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Message-Id: <20200305192146.589093-1-eric@sage.org>
Date: Thu, 5 Mar 2020 11:21:46 -0800
From: Eric Sage <eric@...e.org>
To: bpf@...r.kernel.org
Cc: ast@...nel.org, daniel@...earbox.net, kafai@...com, yhs@...com,
andriin@...com, jakub.kicinski@...ronome.com, hawk@...nel.org,
john.fastabend@...il.com, davem@...emloft.net,
netdev@...r.kernel.org, Eric Sage <eric@...e.org>
Subject: [PATCH] [bpf] Make bpf program autoloading optional
Adds bpf_program__set_autoload which can be used to disable loading
a bpf_prog when loading the bpf_object that contains it after the
bpf_object has been opened. This behavior affect calling load directly
and loading through BPF skel. A single flag is added to bpf_prog
to make this work.
Signed-off-by: Eric Sage <eric@...e.org>
---
tools/lib/bpf/libbpf.c | 9 +
tools/lib/bpf/libbpf.h | 2 +
tools/lib/bpf/libbpf.map | 5 +
tools/testing/selftests/bpf/Makefile | 2 +-
.../selftests/bpf/progs/test_autoload_kern.c | 24 +++
tools/testing/selftests/bpf/test_autoload.c | 158 ++++++++++++++++++
6 files changed, 199 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/bpf/progs/test_autoload_kern.c
create mode 100644 tools/testing/selftests/bpf/test_autoload.c
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 514b1a524abb..fe156ca10d16 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -222,6 +222,7 @@ struct bpf_program {
bpf_program_prep_t preprocessor;
struct bpf_object *obj;
+ bool autoload;
void *priv;
bpf_program_clear_priv_t clear_priv;
@@ -499,6 +500,7 @@ bpf_program__init(void *data, size_t size, char *section_name, int idx,
prog->instances.fds = NULL;
prog->instances.nr = -1;
prog->type = BPF_PROG_TYPE_UNSPEC;
+ prog->autoload = true;
return 0;
errout:
@@ -4933,6 +4935,11 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
return ret;
}
+void bpf_program__set_autoload(struct bpf_program *prog, bool autoload)
+{
+ prog->autoload = autoload;
+}
+
static int libbpf_find_attach_btf_id(struct bpf_program *prog);
int bpf_program__load(struct bpf_program *prog, char *license, __u32 kern_ver)
@@ -5030,6 +5037,8 @@ bpf_object__load_progs(struct bpf_object *obj, int log_level)
int err;
for (i = 0; i < obj->nr_programs; i++) {
+ if (!obj->programs[i].autoload)
+ continue;
if (bpf_program__is_function_storage(&obj->programs[i], obj))
continue;
obj->programs[i].log_level |= log_level;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 3fe12c9d1f92..e5f30f70bac1 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -204,6 +204,8 @@ LIBBPF_API const char *bpf_program__title(const struct bpf_program *prog,
/* returns program size in bytes */
LIBBPF_API size_t bpf_program__size(const struct bpf_program *prog);
+LIBBPF_API void bpf_program__set_autoload(struct bpf_program *prog, bool autoload);
+
LIBBPF_API int bpf_program__load(struct bpf_program *prog, char *license,
__u32 kern_version);
LIBBPF_API int bpf_program__fd(const struct bpf_program *prog);
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index b035122142bb..1d7572806981 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -235,3 +235,8 @@ LIBBPF_0.0.7 {
btf__align_of;
libbpf_find_kernel_btf;
} LIBBPF_0.0.6;
+
+LIBBPF_0.0.8 {
+ global:
+ bpf_program__set_autoload;
+} LIBBPF_0.0.7;
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 257a1aaaa37d..1ee62911992d 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -29,7 +29,7 @@ LDLIBS += -lcap -lelf -lz -lrt -lpthread
# Order correspond to 'make run_tests' order
TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs \
test_align test_verifier_log test_dev_cgroup test_tcpbpf_user \
- test_sock test_btf test_sockmap get_cgroup_id_user test_socket_cookie \
+ test_sock test_btf test_sockmap test_autoload get_cgroup_id_user test_socket_cookie \
test_cgroup_storage \
test_netcnt test_tcpnotify_user test_sock_fields test_sysctl test_hashmap \
test_progs-no_alu32
