diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 6b4955d170ff7..4ea7f4f1a691e 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -230,6 +230,7 @@ struct bpf_program { struct bpf_insn *insns; size_t insns_cnt, main_prog_cnt; enum bpf_prog_type type; + bool load; struct reloc_desc *reloc_desc; int nr_reloc; @@ -541,6 +542,7 @@ 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->load = true; return 0; errout: @@ -2513,6 +2515,8 @@ static int bpf_object__load_vmlinux_btf(struct bpf_object *obj) need_vmlinux_btf = true; bpf_object__for_each_program(prog, obj) { + if (!prog->load) + continue; if (libbpf_prog_needs_vmlinux_btf(prog)) { need_vmlinux_btf = true; break; @@ -5445,6 +5449,12 @@ int bpf_program__load(struct bpf_program *prog, char *license, __u32 kern_ver) { int err = 0, fd, i, btf_id; + if (prog->obj->loaded) { + pr_warn("prog '%s'('%s'): can't load after object was loaded\n", + prog->name, prog->section_name); + return -EINVAL; + } + if ((prog->type == BPF_PROG_TYPE_TRACING || prog->type == BPF_PROG_TYPE_LSM || prog->type == BPF_PROG_TYPE_EXT) && !prog->attach_btf_id) { @@ -5533,16 +5543,21 @@ static bool bpf_program__is_function_storage(const struct bpf_program *prog, static int bpf_object__load_progs(struct bpf_object *obj, int log_level) { + struct bpf_program *prog; size_t i; int err; for (i = 0; i < obj->nr_programs; i++) { - if (bpf_program__is_function_storage(&obj->programs[i], obj)) + prog = &obj->programs[i]; + if (bpf_program__is_function_storage(prog, obj)) continue; - obj->programs[i].log_level |= log_level; - err = bpf_program__load(&obj->programs[i], - obj->license, - obj->kern_version); + if (!prog->load) { + pr_debug("prog '%s'('%s'): skipped loading\n", + prog->name, prog->section_name); + continue; + } + prog->log_level |= log_level; + err = bpf_program__load(prog, obj->license, obj->kern_version); if (err) return err; } @@ -5869,12 +5884,10 @@ int bpf_object__load_xattr(struct bpf_object_load_attr *attr) return -EINVAL; if (obj->loaded) { - pr_warn("object should not be loaded twice\n"); + pr_warn("object '%s': load can't be attempted twice\n", obj->name); return -EINVAL; } - obj->loaded = true; - err = bpf_object__probe_loading(obj); err = err ? : bpf_object__probe_caps(obj); err = err ? : bpf_object__resolve_externs(obj, obj->kconfig); @@ -5889,6 +5902,8 @@ int bpf_object__load_xattr(struct bpf_object_load_attr *attr) btf__free(obj->btf_vmlinux); obj->btf_vmlinux = NULL; + obj->loaded = true; /* doesn't matter if successfully or not */ + if (err) goto out; @@ -6661,6 +6676,20 @@ const char *bpf_program__title(const struct bpf_program *prog, bool needs_copy) return title; } +bool bpf_program__autoload(const struct bpf_program *prog) +{ + return prog->load; +} + +int bpf_program__set_autoload(struct bpf_program *prog, bool autoload) +{ + if (prog->obj->loaded) + return -EINVAL; + + prog->load = autoload; + return 0; +} + int bpf_program__fd(const struct bpf_program *prog) { return bpf_program__nth_fd(prog, 0); @@ -9283,6 +9312,9 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s) const struct bpf_sec_def *sec_def; const char *sec_name = bpf_program__title(prog, false); + if (!prog->load) + continue; + sec_def = find_sec_def(sec_name); if (!sec_def || !sec_def->attach_fn) continue; diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index fdd279fb1866d..2335971ed0bd1 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -200,6 +200,8 @@ LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog, LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog); LIBBPF_API const char *bpf_program__title(const struct bpf_program *prog, bool needs_copy); +LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog); +LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload); /* returns program size in bytes */ LIBBPF_API size_t bpf_program__size(const struct bpf_program *prog); diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 9914e0db48599..6544d2cd1ed63 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -286,4 +286,6 @@ LIBBPF_0.1.0 { bpf_map__set_value_size; bpf_map__type; bpf_map__value_size; + bpf_program__autoload; + bpf_program__set_autoload; } LIBBPF_0.0.9; diff --git a/tools/testing/selftests/bpf/prog_tests/autoload.c b/tools/testing/selftests/bpf/prog_tests/autoload.c new file mode 100644 index 0000000000000..3693f7d133eb0 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/autoload.c @@ -0,0 +1,41 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ + +#include +#include +#include "test_autoload.skel.h" + +void test_autoload(void) +{ + int duration = 0, err; + struct test_autoload* skel; + + skel = test_autoload__open_and_load(); + /* prog3 should be broken */ + if (CHECK(skel, "skel_open_and_load", "unexpected success\n")) + goto cleanup; + + skel = test_autoload__open(); + if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) + goto cleanup; + + /* don't load prog3 */ + bpf_program__set_autoload(skel->progs.prog3, false); + + err = test_autoload__load(skel); + if (CHECK(err, "skel_load", "failed to load skeleton: %d\n", err)) + goto cleanup; + + err = test_autoload__attach(skel); + if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err)) + goto cleanup; + + usleep(1); + + CHECK(!skel->bss->prog1_called, "prog1", "not called\n"); + CHECK(!skel->bss->prog2_called, "prog2", "not called\n"); + CHECK(skel->bss->prog3_called, "prog3", "called?!\n"); + +cleanup: + test_autoload__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_autoload.c b/tools/testing/selftests/bpf/progs/test_autoload.c new file mode 100644 index 0000000000000..62c8cdec6d5de --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_autoload.c @@ -0,0 +1,40 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ + +#include "vmlinux.h" +#include +#include +#include + +bool prog1_called = false; +bool prog2_called = false; +bool prog3_called = false; + +SEC("raw_tp/sys_enter") +int prog1(const void *ctx) +{ + prog1_called = true; + return 0; +} + +SEC("raw_tp/sys_exit") +int prog2(const void *ctx) +{ + prog2_called = true; + return 0; +} + +struct fake_kernel_struct { + int whatever; +} __attribute__((preserve_access_index)); + +SEC("fentry/unexisting-kprobe-will-fail-if-loaded") +int prog3(const void *ctx) +{ + struct fake_kernel_struct *fake = (void *)ctx; + fake->whatever = 123; + prog3_called = true; + return 0; +} + +char _license[] SEC("license") = "GPL";