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-rw-r--r--tools/lib/bpf/bpf_core_read.h24
-rw-r--r--tools/lib/bpf/btf.c16
-rw-r--r--tools/lib/bpf/btf.h4
-rw-r--r--tools/lib/bpf/libbpf.c169
-rw-r--r--tools/lib/bpf/libbpf.h4
-rw-r--r--tools/lib/bpf/libbpf_internal.h25
-rw-r--r--tools/testing/selftests/bpf/prog_tests/core_reloc.c76
-rw-r--r--tools/testing/selftests/bpf/progs/btf__core_reloc_existence.c3
-rw-r--r--tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_arr_kind.c3
-rw-r--r--tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_arr_value_type.c3
-rw-r--r--tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_kind.c3
-rw-r--r--tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_sz.c3
-rw-r--r--tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_type.c3
-rw-r--r--tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_struct_type.c3
-rw-r--r--tools/testing/selftests/bpf/progs/btf__core_reloc_existence___minimal.c3
-rw-r--r--tools/testing/selftests/bpf/progs/core_reloc_types.h56
-rw-r--r--tools/testing/selftests/bpf/progs/test_core_reloc_existence.c79
17 files changed, 392 insertions, 85 deletions
diff --git a/tools/lib/bpf/bpf_core_read.h b/tools/lib/bpf/bpf_core_read.h
index 4daf04c25493..a273df3784f4 100644
--- a/tools/lib/bpf/bpf_core_read.h
+++ b/tools/lib/bpf/bpf_core_read.h
@@ -3,6 +3,28 @@
#define __BPF_CORE_READ_H__
/*
+ * enum bpf_field_info_kind is passed as a second argument into
+ * __builtin_preserve_field_info() built-in to get a specific aspect of
+ * a field, captured as a first argument. __builtin_preserve_field_info(field,
+ * info_kind) returns __u32 integer and produces BTF field relocation, which
+ * is understood and processed by libbpf during BPF object loading. See
+ * selftests/bpf for examples.
+ */
+enum bpf_field_info_kind {
+ BPF_FIELD_BYTE_OFFSET = 0, /* field byte offset */
+ BPF_FIELD_EXISTS = 2, /* field existence in target kernel */
+};
+
+/*
+ * Convenience macro to check that field actually exists in target kernel's.
+ * Returns:
+ * 1, if matching field is present in target kernel;
+ * 0, if no matching field found.
+ */
+#define bpf_core_field_exists(field) \
+ __builtin_preserve_field_info(field, BPF_FIELD_EXISTS)
+
+/*
* bpf_core_read() abstracts away bpf_probe_read() call and captures offset
* relocation for source address using __builtin_preserve_access_index()
* built-in, provided by Clang.
@@ -12,7 +34,7 @@
* a relocation, which records BTF type ID describing root struct/union and an
* accessor string which describes exact embedded field that was used to take
* an address. See detailed description of this relocation format and
- * semantics in comments to struct bpf_offset_reloc in libbpf_internal.h.
+ * semantics in comments to struct bpf_field_reloc in libbpf_internal.h.
