* [PATCH v3 bpf-next 1/5] libbpf: implement type-based CO-RE relocations support
2020-08-19 19:45 [PATCH v3 bpf-next 0/5] Add libbpf support for type- and enum value-based CO-RE relocations Andrii Nakryiko
@ 2020-08-19 19:45 ` Andrii Nakryiko
2020-08-19 19:45 ` [PATCH v3 bpf-next 2/5] selftests/bpf: test TYPE_EXISTS and TYPE_SIZE CO-RE relocations Andrii Nakryiko
` (4 subsequent siblings)
5 siblings, 0 replies; 8+ messages in thread
From: Andrii Nakryiko @ 2020-08-19 19:45 UTC (permalink / raw)
To: bpf, netdev, ast, daniel
Cc: andrii.nakryiko, kernel-team, Andrii Nakryiko, Yonghong Song
Implement support for TYPE_EXISTS/TYPE_SIZE/TYPE_ID_LOCAL/TYPE_ID_REMOTE
relocations. These are examples of type-based relocations, as opposed to
field-based relocations supported already. The difference is that they are
calculating relocation values based on the type itself, not a field within
a struct/union.
Type-based relos have slightly different semantics when matching local types
to kernel target types, see comments in bpf_core_types_are_compat() for
details. Their behavior on failure to find target type in kernel BTF also
differs. Instead of "poisoning" relocatable instruction and failing load
subsequently in kernel, they return 0 (which is rarely a valid return result,
so user BPF code can use that to detect success/failure of the relocation and
deal with it without extra "guarding" relocations). Also, it's always possible
to check existence of the type in target kernel with TYPE_EXISTS relocation,
similarly to a field-based FIELD_EXISTS.
TYPE_ID_LOCAL relocation is a bit special in that it always succeeds (barring
any libbpf/Clang bugs) and resolved to BTF ID using **local** BTF info of BPF
program itself. Tests in subsequent patches demonstrate the usage and
semantics of new relocations.
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
tools/lib/bpf/bpf_core_read.h | 52 ++++++-
tools/lib/bpf/libbpf.c | 231 ++++++++++++++++++++++++++++----
tools/lib/bpf/libbpf_internal.h | 4 +
3 files changed, 263 insertions(+), 24 deletions(-)
diff --git a/tools/lib/bpf/bpf_core_read.h b/tools/lib/bpf/bpf_core_read.h
index 03152cb143b7..684bfb86361a 100644
--- a/tools/lib/bpf/bpf_core_read.h
+++ b/tools/lib/bpf/bpf_core_read.h
@@ -19,6 +19,18 @@ enum bpf_field_info_kind {
BPF_FIELD_RSHIFT_U64 = 5,
};
+/* second argument to __builtin_btf_type_id() built-in */
+enum bpf_type_id_kind {
+ BPF_TYPE_ID_LOCAL = 0, /* BTF type ID in local program */
+ BPF_TYPE_ID_TARGET = 1, /* BTF type ID in target kernel */
+};
+
+/* second argument to __builtin_preserve_type_info() built-in */
+enum bpf_type_info_kind {
+ BPF_TYPE_EXISTS = 0, /* type existence in target kernel */
+ BPF_TYPE_SIZE = 1, /* type size in target kernel */
+};
+
#define __CORE_RELO(src, field, info) \
__builtin_preserve_field_info((src)->field, BPF_FIELD_##info)
@@ -94,12 +106,50 @@ enum bpf_field_info_kind {
__builtin_preserve_field_info(field, BPF_FIELD_EXISTS)
/*
- * Convenience macro to get byte size of a field. Works for integers,
+ * Convenience macro to get the byte size of a field. Works for integers,
* struct/unions, pointers, arrays, and enums.
*/
#define bpf_core_field_size(field) \
__builtin_preserve_field_info(field, BPF_FIELD_BYTE_SIZE)
+/*
+ * Convenience macro to get BTF type ID of a specified type, using a local BTF
+ * information. Return 32-bit unsigned integer with type ID from program's own
+ * BTF. Always succeeds.
+ */
+#define bpf_core_type_id_local(type) \
+ __builtin_btf_type_id(*(typeof(type) *)0, BPF_TYPE_ID_LOCAL)
+
+/*
+ * Convenience macro to get BTF type ID of a target kernel's type that matches
+ * specified local type.
+ * Returns:
+ * - valid 32-bit unsigned type ID in kernel BTF;
+ * - 0, if no matching type was found in a target kernel BTF.
+ */
+#define bpf_core_type_id_kernel(type) \
+ __builtin_btf_type_id(*(typeof(type) *)0, BPF_TYPE_ID_TARGET)
+
+/*
+ * Convenience macro to check that provided named type
+ * (struct/union/enum/typedef) exists in a target kernel.
+ * Returns:
+ * 1, if such type is present in target kernel's BTF;
+ * 0, if no matching type is found.
+ */
+#define bpf_core_type_exists(type) \
+ __builtin_preserve_type_info(*(typeof(type) *)0, BPF_TYPE_EXISTS)
+
+/*
+ * Convenience macro to get the byte size of a provided named type
+ * (struct/union/enum/typedef) in a target kernel.
+ * Returns:
+ * >= 0 size (in bytes), if type is present in target kernel's BTF;
+ * 0, if no matching type is found.
+ */
+#define bpf_core_type_size(type) \
+ __builtin_preserve_type_info(*(typeof(type) *)0, BPF_TYPE_SIZE)
+
/*
* bpf_core_read() abstracts away bpf_probe_read_kernel() call and captures
* offset relocation for source address using __builtin_preserve_access_index()
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 4a81c6b2d21b..882759dfc33e 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -4111,6 +4111,10 @@ static const char *core_relo_kind_str(enum bpf_core_relo_kind kind)
case BPF_FIELD_SIGNED: return "signed";
case BPF_FIELD_LSHIFT_U64: return "lshift_u64";
case BPF_FIELD_RSHIFT_U64: return "rshift_u64";
+ case BPF_TYPE_ID_LOCAL: return "local_type_id";
+ case BPF_TYPE_ID_TARGET: return "target_type_id";
+ case BPF_TYPE_EXISTS: return "type_exists";
+ case BPF_TYPE_SIZE: return "type_size";
default: return "unknown";
}
}
@@ -4130,6 +4134,19 @@ static bool core_relo_is_field_based(enum bpf_core_relo_kind kind)
}
}
+static bool core_relo_is_type_based(enum bpf_core_relo_kind kind)
+{
+ switch (kind) {
+ case BPF_TYPE_ID_LOCAL:
+ case BPF_TYPE_ID_TARGET:
+ case BPF_TYPE_EXISTS:
+ case BPF_TYPE_SIZE:
+ return true;
+ default:
+ return false;
+ }
+}
+
/*
* Turn bpf_core_relo into a low- and high-level spec representation,
* validating correctness along the way, as well as calculating resulting
@@ -4160,6 +4177,9 @@ static bool core_relo_is_field_based(enum bpf_core_relo_kind kind)
* - field 'a' access (corresponds to '2' in low-level spec);
* - array element #3 access (corresponds to '3' in low-level spec).
