Refactor low-level API for BPF program loading to not rely on public API
types. This allows painless extension without constant efforts to cleverly not
break backwards compatibility.
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
---
tools/lib/bpf/bpf.c | 100 ++++++++++++++++++++++----------
tools/lib/bpf/libbpf.c | 34 +++++------
tools/lib/bpf/libbpf_internal.h | 29 +++++++++
3 files changed, 113 insertions(+), 50 deletions(-)
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index d27e34133973..e371ef91f5e8 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -214,59 +214,52 @@ alloc_zero_tailing_info(const void *orecord, __u32 cnt,
return info;
}
-int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
- char *log_buf, size_t log_buf_sz)
+int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr)
{
void *finfo = NULL, *linfo = NULL;
union bpf_attr attr;
- __u32 log_level;
int fd;
- if (!load_attr || !log_buf != !log_buf_sz)
+ if (!load_attr->log_buf != !load_attr->log_buf_sz)
return -EINVAL;
- log_level = load_attr->log_level;
- if (log_level > (4 | 2 | 1) || (log_level && !log_buf))
+ if (load_attr->log_level > (4 | 2 | 1) || (load_attr->log_level && !load_attr->log_buf))
return -EINVAL;
memset(&attr, 0, sizeof(attr));
attr.prog_type = load_attr->prog_type;
attr.expected_attach_type = load_attr->expected_attach_type;
- if (attr.prog_type == BPF_PROG_TYPE_STRUCT_OPS ||
- attr.prog_type == BPF_PROG_TYPE_LSM) {
- attr.attach_btf_id = load_attr->attach_btf_id;
- } else if (attr.prog_type == BPF_PROG_TYPE_TRACING ||
- attr.prog_type == BPF_PROG_TYPE_EXT) {
- attr.attach_btf_id = load_attr->attach_btf_id;
- attr.attach_prog_fd = load_attr->attach_prog_fd;
- } else {
- attr.prog_ifindex = load_attr->prog_ifindex;
- attr.kern_version = load_attr->kern_version;
- }
- attr.insn_cnt = (__u32)load_attr->insns_cnt;
+
+ attr.attach_btf_id = load_attr->attach_btf_id;
+ attr.attach_prog_fd = load_attr->attach_prog_fd;
+
+ attr.prog_ifindex = load_attr->prog_ifindex;
+ attr.kern_version = load_attr->kern_version;
+
+ attr.insn_cnt = (__u32)load_attr->insn_cnt;
attr.insns = ptr_to_u64(load_attr->insns);
attr.license = ptr_to_u64(load_attr->license);
- attr.log_level = log_level;
- if (log_level) {
- attr.log_buf = ptr_to_u64(log_buf);
- attr.log_size = log_buf_sz;
- } else {
- attr.log_buf = ptr_to_u64(NULL);
- attr.log_size = 0;
+ attr.log_level = load_attr->log_level;
+ if (attr.log_level) {
+ attr.log_buf = ptr_to_u64(load_attr->log_buf);
+ attr.log_size = load_attr->log_buf_sz;
}
attr.prog_btf_fd = load_attr->prog_btf_fd;
+ attr.prog_flags = load_attr->prog_flags;
+
attr.func_info_rec_size = load_attr->func_info_rec_size;
attr.func_info_cnt = load_attr->func_info_cnt;
attr.func_info = ptr_to_u64(load_attr->func_info);
+
attr.line_info_rec_size = load_attr->line_info_rec_size;
attr.line_info_cnt = load_attr->line_info_cnt;
attr.line_info = ptr_to_u64(load_attr->line_info);
+
if (load_attr->name)
memcpy(attr.prog_name, load_attr->name,
- min(strlen(load_attr->name), BPF_OBJ_NAME_LEN - 1));
- attr.prog_flags = load_attr->prog_flags;
+ min(strlen(load_attr->name), (size_t)BPF_OBJ_NAME_LEN - 1));
