return (__u64) (unsigned long) ptr;
}
-struct bpf_capabilities {
+enum kern_feature_id {
/* v4.14: kernel support for program & map names. */
- __u32 name:1;
+ FEAT_PROG_NAME,
/* v5.2: kernel support for global data sections. */
- __u32 global_data:1;
+ FEAT_GLOBAL_DATA,
/* BTF_KIND_FUNC and BTF_KIND_FUNC_PROTO support */
- __u32 btf_func:1;
+ FEAT_BTF_FUNC,
/* BTF_KIND_VAR and BTF_KIND_DATASEC support */
- __u32 btf_datasec:1;
- /* BPF_F_MMAPABLE is supported for arrays */
- __u32 array_mmap:1;
+ FEAT_BTF_DATASEC,
/* BTF_FUNC_GLOBAL is supported */
- __u32 btf_func_global:1;
+ FEAT_BTF_GLOBAL_FUNC,
+ /* BPF_F_MMAPABLE is supported for arrays */
+ FEAT_ARRAY_MMAP,
/* kernel support for expected_attach_type in BPF_PROG_LOAD */
- __u32 exp_attach_type:1;
+ FEAT_EXP_ATTACH_TYPE,
+ __FEAT_CNT,
};
+static bool kernel_supports(enum kern_feature_id feat_id);
+
enum reloc_type {
RELO_LD64,
RELO_CALL,
__u32 func_info_rec_size;
__u32 func_info_cnt;
- struct bpf_capabilities *caps;
-
void *line_info;
__u32 line_info_rec_size;
__u32 line_info_cnt;
void *priv;
bpf_object_clear_priv_t clear_priv;
- struct bpf_capabilities caps;
-
char path[];
};
#define obj_elf_valid(o) ((o)->efile.elf)
if (err)
return err;
- prog.caps = &obj->caps;
progs = obj->programs;
nr_progs = obj->nr_programs;
static bool btf_needs_sanitization(struct bpf_object *obj)
{
- bool has_func_global = obj->caps.btf_func_global;
- bool has_datasec = obj->caps.btf_datasec;
- bool has_func = obj->caps.btf_func;
+ bool has_func_global = kernel_supports(FEAT_BTF_GLOBAL_FUNC);
+ bool has_datasec = kernel_supports(FEAT_BTF_DATASEC);
+ bool has_func = kernel_supports(FEAT_BTF_FUNC);
return !has_func || !has_datasec || !has_func_global;
}
static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
{
- bool has_func_global = obj->caps.btf_func_global;
- bool has_datasec = obj->caps.btf_datasec;
- bool has_func = obj->caps.btf_func;
+ bool has_func_global = kernel_supports(FEAT_BTF_GLOBAL_FUNC);
+ bool has_datasec = kernel_supports(FEAT_BTF_DATASEC);
+ bool has_func = kernel_supports(FEAT_BTF_FUNC);
struct btf_type *t;
int i, j, vlen;
return 0;
}
-static int
-bpf_object__probe_name(struct bpf_object *obj)
+static int probe_kern_prog_name(void)
{
struct bpf_load_program_attr attr;
struct bpf_insn insns[] = {
attr.name = "test";
ret = bpf_load_program_xattr(&attr, NULL, 0);
if (ret >= 0) {
- obj->caps.name = 1;
close(ret);
+ return 1;
}
return 0;
}
-static int
-bpf_object__probe_global_data(struct bpf_object *obj)
+static int probe_kern_global_data(void)
{
struct bpf_load_program_attr prg_attr;
struct bpf_create_map_attr map_attr;
prg_attr.license = "GPL";
ret = bpf_load_program_xattr(&prg_attr, NULL, 0);
+ close(map);
if (ret >= 0) {
- obj->caps.global_data = 1;
close(ret);
+ return 1;
}
- close(map);
return 0;
}
-static int bpf_object__probe_btf_func(struct bpf_object *obj)
+static int probe_kern_btf_func(void)
{
static const char strs[] = "\0int\0x\0a";
/* void x(int a) {} */
btf_fd = libbpf__load_raw_btf((char *)types, sizeof(types),
strs, sizeof(strs));
if (btf_fd >= 0) {
- obj->caps.btf_func = 1;
close(btf_fd);
return 1;
}
return 0;
}
-static int bpf_object__probe_btf_func_global(struct bpf_object *obj)
+static int probe_kern_btf_func_global(void)
{
static const char strs[] = "\0int\0x\0a";
/* static void x(int a) {} */
btf_fd = libbpf__load_raw_btf((char *)types, sizeof(types),
strs, sizeof(strs));
if (btf_fd >= 0) {
- obj->caps.btf_func_global = 1;
close(btf_fd);
return 1;
}
return 0;
}
-static int bpf_object__probe_btf_datasec(struct bpf_object *obj)
+static int probe_kern_btf_datasec(void)
{
static const char strs[] = "\0x\0.data";
/* static int a; */
btf_fd = libbpf__load_raw_btf((char *)types, sizeof(types),
strs, sizeof(strs));
if (btf_fd >= 0) {
- obj->caps.btf_datasec = 1;
close(btf_fd);
return 1;
}
return 0;
}
-static int bpf_object__probe_array_mmap(struct bpf_object *obj)
+static int probe_kern_array_mmap(void)
{
struct bpf_create_map_attr attr = {
.map_type = BPF_MAP_TYPE_ARRAY,