*
+ * Type-based relocations (TYPE_EXISTS/TYPE_SIZE,
+ * TYPE_ID_LOCAL/TYPE_ID_TARGET) don't capture any field information. Their
+ * spec and raw_spec are kept empty.
*/
static int bpf_core_parse_spec(const struct btf *btf,
__u32 type_id,
@@ -4182,6 +4202,13 @@ static int bpf_core_parse_spec(const struct btf *btf,
spec->root_type_id = type_id;
spec->relo_kind = relo_kind;
+ /* type-based relocations don't have a field access string */
+ if (core_relo_is_type_based(relo_kind)) {
+ if (strcmp(spec_str, "0"))
+ return -EINVAL;
+ return 0;
+ }
+
/* parse spec_str="0:1:2:3:4" into array raw_spec=[0, 1, 2, 3, 4] */
while (*spec_str) {
if (*spec_str == ':')
@@ -4317,7 +4344,7 @@ static struct ids_vec *bpf_core_find_cands(const struct btf *local_btf,
const struct btf *targ_btf)
{
size_t local_essent_len, targ_essent_len;
- const char *local_name, *targ_name, *targ_kind;
+ const char *local_name, *targ_name;
const struct btf_type *t, *local_t;
struct ids_vec *cand_ids;
__u32 *new_ids;
@@ -4339,13 +4366,11 @@ static struct ids_vec *bpf_core_find_cands(const struct btf *local_btf,
n = btf__get_nr_types(targ_btf);
for (i = 1; i <= n; i++) {
t = btf__type_by_id(targ_btf, i);
- targ_name = btf__name_by_offset(targ_btf, t->name_off);
- if (str_is_empty(targ_name))
+ if (btf_kind(t) != btf_kind(local_t))
continue;
- targ_kind = btf_kind_str(t);
- t = skip_mods_and_typedefs(targ_btf, i, NULL);
- if (!btf_is_composite(t) && !btf_is_array(t))
+ targ_name = btf__name_by_offset(targ_btf, t->name_off);
+ if (str_is_empty(targ_name))
continue;
targ_essent_len = bpf_core_essential_name_len(targ_name);
@@ -4355,7 +4380,7 @@ static struct ids_vec *bpf_core_find_cands(const struct btf *local_btf,
if (strncmp(local_name, targ_name, local_essent_len) == 0) {
pr_debug("CO-RE relocating [%d] %s %s: found target candidate [%d] %s %s\n",
local_type_id, btf_kind_str(local_t),
- local_name, i, targ_kind, targ_name);
+ local_name, i, btf_kind_str(t), targ_name);
new_ids = libbpf_reallocarray(cand_ids->data,
cand_ids->len + 1,
sizeof(*cand_ids->data));
@@ -4373,8 +4398,9 @@ static struct ids_vec *bpf_core_find_cands(const struct btf *local_btf,
return ERR_PTR(err);
}
-/* Check two types for compatibility, skipping const/volatile/restrict and
- * typedefs, to ensure we are relocating compatible entities:
+/* Check two types for compatibility for the purpose of field access
+ * relocation. const/volatile/restrict and typedefs are skipped to ensure we
+ * are relocating semantically compatible entities:
* - any two STRUCTs/UNIONs are compatible and can be mixed;
* - any two FWDs are compatible, if their names match (modulo flavor suffix);
* - any two PTRs are always compatible;
@@ -4529,6 +4555,100 @@ static int bpf_core_match_member(const struct btf *local_btf,
return 0;
}
+/* Check local and target types for compatibility. This check is used for
+ * type-based CO-RE relocations and follow slightly different rules than
+ * field-based relocations. This function assumes that root types were already
+ * checked for name match. Beyond that initial root-level name check, names
+ * are completely ignored. Compatibility rules are as follows:
+ * - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs are considered compatible, but
+ * kind should match for local and target types (i.e., STRUCT is not
+ * compatible with UNION);
+ * - for ENUMs, the size is ignored;
+ * - for INT, size and signedness are ignored;
+ * - for ARRAY, dimensionality is ignored, element types are checked for
+ * compatibility recursively;
+ * - CONST/VOLATILE/RESTRICT modifiers are ignored;
+ * - TYPEDEFs/PTRs are compatible if types they pointing to are compatible;
+ * - FUNC_PROTOs are compatible if they have compatible signature: same
+ * number of input args and compatible return and argument types.
+ * These rules are not set in stone and probably will be adjusted as we get
+ * more experience with using BPF CO-RE relocations.
+ */
+static int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
+ const struct btf *targ_btf, __u32 targ_id)
+{
+ const struct btf_type *local_type, *targ_type;
+ int depth = 32; /* max recursion depth */
+
+ /* caller made sure that names match (ignoring flavor suffix) */
+ local_type = btf__type_by_id(local_btf, local_id);
+ targ_type = btf__type_by_id(local_btf, local_id);
+ if (btf_kind(local_type) != btf_kind(targ_type))
+ return 0;
+
+recur:
+ depth--;
+ if (depth < 0)
+ return -EINVAL;
+
+ local_type = skip_mods_and_typedefs(local_btf, local_id, &local_id);
+ targ_type = skip_mods_and_typedefs(targ_btf, targ_id, &targ_id);
+ if (!local_type || !targ_type)
+ return -EINVAL;
+
+ if (btf_kind(local_type) != btf_kind(targ_type))
+ return 0;
+
+ switch (btf_kind(local_type)) {
+ case BTF_KIND_UNKN:
+ case BTF_KIND_STRUCT:
+ case BTF_KIND_UNION:
+ case BTF_KIND_ENUM:
+ case BTF_KIND_FWD:
+ return 1;
+ case BTF_KIND_INT:
+ /* just reject deprecated bitfield-like integers; all other
+ * integers are by default compatible between each other
+ */
+ return btf_int_offset(local_type) == 0 && btf_int_offset(targ_type) == 0;
+ case BTF_KIND_PTR:
+ local_id = local_type->type;
+ targ_id = targ_type->type;
+ goto recur;
+ case BTF_KIND_ARRAY:
+ local_id = btf_array(local_type)->type;
+ targ_id = btf_array(targ_type)->type;
+ goto recur;
+ case BTF_KIND_FUNC_PROTO: {
+ struct btf_param *local_p = btf_params(local_type);
+ struct btf_param *targ_p = btf_params(targ_type);
+ __u16 local_vlen = btf_vlen(local_type);
+ __u16 targ_vlen = btf_vlen(targ_type);
+ int i, err;
+
+ if (local_vlen != targ_vlen)
+ return 0;
+
+ for (i = 0; i < local_vlen; i++, local_p++, targ_p++) {
+ skip_mods_and_typedefs(local_btf, local_p->type, &local_id);
+ skip_mods_and_typedefs(targ_btf, targ_p->type, &targ_id);
+ err = bpf_core_types_are_compat(local_btf, local_id, targ_btf, targ_id);
+ if (err <= 0)
+ return err;
+ }
+
+ /* tail recurse for return type check */
+ skip_mods_and_typedefs(local_btf, local_type->type, &local_id);
+ skip_mods_and_typedefs(targ_btf, targ_type->type, &targ_id);
+ goto recur;
+ }
+ default:
+ pr_warn("unexpected kind %s relocated, local [%d], target [%d]\n",
+ btf_kind_str(local_type), local_id, targ_id);
+ return 0;
+ }
+}
+
/*
* Try to match local spec to a target type and, if successful, produce full
* target spec (high-level, low-level + bit offset).
