup_id is invalid. */
+static void test_invalid_cgroup_spec(struct cgroup_iter *skel)
+{
+	DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts);
+	union bpf_iter_link_info linfo;
+	struct bpf_link *link;
+
+	memset(&linfo, 0, sizeof(linfo));
+	linfo.cgroup.cgroup_fd = (__u32)cg_fd[PARENT];
+	linfo.cgroup.cgroup_id = (__u64)cg_id[PARENT];
+	opts.link_info = &linfo;
+	opts.link_info_len = sizeof(linfo);
+
+	link = bpf_program__attach_iter(skel->progs.cgroup_id_printer, &opts);
+	ASSERT_ERR_PTR(link, "attach_iter");
+	bpf_link__destroy(link);
+}
+
+/* Preorder walk prints parent and child in order. */
+static void test_walk_preorder(struct cgroup_iter *skel)
+{
+	snprintf(expected_output, sizeof(expected_output),
+		 PROLOGUE "%8llu\n%8llu\n%8llu\n" EPILOGUE,
+		 cg_id[PARENT], cg_id[CHILD1], cg_id[CHILD2]);
+
+	read_from_cgroup_iter(skel->progs.cgroup_id_printer, cg_fd[PARENT],
+			      BPF_CGROUP_ITER_DESCENDANTS_PRE, "preorder");
+}
+
+/* Postorder walk prints child and parent in order. */
+static void test_walk_postorder(struct cgroup_iter *skel)
+{
+	snprintf(expected_output, sizeof(expected_output),
+		 PROLOGUE "%8llu\n%8llu\n%8llu\n" EPILOGUE,
+		 cg_id[CHILD1], cg_id[CHILD2], cg_id[PARENT]);
+
+	read_from_cgroup_iter(skel->progs.cgroup_id_printer, cg_fd[PARENT],
+			      BPF_CGROUP_ITER_DESCENDANTS_POST, "postorder");
+}
+
+/* Walking parents prints parent and then root. */
+static void test_walk_ancestors_up(struct cgroup_iter *skel)
+{
+	/* terminate the walk when ROOT is met. */
+	skel->bss->terminal_cgroup = cg_id[ROOT];
+
+	snprintf(expected_output, sizeof(expected_output),
+		 PROLOGUE "%8llu\n%8llu\n" EPILOGUE,
+		 cg_id[PARENT], cg_id[ROOT]);
+
+	read_from_cgroup_iter(skel->progs.cgroup_id_printer, cg_fd[PARENT],
+			      BPF_CGROUP_ITER_ANCESTORS_UP, "ancestors_up");
+
+	skel->bss->terminal_cgroup = 0;
+}
+
+/* Early termination prints parent only. */
+static void test_early_termination(struct cgroup_iter *skel)
+{
+	/* terminate the walk after the first element is processed. */
+	skel->bss->terminate_early = 1;
+
+	snprintf(expected_output, sizeof(expected_output),
+		 PROLOGUE "%8llu\n" EPILOGUE, cg_id[PARENT]);
+
+	read_from_cgroup_iter(skel->progs.cgroup_id_printer, cg_fd[PARENT],
+			      BPF_CGROUP_ITER_DESCENDANTS_PRE, "early_termination");
+
+	skel->bss->terminate_early = 0;
+}
+
+/* Waling self prints self only. */
+static void test_walk_self_only(struct cgroup_iter *skel)
+{
+	snprintf(expected_output, sizeof(expected_output),
+		 PROLOGUE "%8llu\n" EPILOGUE, cg_id[PARENT]);
+
+	read_from_cgroup_iter(skel->progs.cgroup_id_printer, cg_fd[PARENT],
+			      BPF_CGROUP_ITER_SELF_ONLY, "self_only");
+}
+
+void test_cgroup_iter(void)
+{
+	struct cgroup_iter *skel = NULL;
+
+	if (setup_cgroup_environment())
+		return;
+
+	if (setup_cgroups())
+		goto out;
+
+	skel = cgroup_iter__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "cgroup_iter__open_and_load"))
+		goto out;
+
+	if (test__start_subtest("cgroup_iter__invalid_cgroup"))
+		test_invalid_cgroup(skel);
+	if (test__start_subtest("cgroup_iter__invalid_cgroup_spec"))
+		test_invalid_cgroup_spec(skel);
+	if (test__start_subtest("cgroup_iter__preorder"))
+		test_walk_preorder(skel);
+	if (test__start_subtest("cgroup_iter__postorder"))
+		test_walk_postorder(skel);
+	if (test__start_subtest("cgroup_iter__ancestors_up_walk"))
+		test_walk_ancestors_up(skel);
+	if (test__start_subtest("cgroup_iter__early_termination"))
+		test_early_termination(skel);
+	if (test__start_subtest("cgroup_iter__self_only"))
+		test_walk_self_only(skel);
+out:
+	cgroup_iter__destroy(skel);
+	cleanup_cgroups();
+	cleanup_cgroup_environment();
+}