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Diffstat (limited to 'tools/lib/bpf/libbpf.c')
-rw-r--r--tools/lib/bpf/libbpf.c139
1 files changed, 95 insertions, 44 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 59b748ebd15f..4ea3368bf803 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -167,7 +167,7 @@ struct bpf_program {
int btf_fd;
void *func_info;
__u32 func_info_rec_size;
- __u32 func_info_len;
+ __u32 func_info_cnt;
struct bpf_capabilities *caps;
};
@@ -779,6 +779,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
{
Elf *elf = obj->efile.elf;
GElf_Ehdr *ep = &obj->efile.ehdr;
+ Elf_Data *btf_ext_data = NULL;
Elf_Scn *scn = NULL;
int idx = 0, err = 0;
@@ -841,14 +842,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
obj->btf = NULL;
}
} else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) {
- obj->btf_ext = btf_ext__new(data->d_buf, data->d_size,
- __pr_debug);
- if (IS_ERR(obj->btf_ext)) {
- pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
- BTF_EXT_ELF_SEC,
- PTR_ERR(obj->btf_ext));
- obj->btf_ext = NULL;
- }
+ btf_ext_data = data;
} else if (sh.sh_type == SHT_SYMTAB) {
if (obj->efile.symbols) {
pr_warning("bpf: multiple SYMTAB in %s\n",
@@ -910,6 +904,22 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
pr_warning("Corrupted ELF file: index of strtab invalid\n");
return LIBBPF_ERRNO__FORMAT;
}
+ if (btf_ext_data) {
+ if (!obj->btf) {
+ pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n",
+ BTF_EXT_ELF_SEC, BTF_ELF_SEC);
+ } else {
+ obj->btf_ext = btf_ext__new(btf_ext_data->d_buf,
+ btf_ext_data->d_size,
+ __pr_debug);
+ if (IS_ERR(obj->btf_ext)) {
+ pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
+ BTF_EXT_ELF_SEC,
+ PTR_ERR(obj->btf_ext));
+ obj->btf_ext = NULL;
+ }
+ }
+ }
if (obj->efile.maps_shndx >= 0) {
err = bpf_object__init_maps(obj, flags);
if (err)
@@ -1276,6 +1286,69 @@ bpf_object__create_maps(struct bpf_object *obj)
}
static int
+check_btf_ext_reloc_err(struct bpf_program *prog, int err,
+ void *btf_prog_info, const char *info_name)
+{
+ if (err != -ENOENT) {
+ pr_warning("Error in loading %s for sec %s.\n",
+ info_name, prog->section_name);
+ return err;
+ }
+
+ /* err == -ENOENT (i.e. prog->section_name not found in btf_ext) */
+
+ if (btf_prog_info) {
+ /*
+ * Some info has already been found but has problem
+ * in the last btf_ext reloc. Must have to error
+ * out.
+ */
+ pr_warning("Error in relocating %s for sec %s.\n",
+ info_name, prog->section_name);
+ return err;
+ }
+
+ /*
+ * Have problem loading the very first info. Ignore
+ * the rest.