@@ -4547,6 +4667,12 @@ static int bpf_core_spec_match(struct bpf_core_spec *local_spec,
targ_spec->root_type_id = targ_id;
targ_spec->relo_kind = local_spec->relo_kind;
+ if (core_relo_is_type_based(local_spec->relo_kind)) {
+ return bpf_core_types_are_compat(local_spec->btf,
+ local_spec->root_type_id,
+ targ_btf, targ_id);
+ }
+
local_acc = &local_spec->spec[0];
targ_acc = &targ_spec->spec[0];
@@ -4720,6 +4846,40 @@ static int bpf_core_calc_field_relo(const struct bpf_program *prog,
return 0;
}
+static int bpf_core_calc_type_relo(const struct bpf_core_relo *relo,
+ const struct bpf_core_spec *spec,
+ __u32 *val)
+{
+ __s64 sz;
+
+ /* type-based relos return zero when target type is not found */
+ if (!spec) {
+ *val = 0;
+ return 0;
+ }
+
+ switch (relo->kind) {
+ case BPF_TYPE_ID_TARGET:
+ *val = spec->root_type_id;
+ break;
+ case BPF_TYPE_EXISTS:
+ *val = 1;
+ break;
+ case BPF_TYPE_SIZE:
+ sz = btf__resolve_size(spec->btf, spec->root_type_id);
+ if (sz < 0)
+ return -EINVAL;
+ *val = sz;
+ break;
+ case BPF_TYPE_ID_LOCAL:
+ /* BPF_TYPE_ID_LOCAL is handled specially and shouldn't get here */
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
struct bpf_core_relo_res
{
/* expected value in the instruction, unless validate == false */
@@ -4755,6 +4915,9 @@ static int bpf_core_calc_relo(const struct bpf_program *prog,
if (core_relo_is_field_based(relo->kind)) {
err = bpf_core_calc_field_relo(prog, relo, local_spec, &res->orig_val, &res->validate);
err = err ?: bpf_core_calc_field_relo(prog, relo, targ_spec, &res->new_val, NULL);
+ } else if (core_relo_is_type_based(relo->kind)) {
+ err = bpf_core_calc_type_relo(relo, local_spec, &res->orig_val);
+ err = err ?: bpf_core_calc_type_relo(relo, targ_spec, &res->new_val);
}
if (err == -EUCLEAN) {
@@ -4894,6 +5057,9 @@ static void bpf_core_dump_spec(int level, const struct bpf_core_spec *spec)
libbpf_print(level, "[%u] %s %s", type_id, btf_kind_str(t), str_is_empty(s) ? "<anon>" : s);
+ if (core_relo_is_type_based(spec->relo_kind))
+ return;
+
if (core_relo_is_field_based(spec->relo_kind)) {
for (i = 0; i < spec->len; i++) {
if (spec->spec[i].name)
@@ -4911,6 +5077,7 @@ static void bpf_core_dump_spec(int level, const struct bpf_core_spec *spec)
spec->bit_offset / 8, spec->bit_offset % 8);
else
libbpf_print(level, " @ offset %u)", spec->bit_offset / 8);
+ return;
}
}
@@ -4979,12 +5146,12 @@ static void *u32_as_hash_key(__u32 x)
* 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_field(struct bpf_program *prog,
- const struct bpf_core_relo *relo,
- int relo_idx,
- const struct btf *local_btf,
- const struct btf *targ_btf,
- struct hashmap *cand_cache)
+static int bpf_core_apply_relo(struct bpf_program *prog,
+ const struct bpf_core_relo *relo,
+ int relo_idx,
+ const struct btf *local_btf,
+ const struct btf *targ_btf,
+ struct hashmap *cand_cache)
{
const char *prog_name = bpf_program__title(prog, false);
struct bpf_core_spec local_spec, cand_spec, targ_spec;
@@ -5003,7 +5170,7 @@ static int bpf_core_reloc_field(struct bpf_program *prog,
return -EINVAL;
local_name = btf__name_by_offset(local_btf, local_type->name_off);
- if (str_is_empty(local_name))
+ if (!local_name)
return -EINVAL;
spec_str = btf__name_by_offset(local_btf, relo->access_str_off);
@@ -5014,7 +5181,8 @@ static int bpf_core_reloc_field(struct bpf_program *prog,
if (err) {
pr_warn("prog '%s': relo #%d: parsing [%d] %s %s + %s failed: %d\n",
prog_name, relo_idx, local_id, btf_kind_str(local_type),
- local_name, spec_str, err);
+ str_is_empty(local_name) ? "<anon>" : local_name,
+ spec_str, err);
return -EINVAL;
}
@@ -5023,12 +5191,28 @@ static int bpf_core_reloc_field(struct bpf_program *prog,
bpf_core_dump_spec(LIBBPF_DEBUG, &local_spec);
libbpf_print(LIBBPF_DEBUG, "\n");
+ /* TYPE_ID_LOCAL relo is special and doesn't need candidate search */
+ if (relo->kind == BPF_TYPE_ID_LOCAL) {
+ targ_res.validate = true;
+ targ_res.poison = false;
+ targ_res.orig_val = local_spec.root_type_id;
+ targ_res.new_val = local_spec.root_type_id;
+ goto patch_insn;
+ }
+
+ /* libbpf doesn't support candidate search for anonymous types */
+ if (str_is_empty(spec_str)) {
+ pr_warn("prog '%s': relo #%d: <%s> (%d) relocation doesn't support anonymous types\n",
+ prog_name, relo_idx, core_relo_kind_str(relo->kind), relo->kind);
+ return -EOPNOTSUPP;
+ }
+
if (!hashmap__find(cand_cache, type_key, (void **)&cand_ids)) {
cand_ids = bpf_core_find_cands(local_btf, local_id, targ_btf);
if (IS_ERR(cand_ids)) {
pr_warn("prog '%s': relo #%d: target candidate search failed for [%d] %s %s: %ld",
- prog_name, relo_idx, local_id, btf_kind_str(local_type), local_name,
- PTR_ERR(cand_ids));
+ prog_name, relo_idx, local_id, btf_kind_str(local_type),
+ local_name, PTR_ERR(cand_ids));
return PTR_ERR(cand_ids);
}
err = hashmap__set(cand_cache, type_key, cand_ids, NULL, NULL);
@@ -5084,7 +5268,7 @@ static int bpf_core_reloc_field(struct bpf_program *prog,
return -EINVAL;
}
- cand_ids->data[j++] = cand_spec.spec[0].type_id;
+ cand_ids->data[j++] = cand_spec.root_type_id;
}
/*
@@ -5103,7 +5287,7 @@ static int bpf_core_reloc_field(struct bpf_program *prog,
* as well as expected case, depending whether instruction w/
* relocation is guarded in some way that makes it unreachable (dead
* code) if relocation can't be resolved. This is handled in
- * bpf_core_reloc_insn() uniformly by replacing that instruction with
