This selftest contains a testcase that utilizes light skeleton eBPF
loaders. One version of the light skeleton is signed with the
autogenerated module signing key, another is not. A test driver
attempts to load the programs. With Hornet enabled, the signed version
should successfully be loaded, and the unsigned version should fail.
Signed-off-by: Blaise Boscaccy <bbosca...@linux.microsoft.com>
---
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/hornet/Makefile | 58 +++
tools/testing/selftests/hornet/fail_loader.sh | 3 +
tools/testing/selftests/hornet/frozen_skel.h | 393 ++++++++++++++++++
tools/testing/selftests/hornet/loader.c | 22 +
tools/testing/selftests/hornet/trivial.bpf.c | 33 ++
6 files changed, 510 insertions(+)
create mode 100644 tools/testing/selftests/hornet/Makefile
create mode 100755 tools/testing/selftests/hornet/fail_loader.sh
create mode 100644 tools/testing/selftests/hornet/frozen_skel.h
create mode 100644 tools/testing/selftests/hornet/loader.c
create mode 100644 tools/testing/selftests/hornet/trivial.bpf.c
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index c77c8c8e3d9b..14f5d8ede199 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -42,6 +42,7 @@ TARGETS += ftrace
TARGETS += futex
TARGETS += gpio
TARGETS += hid
+TARGETS += hornet
TARGETS += intel_pstate
TARGETS += iommu
TARGETS += ipc
diff --git a/tools/testing/selftests/hornet/Makefile
b/tools/testing/selftests/hornet/Makefile
new file mode 100644
index 000000000000..cd6902918564
--- /dev/null
+++ b/tools/testing/selftests/hornet/Makefile
@@ -0,0 +1,58 @@
+# SPDX-License-Identifier: GPL-2.0
+include ../../../build/Build.include
+include ../../../scripts/Makefile.arch
+include ../../../scripts/Makefile.include
+
+CLANG ?= clang
+CFLAGS := -g -O2 -Wall
+BPFTOOL ?= bpftool
+SCRIPTSDIR := $(abspath ../../../../scripts/hornet)
+TOOLSDIR := $(abspath ../../..)
+LIBDIR := $(TOOLSDIR)/lib
+BPFDIR := $(LIBDIR)/bpf
+TOOLSINCDIR := $(TOOLSDIR)/include
+APIDIR := $(TOOLSINCDIR)/uapi
+CERTDIR := $(abspath ../../../../certs)
+PKG_CONFIG ?= $(CROSS_COMPILE)pkg-config
+
+TEST_GEN_PROGS_EXTENDED := loader
+TEST_GEN_PROGS := signed_loader
+TEST_PROGS := fail_loader.sh
+TEST_GEN_FILES := vmlinux.h loader.h trivial.bin trivial.bpf.o
+$(TEST_GEN_PROGS): LDLIBS += -lbpf
+$(TEST_GEN_PROGS): $(TEST_GEN_FILES)
+
+include ../lib.mk
+
+BPF_CFLAGS := -target bpf \
+ -D__TARGET_ARCH_$(ARCH) \
+ -I/usr/include/$(shell uname -m)-linux-gnu \
+ $(KHDR_INCLUDES)
+
+vmlinux.h:
+ $(BPFTOOL) btf dump file /sys/kernel/btf/vmlinux format c > vmlinux.h
+
+trivial.bpf.o: trivial.bpf.c vmlinux.h
+ $(CLANG) $(CFLAGS) $(BPF_CFLAGS) -c $< -o $@
+
+loader.h: trivial.bpf.o
+ $(BPFTOOL) gen skeleton -L $< name trivial > $@
+
+trivial.bin: loader.h
+ $(SCRIPTSDIR)/extract-skel.sh $< $@
+
+loader: loader.c loader.h
+ $(CC) $(CFLAGS) -I$(LIBDIR) -I$(APIDIR) $< -o $@ -lbpf
+
+$(OUTPUT)/sign-ebpf: ../../../../scripts/hornet/sign-ebpf.c
+ $(call msg,SIGN-EBPF,,$@)
+ $(Q)$(CC) $(shell $(PKG_CONFIG) --cflags libcrypto 2> /dev/null) \
+ $< -o $@ \
+ $(shell $(PKG_CONFIG) --libs libcrypto 2> /dev/null || echo
-lcrypto)