*
* This relocation allows libbpf to adjust BPF instruction to use correct
* actual field offset, based on target kernel BTF type that matches original
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 1aa189a9112a..3eae8d1addfa 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -888,14 +888,14 @@ static int btf_ext_setup_line_info(struct btf_ext *btf_ext)
return btf_ext_setup_info(btf_ext, &param);
}
-static int btf_ext_setup_offset_reloc(struct btf_ext *btf_ext)
+static int btf_ext_setup_field_reloc(struct btf_ext *btf_ext)
{
struct btf_ext_sec_setup_param param = {
- .off = btf_ext->hdr->offset_reloc_off,
- .len = btf_ext->hdr->offset_reloc_len,
- .min_rec_size = sizeof(struct bpf_offset_reloc),
- .ext_info = &btf_ext->offset_reloc_info,
- .desc = "offset_reloc",
+ .off = btf_ext->hdr->field_reloc_off,
+ .len = btf_ext->hdr->field_reloc_len,
+ .min_rec_size = sizeof(struct bpf_field_reloc),
+ .ext_info = &btf_ext->field_reloc_info,
+ .desc = "field_reloc",
};
return btf_ext_setup_info(btf_ext, &param);
@@ -975,9 +975,9 @@ struct btf_ext *btf_ext__new(__u8 *data, __u32 size)
goto done;
if (btf_ext->hdr->hdr_len <
- offsetofend(struct btf_ext_header, offset_reloc_len))
+ offsetofend(struct btf_ext_header, field_reloc_len))
goto done;
- err = btf_ext_setup_offset_reloc(btf_ext);
+ err = btf_ext_setup_field_reloc(btf_ext);
if (err)
goto done;
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 9cb44b4fbf60..b18994116a44 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -60,8 +60,8 @@ struct btf_ext_header {
__u32 line_info_len;
/* optional part of .BTF.ext header */
- __u32 offset_reloc_off;
- __u32 offset_reloc_len;
+ __u32 field_reloc_off;
+ __u32 field_reloc_len;
};
LIBBPF_API void btf__free(struct btf *btf);
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index a02cdedc4e3f..8d565590ce05 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -249,6 +249,7 @@ struct bpf_object {
bool loaded;
bool has_pseudo_calls;
+ bool relaxed_core_relocs;
/*
* Information when doing elf related work. Only valid if fd
@@ -1322,9 +1323,9 @@ static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict)
return 0;
}
-static int bpf_object__init_maps(struct bpf_object *obj, int flags)
+static int bpf_object__init_maps(struct bpf_object *obj, bool relaxed_maps)
{
- bool strict = !(flags & MAPS_RELAX_COMPAT);
+ bool strict = !relaxed_maps;
int err;
err = bpf_object__init_user_maps(obj, strict);
@@ -1521,7 +1522,7 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj)
return 0;
}
-static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
+static int bpf_object__elf_collect(struct bpf_object *obj, bool relaxed_maps)
{
Elf *elf = obj->efile.elf;
GElf_Ehdr *ep = &obj->efile.ehdr;
@@ -1652,7 +1653,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
}
err = bpf_object__init_btf(obj, btf_data, btf_ext_data);
if (!err)
- err = bpf_object__init_maps(obj, flags);
+ err = bpf_object__init_maps(obj, relaxed_maps);
if (!err)
err = bpf_object__sanitize_and_load_btf(obj);
if (!err)
@@ -2326,7 +2327,7 @@ static bool str_is_empty(const char *s)
}
/*
- * Turn bpf_offset_reloc into a low- and high-level spec representation,
+ * Turn bpf_field_reloc into a low- and high-level spec representation,
* validating correctness along the way, as well as calculating resulting
* field offset (in bytes), specified by accessor string. Low-level spec
* captures every single level of nestedness, including traversing anonymous
@@ -2771,26 +2772,54 @@ static int bpf_core_spec_match(struct bpf_core_spec *local_spec,
/*
* Patch relocatable BPF instruction.
- * Expected insn->imm value is provided for validation, as well as the new
- * relocated value.
+ *
+ * Patched value is determined by relocation kind and target specification.
+ * For field existence relocation target spec will be NULL if field is not
+ * found.
+ * Expected insn->imm value is determined using relocation kind and local
+ * spec, and is checked before patching instruction. If actual insn->imm value
+ * is wrong, bail out with error.
*
* Currently three kinds of BPF instructions are supported:
* 1. rX = <imm> (assignment with immediate operand);
* 2. rX += <imm> (arithmetic operations with immediate operand);
- * 3. *(rX) = <imm> (indirect memory assignment with immediate operand).
- *
- * If actual insn->imm value is wrong, bail out.