diff --git a/tools/testing/selftests/bpf/progs/test_autoload_kern.c b/tools/testing/selftests/bpf/progs/test_autoload_kern.c
new file mode 100644
index 000000000000..e4cfe9b90606
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_autoload_kern.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+SEC("xdp_prog_0")
+int prog_0(struct xdp_md *xdp)
+{
+ return XDP_PASS;
+}
+
+SEC("xdp_prog_1")
+int prog_1(struct xdp_md *xdp)
+{
+ return XDP_PASS;
+}
+
+SEC("xdp_prog_2")
+int prog_2(struct xdp_md *xdp)
+{
+ return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/test_autoload.c b/tools/testing/selftests/bpf/test_autoload.c
new file mode 100644
index 000000000000..3294c167bbfd
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_autoload.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/resource.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#include "test_autoload_kern.skel.h"
+
+#define AUTOLOAD_KERN "test_autoload_kern.o"
+#define TEST_NO_AUTOLOAD_PROG "prog_2"
+
+int print_libbpf_log(enum libbpf_print_level lvl, const char *fmt, va_list args)
+{
+ return 0;
+}
+
+int test_libbpf(void)
+{
+ struct bpf_object *obj;
+ struct bpf_program *unloaded_prog, *prog;
+ struct bpf_prog_info *info;
+ __u32 info_len;
+ int prog_fd;
+
+ obj = bpf_object__open(AUTOLOAD_KERN);
+ if (obj == NULL) {
+ fprintf(stderr, "failed to load %s\n", AUTOLOAD_KERN);
+ return -1;
+ }
+
+ unloaded_prog =
+ bpf_object__find_program_by_name(obj, TEST_NO_AUTOLOAD_PROG);
+ if (unloaded_prog == NULL) {
+ fprintf(stderr, "failed to find test xdp prog %s\n",
+ TEST_NO_AUTOLOAD_PROG);
+ goto fail;
+ }
+
+ bpf_program__set_autoload(unloaded_prog, false);
+
+ bpf_object__load(obj);
+
+ bpf_object__for_each_program(prog, obj) {
+ prog_fd = bpf_program__fd(prog);
+
+ if (unloaded_prog == prog) {
+ if (-prog_fd != EINVAL) {
+ fprintf(stderr,
+ "non-autoloaded prog should not be loaded\n");
+ goto fail;
+ }
+ continue;
+ }
+
+ info_len = sizeof(struct bpf_prog_info);
+ info = calloc(1, info_len);
+
+ if (bpf_obj_get_info_by_fd(prog_fd, info, &info_len) < 0) {
+ fprintf(stderr, "could not get bpf prog info\n");
+ goto fail;
+ }
+
+ if (info->id == 0) {
+ fprintf(stderr, "expected valid prog id\n");
+ goto fail;
+ }
+ }
+
+ bpf_object__close(obj);
+ return 0;
+fail:
+ bpf_object__close(obj);
+ return -1;
+}
+
+int test_skel(void)
+{
+ struct test_autoload_kern *kern;
+ struct bpf_object *obj;
+ struct bpf_program *unloaded_prog, *prog;
+ struct bpf_prog_info *info;
+ __u32 info_len;
+ int prog_fd;
+
+ kern = test_autoload_kern__open();
+ if (kern == NULL) {
+ fprintf(stderr, "failed to autoload skel\n");
+ return -1;
+ }
+
+ obj = kern->obj;
+
+ unloaded_prog =
+ bpf_object__find_program_by_name(obj, TEST_NO_AUTOLOAD_PROG);
+ if (unloaded_prog == NULL) {
+ fprintf(stderr, "failed to find test xdp prog %s\n",
+ TEST_NO_AUTOLOAD_PROG);
+ goto fail;
+ }
+
+ bpf_program__set_autoload(unloaded_prog, false);
+
+ bpf_object__load(obj);
+
+ bpf_object__for_each_program(prog, obj) {
+ prog_fd = bpf_program__fd(prog);
+
+ if (unloaded_prog == prog) {
+ if (-prog_fd != EINVAL) {
+ fprintf(stderr,
+ "non-autoloaded prog should not be loaded\n");
+ goto fail;
+ }
+ continue;
+ }
+
+ info_len = sizeof(struct bpf_prog_info);
+ info = calloc(1, info_len);
+
+ if (bpf_obj_get_info_by_fd(prog_fd, info, &info_len) < 0) {
+ fprintf(stderr, "could not get bpf prog info\n");
+ goto fail;
+ }
+
+ if (info->id == 0) {
+ fprintf(stderr, "expected valid prog id\n");
+ goto fail;
+ }
+ }
+
+ test_autoload_kern__destroy(kern);
+ return 0;
+fail:
+ test_autoload_kern__destroy(kern);
+ return -1;
+}
+
+int main(void)
+{
+ struct rlimit r = { RLIM_INFINITY, RLIM_INFINITY };
+
+ if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+ perror("setrlimit(RLIMIT_MEMLOCK)");
+ return EXIT_FAILURE;
+ }
+
+ libbpf_set_print(print_libbpf_log);
+
+ if (test_libbpf() < 0)
+ return EXIT_FAILURE;
+
+ if (test_skel() < 0)
+ return EXIT_FAILURE;
+}
--
2.24.1
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