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, 357 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_hierarchical_stats.c b/tools/testing/selftests/bpf/prog_tests/cgroup_hierarchical_stats.c
new file mode 100644
index 000000000000..bed1661596f7
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/cgroup_hierarchical_stats.c
@@ -0,0 +1,357 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Functions to manage eBPF programs attached to cgroup subsystems
+ *
+ * Copyright 2022 Google LLC.
+ */
+#include <asm-generic/errno.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include <test_progs.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+
+#include "cgroup_helpers.h"
+#include "cgroup_hierarchical_stats.skel.h"
+
+#define PAGE_SIZE 4096
+#define MB(x) (x << 20)
+
+#define BPFFS_ROOT "/sys/fs/bpf/"
+#define BPFFS_VMSCAN BPFFS_ROOT"vmscan/"
+
+#define CG_ROOT_NAME "root"
+#define CG_ROOT_ID 1
+
+#define CGROUP_PATH(p, n) {.path = p"/"n, .name = n}
+
+static struct {
+	const char *path, *name;
+	unsigned long long id;
+	int fd;
+} cgroups[] = {
+	CGROUP_PATH("/", "test"),
+	CGROUP_PATH("/test", "child1"),
+	CGROUP_PATH("/test", "child2"),
+	CGROUP_PATH("/test/child1", "child1_1"),
+	CGROUP_PATH("/test/child1", "child1_2"),
+	CGROUP_PATH("/test/child2", "child2_1"),
+	CGROUP_PATH("/test/child2", "child2_2"),
+};
+
+#define N_CGROUPS ARRAY_SIZE(cgroups)
+#define N_NON_LEAF_CGROUPS 3
+
+static int root_cgroup_fd;
+static bool mounted_bpffs;
+
+/* reads file at 'path' to 'buf', returns 0 on success. */
+static int read_from_file(const char *path, char *buf, size_t size)
+{
+	int fd, len;
+
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		return fd;
+
+	len = read(fd, buf, size);
+	close(fd);
+	if (len < 0)
+		return len;
+
+	buf[len] = 0;
+	return 0;
+}
+
+/* mounts bpffs and mkdir for reading stats, returns 0 on success. */
+static int setup_bpffs(void)
+{
+	int err;
+
+	/* Mount bpffs */
+	err = mount("bpf", BPFFS_ROOT, "bpf", 0, NULL);
+	mounted_bpffs = !err;
+	if (ASSERT_FALSE(err && errno != EBUSY, "mount"))
+		return err;
+
+	/* Create a directory to contain stat files in bpffs */
+	err = mkdir(BPFFS_VMSCAN, 0755);
+	if (!ASSERT_OK(err, "mkdir"))
+		return err;
+
+	return 0;
+}
+
+static void cleanup_bpffs(void)
+{
+	/* Remove created directory in bpffs */
+	ASSERT_OK(rmdir(BPFFS_VMSCAN), "rmdir "BPFFS_VMSCAN);
+
+	/* Unmount bpffs, if it wasn't already mounted when we started */
+	if (mounted_bpffs)
+		return;
+
+	ASSERT_OK(umount(BPFFS_ROOT), "unmount bpffs");
+}
+
+/* sets up cgroups, returns 0 on success. */
+static int setup_cgroups(void)
+{
+	int i, fd, err;
+
+	err = setup_cgroup_environment();
+	if (!ASSERT_OK(err, "setup_cgroup_environment"))
+		return err;
+
+	root_cgroup_fd = get_root_cgroup();
+	if (!ASSERT_GE(root_cgroup_fd, 0, "get_root_cgroup"))
+		return root_cgroup_fd;
+
+	for (i = 0; i < N_CGROUPS; i++) {
+		fd = create_and_get_cgroup(cgroups[i].path);
+		if (!ASSERT_GE(fd, 0, "create_and_get_cgroup"))
+			return fd;
+
+		cgroups[i].fd = fd;
+		cgroups[i].id = get_cgroup_id(cgroups[i].path);
+
+		/*
+		 * Enable memcg controller for the entire hierarchy.
+		 * Note that stats are collected for all cgroups in a hierarchy
+		 * with memcg enabled anyway, but are only exposed for cgroups
+		 * that have memcg enabled.