*/
-static int bpf_core_reloc_insn(struct bpf_program *prog, int insn_off,
- __u32 orig_off, __u32 new_off)
+static int bpf_core_reloc_insn(struct bpf_program *prog,
+ const struct bpf_field_reloc *relo,
+ const struct bpf_core_spec *local_spec,
+ const struct bpf_core_spec *targ_spec)
{
+ __u32 orig_val, new_val;
struct bpf_insn *insn;
int insn_idx;
__u8 class;
- if (insn_off % sizeof(struct bpf_insn))
+ if (relo->insn_off % sizeof(struct bpf_insn))
+ return -EINVAL;
+ insn_idx = relo->insn_off / sizeof(struct bpf_insn);
+
+ switch (relo->kind) {
+ case BPF_FIELD_BYTE_OFFSET:
+ orig_val = local_spec->offset;
+ if (targ_spec) {
+ new_val = targ_spec->offset;
+ } else {
+ pr_warning("prog '%s': patching insn #%d w/ failed reloc, imm %d -> %d\n",
+ bpf_program__title(prog, false), insn_idx,
+ orig_val, -1);
+ new_val = (__u32)-1;
+ }
+ break;
+ case BPF_FIELD_EXISTS:
+ orig_val = 1; /* can't generate EXISTS relo w/o local field */
+ new_val = targ_spec ? 1 : 0;
+ break;
+ default:
+ pr_warning("prog '%s': unknown relo %d at insn #%d'\n",
+ bpf_program__title(prog, false),
+ relo->kind, insn_idx);
return -EINVAL;
- insn_idx = insn_off / sizeof(struct bpf_insn);
+ }
insn = &prog->insns[insn_idx];
class = BPF_CLASS(insn->code);
@@ -2798,12 +2827,12 @@ static int bpf_core_reloc_insn(struct bpf_program *prog, int insn_off,
if (class == BPF_ALU || class == BPF_ALU64) {
if (BPF_SRC(insn->code) != BPF_K)
return -EINVAL;
- if (insn->imm != orig_off)
+ if (insn->imm != orig_val)
return -EINVAL;
- insn->imm = new_off;
+ insn->imm = new_val;
pr_debug("prog '%s': patched insn #%d (ALU/ALU64) imm %d -> %d\n",
bpf_program__title(prog, false),
- insn_idx, orig_off, new_off);
+ insn_idx, orig_val, new_val);
} else {
pr_warning("prog '%s': trying to relocate unrecognized insn #%d, code:%x, src:%x, dst:%x, off:%x, imm:%x\n",
bpf_program__title(prog, false),
@@ -2811,6 +2840,7 @@ static int bpf_core_reloc_insn(struct bpf_program *prog, int insn_off,
insn->off, insn->imm);
return -EINVAL;
}
+
return 0;
}
@@ -2977,7 +3007,7 @@ static void *u32_as_hash_key(__u32 x)
* types should be compatible (see bpf_core_fields_are_compat for details).
* 3. It is supported and expected that there might be multiple flavors
* matching the spec. As long as all the specs resolve to the same set of
- * offsets across all candidates, there is not error. If there is any
+ * offsets across all candidates, there is no error. If there is any
* ambiguity, CO-RE relocation will fail. This is necessary to accomodate
* imprefection of BTF deduplication, which can cause slight duplication of
* the same BTF type, if some directly or indirectly referenced (by
@@ -2992,12 +3022,12 @@ static void *u32_as_hash_key(__u32 x)
* CPU-wise compared to prebuilding a map from all local type names to
* a list of candidate type names. It's also sped up by caching resolved
* list of matching candidates per each local "root" type ID, that has at
- * least one bpf_offset_reloc associated with it. This list is shared
+ * least one bpf_field_reloc associated with it. This list is shared
* between multiple relocations for the same type ID and is updated as some
* of the candidates are pruned due to structural incompatibility.
*/
-static int bpf_core_reloc_offset(struct bpf_program *prog,
- const struct bpf_offset_reloc *relo,
+static int bpf_core_reloc_field(struct bpf_program *prog,
+ const struct bpf_field_reloc *relo,
int relo_idx,
const struct btf *local_btf,
const struct btf *targ_btf,
@@ -3087,15 +3117,26 @@ static int bpf_core_reloc_offset(struct bpf_program *prog,
cand_ids->data[j++] = cand_spec.spec[0].type_id;
}
- cand_ids->len = j;
- if (cand_ids->len == 0) {
+ /*
+ * For BPF_FIELD_EXISTS relo or when relaxed CO-RE reloc mode is
+ * requested, it's expected that we might not find any candidates.
+ * In this case, if field wasn't found in any candidate, the list of
+ * candidates shouldn't change at all, we'll just handle relocating
+ * appropriately, depending on relo's kind.
