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-rw-r--r--tools/lib/bpf/libbpf.c34
-rw-r--r--tools/lib/bpf/libbpf.h9
-rw-r--r--tools/testing/selftests/bpf/prog_tests/core_autosize.c22
-rw-r--r--tools/testing/selftests/bpf/prog_tests/core_reloc.c25
4 files changed, 57 insertions, 33 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 4ccfae30e681..17bc922f543f 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -498,6 +498,10 @@ struct bpf_object {
* it at load time.
*/
struct btf *btf_vmlinux;
+ /* Path to the custom BTF to be used for BPF CO-RE relocations as an
+ * override for vmlinux BTF.
+ */
+ char *btf_custom_path;
/* vmlinux BTF override for CO-RE relocations */
struct btf *btf_vmlinux_override;
/* Lazily initialized kernel module BTFs */
@@ -2645,8 +2649,10 @@ static bool obj_needs_vmlinux_btf(const struct bpf_object *obj)
struct bpf_program *prog;
int i;
- /* CO-RE relocations need kernel BTF */
- if (obj->btf_ext && obj->btf_ext->core_relo_info.len)
+ /* CO-RE relocations need kernel BTF, only when btf_custom_path
+ * is not specified
+ */
+ if (obj->btf_ext && obj->btf_ext->core_relo_info.len && !obj->btf_custom_path)
return true;
/* Support for typed ksyms needs kernel BTF */
@@ -7596,7 +7602,7 @@ static struct bpf_object *
__bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
const struct bpf_object_open_opts *opts)
{
- const char *obj_name, *kconfig;
+ const char *obj_name, *kconfig, *btf_tmp_path;
struct bpf_program *prog;
struct bpf_object *obj;
char tmp_name[64];
@@ -7627,11 +7633,26 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
if (IS_ERR(obj))
return obj;
+ btf_tmp_path = OPTS_GET(opts, btf_custom_path, NULL);
+ if (btf_tmp_path) {
+ if (strlen(btf_tmp_path) >= PATH_MAX) {
+ err = -ENAMETOOLONG;
+ goto out;
+ }
+ obj->btf_custom_path = strdup(btf_tmp_path);
+ if (!obj->btf_custom_path) {
+ err = -ENOMEM;
+ goto out;
+ }
+ }
+
kconfig = OPTS_GET(opts, kconfig, NULL);
if (kconfig) {
obj->kconfig = strdup(kconfig);
- if (!obj->kconfig)
- return ERR_PTR(-ENOMEM);
+ if (!obj->kconfig) {
+ err = -ENOMEM;
+ goto out;
+ }
}
err = bpf_object__elf_init(obj);
@@ -8097,7 +8118,7 @@ int bpf_object__load_xattr(struct bpf_object_load_attr *attr)
err = err ? : bpf_object__sanitize_maps(obj);
err = err ? : bpf_object__init_kern_struct_ops_maps(obj);
err = err ? : bpf_object__create_maps(obj);
- err = err ? : bpf_object__relocate(obj, attr->target_btf_path);
+ err = err ? : bpf_object__relocate(obj, obj->btf_custom_path ? : attr->target_btf_path);
err = err ? : bpf_object__load_progs(obj, attr->log_level);
if (obj->gen_loader) {
@@ -8744,6 +8765,7 @@ void bpf_object__close(struct bpf_object *obj)
for (i = 0; i < obj->nr_maps; i++)
bpf_map__destroy(&obj->maps[i]);
+ zfree(&obj->btf_custom_path);
zfree(&obj->kconfig);
zfree(&obj->externs);
obj->nr_extern = 0;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 6e61342ba56c..6b08c1023609 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -94,8 +94,15 @@ struct bpf_object_open_opts {
* system Kconfig for CONFIG_xxx externs.
*/
const char *kconfig;
+ /* Path to the custom BTF to be used for BPF CO-RE relocations.
+ * This custom BTF completely replaces the use of vmlinux BTF
+ * for the purpose of CO-RE relocations.
+ * NOTE: any other BPF feature (e.g., fentry/fexit programs,
+ * struct_ops, etc) will need actual kernel BTF at /sys/kernel/btf/vmlinux.