fd = bpf_create_map_xattr(&attr);
if (fd >= 0) {
- obj->caps.array_mmap = 1;
close(fd);
return 1;
}
-
return 0;
}
-static int
-bpf_object__probe_exp_attach_type(struct bpf_object *obj)
+static int probe_kern_exp_attach_type(void)
{
struct bpf_load_program_attr attr;
struct bpf_insn insns[] = {
fd = bpf_load_program_xattr(&attr, NULL, 0);
if (fd >= 0) {
- obj->caps.exp_attach_type = 1;
close(fd);
return 1;
}
return 0;
}
-static int
-bpf_object__probe_caps(struct bpf_object *obj)
-{
- int (*probe_fn[])(struct bpf_object *obj) = {
- bpf_object__probe_name,
- bpf_object__probe_global_data,
- bpf_object__probe_btf_func,
- bpf_object__probe_btf_func_global,
- bpf_object__probe_btf_datasec,
- bpf_object__probe_array_mmap,
- bpf_object__probe_exp_attach_type,
- };
- int i, ret;
+enum kern_feature_result {
+ FEAT_UNKNOWN = 0,
+ FEAT_SUPPORTED = 1,
+ FEAT_MISSING = 2,
+};
- for (i = 0; i < ARRAY_SIZE(probe_fn); i++) {
- ret = probe_fn[i](obj);
- if (ret < 0)
- pr_debug("Probe #%d failed with %d.\n", i, ret);
+typedef int (*feature_probe_fn)(void);
+
+static struct kern_feature_desc {
+ const char *desc;
+ feature_probe_fn probe;
+ enum kern_feature_result res;
+} feature_probes[__FEAT_CNT] = {
+ [FEAT_PROG_NAME] = {
+ "BPF program name", probe_kern_prog_name,
+ },
+ [FEAT_GLOBAL_DATA] = {
+ "global variables", probe_kern_global_data,
+ },
+ [FEAT_BTF_FUNC] = {
+ "BTF functions", probe_kern_btf_func,
+ },
+ [FEAT_BTF_GLOBAL_FUNC] = {
+ "BTF global function", probe_kern_btf_func_global,
+ },
+ [FEAT_BTF_DATASEC] = {
+ "BTF data section and variable", probe_kern_btf_datasec,
+ },
+ [FEAT_ARRAY_MMAP] = {
+ "ARRAY map mmap()", probe_kern_array_mmap,
+ },
+ [FEAT_EXP_ATTACH_TYPE] = {
+ "BPF_PROG_LOAD expected_attach_type attribute",
+ probe_kern_exp_attach_type,
+ },
+};
+
+static bool kernel_supports(enum kern_feature_id feat_id)
+{
+ struct kern_feature_desc *feat = &feature_probes[feat_id];
+ int ret;
+
+ if (READ_ONCE(feat->res) == FEAT_UNKNOWN) {
+ ret = feat->probe();
+ if (ret > 0) {
+ WRITE_ONCE(feat->res, FEAT_SUPPORTED);
+ } else if (ret == 0) {
+ WRITE_ONCE(feat->res, FEAT_MISSING);
+ } else {
+ pr_warn("Detection of kernel %s support failed: %d\n", feat->desc, ret);
+ WRITE_ONCE(feat->res, FEAT_MISSING);
+ }
}
- return 0;
+ return READ_ONCE(feat->res) == FEAT_SUPPORTED;
}
static bool map_is_reuse_compat(const struct bpf_map *map, int map_fd)
memset(&create_attr, 0, sizeof(create_attr));
- if (obj->caps.name)
+ if (kernel_supports(FEAT_PROG_NAME))
create_attr.name = map->name;
create_attr.map_ifindex = map->map_ifindex;
create_attr.map_type = def->type;
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 (!prog->caps->exp_attach_type && prog->sec_def &&
+ if (!kernel_supports(FEAT_EXP_ATTACH_TYPE) && prog->sec_def &&
prog->sec_def->is_exp_attach_type_optional)
load_attr.expected_attach_type = 0;
else
load_attr.expected_attach_type = prog->expected_attach_type;
- if (prog->caps->name)
+ if (kernel_supports(FEAT_PROG_NAME))
load_attr.name = prog->name;
load_attr.insns = insns;
load_attr.insns_cnt = insns_cnt;
}
/* specify func_info/line_info only if kernel supports them */
btf_fd = bpf_object__btf_fd(prog->obj);
- if (btf_fd >= 0 && prog->obj->caps.btf_func) {
+ if (btf_fd >= 0 && kernel_supports(FEAT_BTF_FUNC)) {
load_attr.prog_btf_fd = btf_fd;
load_attr.func_info = prog->func_info;
load_attr.func_info_rec_size = prog->func_info_rec_size;
bpf_object__for_each_map(m, obj) {
if (!bpf_map__is_internal(m))
continue;
- if (!obj->caps.global_data) {
+ if (!kernel_supports(FEAT_GLOBAL_DATA)) {
pr_warn("kernel doesn't support global data\n");
return -ENOTSUP;
}
- if (!obj->caps.array_mmap)
+ if (!kernel_supports(FEAT_ARRAY_MMAP))
m->def.map_flags ^= BPF_F_MMAPABLE;
}
}
err = bpf_object__probe_loading(obj);
- err = err ? : bpf_object__probe_caps(obj);
err = err ? : bpf_object__resolve_externs(obj, obj->kconfig);
err = err ? : bpf_object__sanitize_and_load_btf(obj);
err = err ? : bpf_object__sanitize_maps(obj);
projects / linux-2.6-block.git / commitdiff