+
+signed_loader: trivial.bin loader $(OUTPUT)/sign-ebpf
+ $(OUTPUT)/sign-ebpf sha256 $(CERTDIR)/signing_key.pem
$(CERTDIR)/signing_key.x509 \
+ trivial.bin loader signed_loader
+ chmod u+x $@
+
+EXTRA_CLEAN = $(OUTPUT)/sign-ebpf
diff --git a/tools/testing/selftests/hornet/fail_loader.sh
b/tools/testing/selftests/hornet/fail_loader.sh
new file mode 100755
index 000000000000..99314369f5de
--- /dev/null
+++ b/tools/testing/selftests/hornet/fail_loader.sh
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+./loader && exit 1; exit 0
diff --git a/tools/testing/selftests/hornet/frozen_skel.h
b/tools/testing/selftests/hornet/frozen_skel.h
new file mode 100644
index 000000000000..2e31a52f41c2
--- /dev/null
+++ b/tools/testing/selftests/hornet/frozen_skel.h
@@ -0,0 +1,393 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+/* Copyright (c) 2021 Facebook */
+#ifndef __SKEL_INTERNAL_H
+#define __SKEL_INTERNAL_H
+
+#ifdef __KERNEL__
+#include <linux/fdtable.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/slab.h>
+#include <linux/bpf.h>
+#else
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <sys/mman.h>
+#include <stdlib.h>
+#include <bpf/bpf.h>
+#endif
+
+#ifndef __NR_bpf
+# if defined(__mips__) && defined(_ABIO32)
+# define __NR_bpf 4355
+# elif defined(__mips__) && defined(_ABIN32)
+# define __NR_bpf 6319
+# elif defined(__mips__) && defined(_ABI64)
+# define __NR_bpf 5315
+# endif
+#endif
+
+/* This file is a base header for auto-generated *.lskel.h files.
+ * Its contents will change and may become part of auto-generation in the
future.
+ *
+ * The layout of bpf_[map|prog]_desc and bpf_loader_ctx is feature dependent
+ * and will change from one version of libbpf to another and features
+ * requested during loader program generation.
+ */
+struct bpf_map_desc {
+ /* output of the loader prog */
+ int map_fd;
+ /* input for the loader prog */
+ __u32 max_entries;
+ __aligned_u64 initial_value;
+};
+struct bpf_prog_desc {
+ int prog_fd;
+};
+
+enum {
+ BPF_SKEL_KERNEL = (1ULL << 0),
+};
+
+struct bpf_loader_ctx {
+ __u32 sz;
+ __u32 flags;
+ __u32 log_level;
+ __u32 log_size;
+ __u64 log_buf;
+};
+
+struct bpf_load_and_run_opts {
+ struct bpf_loader_ctx *ctx;
+ const void *data;
+ const void *insns;
+ __u32 data_sz;
+ __u32 insns_sz;
+ const char *errstr;
+};
+
+long kern_sys_bpf(__u32 cmd, void *attr, __u32 attr_size);
+
+static inline int skel_sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
+ unsigned int size)
+{
+#ifdef __KERNEL__
+ return kern_sys_bpf(cmd, attr, size);
+#else
+ return syscall(__NR_bpf, cmd, attr, size);
+#endif
+}
+
+#ifdef __KERNEL__
+static inline int close(int fd)
+{
+ return close_fd(fd);
+}
+
+static inline void *skel_alloc(size_t size)
+{
+ struct bpf_loader_ctx *ctx = kzalloc(size, GFP_KERNEL);
+
+ if (!ctx)
+ return NULL;
+ ctx->flags |= BPF_SKEL_KERNEL;
+ return ctx;
+}
+
+static inline void skel_free(const void *p)
+{
+ kfree(p);
+}
+
+/* skel->bss/rodata maps are populated the following way:
+ *
+ * For kernel use:
+ * skel_prep_map_data() allocates kernel memory that kernel module can
directly access.