+		 */
+		if (i < N_NON_LEAF_CGROUPS) {
+			err = enable_controllers(cgroups[i].path, "memory");
+			if (!ASSERT_OK(err, "enable_controllers"))
+				return err;
+		}
+	}
+	return 0;
+}
+
+static void cleanup_cgroups(void)
+{
+	close(root_cgroup_fd);
+	for (int i = 0; i < N_CGROUPS; i++)
+		close(cgroups[i].fd);
+	cleanup_cgroup_environment();
+}
+
+/* Sets up cgroup hiearchary, returns 0 on success. */
+static int setup_hierarchy(void)
+{
+	return setup_bpffs() || setup_cgroups();
+}
+
+static void destroy_hierarchy(void)
+{
+	cleanup_cgroups();
+	cleanup_bpffs();
+}
+
+static int reclaimer(const char *cgroup_path, size_t size)
+{
+	static char size_buf[128];
+	char *buf, *ptr;
+	int err;
+
+	/* Join cgroup in the parent process workdir */
+	if (join_parent_cgroup(cgroup_path))
+		return EACCES;
+
+	/* Allocate memory */
+	buf = malloc(size);
+	if (!buf)
+		return ENOMEM;
+
+	/* Write to memory to make sure it's actually allocated */
+	for (ptr = buf; ptr < buf + size; ptr += PAGE_SIZE)
+		*ptr = 1;
+
+	/* Try to reclaim memory */
+	snprintf(size_buf, 128, "%lu", size);
+	err = write_cgroup_file_parent(cgroup_path, "memory.reclaim", size_buf);
+
+	free(buf);
+	/* memory.reclaim returns EAGAIN if the amount is not fully reclaimed */
+	if (err && errno != EAGAIN)
+		return errno;
+
+	return 0;
+}
+
+static int induce_vmscan(void)
+{
+	int i, status;
+
+	/*
+	 * In every leaf cgroup, run a child process that allocates some memory
+	 * and attempts to reclaim some of it.
+	 */
+	for (i = N_NON_LEAF_CGROUPS; i < N_CGROUPS; i++) {
+		pid_t pid;
+
+		/* Create reclaimer child */
+		pid = fork();
+		if (pid == 0) {
+			status = reclaimer(cgroups[i].path, MB(5));
+			exit(status);
+		}
+
+		/* Cleanup reclaimer child */
+		waitpid(pid, &status, 0);
+		ASSERT_TRUE(WIFEXITED(status), "reclaimer exited");
+		ASSERT_EQ(WEXITSTATUS(status), 0, "reclaim exit code");
+	}
+	return 0;
+}
+
+static unsigned long long
+get_cgroup_vmscan_delay(unsigned long long cgroup_id, const char *file_name)
+{
+	unsigned long long vmscan = 0, id = 0;
+	static char buf[128], path[128];
+
+	/* For every cgroup, read the file generated by cgroup_iter */
+	snprintf(path, 128, "%s%s", BPFFS_VMSCAN, file_name);
+	if (!ASSERT_OK(read_from_file(path, buf, 128), "read cgroup_iter"))
+		return 0;
+
+	/* Check the output file formatting */
+	ASSERT_EQ(sscanf(buf, "cg_id: %llu, total_vmscan_delay: %llu\n",
+			 &id, &vmscan), 2, "output format");
+
+	/* Check that the cgroup_id is displayed correctly */
+	ASSERT_EQ(id, cgroup_id, "cgroup_id");
+	/* Check that the vmscan reading is non-zero */
+	ASSERT_GT(vmscan, 0, "vmscan_reading");
+	return vmscan;
+}
+
+static void check_vmscan_stats(void)
+{
+	unsigned long long vmscan_readings[N_CGROUPS], vmscan_root;
+	int i;
+
+	for (i = 0; i < N_CGROUPS; i++) {
+		vmscan_readings[i] = get_cgroup_vmscan_delay(cgroups[i].id,
+							     cgroups[i].name);
+	}
+
+	/* Read stats for root too */
+	vmscan_root = get_cgroup_vmscan_delay(CG_ROOT_ID, CG_ROOT_NAME);
+
+	/* Check that child1 == child1_1 + child1_2 */
+	ASSERT_EQ(vmscan_readings[1], vmscan_readings[3] + vmscan_readings[4],
+		  "child1_vmscan");
+	/* Check that child2 == child2_1 + child2_2 */
+	ASSERT_EQ(vmscan_readings[2], vmscan_readings[5] + vmscan_readings[6],
+		  "child2_vmscan");
+	/* Check that test == child1 + child2 */
+	ASSERT_EQ(vmscan_readings[0], vmscan_readings[1] + vmscan_readings[2],
+		  "test_vmscan");
+	/* Check that root >= test */
+	ASSERT_GE(vmscan_root, vmscan_readings[1], "root_vmscan");
+}
+
+/* Creates iter link and pins in bpffs, returns 0 on success, -errno on failure.