+ * bpf_core_patch_insn() uniformly by replacing that instruction with
* BPF helper call insn (using invalid helper ID). If that instruction
* is indeed unreachable, then it will be ignored and eliminated by
* verifier. If it was an error, then verifier will complain and point
@@ -5119,6 +5303,7 @@ static int bpf_core_reloc_field(struct bpf_program *prog,
return err;
}
+patch_insn:
/* bpf_core_patch_insn() should know how to handle missing targ_spec */
err = bpf_core_patch_insn(prog, relo, relo_idx, &targ_res);
if (err) {
@@ -5186,8 +5371,8 @@ bpf_object__relocate_core(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_field(prog, rec, i, obj->btf,
- targ_btf, cand_cache);
+ err = bpf_core_apply_relo(prog, rec, i, obj->btf,
+ targ_btf, cand_cache);
if (err) {
pr_warn("prog '%s': relo #%d: failed to relocate: %d\n",
sec_name, i, err);
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index c8ed352671d5..edd3511aa242 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -238,6 +238,10 @@ enum bpf_core_relo_kind {
BPF_FIELD_SIGNED = 3, /* field signedness (0 - unsigned, 1 - signed) */
BPF_FIELD_LSHIFT_U64 = 4, /* bitfield-specific left bitshift */
BPF_FIELD_RSHIFT_U64 = 5, /* bitfield-specific right bitshift */
+ BPF_TYPE_ID_LOCAL = 6, /* type ID in local BPF object */
+ BPF_TYPE_ID_TARGET = 7, /* type ID in target kernel */
+ BPF_TYPE_EXISTS = 8, /* type existence in target kernel */
+ BPF_TYPE_SIZE = 9, /* type size in bytes */
};
/* The minimum bpf_core_relo checked by the loader
--
2.24.1
^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH v3 bpf-next 2/5] selftests/bpf: test TYPE_EXISTS and TYPE_SIZE CO-RE relocations
2020-08-19 19:45 [PATCH v3 bpf-next 0/5] Add libbpf support for type- and enum value-based CO-RE relocations Andrii Nakryiko
2020-08-19 19:45 ` [PATCH v3 bpf-next 1/5] libbpf: implement type-based CO-RE relocations support Andrii Nakryiko
@ 2020-08-19 19:45 ` Andrii Nakryiko
2020-08-19 19:45 ` [PATCH v3 bpf-next 3/5] selftests/bpf: add CO-RE relo test for TYPE_ID_LOCAL/TYPE_ID_TARGET Andrii Nakryiko
` (3 subsequent siblings)
5 siblings, 0 replies; 8+ messages in thread
From: Andrii Nakryiko @ 2020-08-19 19:45 UTC (permalink / raw)
To: bpf, netdev, ast, daniel
Cc: andrii.nakryiko, kernel-team, Andrii Nakryiko, Yonghong Song
Add selftests for TYPE_EXISTS and TYPE_SIZE relocations, testing correctness
of relocations and handling of type compatiblity/incompatibility.
If __builtin_preserve_type_info() is not supported by compiler, skip tests.
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
.../selftests/bpf/prog_tests/core_reloc.c | 125 +++++++++--
.../bpf/progs/btf__core_reloc_type_based.c | 3 +
...btf__core_reloc_type_based___all_missing.c | 3 +
.../btf__core_reloc_type_based___diff_sz.c | 3 +
...f__core_reloc_type_based___fn_wrong_args.c | 3 +
.../btf__core_reloc_type_based___incompat.c | 3 +
.../selftests/bpf/progs/core_reloc_types.h | 202 +++++++++++++++++-
.../bpf/progs/test_core_reloc_kernel.c | 2 +
.../bpf/progs/test_core_reloc_type_based.c | 124 +++++++++++
9 files changed, 446 insertions(+), 22 deletions(-)
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_type_based.c
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___all_missing.c
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___diff_sz.c
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___fn_wrong_args.c
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___incompat.c
create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_type_based.c
diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
index 4d650e99be28..b775ce0ede41 100644
--- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c
+++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
@@ -177,14 +177,13 @@
.fails = true, \
}
-#define EXISTENCE_CASE_COMMON(name) \
+#define FIELD_EXISTS_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
+ .btf_src_file = "btf__core_reloc_" #name ".o" \
-#define EXISTENCE_ERR_CASE(name) { \
- EXISTENCE_CASE_COMMON(name), \
+#define FIELD_EXISTS_ERR_CASE(name) { \
+ FIELD_EXISTS_CASE_COMMON(name), \
.fails = true, \
}
@@ -253,6 +252,23 @@
.fails = true, \
}
+#define TYPE_BASED_CASE_COMMON(name) \
+ .case_name = #name, \
+ .bpf_obj_file = "test_core_reloc_type_based.o", \
+ .btf_src_file = "btf__core_reloc_" #name ".o" \
+
+#define TYPE_BASED_CASE(name, ...) { \
+ TYPE_BASED_CASE_COMMON(name), \
+ .output = STRUCT_TO_CHAR_PTR(core_reloc_type_based_output) \
+ __VA_ARGS__, \
+ .output_len = sizeof(struct core_reloc_type_based_output), \
+}
+
+#define TYPE_BASED_ERR_CASE(name) { \
+ TYPE_BASED_CASE_COMMON(name), \
+ .fails = true, \
+}
+
struct core_reloc_test_case {
const char *case_name;
const char *bpf_obj_file;
@@ -364,7 +380,7 @@ static struct core_reloc_test_case test_cases[] = {
/* validate field existence checks */
{
- EXISTENCE_CASE_COMMON(existence),
+ FIELD_EXISTS_CASE_COMMON(existence),
.input = STRUCT_TO_CHAR_PTR(core_reloc_existence) {
.a = 1,
.b = 2,
@@ -388,7 +404,7 @@ static struct core_reloc_test_case test_cases[] = {
.output_len = sizeof(struct core_reloc_existence_output),
},
{
- EXISTENCE_CASE_COMMON(existence___minimal),
+ FIELD_EXISTS_CASE_COMMON(existence___minimal),
.input = STRUCT_TO_CHAR_PTR(core_reloc_existence___minimal) {
.a = 42,
},
@@ -408,12 +424,12 @@ static struct core_reloc_test_case test_cases[] = {
.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),