+ */
+ pr_warning("Cannot find %s for main program sec %s. Ignore all %s.\n",
+ info_name, prog->section_name, info_name);
+ return 0;
+}
+
+static int
+bpf_program_reloc_btf_ext(struct bpf_program *prog, struct bpf_object *obj,
+ const char *section_name, __u32 insn_offset)
+{
+ int err;
+
+ if (!insn_offset || prog->func_info) {
+ /*
+ * !insn_offset => main program
+ *
+ * For sub prog, the main program's func_info has to
+ * be loaded first (i.e. prog->func_info != NULL)
+ */
+ err = btf_ext__reloc_func_info(obj->btf, obj->btf_ext,
+ section_name, insn_offset,
+ &prog->func_info,
+ &prog->func_info_cnt);
+ if (err)
+ return check_btf_ext_reloc_err(prog, err,
+ prog->func_info,
+ "bpf_func_info");
+
+ prog->func_info_rec_size = btf_ext__func_info_rec_size(obj->btf_ext);
+ }
+
+ if (!insn_offset)
+ prog->btf_fd = btf__fd(obj->btf);
+
+ return 0;
+}
+
+static int
bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj,
struct reloc_desc *relo)
{
@@ -1306,17 +1379,12 @@ bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj,
return -ENOMEM;
}
- if (obj->btf && obj->btf_ext) {
- err = btf_ext__reloc(obj->btf, obj->btf_ext,
- text->section_name,
- prog->insns_cnt,
- &prog->func_info,
- &prog->func_info_len);
- if (err) {
- pr_warning("error in btf_ext__reloc for sec %s\n",
- text->section_name);
+ if (obj->btf_ext) {
+ err = bpf_program_reloc_btf_ext(prog, obj,
+ text->section_name,
+ prog->insns_cnt);
+ if (err)
return err;
- }
}
memcpy(new_insn + prog->insns_cnt, text->insns,
@@ -1341,18 +1409,11 @@ bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj)
if (!prog)
return 0;
- if (obj->btf && obj->btf_ext) {
- err = btf_ext__reloc_init(obj->btf, obj->btf_ext,
- prog->section_name,
- &prog->func_info,
- &prog->func_info_rec_size,
- &prog->func_info_len);
- if (err) {
- pr_warning("err in btf_ext__reloc_init for sec %s\n",
- prog->section_name);
+ if (obj->btf_ext) {
+ err = bpf_program_reloc_btf_ext(prog, obj,
+ prog->section_name, 0);
+ if (err)
return err;
- }
- prog->btf_fd = btf__fd(obj->btf);
}
if (!prog->reloc_desc)
@@ -1444,8 +1505,7 @@ static int bpf_object__collect_reloc(struct bpf_object *obj)
static int
load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
- char *license, __u32 kern_version, int *pfd,
- __u32 func_info_cnt)
+ char *license, __u32 kern_version, int *pfd)
{
struct bpf_load_program_attr load_attr;
char *cp, errmsg[STRERR_BUFSIZE];
@@ -1465,8 +1525,7 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
load_attr.prog_btf_fd = prog->btf_fd >= 0 ? prog->btf_fd : 0;
load_attr.func_info = prog->func_info;
load_attr.func_info_rec_size = prog->func_info_rec_size;
- load_attr.func_info_cnt = func_info_cnt;
-
+ load_attr.func_info_cnt = prog->func_info_cnt;
if (!load_attr.insns || !load_attr.insns_cnt)
return -EINVAL;
@@ -1523,14 +1582,8 @@ int
bpf_program__load(struct bpf_program *prog,
char *license, __u32 kern_version)
{
- __u32 func_info_cnt;
int err = 0, fd, i;
- if (prog->func_info_len == 0)
- func_info_cnt = 0;
- else
- func_info_cnt = prog->func_info_len / prog->func_info_rec_size;
-
if (prog->instances.nr < 0 || !prog->instances.fds) {
if (prog->preprocessor) {
pr_warning("Internal error: can't load program '%s'\n",
@@ -1553,8 +1606,7 @@ bpf_program__load(struct bpf_program *prog,
prog->section_name, prog->instances.nr);
}
err = load_program(prog, prog->insns, prog->insns_cnt,
- license, kern_version, &fd,
- func_info_cnt);
+ license, kern_version, &fd);
if (!err)
prog->instances.fds[0] = fd;
goto out;
@@ -1584,8 +1636,7 @@ bpf_program__load(struct bpf_program *prog,
err = load_program(prog, result.new_insn_ptr,
result.new_insn_cnt,
- license, kern_version, &fd,
- func_info_cnt);
+ license, kern_version, &fd);
if (err) {
pr_warning("Loading the %dth instance of program '%s' failed\n",
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.