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-rw-r--r--tools/lib/bpf/libbpf.c87
-rw-r--r--tools/lib/bpf/libbpf.h46
-rw-r--r--tools/lib/bpf/libbpf.map3
-rw-r--r--tools/lib/bpf/libbpf_internal.h32
4 files changed, 146 insertions, 22 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 024334b29b54..d471d33400ae 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -505,7 +505,8 @@ static __u32 get_kernel_version(void)
static struct bpf_object *bpf_object__new(const char *path,
const void *obj_buf,
- size_t obj_buf_sz)
+ size_t obj_buf_sz,
+ const char *obj_name)
{
struct bpf_object *obj;
char *end;
@@ -517,11 +518,17 @@ static struct bpf_object *bpf_object__new(const char *path,
}
strcpy(obj->path, path);
- /* Using basename() GNU version which doesn't modify arg. */
- strncpy(obj->name, basename((void *)path), sizeof(obj->name) - 1);
- end = strchr(obj->name, '.');
- if (end)
- *end = 0;
+ if (obj_name) {
+ strncpy(obj->name, obj_name, sizeof(obj->name) - 1);
+ obj->name[sizeof(obj->name) - 1] = 0;
+ } else {
+ /* Using basename() GNU version which doesn't modify arg. */
+ strncpy(obj->name, basename((void *)path),
+ sizeof(obj->name) - 1);
+ end = strchr(obj->name, '.');
+ if (end)
+ *end = 0;
+ }
obj->efile.fd = -1;
/*
@@ -3547,7 +3554,7 @@ bpf_object__load_progs(struct bpf_object *obj, int log_level)
static struct bpf_object *
__bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
- int flags)
+ const char *obj_name, int flags)
{
struct bpf_object *obj;
int err;
@@ -3557,7 +3564,7 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
return ERR_PTR(-LIBBPF_ERRNO__LIBELF);
}
- obj = bpf_object__new(path, obj_buf, obj_buf_sz);
+ obj = bpf_object__new(path, obj_buf, obj_buf_sz, obj_name);
if (IS_ERR(obj))
return obj;
@@ -3583,7 +3590,7 @@ __bpf_object__open_xattr(struct bpf_object_open_attr *attr, int flags)
pr_debug("loading %s\n", attr->file);
- return __bpf_object__open(attr->file, NULL, 0, flags);
+ return __bpf_object__open(attr->file, NULL, 0, NULL, flags);
}
struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr)
@@ -3601,25 +3608,67 @@ struct bpf_object *bpf_object__open(const char *path)
return bpf_object__open_xattr(&attr);
}
-struct bpf_object *bpf_object__open_buffer(void *obj_buf,
- size_t obj_buf_sz,
- const char *name)
+struct bpf_object *
+bpf_object__open_file(const char *path, struct bpf_object_open_opts *opts)
+{
+ const char *obj_name;
+ bool relaxed_maps;
+
+ if (!OPTS_VALID(opts, bpf_object_open_opts))
+ return ERR_PTR(-EINVAL);
+ if (!path)
+ return ERR_PTR(-EINVAL);
+
+ pr_debug("loading %s\n", path);
+
+ obj_name = OPTS_GET(opts, object_name, path);
+ relaxed_maps = OPTS_GET(opts, relaxed_maps, false);
+ return __bpf_object__open(path, NULL, 0, obj_name,
+ relaxed_maps ? MAPS_RELAX_COMPAT : 0);
+}
+
+struct bpf_object *
+bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
+ struct bpf_object_open_opts *opts)
{
char tmp_name[64];
+ const char *obj_name;
+ bool relaxed_maps;
- /* param validation */
- if (!obj_buf || obj_buf_sz <= 0)
- return NULL;
+ if (!OPTS_VALID(opts, bpf_object_open_opts))
+ return ERR_PTR(-EINVAL);
+ if (!obj_buf || obj_buf_sz == 0)
+ return ERR_PTR(-EINVAL);
- if (!name) {
+ obj_name = OPTS_GET(opts, object_name, NULL);
+ if (!obj_name) {
snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx",
(unsigned long)obj_buf,
(unsigned long)obj_buf_sz);
- name = tmp_name;
+ obj_name = tmp_name;
}
- pr_debug("loading object '%s' from buffer\n", name);
+ pr_debug("loading object '%s' from buffer\n", obj_name);
+
+ relaxed_maps = OPTS_GET(opts, relaxed_maps, false);
+ return __bpf_object__open(obj_name, obj_buf, obj_buf_sz, obj_name,
+ relaxed_maps ? MAPS_RELAX_COMPAT : 0);
+}
+
+struct bpf_object *
+bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz,
+ const char *name)
+{
+ LIBBPF_OPTS(bpf_object_open_opts, opts,
+ .object_name = name,
+ /* wrong default, but backwards-compatible */
+ .relaxed_maps = true,
+ );
+
+ /* returning NULL is wrong, but backwards-compatible */
+ if (!obj_buf || obj_buf_sz == 0)
+ return NULL;
- return __bpf_object__open(name, obj_buf, obj_buf_sz, true);
+ return bpf_object__open_mem(obj_buf, obj_buf_sz, &opts);
}
int bpf_object__unload(struct bpf_object *obj)
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 2905dffd70b2..667e6853e51f 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -67,12 +67,52 @@ struct bpf_object_open_attr {
enum bpf_prog_type prog_type;
};
+/* Helper macro to declare and initialize libbpf options struct
+ *
+ * This dance with uninitialized declaration, followed by memset to zero,
+ * followed by assignment using compound literal syntax is done to preserve
+ * ability to use a nice struct field initialization syntax and **hopefully**
+ * have all the padding bytes initialized to zero. It's not guaranteed though,
+ * when copying literal, that compiler won't copy garbage in literal's padding
+ * bytes, but that's the best way I've found and it seems to work in practice.