+ */
+ if (j > 0)
+ cand_ids->len = j;
+
+ if (j == 0 && !prog->obj->relaxed_core_relocs &&
+ relo->kind != BPF_FIELD_EXISTS) {
pr_warning("prog '%s': relo #%d: no matching targets found for [%d] %s + %s\n",
prog_name, relo_idx, local_id, local_name, spec_str);
return -ESRCH;
}
- err = bpf_core_reloc_insn(prog, relo->insn_off,
- local_spec.offset, targ_spec.offset);
+ /* bpf_core_reloc_insn should know how to handle missing targ_spec */
+ err = bpf_core_reloc_insn(prog, relo, &local_spec,
+ j ? &targ_spec : NULL);
if (err) {
pr_warning("prog '%s': relo #%d: failed to patch insn at offset %d: %d\n",
prog_name, relo_idx, relo->insn_off, err);
@@ -3106,10 +3147,10 @@ static int bpf_core_reloc_offset(struct bpf_program *prog,
}
static int
-bpf_core_reloc_offsets(struct bpf_object *obj, const char *targ_btf_path)
+bpf_core_reloc_fields(struct bpf_object *obj, const char *targ_btf_path)
{
const struct btf_ext_info_sec *sec;
- const struct bpf_offset_reloc *rec;
+ const struct bpf_field_reloc *rec;
const struct btf_ext_info *seg;
struct hashmap_entry *entry;
struct hashmap *cand_cache = NULL;
@@ -3134,7 +3175,7 @@ bpf_core_reloc_offsets(struct bpf_object *obj, const char *targ_btf_path)
goto out;
}
- seg = &obj->btf_ext->offset_reloc_info;
+ seg = &obj->btf_ext->field_reloc_info;
for_each_btf_ext_sec(seg, sec) {
sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off);
if (str_is_empty(sec_name)) {
@@ -3153,8 +3194,8 @@ bpf_core_reloc_offsets(struct bpf_object *obj, const char *targ_btf_path)
sec_name, sec->num_info);
for_each_btf_ext_rec(seg, sec, i, rec) {
- err = bpf_core_reloc_offset(prog, rec, i, obj->btf,
- targ_btf, cand_cache);
+ err = bpf_core_reloc_field(prog, rec, i, obj->btf,
+ targ_btf, cand_cache);
if (err) {
pr_warning("prog '%s': relo #%d: failed to relocate: %d\n",
sec_name, i, err);
@@ -3179,8 +3220,8 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path)
{
int err = 0;
- if (obj->btf_ext->offset_reloc_info.len)
- err = bpf_core_reloc_offsets(obj, targ_btf_path);
+ if (obj->btf_ext->field_reloc_info.len)
+ err = bpf_core_reloc_fields(obj, targ_btf_path);
return err;
}
@@ -3554,24 +3595,46 @@ 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,
- const char *obj_name, int flags)
+ struct bpf_object_open_opts *opts)
{
struct bpf_object *obj;
+ const char *obj_name;
+ char tmp_name[64];
+ bool relaxed_maps;
int err;
if (elf_version(EV_CURRENT) == EV_NONE) {
- pr_warning("failed to init libelf for %s\n", path);
+ pr_warning("failed to init libelf for %s\n",
+ path ? : "(mem buf)");
return ERR_PTR(-LIBBPF_ERRNO__LIBELF);
}
+ if (!OPTS_VALID(opts, bpf_object_open_opts))
+ return ERR_PTR(-EINVAL);
+
+ obj_name = OPTS_GET(opts, object_name, path);
+ if (obj_buf) {
+ if (!obj_name) {
+ snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx",
+ (unsigned long)obj_buf,
+ (unsigned long)obj_buf_sz);
+ obj_name = tmp_name;
+ }
+ path = obj_name;
+ pr_debug("loading object '%s' from buffer\n", obj_name);
+ }
+
obj = bpf_object__new(path, obj_buf, obj_buf_sz, obj_name);
if (IS_ERR(obj))
return obj;
+ obj->relaxed_core_relocs = OPTS_GET(opts, relaxed_core_relocs, false);
+ relaxed_maps = OPTS_GET(opts, relaxed_maps, false);
+
CHECK_ERR(bpf_object__elf_init(obj), err, out);
CHECK_ERR(bpf_object__check_endianness(obj), err, out);
CHECK_ERR(bpf_object__probe_caps(obj), err, out);
- CHECK_ERR(bpf_object__elf_collect(obj, flags), err, out);
+ CHECK_ERR(bpf_object__elf_collect(obj, relaxed_maps), err, out);
CHECK_ERR(bpf_object__collect_reloc(obj), err, out);
bpf_object__elf_finish(obj);
@@ -3584,13 +3647,16 @@ out:
static struct bpf_object *
__bpf_object__open_xattr(struct bpf_object_open_attr *attr, int flags)
{
+ LIBBPF_OPTS(bpf_object_open_opts, opts,
+ .relaxed_maps = flags & MAPS_RELAX_COMPAT,
+ );
+
/* param validation */
if (!attr->file)
return NULL;
pr_debug("loading %s\n", attr->file);
-
- return __bpf_object__open(attr->file, NULL, 0, NULL, flags);
+ return __bpf_object__open(attr->file, NULL, 0, &opts);
}
struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr)
@@ -3611,47 +3677,22 @@ struct bpf_object *bpf_object__open(const char *path)
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);
+ return __bpf_object__open(path, NULL, 0, opts);
}
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;
-
- if (!OPTS_VALID(opts, bpf_object_open_opts))
- return ERR_PTR(-EINVAL);
if (!obj_buf || obj_buf_sz == 0)
return ERR_PTR(-EINVAL);
- 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);
- obj_name = tmp_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);
+ return __bpf_object__open(NULL, obj_buf, obj_buf_sz, opts);
}
struct bpf_object *
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 667e6853e51f..53ce212764e0 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -96,8 +96,10 @@ struct bpf_object_open_opts {
const char *object_name;
/* parse map definitions non-strictly, allowing extra attributes/data */
bool relaxed_maps;
+ /* process CO-RE relocations non-strictly, allowing them to fail */
+ bool relaxed_core_relocs;
};
-#define bpf_object_open_opts__last_field relaxed_maps
+#define bpf_object_open_opts__last_field relaxed_core_relocs
LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
LIBBPF_API struct bpf_object *
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index f51444fc7eb7..5bfe85d4f8aa 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -110,7 +110,7 @@ struct btf_ext {
};
struct btf_ext_info func_info;
struct btf_ext_info line_info;
- struct btf_ext_info offset_reloc_info;
+ struct btf_ext_info field_reloc_info;
__u32 data_size;
};
@@ -135,13 +135,23 @@ struct bpf_line_info_min {
__u32 line_col;
};
-/* The minimum bpf_offset_reloc checked by the loader
+/* bpf_field_info_kind encodes which aspect of captured field has to be
+ * adjusted by relocations. Currently supported values are:
+ * - BPF_FIELD_BYTE_OFFSET: field offset (in bytes);
+ * - BPF_FIELD_EXISTS: field existence (1, if field exists; 0, otherwise);
+ */
+enum bpf_field_info_kind {
+ BPF_FIELD_BYTE_OFFSET = 0, /* field byte offset */
+ BPF_FIELD_EXISTS = 2, /* field existence in target kernel */
+};
+
+/* The minimum bpf_field_reloc checked by the loader
*
- * Offset relocation captures the following data:
+ * Field relocation captures the following data:
* - insn_off - instruction offset (in bytes) within a BPF program that needs
- * its insn->imm field to be relocated with actual offset;
+ * its insn->imm field to be relocated with actual field info;
* - type_id - BTF type ID of the "root" (containing) entity of a relocatable
- * offset;
+ * field;
* - access_str_off - offset into corresponding .BTF string section. String
* itself encodes an accessed field using a sequence of field and array
* indicies, separated by colon (:). It's conceptually very close to LLVM's
@@ -172,15 +182,16 @@ struct bpf_line_info_min {
* bpf_probe_read(&dst, sizeof(dst),
* __builtin_preserve_access_index(&src->a.b.c));
*
- * In this case Clang will emit offset relocation recording necessary data to
+ * In this case Clang will emit field relocation recording necessary data to
* be able to find offset of embedded `a.b.c` field within `src` struct.