+ * Generated lskel stores the pointer in skel->rodata and in
skel->maps.rodata.initial_value.
+ * The loader program will perform probe_read_kernel() from
maps.rodata.initial_value.
+ * skel_finalize_map_data() sets skel->rodata to point to actual value in a
bpf map and
+ * does maps.rodata.initial_value = ~0ULL to signal skel_free_map_data() that
kvfree
+ * is not necessary.
+ *
+ * For user space:
+ * skel_prep_map_data() mmaps anon memory into skel->rodata that can be
accessed directly.
+ * Generated lskel stores the pointer in skel->rodata and in
skel->maps.rodata.initial_value.
+ * The loader program will perform copy_from_user() from
maps.rodata.initial_value.
+ * skel_finalize_map_data() remaps bpf array map value from the kernel memory
into
+ * skel->rodata address.
+ *
+ * The "bpftool gen skeleton -L" command generates lskel.h that is suitable for
+ * both kernel and user space. The generated loader program does
+ * either bpf_probe_read_kernel() or bpf_copy_from_user() from initial_value
+ * depending on bpf_loader_ctx->flags.
+ */
+static inline void skel_free_map_data(void *p, __u64 addr, size_t sz)
+{
+ if (addr != ~0ULL)
+ kvfree(p);
+ /* When addr == ~0ULL the 'p' points to
+ * ((struct bpf_array *)map)->value. See skel_finalize_map_data.
+ */
+}
+
+static inline void *skel_prep_map_data(const void *val, size_t mmap_sz, size_t
val_sz)
+{
+ void *addr;
+
+ addr = kvmalloc(val_sz, GFP_KERNEL);
+ if (!addr)
+ return NULL;
+ memcpy(addr, val, val_sz);
+ return addr;
+}
+
+static inline void *skel_finalize_map_data(__u64 *init_val, size_t mmap_sz,
int flags, int fd)
+{
+ struct bpf_map *map;
+ void *addr = NULL;
+
+ kvfree((void *) (long) *init_val);
+ *init_val = ~0ULL;
+
+ /* At this point bpf_load_and_run() finished without error and
+ * 'fd' is a valid bpf map FD. All sanity checks below should succeed.
+ */
+ map = bpf_map_get(fd);
+ if (IS_ERR(map))
+ return NULL;
+ if (map->map_type != BPF_MAP_TYPE_ARRAY)
+ goto out;
+ addr = ((struct bpf_array *)map)->value;
+ /* the addr stays valid, since FD is not closed */
+out:
+ bpf_map_put(map);
+ return addr;
+}
+
+#else
+
+static inline void *skel_alloc(size_t size)
+{
+ return calloc(1, size);
+}
+
+static inline void skel_free(void *p)
+{
+ free(p);
+}
+
+static inline void skel_free_map_data(void *p, __u64 addr, size_t sz)
+{
+ munmap(p, sz);
+}
+
+static inline void *skel_prep_map_data(const void *val, size_t mmap_sz, size_t
val_sz)
+{
+ void *addr;
+
+ addr = mmap(NULL, mmap_sz, PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+ if (addr == (void *) -1)
+ return NULL;
+ memcpy(addr, val, val_sz);
+ return addr;
+}
+
+static inline void *skel_finalize_map_data(__u64 *init_val, size_t mmap_sz,
int flags, int fd)
+{
+ void *addr;
+
+ addr = mmap((void *) (long) *init_val, mmap_sz, flags, MAP_SHARED |
MAP_FIXED, fd, 0);
+ if (addr == (void *) -1)
+ return NULL;
+ return addr;
+}
+#endif
+
+static inline int skel_closenz(int fd)
+{
+ if (fd > 0)
+ return close(fd);
+ return -EINVAL;
+}
+
+#ifndef offsetofend
+#define offsetofend(TYPE, MEMBER) \
+ (offsetof(TYPE, MEMBER) + sizeof((((TYPE *)0)->MEMBER)))