+ FIELD_EXISTS_ERR_CASE(existence__err_int_sz),
+ FIELD_EXISTS_ERR_CASE(existence__err_int_type),
+ FIELD_EXISTS_ERR_CASE(existence__err_int_kind),
+ FIELD_EXISTS_ERR_CASE(existence__err_arr_kind),
+ FIELD_EXISTS_ERR_CASE(existence__err_arr_value_type),
+ FIELD_EXISTS_ERR_CASE(existence__err_struct_type),
/* bitfield relocation checks */
BITFIELDS_CASE(bitfields, {
@@ -453,11 +469,73 @@ static struct core_reloc_test_case test_cases[] = {
SIZE_CASE(size),
SIZE_CASE(size___diff_sz),
SIZE_ERR_CASE(size___err_ambiguous),
+
+ /* validate type existence and size relocations */
+ TYPE_BASED_CASE(type_based, {
+ .struct_exists = 1,
+ .union_exists = 1,
+ .enum_exists = 1,
+ .typedef_named_struct_exists = 1,
+ .typedef_anon_struct_exists = 1,
+ .typedef_struct_ptr_exists = 1,
+ .typedef_int_exists = 1,
+ .typedef_enum_exists = 1,
+ .typedef_void_ptr_exists = 1,
+ .typedef_func_proto_exists = 1,
+ .typedef_arr_exists = 1,
+ .struct_sz = sizeof(struct a_struct),
+ .union_sz = sizeof(union a_union),
+ .enum_sz = sizeof(enum an_enum),
+ .typedef_named_struct_sz = sizeof(named_struct_typedef),
+ .typedef_anon_struct_sz = sizeof(anon_struct_typedef),
+ .typedef_struct_ptr_sz = sizeof(struct_ptr_typedef),
+ .typedef_int_sz = sizeof(int_typedef),
+ .typedef_enum_sz = sizeof(enum_typedef),
+ .typedef_void_ptr_sz = sizeof(void_ptr_typedef),
+ .typedef_func_proto_sz = sizeof(func_proto_typedef),
+ .typedef_arr_sz = sizeof(arr_typedef),
+ }),
+ TYPE_BASED_CASE(type_based___all_missing, {
+ /* all zeros */
+ }),
+ TYPE_BASED_CASE(type_based___diff_sz, {
+ .struct_exists = 1,
+ .union_exists = 1,
+ .enum_exists = 1,
+ .typedef_named_struct_exists = 1,
+ .typedef_anon_struct_exists = 1,
+ .typedef_struct_ptr_exists = 1,
+ .typedef_int_exists = 1,
+ .typedef_enum_exists = 1,
+ .typedef_void_ptr_exists = 1,
+ .typedef_func_proto_exists = 1,
+ .typedef_arr_exists = 1,
+ .struct_sz = sizeof(struct a_struct___diff_sz),
+ .union_sz = sizeof(union a_union___diff_sz),
+ .enum_sz = sizeof(enum an_enum___diff_sz),
+ .typedef_named_struct_sz = sizeof(named_struct_typedef___diff_sz),
+ .typedef_anon_struct_sz = sizeof(anon_struct_typedef___diff_sz),
+ .typedef_struct_ptr_sz = sizeof(struct_ptr_typedef___diff_sz),
+ .typedef_int_sz = sizeof(int_typedef___diff_sz),
+ .typedef_enum_sz = sizeof(enum_typedef___diff_sz),
+ .typedef_void_ptr_sz = sizeof(void_ptr_typedef___diff_sz),
+ .typedef_func_proto_sz = sizeof(func_proto_typedef___diff_sz),
+ .typedef_arr_sz = sizeof(arr_typedef___diff_sz),
+ }),
+ TYPE_BASED_CASE(type_based___incompat, {
+ .enum_exists = 1,
+ .enum_sz = sizeof(enum an_enum),
+ }),
+ TYPE_BASED_CASE(type_based___fn_wrong_args, {
+ .struct_exists = 1,
+ .struct_sz = sizeof(struct a_struct),
+ }),
};
struct data {
char in[256];
char out[256];
+ bool skip;
uint64_t my_pid_tgid;
};
@@ -516,15 +594,10 @@ void test_core_reloc(void)
load_attr.log_level = 0;
load_attr.target_btf_path = test_case->btf_src_file;
err = bpf_object__load_xattr(&load_attr);
- if (test_case->fails) {
- CHECK(!err, "obj_load_fail",
- "should fail to load prog '%s'\n", probe_name);
+ if (err) {
+ if (!test_case->fails)
+ CHECK(false, "obj_load", "failed to load prog '%s': %d\n", probe_name, err);
goto cleanup;
- } else {
- if (CHECK(err, "obj_load",
- "failed to load prog '%s': %d\n",
- probe_name, err))
- goto cleanup;
}
data_map = bpf_object__find_map_by_name(obj, "test_cor.bss");
@@ -552,6 +625,16 @@ void test_core_reloc(void)
/* trigger test run */
usleep(1);
+ if (data->skip) {
+ test__skip();
+ goto cleanup;
+ }
+
+ if (test_case->fails) {
+ CHECK(false, "obj_load_fail", "should fail to load prog '%s'\n", probe_name);
+ goto cleanup;
+ }
+
equal = memcmp(data->out, test_case->output,
test_case->output_len) == 0;
if (CHECK(!equal, "check_result",
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based.c
new file mode 100644
index 000000000000..fc3f69e58c71
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_type_based x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___all_missing.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___all_missing.c
new file mode 100644
index 000000000000..51511648b4ec
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___all_missing.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_type_based___all_missing x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___diff_sz.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___diff_sz.c
new file mode 100644
index 000000000000..67db3dceb279
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___diff_sz.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_type_based___diff_sz x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___fn_wrong_args.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___fn_wrong_args.c
new file mode 100644
index 000000000000..b357fc65431d
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___fn_wrong_args.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_type_based___fn_wrong_args x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___incompat.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___incompat.c
new file mode 100644
index 000000000000..8ddf20d33d9e
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___incompat.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_type_based___incompat x) {}
diff --git a/tools/testing/selftests/bpf/progs/core_reloc_types.h b/tools/testing/selftests/bpf/progs/core_reloc_types.h