*
* [0] https://llvm.org/docs/LangRef.html#getelementptr-instruction
*/
-struct bpf_offset_reloc {
+struct bpf_field_reloc {
__u32 insn_off;
__u32 type_id;
__u32 access_str_off;
+ enum bpf_field_info_kind kind;
};
#endif /* __LIBBPF_LIBBPF_INTERNAL_H */
diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
index 21a0dff66241..7e2f5b4bf7f3 100644
--- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c
+++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
@@ -174,6 +174,21 @@
.fails = true, \
}
+#define EXISTENCE_DATA(struct_name) STRUCT_TO_CHAR_PTR(struct_name) { \
+ .a = 42, \
+}
+
+#define EXISTENCE_CASE_COMMON(name) \
+ .case_name = #name, \
+ .bpf_obj_file = "test_core_reloc_existence.o", \
+ .btf_src_file = "btf__core_reloc_" #name ".o", \
+ .relaxed_core_relocs = true \
+
+#define EXISTENCE_ERR_CASE(name) { \
+ EXISTENCE_CASE_COMMON(name), \
+ .fails = true, \
+}
+
struct core_reloc_test_case {
const char *case_name;
const char *bpf_obj_file;
@@ -183,6 +198,7 @@ struct core_reloc_test_case {
const char *output;
int output_len;
bool fails;
+ bool relaxed_core_relocs;
};
static struct core_reloc_test_case test_cases[] = {
@@ -283,6 +299,59 @@ static struct core_reloc_test_case test_cases[] = {
},
.output_len = sizeof(struct core_reloc_misc_output),
},
+
+ /* validate field existence checks */
+ {
+ EXISTENCE_CASE_COMMON(existence),
+ .input = STRUCT_TO_CHAR_PTR(core_reloc_existence) {
+ .a = 1,
+ .b = 2,
+ .c = 3,
+ .arr = { 4 },
+ .s = { .x = 5 },
+ },
+ .input_len = sizeof(struct core_reloc_existence),
+ .output = STRUCT_TO_CHAR_PTR(core_reloc_existence_output) {
+ .a_exists = 1,
+ .b_exists = 1,
+ .c_exists = 1,
+ .arr_exists = 1,
+ .s_exists = 1,
+ .a_value = 1,
+ .b_value = 2,
+ .c_value = 3,
+ .arr_value = 4,
+ .s_value = 5,
+ },
+ .output_len = sizeof(struct core_reloc_existence_output),
+ },
+ {
+ EXISTENCE_CASE_COMMON(existence___minimal),
+ .input = STRUCT_TO_CHAR_PTR(core_reloc_existence___minimal) {
+ .a = 42,
+ },
+ .input_len = sizeof(struct core_reloc_existence),
+ .output = STRUCT_TO_CHAR_PTR(core_reloc_existence_output) {
+ .a_exists = 1,
+ .b_exists = 0,
+ .c_exists = 0,
+ .arr_exists = 0,
+ .s_exists = 0,
+ .a_value = 42,
+ .b_value = 0xff000002u,
+ .c_value = 0xff000003u,
+ .arr_value = 0xff000004u,
+ .s_value = 0xff000005u,
+ },
+ .output_len = sizeof(struct core_reloc_existence_output),
+ },
+
+ EXISTENCE_ERR_CASE(existence__err_int_sz),
+ EXISTENCE_ERR_CASE(existence__err_int_type),
+ EXISTENCE_ERR_CASE(existence__err_int_kind),
+ EXISTENCE_ERR_CASE(existence__err_arr_kind),
+ EXISTENCE_ERR_CASE(existence__err_arr_value_type),
+ EXISTENCE_ERR_CASE(existence__err_struct_type),
};
struct data {
@@ -305,11 +374,14 @@ void test_core_reloc(void)
for (i = 0; i < ARRAY_SIZE(test_cases); i++) {
test_case = &test_cases[i];
-
if (!test__start_subtest(test_case->case_name))
continue;
- obj = bpf_object__open(test_case->bpf_obj_file);
+ LIBBPF_OPTS(bpf_object_open_opts, opts,
+ .relaxed_core_relocs = test_case->relaxed_core_relocs,
+ );
+
+ obj = bpf_object__open_file(test_case->bpf_obj_file, &opts);
if (CHECK(IS_ERR_OR_NULL(obj), "obj_open",
"failed to open '%s': %ld\n",
test_case->bpf_obj_file, PTR_ERR(obj)))
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence.c
new file mode 100644
index 000000000000..0b62315ad46c
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_existence x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_arr_kind.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_arr_kind.c
new file mode 100644
index 000000000000..dd0ffa518f36
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_arr_kind.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_existence___err_wrong_arr_kind x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_arr_value_type.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_arr_value_type.c
new file mode 100644
index 000000000000..bc83372088ad
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_arr_value_type.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_existence___err_wrong_arr_value_type x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_kind.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_kind.c
new file mode 100644
index 000000000000..917bec41be08
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_kind.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_existence___err_wrong_int_kind x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_sz.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_sz.c