+#endif
+
+static inline int skel_map_create(enum bpf_map_type map_type,
+ const char *map_name,
+ __u32 key_size,
+ __u32 value_size,
+ __u32 max_entries)
+{
+ const size_t attr_sz = offsetofend(union bpf_attr, map_extra);
+ union bpf_attr attr;
+
+ memset(&attr, 0, attr_sz);
+
+ attr.map_type = map_type;
+ strncpy(attr.map_name, map_name, sizeof(attr.map_name));
+ attr.key_size = key_size;
+ attr.value_size = value_size;
+ attr.max_entries = max_entries;
+
+ return skel_sys_bpf(BPF_MAP_CREATE, &attr, attr_sz);
+}
+
+static inline int skel_map_update_elem(int fd, const void *key,
+ const void *value, __u64 flags)
+{
+ const size_t attr_sz = offsetofend(union bpf_attr, flags);
+ union bpf_attr attr;
+
+ memset(&attr, 0, attr_sz);
+ attr.map_fd = fd;
+ attr.key = (long) key;
+ attr.value = (long) value;
+ attr.flags = flags;
+
+ return skel_sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, attr_sz);
+}
+
+static inline int skel_map_delete_elem(int fd, const void *key)
+{
+ const size_t attr_sz = offsetofend(union bpf_attr, flags);
+ union bpf_attr attr;
+
+ memset(&attr, 0, attr_sz);
+ attr.map_fd = fd;
+ attr.key = (long)key;
+
+ return skel_sys_bpf(BPF_MAP_DELETE_ELEM, &attr, attr_sz);
+}
+
+static inline int skel_map_freeze(int fd)
+{
+ const size_t attr_sz = offsetofend(union bpf_attr, map_fd);
+ union bpf_attr attr;
+
+ memset(&attr, 0, attr_sz);
+ attr.map_fd = fd;
+
+ return skel_sys_bpf(BPF_MAP_FREEZE, &attr, attr_sz);
+}
+
+static inline int skel_map_get_fd_by_id(__u32 id)
+{
+ const size_t attr_sz = offsetofend(union bpf_attr, flags);
+ union bpf_attr attr;
+
+ memset(&attr, 0, attr_sz);
+ attr.map_id = id;
+
+ return skel_sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, attr_sz);
+}
+
+static inline int skel_raw_tracepoint_open(const char *name, int prog_fd)
+{
+ const size_t attr_sz = offsetofend(union bpf_attr,
raw_tracepoint.prog_fd);
+ union bpf_attr attr;
+
+ memset(&attr, 0, attr_sz);
+ attr.raw_tracepoint.name = (long) name;
+ attr.raw_tracepoint.prog_fd = prog_fd;
+
+ return skel_sys_bpf(BPF_RAW_TRACEPOINT_OPEN, &attr, attr_sz);
+}
+
+static inline int skel_link_create(int prog_fd, int target_fd,
+ enum bpf_attach_type attach_type)
+{
+ const size_t attr_sz = offsetofend(union bpf_attr,
link_create.iter_info_len);
+ union bpf_attr attr;
+
+ memset(&attr, 0, attr_sz);
+ attr.link_create.prog_fd = prog_fd;
+ attr.link_create.target_fd = target_fd;
+ attr.link_create.attach_type = attach_type;
+
+ return skel_sys_bpf(BPF_LINK_CREATE, &attr, attr_sz);
+}
+
+#ifdef __KERNEL__
+#define set_err
+#else
+#define set_err err = -errno
+#endif
+
+static inline int bpf_load_and_run(struct bpf_load_and_run_opts *opts)
+{
+ const size_t prog_load_attr_sz = offsetofend(union bpf_attr, fd_array);
+ const size_t test_run_attr_sz = offsetofend(union bpf_attr, test);
+ int map_fd = -1, prog_fd = -1, key = 0, err;
+ union bpf_attr attr;
+
+ err = map_fd = skel_map_create(BPF_MAP_TYPE_ARRAY, "__loader.map", 4,
opts->data_sz, 1);
+ if (map_fd < 0) {
+ opts->errstr = "failed to create loader map";
+ set_err;
+ goto out;
+ }
+