index 3b1126c0bc8f..d998537867a2 100644
--- a/tools/testing/selftests/bpf/progs/core_reloc_types.h
+++ b/tools/testing/selftests/bpf/progs/core_reloc_types.h
@@ -652,7 +652,7 @@ struct core_reloc_misc_extensible {
};
/*
- * EXISTENCE
+ * FIELD EXISTENCE
*/
struct core_reloc_existence_output {
int a_exists;
@@ -834,3 +834,203 @@ struct core_reloc_size___err_ambiguous2 {
void *ptr_field;
enum { VALUE___2 = 123 } enum_field;
};
+
+/*
+ * TYPE EXISTENCE & SIZE
+ */
+struct core_reloc_type_based_output {
+ bool struct_exists;
+ bool union_exists;
+ bool enum_exists;
+ bool typedef_named_struct_exists;
+ bool typedef_anon_struct_exists;
+ bool typedef_struct_ptr_exists;
+ bool typedef_int_exists;
+ bool typedef_enum_exists;
+ bool typedef_void_ptr_exists;
+ bool typedef_func_proto_exists;
+ bool typedef_arr_exists;
+
+ int struct_sz;
+ int union_sz;
+ int enum_sz;
+ int typedef_named_struct_sz;
+ int typedef_anon_struct_sz;
+ int typedef_struct_ptr_sz;
+ int typedef_int_sz;
+ int typedef_enum_sz;
+ int typedef_void_ptr_sz;
+ int typedef_func_proto_sz;
+ int typedef_arr_sz;
+};
+
+struct a_struct {
+ int x;
+};
+
+union a_union {
+ int y;
+ int z;
+};
+
+typedef struct a_struct named_struct_typedef;
+
+typedef struct { int x, y, z; } anon_struct_typedef;
+
+typedef struct {
+ int a, b, c;
+} *struct_ptr_typedef;
+
+enum an_enum {
+ AN_ENUM_VAL1 = 1,
+ AN_ENUM_VAL2 = 2,
+ AN_ENUM_VAL3 = 3,
+};
+
+typedef int int_typedef;
+
+typedef enum { TYPEDEF_ENUM_VAL1, TYPEDEF_ENUM_VAL2 } enum_typedef;
+
+typedef void *void_ptr_typedef;
+
+typedef int (*func_proto_typedef)(long);
+
+typedef char arr_typedef[20];
+
+struct core_reloc_type_based {
+ struct a_struct f1;
+ union a_union f2;
+ enum an_enum f3;
+ named_struct_typedef f4;
+ anon_struct_typedef f5;
+ struct_ptr_typedef f6;
+ int_typedef f7;
+ enum_typedef f8;
+ void_ptr_typedef f9;
+ func_proto_typedef f10;
+ arr_typedef f11;
+};
+
+/* no types in target */
+struct core_reloc_type_based___all_missing {
+};
+
+/* different type sizes, extra modifiers, anon vs named enums, etc */
+struct a_struct___diff_sz {
+ long x;
+ int y;
+ char z;
+};
+
+union a_union___diff_sz {
+ char yy;
+ char zz;
+};
+
+typedef struct a_struct___diff_sz named_struct_typedef___diff_sz;
+
+typedef struct { long xx, yy, zzz; } anon_struct_typedef___diff_sz;
+
+typedef struct {
+ char aa[1], bb[2], cc[3];
+} *struct_ptr_typedef___diff_sz;
+
+enum an_enum___diff_sz {
+ AN_ENUM_VAL1___diff_sz = 0x123412341234,
+ AN_ENUM_VAL2___diff_sz = 2,
+};
+
+typedef unsigned long int_typedef___diff_sz;
+
+typedef enum an_enum___diff_sz enum_typedef___diff_sz;
+
+typedef const void * const void_ptr_typedef___diff_sz;
+
+typedef int_typedef___diff_sz (*func_proto_typedef___diff_sz)(char);
+
+typedef int arr_typedef___diff_sz[2];
+
+struct core_reloc_type_based___diff_sz {
+ struct a_struct___diff_sz f1;
+ union a_union___diff_sz f2;
+ enum an_enum___diff_sz f3;
+ named_struct_typedef___diff_sz f4;
+ anon_struct_typedef___diff_sz f5;
+ struct_ptr_typedef___diff_sz f6;
+ int_typedef___diff_sz f7;
+ enum_typedef___diff_sz f8;
+ void_ptr_typedef___diff_sz f9;
+ func_proto_typedef___diff_sz f10;
+ arr_typedef___diff_sz f11;
+};
+
+/* incompatibilities between target and local types */
+union a_struct___incompat { /* union instead of struct */
+ int x;
+};
+
+struct a_union___incompat { /* struct instead of union */
+ int y;
+ int z;
+};
+
+/* typedef to union, not to struct */
+typedef union a_struct___incompat named_struct_typedef___incompat;
+
+/* typedef to void pointer, instead of struct */
+typedef void *anon_struct_typedef___incompat;
+
+/* extra pointer indirection */
+typedef struct {
+ int a, b, c;
+} **struct_ptr_typedef___incompat;
+
+/* typedef of a struct with int, instead of int */
+typedef struct { int x; } int_typedef___incompat;
+
+/* typedef to func_proto, instead of enum */
+typedef int (*enum_typedef___incompat)(void);
+
+/* pointer to char instead of void */
+typedef char *void_ptr_typedef___incompat;
+
+/* void return type instead of int */
+typedef void (*func_proto_typedef___incompat)(long);
+
+/* multi-dimensional array instead of a single-dimensional */
+typedef int arr_typedef___incompat[20][2];
+
+struct core_reloc_type_based___incompat {
+ union a_struct___incompat f1;
+ struct a_union___incompat f2;
+ /* the only valid one is enum, to check that something still succeeds */
+ enum an_enum f3;
+ named_struct_typedef___incompat f4;
+ anon_struct_typedef___incompat f5;
+ struct_ptr_typedef___incompat f6;
+ int_typedef___incompat f7;
+ enum_typedef___incompat f8;
+ void_ptr_typedef___incompat f9;
+ func_proto_typedef___incompat f10;
+ arr_typedef___incompat f11;
+};
+
+/* func_proto with incompatible signature */
+typedef void (*func_proto_typedef___fn_wrong_ret1)(long);
+typedef int * (*func_proto_typedef___fn_wrong_ret2)(long);
+typedef struct { int x; } int_struct_typedef;
+typedef int_struct_typedef (*func_proto_typedef___fn_wrong_ret3)(long);
+typedef int (*func_proto_typedef___fn_wrong_arg)(void *);
+typedef int (*func_proto_typedef___fn_wrong_arg_cnt1)(long, long);
+typedef int (*func_proto_typedef___fn_wrong_arg_cnt2)(void);
+
+struct core_reloc_type_based___fn_wrong_args {
+ /* one valid type to make sure relos still work */
+ struct a_struct f1;
+ func_proto_typedef___fn_wrong_ret1 f2;
+ func_proto_typedef___fn_wrong_ret2 f3;
+ func_proto_typedef___fn_wrong_ret3 f4;