fd = sys_bpf_prog_load(&attr, sizeof(attr));
if (fd >= 0)
@@ -306,19 +299,19 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
}
fd = sys_bpf_prog_load(&attr, sizeof(attr));
-
if (fd >= 0)
goto done;
}
- if (log_level || !log_buf)
+ if (load_attr->log_level || !load_attr->log_buf)
goto done;
/* Try again with log */
- attr.log_buf = ptr_to_u64(log_buf);
- attr.log_size = log_buf_sz;
+ attr.log_buf = ptr_to_u64(load_attr->log_buf);
+ attr.log_size = load_attr->log_buf_sz;
attr.log_level = 1;
- log_buf[0] = 0;
+ load_attr->log_buf[0] = 0;
+
fd = sys_bpf_prog_load(&attr, sizeof(attr));
done:
free(finfo);
@@ -326,6 +319,49 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
return fd;
}
+int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
+ char *log_buf, size_t log_buf_sz)
+{
+ struct bpf_prog_load_params p = {};
+
+ if (!load_attr || !log_buf != !log_buf_sz)
+ return -EINVAL;
+
+ p.prog_type = load_attr->prog_type;
+ p.expected_attach_type = load_attr->expected_attach_type;
+ switch (p.prog_type) {
+ case BPF_PROG_TYPE_STRUCT_OPS:
+ case BPF_PROG_TYPE_LSM:
+ p.attach_btf_id = load_attr->attach_btf_id;
+ break;
+ case BPF_PROG_TYPE_TRACING:
+ case BPF_PROG_TYPE_EXT:
+ p.attach_btf_id = load_attr->attach_btf_id;
+ p.attach_prog_fd = load_attr->attach_prog_fd;
+ break;
+ default:
+ p.prog_ifindex = load_attr->prog_ifindex;
+ p.kern_version = load_attr->kern_version;
+ }
+ p.insn_cnt = load_attr->insns_cnt;
+ p.insns = load_attr->insns;
+ p.license = load_attr->license;
+ p.log_level = load_attr->log_level;
+ p.log_buf = log_buf;
+ p.log_buf_sz = log_buf_sz;
+ p.prog_btf_fd = load_attr->prog_btf_fd;
+ p.func_info_rec_size = load_attr->func_info_rec_size;
+ p.func_info_cnt = load_attr->func_info_cnt;
+ p.func_info = load_attr->func_info;
+ p.line_info_rec_size = load_attr->line_info_rec_size;
+ p.line_info_cnt = load_attr->line_info_cnt;
+ p.line_info = load_attr->line_info;
+ p.name = load_attr->name;
+ p.prog_flags = load_attr->prog_flags;
+
+ return libbpf__bpf_prog_load(&p);
+}
+
int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
size_t insns_cnt, const char *license,
__u32 kern_version, char *log_buf,
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 375698999375..0280df77cf5f 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -6808,7 +6808,7 @@ static int
load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
char *license, __u32 kern_version, int *pfd)
{
- struct bpf_load_program_attr load_attr;
+ struct bpf_prog_load_params load_attr = {};
char *cp, errmsg[STRERR_BUFSIZE];
size_t log_buf_size = 0;
char *log_buf = NULL;
@@ -6817,7 +6817,6 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
if (!insns || !insns_cnt)
return -EINVAL;
- memset(&load_attr, 0, sizeof(struct bpf_load_program_attr));
load_attr.prog_type = prog->type;
/* old kernels might not support specifying expected_attach_type */
if (!kernel_supports(FEAT_EXP_ATTACH_TYPE) && prog->sec_def &&
@@ -6828,19 +6827,14 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
if (kernel_supports(FEAT_PROG_NAME))
load_attr.name = prog->name;
load_attr.insns = insns;
- load_attr.insns_cnt = insns_cnt;
+ load_attr.insn_cnt = insns_cnt;