+ */
+#define LIBBPF_OPTS(TYPE, NAME, ...) \
+ struct TYPE NAME; \
+ memset(&NAME, 0, sizeof(struct TYPE)); \
+ NAME = (struct TYPE) { \
+ .sz = sizeof(struct TYPE), \
+ __VA_ARGS__ \
+ }
+
+struct bpf_object_open_opts {
+ /* size of this struct, for forward/backward compatiblity */
+ size_t sz;
+ /* object name override, if provided:
+ * - for object open from file, this will override setting object
+ * name from file path's base name;
+ * - for object open from memory buffer, this will specify an object
+ * name and will override default "<addr>-<buf-size>" name;
+ */
+ const char *object_name;
+ /* parse map definitions non-strictly, allowing extra attributes/data */
+ bool relaxed_maps;
+};
+#define bpf_object_open_opts__last_field relaxed_maps
+
LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
LIBBPF_API struct bpf_object *
+bpf_object__open_file(const char *path, struct bpf_object_open_opts *opts);
+LIBBPF_API struct bpf_object *
+bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
+ struct bpf_object_open_opts *opts);
+
+/* deprecated bpf_object__open variants */
+LIBBPF_API struct bpf_object *
+bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz,
+ const char *name);
+LIBBPF_API struct bpf_object *
bpf_object__open_xattr(struct bpf_object_open_attr *attr);
-LIBBPF_API struct bpf_object *bpf_object__open_buffer(void *obj_buf,
- size_t obj_buf_sz,
- const char *name);
+
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,
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 8d10ca03d78d..4d241fd92dd4 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -192,4 +192,7 @@ LIBBPF_0.0.5 {
} LIBBPF_0.0.4;
LIBBPF_0.0.6 {
+ global:
+ bpf_object__open_file;
+ bpf_object__open_mem;
} LIBBPF_0.0.5;
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index 2e83a34f8c79..f51444fc7eb7 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -47,6 +47,38 @@ do { \
#define pr_info(fmt, ...) __pr(LIBBPF_INFO, fmt, ##__VA_ARGS__)
#define pr_debug(fmt, ...) __pr(LIBBPF_DEBUG, fmt, ##__VA_ARGS__)
+static inline bool libbpf_validate_opts(const char *opts,
+ size_t opts_sz, size_t user_sz,
+ const char *type_name)
+{
+ if (user_sz < sizeof(size_t)) {
+ pr_warning("%s size (%zu) is too small\n", type_name, user_sz);
+ return false;
+ }
+ if (user_sz > opts_sz) {
+ size_t i;
+
+ for (i = opts_sz; i < user_sz; i++) {
+ if (opts[i]) {
+ pr_warning("%s has non-zero extra bytes",
+ type_name);
+ return false;
+ }
+ }
+ }
+ return true;
+}
+
+#define OPTS_VALID(opts, type) \
+ (!(opts) || libbpf_validate_opts((const char *)opts, \
+ offsetofend(struct type, \
+ type##__last_field), \
+ (opts)->sz, #type))
+#define OPTS_HAS(opts, field) \
+ ((opts) && opts->sz >= offsetofend(typeof(*(opts)), field))
+#define OPTS_GET(opts, field, fallback_value) \
+ (OPTS_HAS(opts, field) ? (opts)->field : fallback_value)
+
int libbpf__load_raw_btf(const char *raw_types, size_t types_len,
const char *str_sec, size_t str_len);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.