+ func_proto_typedef___fn_wrong_arg f5;
+ func_proto_typedef___fn_wrong_arg_cnt1 f6;
+ func_proto_typedef___fn_wrong_arg_cnt2 f7;
+};
diff --git a/tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c b/tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c
index aba928fd60d3..145028b52ad8 100644
--- a/tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c
+++ b/tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c
@@ -3,6 +3,7 @@
#include <linux/bpf.h>
#include <stdint.h>
+#include <stdbool.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_core_read.h>
@@ -11,6 +12,7 @@ char _license[] SEC("license") = "GPL";
struct {
char in[256];
char out[256];
+ bool skip;
uint64_t my_pid_tgid;
} data = {};
diff --git a/tools/testing/selftests/bpf/progs/test_core_reloc_type_based.c b/tools/testing/selftests/bpf/progs/test_core_reloc_type_based.c
new file mode 100644
index 000000000000..6ab259d02dc0
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_core_reloc_type_based.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2020 Facebook
+
+#include <linux/bpf.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_core_read.h>
+
+char _license[] SEC("license") = "GPL";
+
+struct {
+ char in[256];
+ char out[256];
+ bool skip;
+} data = {};
+
+struct a_struct {
+ int x;
+};
+
+union a_union {
+ int y;
+ int z;
+};
+
+typedef struct a_struct named_struct_typedef;
+
+typedef struct { int x, y, z; } anon_struct_typedef;
+
+typedef struct {
+ int a, b, c;
+} *struct_ptr_typedef;
+
+enum an_enum {
+ AN_ENUM_VAL1 = 1,
+ AN_ENUM_VAL2 = 2,
+ AN_ENUM_VAL3 = 3,
+};
+
+typedef int int_typedef;
+
+typedef enum { TYPEDEF_ENUM_VAL1, TYPEDEF_ENUM_VAL2 } enum_typedef;
+
+typedef void *void_ptr_typedef;
+
+typedef int (*func_proto_typedef)(long);
+
+typedef char arr_typedef[20];
+
+struct core_reloc_type_based {
+ struct a_struct f1;
+ union a_union f2;
+ enum an_enum f3;
+ named_struct_typedef f4;
+ anon_struct_typedef f5;
+ struct_ptr_typedef f6;
+ int_typedef f7;
+ enum_typedef f8;
+ void_ptr_typedef f9;
+ func_proto_typedef f10;
+ arr_typedef f11;
+};
+
+struct core_reloc_type_based_output {
+ bool struct_exists;
+ bool union_exists;
+ bool enum_exists;
+ bool typedef_named_struct_exists;
+ bool typedef_anon_struct_exists;
+ bool typedef_struct_ptr_exists;
+ bool typedef_int_exists;
+ bool typedef_enum_exists;
+ bool typedef_void_ptr_exists;
+ bool typedef_func_proto_exists;
+ bool typedef_arr_exists;
+
+ int struct_sz;
+ int union_sz;
+ int enum_sz;
+ int typedef_named_struct_sz;
+ int typedef_anon_struct_sz;
+ int typedef_struct_ptr_sz;
+ int typedef_int_sz;
+ int typedef_enum_sz;
+ int typedef_void_ptr_sz;
+ int typedef_func_proto_sz;
+ int typedef_arr_sz;
+};
+
+SEC("raw_tracepoint/sys_enter")
+int test_core_type_based(void *ctx)
+{
+#if __has_builtin(__builtin_preserve_type_info)
+ struct core_reloc_type_based_output *out = (void *)&data.out;
+
+ out->struct_exists = bpf_core_type_exists(struct a_struct);
+ out->union_exists = bpf_core_type_exists(union a_union);
+ out->enum_exists = bpf_core_type_exists(enum an_enum);
+ out->typedef_named_struct_exists = bpf_core_type_exists(named_struct_typedef);
+ out->typedef_anon_struct_exists = bpf_core_type_exists(anon_struct_typedef);
+ out->typedef_struct_ptr_exists = bpf_core_type_exists(struct_ptr_typedef);
+ out->typedef_int_exists = bpf_core_type_exists(int_typedef);
+ out->typedef_enum_exists = bpf_core_type_exists(enum_typedef);
+ out->typedef_void_ptr_exists = bpf_core_type_exists(void_ptr_typedef);
+ out->typedef_func_proto_exists = bpf_core_type_exists(func_proto_typedef);
+ out->typedef_arr_exists = bpf_core_type_exists(arr_typedef);
+
+ out->struct_sz = bpf_core_type_size(struct a_struct);
+ out->union_sz = bpf_core_type_size(union a_union);
+ out->enum_sz = bpf_core_type_size(enum an_enum);
+ out->typedef_named_struct_sz = bpf_core_type_size(named_struct_typedef);
+ out->typedef_anon_struct_sz = bpf_core_type_size(anon_struct_typedef);
+ out->typedef_struct_ptr_sz = bpf_core_type_size(struct_ptr_typedef);
+ out->typedef_int_sz = bpf_core_type_size(int_typedef);
+ out->typedef_enum_sz = bpf_core_type_size(enum_typedef);
+ out->typedef_void_ptr_sz = bpf_core_type_size(void_ptr_typedef);
+ out->typedef_func_proto_sz = bpf_core_type_size(func_proto_typedef);
+ out->typedef_arr_sz = bpf_core_type_size(arr_typedef);
+#else
+ data.skip = true;
+#endif
+ return 0;
+}
--
2.24.1
^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH v3 bpf-next 3/5] selftests/bpf: add CO-RE relo test for TYPE_ID_LOCAL/TYPE_ID_TARGET
2020-08-19 19:45 [PATCH v3 bpf-next 0/5] Add libbpf support for type- and enum value-based CO-RE relocations Andrii Nakryiko
2020-08-19 19:45 ` [PATCH v3 bpf-next 1/5] libbpf: implement type-based CO-RE relocations support Andrii Nakryiko
2020-08-19 19:45 ` [PATCH v3 bpf-next 2/5] selftests/bpf: test TYPE_EXISTS and TYPE_SIZE CO-RE relocations Andrii Nakryiko
@ 2020-08-19 19:45 ` Andrii Nakryiko
2020-08-19 19:45 ` [PATCH v3 bpf-next 4/5] libbpf: implement enum value-based CO-RE relocations Andrii Nakryiko
` (2 subsequent siblings)
5 siblings, 0 replies; 8+ messages in thread
From: Andrii Nakryiko @ 2020-08-19 19:45 UTC (permalink / raw)
To: bpf, netdev, ast, daniel
Cc: andrii.nakryiko, kernel-team, Andrii Nakryiko, Yonghong Song
Add tests for BTF type ID relocations. To allow testing this, enhance
core_relo.c test runner to allow dynamic initialization of test inputs.