load_attr.license = license;
- if (prog->type == BPF_PROG_TYPE_STRUCT_OPS ||
- prog->type == BPF_PROG_TYPE_LSM) {
- load_attr.attach_btf_id = prog->attach_btf_id;
- } else if (prog->type == BPF_PROG_TYPE_TRACING ||
- prog->type == BPF_PROG_TYPE_EXT) {
- load_attr.attach_prog_fd = prog->attach_prog_fd;
- load_attr.attach_btf_id = prog->attach_btf_id;
- } else {
- load_attr.kern_version = kern_version;
- load_attr.prog_ifindex = prog->prog_ifindex;
- }
+ load_attr.attach_btf_id = prog->attach_btf_id;
+ load_attr.attach_prog_fd = prog->attach_prog_fd;
+ load_attr.attach_btf_id = prog->attach_btf_id;
+ load_attr.kern_version = kern_version;
+ load_attr.prog_ifindex = prog->prog_ifindex;
+
/* specify func_info/line_info only if kernel supports them */
btf_fd = bpf_object__btf_fd(prog->obj);
if (btf_fd >= 0 && kernel_supports(FEAT_BTF_FUNC)) {
@@ -6864,7 +6858,9 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
*log_buf = 0;
}
- ret = bpf_load_program_xattr(&load_attr, log_buf, log_buf_size);
+ load_attr.log_buf = log_buf;
+ load_attr.log_buf_sz = log_buf_size;
+ ret = libbpf__bpf_prog_load(&load_attr);
if (ret >= 0) {
if (log_buf && load_attr.log_level)
@@ -6905,9 +6901,9 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
pr_warn("-- BEGIN DUMP LOG ---\n");
pr_warn("\n%s\n", log_buf);
pr_warn("-- END LOG --\n");
- } else if (load_attr.insns_cnt >= BPF_MAXINSNS) {
+ } else if (load_attr.insn_cnt >= BPF_MAXINSNS) {
pr_warn("Program too large (%zu insns), at most %d insns\n",
- load_attr.insns_cnt, BPF_MAXINSNS);
+ load_attr.insn_cnt, BPF_MAXINSNS);
ret = -LIBBPF_ERRNO__PROG2BIG;
} else if (load_attr.prog_type != BPF_PROG_TYPE_KPROBE) {
/* Wrong program type? */
@@ -6915,7 +6911,9 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
load_attr.prog_type = BPF_PROG_TYPE_KPROBE;
load_attr.expected_attach_type = 0;
- fd = bpf_load_program_xattr(&load_attr, NULL, 0);
+ load_attr.log_buf = NULL;
+ load_attr.log_buf_sz = 0;
+ fd = libbpf__bpf_prog_load(&load_attr);
if (fd >= 0) {
close(fd);
ret = -LIBBPF_ERRNO__PROGTYPE;
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index e569ae63808e..681073a67ae3 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -151,6 +151,35 @@ int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz);
int libbpf__load_raw_btf(const char *raw_types, size_t types_len,
const char *str_sec, size_t str_len);
+struct bpf_prog_load_params {
+ enum bpf_prog_type prog_type;
+ enum bpf_attach_type expected_attach_type;
+ const char *name;
+ const struct bpf_insn *insns;
+ size_t insn_cnt;
+ const char *license;
+ __u32 kern_version;
+ __u32 attach_prog_fd;
+ __u32 attach_btf_id;
+ __u32 prog_ifindex;
+ __u32 prog_btf_fd;
+ __u32 prog_flags;
+
+ __u32 func_info_rec_size;
+ const void *func_info;
+ __u32 func_info_cnt;
+
+ __u32 line_info_rec_size;
+ const void *line_info;
+ __u32 line_info_cnt;
+
+ __u32 log_level;
+ char *log_buf;
+ size_t log_buf_sz;
+};
+
+int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr);
+
int bpf_object__section_size(const struct bpf_object *obj, const char *name,
__u32 *size);
int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,
--
2.24.1