+ err = skel_map_update_elem(map_fd, &key, opts->data, 0);
+ if (err < 0) {
+ opts->errstr = "failed to update loader map";
+ set_err;
+ goto out;
+ }
+
+ err = skel_map_freeze(map_fd);
+ if (err < 0) {
+ opts->errstr = "failed to freeze map";
+ set_err;
+ goto out;
+ }
+
+ memset(&attr, 0, prog_load_attr_sz);
+ attr.prog_type = BPF_PROG_TYPE_SYSCALL;
+ attr.insns = (long) opts->insns;
+ attr.insn_cnt = opts->insns_sz / sizeof(struct bpf_insn);
+ attr.license = (long) "Dual BSD/GPL";
+ memcpy(attr.prog_name, "__loader.prog", sizeof("__loader.prog"));
+ attr.fd_array = (long) &map_fd;
+ attr.log_level = opts->ctx->log_level;
+ attr.log_size = opts->ctx->log_size;
+ attr.log_buf = opts->ctx->log_buf;
+ attr.prog_flags = BPF_F_SLEEPABLE;
+ err = prog_fd = skel_sys_bpf(BPF_PROG_LOAD, &attr, prog_load_attr_sz);
+ if (prog_fd < 0) {
+ opts->errstr = "failed to load loader prog";
+ set_err;
+ goto out;
+ }
+
+ memset(&attr, 0, test_run_attr_sz);
+ attr.test.prog_fd = prog_fd;
+ attr.test.ctx_in = (long) opts->ctx;
+ attr.test.ctx_size_in = opts->ctx->sz;
+ err = skel_sys_bpf(BPF_PROG_RUN, &attr, test_run_attr_sz);
+ if (err < 0 || (int)attr.test.retval < 0) {
+ if (err < 0) {
+ opts->errstr = "failed to execute loader prog";
+ set_err;
+ } else {
+ opts->errstr = "error returned by loader prog";
+ err = (int)attr.test.retval;
+#ifndef __KERNEL__
+ errno = -err;
+#endif
+ }
+ goto out;
+ }
+ err = 0;
+out:
+ if (map_fd >= 0)
+ close(map_fd);
+ if (prog_fd >= 0)
+ close(prog_fd);
+ return err;
+}
+
+#endif
diff --git a/tools/testing/selftests/hornet/loader.c
b/tools/testing/selftests/hornet/loader.c
new file mode 100644
index 000000000000..548b50a0c1fe
--- /dev/null
+++ b/tools/testing/selftests/hornet/loader.c
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stddef.h>
+#include <sys/resource.h>
+#include <bpf/libbpf.h>
+#include <errno.h>
+#include "frozen_skel.h"
+#include "loader.h"
+
+int main(int argc, char **argv)
+{
+ struct trivial *skel;
+
+ skel = trivial__open_and_load();
+ if (!skel)
+ return -1;
+
+ trivial__destroy(skel);
+ return 0;
+}
diff --git a/tools/testing/selftests/hornet/trivial.bpf.c
b/tools/testing/selftests/hornet/trivial.bpf.c
new file mode 100644
index 000000000000..d38c5b53ff93
--- /dev/null
+++ b/tools/testing/selftests/hornet/trivial.bpf.c
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+
+#include "vmlinux.h"
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";
+
+int monitored_pid = 0;
+
+SEC("tracepoint/syscalls/sys_enter_unlinkat")
+int handle_enter_unlink(struct trace_event_raw_sys_enter *ctx)
+{
+ char filename[128] = { 0 };
+ struct task_struct *task;
+ unsigned long start_time = 0;
+ int pid = bpf_get_current_pid_tgid() >> 32;
+ char *pathname_ptr = (char *) BPF_CORE_READ(ctx, args[1]);
+
+ bpf_probe_read_str(filename, sizeof(filename), pathname_ptr);
+ task = (struct task_struct *)bpf_get_current_task();
+ start_time = BPF_CORE_READ(task, start_time);
+
+ bpf_printk("BPF triggered unlinkat by PID: %d, start_time %ld. pathname
= %s",
+ pid, start_time, filename);
+
+ if (monitored_pid == pid)
+ bpf_printk("target pid found");
+
+ return 0;
+}
--
2.48.1