+ */
+ const char *btf_custom_path;
};
-#define bpf_object_open_opts__last_field kconfig
+#define bpf_object_open_opts__last_field btf_custom_path
LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
LIBBPF_API struct bpf_object *
diff --git a/tools/testing/selftests/bpf/prog_tests/core_autosize.c b/tools/testing/selftests/bpf/prog_tests/core_autosize.c
index 981c251453d9..3d4b2a358d47 100644
--- a/tools/testing/selftests/bpf/prog_tests/core_autosize.c
+++ b/tools/testing/selftests/bpf/prog_tests/core_autosize.c
@@ -53,8 +53,8 @@ void test_core_autosize(void)
char btf_file[] = "/tmp/core_autosize.btf.XXXXXX";
int err, fd = -1, zero = 0;
int char_id, short_id, int_id, long_long_id, void_ptr_id, id;
+ DECLARE_LIBBPF_OPTS(bpf_object_open_opts, open_opts);
struct test_core_autosize* skel = NULL;
- struct bpf_object_load_attr load_attr = {};
struct bpf_program *prog;
struct bpf_map *bss_map;
struct btf *btf = NULL;
@@ -125,9 +125,10 @@ void test_core_autosize(void)
fd = -1;
/* open and load BPF program with custom BTF as the kernel BTF */
- skel = test_core_autosize__open();
+ open_opts.btf_custom_path = btf_file;
+ skel = test_core_autosize__open_opts(&open_opts);
if (!ASSERT_OK_PTR(skel, "skel_open"))
- return;
+ goto cleanup;
/* disable handle_signed() for now */
prog = bpf_object__find_program_by_name(skel->obj, "handle_signed");
@@ -135,9 +136,7 @@ void test_core_autosize(void)
goto cleanup;
bpf_program__set_autoload(prog, false);
- load_attr.obj = skel->obj;
- load_attr.target_btf_path = btf_file;
- err = bpf_object__load_xattr(&load_attr);
+ err = bpf_object__load(skel->obj);
if (!ASSERT_OK(err, "prog_load"))
goto cleanup;
@@ -204,14 +203,13 @@ void test_core_autosize(void)
skel = NULL;
/* now re-load with handle_signed() enabled, it should fail loading */
- skel = test_core_autosize__open();
+ open_opts.btf_custom_path = btf_file;
+ skel = test_core_autosize__open_opts(&open_opts);
if (!ASSERT_OK_PTR(skel, "skel_open"))
- return;
+ goto cleanup;
- load_attr.obj = skel->obj;
- load_attr.target_btf_path = btf_file;
- err = bpf_object__load_xattr(&load_attr);
- if (!ASSERT_ERR(err, "bad_prog_load"))
+ err = test_core_autosize__load(skel);
+ if (!ASSERT_ERR(err, "skel_load"))
goto cleanup;
cleanup:
diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
index d02e064c535f..4739b15b2a97 100644
--- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c
+++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
@@ -816,7 +816,7 @@ static size_t roundup_page(size_t sz)
void test_core_reloc(void)
{
const size_t mmap_sz = roundup_page(sizeof(struct data));
- struct bpf_object_load_attr load_attr = {};
+ DECLARE_LIBBPF_OPTS(bpf_object_open_opts, open_opts);
struct core_reloc_test_case *test_case;
const char *tp_name, *probe_name;
int err, i, equal;
@@ -846,9 +846,16 @@ void test_core_reloc(void)
continue;
}
- obj = bpf_object__open_file(test_case->bpf_obj_file, NULL);
+ if (test_case->btf_src_file) {
+ err = access(test_case->btf_src_file, R_OK);
+ if (!ASSERT_OK(err, "btf_src_file"))
+ goto cleanup;
+ }
+
+ open_opts.btf_custom_path = test_case->btf_src_file;
+ obj = bpf_object__open_file(test_case->bpf_obj_file, &open_opts);
if (!ASSERT_OK_PTR(obj, "obj_open"))
- continue;
+ goto cleanup;
probe_name = "raw_tracepoint/sys_enter";
tp_name = "sys_enter";
@@ -862,17 +869,7 @@ void test_core_reloc(void)
"prog '%s' not found\n", probe_name))
goto cleanup;
-
- if (test_case->btf_src_file) {
- err = access(test_case->btf_src_file, R_OK);
- if (!ASSERT_OK(err, "btf_src_file"))
- goto cleanup;
- }
-
- load_attr.obj = obj;
- load_attr.log_level = 0;
- load_attr.target_btf_path = test_case->btf_src_file;
- err = bpf_object__load_xattr(&load_attr);
+ err = bpf_object__load(obj);
if (err) {
if (!test_case->fails)
ASSERT_OK(err, "obj_load");
generated by cgit (git 2.34.1) at 2025-04-19 01:19:06 +0000