new file mode 100644
index 000000000000..6ec7e6ec1c91
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_sz.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_existence___err_wrong_int_sz x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_type.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_type.c
new file mode 100644
index 000000000000..7bbcacf2b0d1
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_type.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_existence___err_wrong_int_type x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_struct_type.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_struct_type.c
new file mode 100644
index 000000000000..f384dd38ec70
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_struct_type.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_existence___err_wrong_struct_type x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___minimal.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___minimal.c
new file mode 100644
index 000000000000..aec2dec20e90
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___minimal.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_existence___minimal x) {}
diff --git a/tools/testing/selftests/bpf/progs/core_reloc_types.h b/tools/testing/selftests/bpf/progs/core_reloc_types.h
index 9a6bdeb4894c..ad763ec0ba8f 100644
--- a/tools/testing/selftests/bpf/progs/core_reloc_types.h
+++ b/tools/testing/selftests/bpf/progs/core_reloc_types.h
@@ -674,3 +674,59 @@ struct core_reloc_misc_extensible {
int c;
int d;
};
+
+/*
+ * EXISTENCE
+ */
+struct core_reloc_existence_output {
+ int a_exists;
+ int a_value;
+ int b_exists;
+ int b_value;
+ int c_exists;
+ int c_value;
+ int arr_exists;
+ int arr_value;
+ int s_exists;
+ int s_value;
+};
+
+struct core_reloc_existence {
+ int a;
+ struct {
+ int b;
+ };
+ int c;
+ int arr[1];
+ struct {
+ int x;
+ } s;
+};
+
+struct core_reloc_existence___minimal {
+ int a;
+};
+
+struct core_reloc_existence___err_wrong_int_sz {
+ short a;
+};
+
+struct core_reloc_existence___err_wrong_int_type {
+ int b[1];
+};
+
+struct core_reloc_existence___err_wrong_int_kind {
+ struct{ int x; } c;
+};
+
+struct core_reloc_existence___err_wrong_arr_kind {
+ int arr;
+};
+
+struct core_reloc_existence___err_wrong_arr_value_type {
+ short arr[1];
+};
+
+struct core_reloc_existence___err_wrong_struct_type {
+ int s;
+};
diff --git a/tools/testing/selftests/bpf/progs/test_core_reloc_existence.c b/tools/testing/selftests/bpf/progs/test_core_reloc_existence.c
new file mode 100644
index 000000000000..c3cac95a19f1
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_core_reloc_existence.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2019 Facebook
+
+#include <linux/bpf.h>
+#include <stdint.h>
+#include "bpf_helpers.h"
+#include "bpf_core_read.h"
+
+char _license[] SEC("license") = "GPL";
+
+static volatile struct data {
+ char in[256];
+ char out[256];
+} data;
+
+struct core_reloc_existence_output {
+ int a_exists;
+ int a_value;
+ int b_exists;
+ int b_value;
+ int c_exists;
+ int c_value;
+ int arr_exists;
+ int arr_value;
+ int s_exists;
+ int s_value;
+};
+
+struct core_reloc_existence {
+ struct {
+ int x;
+ } s;
+ int arr[1];
+ int a;
+ struct {
+ int b;
+ };
+ int c;
+};
+
+SEC("raw_tracepoint/sys_enter")
+int test_core_existence(void *ctx)
+{
+ struct core_reloc_existence *in = (void *)&data.in;
+ struct core_reloc_existence_output *out = (void *)&data.out;
+
+ out->a_exists = bpf_core_field_exists(in->a);
+ if (bpf_core_field_exists(in->a))
+ out->a_value = BPF_CORE_READ(in, a);
+ else
+ out->a_value = 0xff000001u;
+
+ out->b_exists = bpf_core_field_exists(in->b);
+ if (bpf_core_field_exists(in->b))
+ out->b_value = BPF_CORE_READ(in, b);
+ else
+ out->b_value = 0xff000002u;
+
+ out->c_exists = bpf_core_field_exists(in->c);
+ if (bpf_core_field_exists(in->c))
+ out->c_value = BPF_CORE_READ(in, c);
+ else
+ out->c_value = 0xff000003u;
+
+ out->arr_exists = bpf_core_field_exists(in->arr);
+ if (bpf_core_field_exists(in->arr))
+ out->arr_value = BPF_CORE_READ(in, arr[0]);
+ else
+ out->arr_value = 0xff000004u;
+
+ out->s_exists = bpf_core_field_exists(in->s);
+ if (bpf_core_field_exists(in->s))
+ out->s_value = BPF_CORE_READ(in, s.x);
+ else
+ out->s_value = 0xff000005u;
+
+ return 0;
+}
+