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

Alexei Starovoitov says:

====================
pull-request: bpf-next 2023-12-18

This PR is larger than usual and contains changes in various parts
of the kernel.

The main changes are:

1) Fix kCFI bugs in BPF, from Peter Zijlstra.

End result: all forms of indirect calls from BPF into kernel
and from kernel into BPF work with CFI enabled. This allows BPF
to work with CONFIG_FINEIBT=y.

2) Introduce BPF token object, from Andrii Nakryiko.

It adds an ability to delegate a subset of BPF features from privileged
daemon (e.g., systemd) through special mount options for userns-bound
BPF FS to a trusted unprivileged application. The design accommodates
suggestions from Christian Brauner and Paul Moore.

Example:
$ sudo mkdir -p /sys/fs/bpf/token
$ sudo mount -t bpf bpffs /sys/fs/bpf/token \
             -o delegate_cmds=prog_load:MAP_CREATE \
             -o delegate_progs=kprobe \
             -o delegate_attachs=xdp

3) Various verifier improvements and fixes, from Andrii Nakryiko, Andrei Matei.

 - Complete precision tracking support for register spills
 - Fix verification of possibly-zero-sized stack accesses
 - Fix access to uninit stack slots
 - Track aligned STACK_ZERO cases as imprecise spilled registers.
   It improves the verifier "instructions processed" metric from single
   digit to 50-60% for some programs.
 - Fix verifier retval logic

4) Support for VLAN tag in XDP hints, from Larysa Zaremba.

5) Allocate BPF trampoline via bpf_prog_pack mechanism, from Song Liu.

End result: better memory utilization and lower I$ miss for calls to BPF
via BPF trampoline.

6) Fix race between BPF prog accessing inner map and parallel delete,
from Hou Tao.

7) Add bpf_xdp_get_xfrm_state() kfunc, from Daniel Xu.

It allows BPF interact with IPSEC infra. The intent is to support
software RSS (via XDP) for the upcoming ipsec pcpu work.
Experiments on AWS demonstrate single tunnel pcpu ipsec reaching
line rate on 100G ENA nics.

8) Expand bpf_cgrp_storage to support cgroup1 non-attach, from Yafang Shao.

9) BPF file verification via fsverity, from Song Liu.

It allows BPF progs get fsverity digest.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (164 commits)
  bpf: Ensure precise is reset to false in __mark_reg_const_zero()
  selftests/bpf: Add more uprobe multi fail tests
  bpf: Fail uprobe multi link with negative offset
  selftests/bpf: Test the release of map btf
  s390/bpf: Fix indirect trampoline generation
  selftests/bpf: Temporarily disable dummy_struct_ops test on s390
  x86/cfi,bpf: Fix bpf_exception_cb() signature
  bpf: Fix dtor CFI
  cfi: Add CFI_NOSEAL()
  x86/cfi,bpf: Fix bpf_struct_ops CFI
  x86/cfi,bpf: Fix bpf_callback_t CFI
  x86/cfi,bpf: Fix BPF JIT call
  cfi: Flip headers
  selftests/bpf: Add test for abnormal cnt during multi-kprobe attachment
  selftests/bpf: Don't use libbpf_get_error() in kprobe_multi_test
  selftests/bpf: Add test for abnormal cnt during multi-uprobe attachment
  bpf: Limit the number of kprobes when attaching program to multiple kprobes
  bpf: Limit the number of uprobes when attaching program to multiple uprobes
  bpf: xdp: Register generic_kfunc_set with XDP programs
  selftests/bpf: utilize string values for delegate_xxx mount options
  ...
====================

Link: https://lore.kernel.org/r/20231219000520.34178-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 98 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/map_btf.c b/tools/testing/selftests/bpf/prog_tests/map_btf.c
new file mode 100644
index 000000000000..2c4ef6037573
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/map_btf.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2023. Huawei Technologies Co., Ltd */
+#include <test_progs.h>
+
+#include "normal_map_btf.skel.h"
+#include "map_in_map_btf.skel.h"
+
+static void do_test_normal_map_btf(void)
+{
+	struct normal_map_btf *skel;
+	int i, err, new_fd = -1;
+	int map_fd_arr[64];
+
+	skel = normal_map_btf__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "open_load"))
+		return;
+
+	err = normal_map_btf__attach(skel);
+	if (!ASSERT_OK(err, "attach"))
+		goto out;
+
+	skel->bss->pid = getpid();
+	usleep(1);
+	ASSERT_TRUE(skel->bss->done, "done");
+
+	/* Use percpu_array to slow bpf_map_free_deferred() down.
+	 * The memory allocation may fail, so doesn't check the returned fd.
+	 */
+	for (i = 0; i < ARRAY_SIZE(map_fd_arr); i++)
+		map_fd_arr[i] = bpf_map_create(BPF_MAP_TYPE_PERCPU_ARRAY, NULL, 4, 4, 256, NULL);
+
+	/* Close array fd later */
+	new_fd = dup(bpf_map__fd(skel->maps.array));
+out:
+	normal_map_btf__destroy(skel);
+	if (new_fd < 0)
+		return;
+	/* Use kern_sync_rcu() to wait for the start of the free of the bpf
+	 * program and use an assumed delay to wait for the release of the map
+	 * btf which is held by other maps (e.g, bss). After that, array map
+	 * holds the last reference of map btf.
+	 */
+	kern_sync_rcu();
+	usleep(4000);
+	/* Spawn multiple kworkers to delay the invocation of
+	 * bpf_map_free_deferred() for array map.
+	 */
+	for (i = 0; i < ARRAY_SIZE(map_fd_arr); i++) {
+		if (map_fd_arr[i] < 0)
+			continue;
+		close(map_fd_arr[i]);
+	}
+	close(new_fd);
+}
+
+static void do_test_map_in_map_btf(void)
+{
+	int err, zero = 0, new_fd = -1;
+	struct map_in_map_btf *skel;
+
+	skel = map_in_map_btf__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "open_load"))
+		return;
+
+	err = map_in_map_btf__attach(skel);
+	if (!ASSERT_OK(err, "attach"))
+		goto out;
+
+	skel->bss->pid = getpid();
+	usleep(1);
+	ASSERT_TRUE(skel->bss->done, "done");
+
+	/* Close inner_array fd later */
+	new_fd = dup(bpf_map__fd(skel->maps.inner_array));
+	/* Defer the free of inner_array */
+	err = bpf_map__delete_elem(skel->maps.outer_array, &zero, sizeof(zero), 0);
+	ASSERT_OK(err, "delete inner map");
+out:
+	map_in_map_btf__destroy(skel);
+	if (new_fd < 0)
+		return;
+	/* Use kern_sync_rcu() to wait for the start of the free of the bpf
+	 * program and use an assumed delay to wait for the free of the outer
+	 * map and the release of map btf. After that, inner map holds the last
+	 * reference of map btf.
+	 */
+	kern_sync_rcu();
+	usleep(10000);
+	close(new_fd);
+}
+
+void test_map_btf(void)
+{
+	if (test__start_subtest("array_btf"))
+		do_test_normal_map_btf();
+	if (test__start_subtest("inner_array_btf"))
+		do_test_map_in_map_btf();
+}