+ */
+static int setup_cgroup_iter(struct cgroup_hierarchical_stats *obj,
+			     int cgroup_fd, const char *file_name)
+{
+	DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts);
+	union bpf_iter_link_info linfo = {};
+	struct bpf_link *link;
+	static char path[128];
+	int err;
+
+	/*
+	 * Create an iter link, parameterized by cgroup_fd. We only want to
+	 * traverse one cgroup, so set the traversal order to "self".
+	 */
+	linfo.cgroup.cgroup_fd = cgroup_fd;
+	linfo.cgroup.order = BPF_CGROUP_ITER_SELF_ONLY;
+	opts.link_info = &linfo;
+	opts.link_info_len = sizeof(linfo);
+	link = bpf_program__attach_iter(obj->progs.dump_vmscan, &opts);
+	if (!ASSERT_OK_PTR(link, "attach_iter"))
+		return -EFAULT;
+
+	/* Pin the link to a bpffs file */
+	snprintf(path, 128, "%s%s", BPFFS_VMSCAN, file_name);
+	err = bpf_link__pin(link, path);
+	ASSERT_OK(err, "pin cgroup_iter");
+
+	/* Remove the link, leaving only the ref held by the pinned file */
+	bpf_link__destroy(link);
+	return err;
+}
+
+/* Sets up programs for collecting stats, returns 0 on success. */
+static int setup_progs(struct cgroup_hierarchical_stats **skel)
+{
+	int i, err;
+
+	*skel = cgroup_hierarchical_stats__open_and_load();
+	if (!ASSERT_OK_PTR(*skel, "open_and_load"))
+		return 1;
+
+	/* Attach cgroup_iter program that will dump the stats to cgroups */
+	for (i = 0; i < N_CGROUPS; i++) {
+		err = setup_cgroup_iter(*skel, cgroups[i].fd, cgroups[i].name);
+		if (!ASSERT_OK(err, "setup_cgroup_iter"))
+			return err;
+	}
+
+	/* Also dump stats for root */
+	err = setup_cgroup_iter(*skel, root_cgroup_fd, CG_ROOT_NAME);
+	if (!ASSERT_OK(err, "setup_cgroup_iter"))
+		return err;
+
+	bpf_program__set_autoattach((*skel)->progs.dump_vmscan, false);
+	err = cgroup_hierarchical_stats__attach(*skel);
+	if (!ASSERT_OK(err, "attach"))
+		return err;
+
+	return 0;
+}
+
+static void destroy_progs(struct cgroup_hierarchical_stats *skel)
+{
+	static char path[128];
+	int i;
+
+	for (i = 0; i < N_CGROUPS; i++) {
+		/* Delete files in bpffs that cgroup_iters are pinned in */
+		snprintf(path, 128, "%s%s", BPFFS_VMSCAN,
+			 cgroups[i].name);
+		ASSERT_OK(remove(path), "remove cgroup_iter pin");
+	}
+
+	/* Delete root file in bpffs */
+	snprintf(path, 128, "%s%s", BPFFS_VMSCAN, CG_ROOT_NAME);
+	ASSERT_OK(remove(path), "remove cgroup_iter root pin");
+	cgroup_hierarchical_stats__destroy(skel);
+}
+
+void test_cgroup_hierarchical_stats(void)
+{
+	struct cgroup_hierarchical_stats *skel = NULL;
+
+	if (setup_hierarchy())
+		goto hierarchy_cleanup;
+	if (setup_progs(&skel))
+		goto cleanup;
+	if (induce_vmscan())
+		goto cleanup;
+	check_vmscan_stats();
+cleanup:
+	destroy_progs(skel);
+hierarchy_cleanup:
+	destroy_hierarchy();
+}