If Clang doesn't have necessary support for new functionality, test is
skipped.
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
.../selftests/bpf/prog_tests/core_reloc.c | 168 +++++++++++++++++-
.../bpf/progs/btf__core_reloc_type_id.c | 3 +
...tf__core_reloc_type_id___missing_targets.c | 3 +
.../selftests/bpf/progs/core_reloc_types.h | 41 +++++
.../bpf/progs/test_core_reloc_type_based.c | 14 --
.../bpf/progs/test_core_reloc_type_id.c | 113 ++++++++++++
6 files changed, 323 insertions(+), 19 deletions(-)
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_type_id.c
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_type_id___missing_targets.c
create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_type_id.c
diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
index b775ce0ede41..ad550510ef69 100644
--- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c
+++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
@@ -3,6 +3,9 @@
#include "progs/core_reloc_types.h"
#include <sys/mman.h>
#include <sys/syscall.h>
+#include <bpf/btf.h>
+
+static int duration = 0;
#define STRUCT_TO_CHAR_PTR(struct_name) (const char *)&(struct struct_name)
@@ -269,6 +272,27 @@
.fails = true, \
}
+#define TYPE_ID_CASE_COMMON(name) \
+ .case_name = #name, \
+ .bpf_obj_file = "test_core_reloc_type_id.o", \
+ .btf_src_file = "btf__core_reloc_" #name ".o" \
+
+#define TYPE_ID_CASE(name, setup_fn) { \
+ TYPE_ID_CASE_COMMON(name), \
+ .output = STRUCT_TO_CHAR_PTR(core_reloc_type_id_output) {}, \
+ .output_len = sizeof(struct core_reloc_type_id_output), \
+ .setup = setup_fn, \
+}
+
+#define TYPE_ID_ERR_CASE(name) { \
+ TYPE_ID_CASE_COMMON(name), \
+ .fails = true, \
+}
+
+struct core_reloc_test_case;
+
+typedef int (*setup_test_fn)(struct core_reloc_test_case *test);
+
struct core_reloc_test_case {
const char *case_name;
const char *bpf_obj_file;
@@ -280,8 +304,136 @@ struct core_reloc_test_case {
bool fails;
bool relaxed_core_relocs;
bool direct_raw_tp;
+ setup_test_fn setup;
};
+static int find_btf_type(const struct btf *btf, const char *name, __u32 kind)
+{
+ int id;
+
+ id = btf__find_by_name_kind(btf, name, kind);
+ if (CHECK(id <= 0, "find_type_id", "failed to find '%s', kind %d: %d\n", name, kind, id))
+ return -1;
+
+ return id;
+}
+
+static int setup_type_id_case_local(struct core_reloc_test_case *test)
+{
+ struct core_reloc_type_id_output *exp = (void *)test->output;
+ struct btf *local_btf = btf__parse(test->bpf_obj_file, NULL);
+ struct btf *targ_btf = btf__parse(test->btf_src_file, NULL);
+ const struct btf_type *t;
+ const char *name;
+ int i;
+
+ if (CHECK(IS_ERR(local_btf), "local_btf", "failed: %ld\n", PTR_ERR(local_btf)) ||
+ CHECK(IS_ERR(targ_btf), "targ_btf", "failed: %ld\n", PTR_ERR(targ_btf))) {
+ btf__free(local_btf);
+ btf__free(targ_btf);
+ return -EINVAL;
+ }
+
+ exp->local_anon_struct = -1;
+ exp->local_anon_union = -1;
+ exp->local_anon_enum = -1;
+ exp->local_anon_func_proto_ptr = -1;
+ exp->local_anon_void_ptr = -1;
+ exp->local_anon_arr = -1;
+
+ for (i = 1; i <= btf__get_nr_types(local_btf); i++)
+ {
+ t = btf__type_by_id(local_btf, i);
+ /* we are interested only in anonymous types */
+ if (t->name_off)
+ continue;
+
+ if (btf_is_struct(t) && btf_vlen(t) &&
+ (name = btf__name_by_offset(local_btf, btf_members(t)[0].name_off)) &&
+ strcmp(name, "marker_field") == 0) {
+ exp->local_anon_struct = i;
+ } else if (btf_is_union(t) && btf_vlen(t) &&
+ (name = btf__name_by_offset(local_btf, btf_members(t)[0].name_off)) &&
+ strcmp(name, "marker_field") == 0) {
+ exp->local_anon_union = i;
+ } else if (btf_is_enum(t) && btf_vlen(t) &&
+ (name = btf__name_by_offset(local_btf, btf_enum(t)[0].name_off)) &&
+ strcmp(name, "MARKER_ENUM_VAL") == 0) {
+ exp->local_anon_enum = i;
+ } else if (btf_is_ptr(t) && (t = btf__type_by_id(local_btf, t->type))) {
+ if (btf_is_func_proto(t) && (t = btf__type_by_id(local_btf, t->type)) &&
+ btf_is_int(t) && (name = btf__name_by_offset(local_btf, t->name_off)) &&
+ strcmp(name, "_Bool") == 0) {
+ /* ptr -> func_proto -> _Bool */
+ exp->local_anon_func_proto_ptr = i;
+ } else if (btf_is_void(t)) {
+ /* ptr -> void */
+ exp->local_anon_void_ptr = i;
+ }
+ } else if (btf_is_array(t) && (t = btf__type_by_id(local_btf, btf_array(t)->type)) &&
+ btf_is_int(t) && (name = btf__name_by_offset(local_btf, t->name_off)) &&
+ strcmp(name, "_Bool") == 0) {
+ /* _Bool[] */
+ exp->local_anon_arr = i;
+ }
+ }
+
+ exp->local_struct = find_btf_type(local_btf, "a_struct", BTF_KIND_STRUCT);
+ exp->local_union = find_btf_type(local_btf, "a_union", BTF_KIND_UNION);
+ exp->local_enum = find_btf_type(local_btf, "an_enum", BTF_KIND_ENUM);
+ exp->local_int = find_btf_type(local_btf, "int", BTF_KIND_INT);
+ exp->local_struct_typedef = find_btf_type(local_btf, "named_struct_typedef", BTF_KIND_TYPEDEF);
+ exp->local_func_proto_typedef = find_btf_type(local_btf, "func_proto_typedef", BTF_KIND_TYPEDEF);
+ exp->local_arr_typedef = find_btf_type(local_btf, "arr_typedef", BTF_KIND_TYPEDEF);
+
+ btf__free(local_btf);
+ btf__free(targ_btf);
+ return 0;
+}
+
+static int setup_type_id_case_success(struct core_reloc_test_case *test) {
+ struct core_reloc_type_id_output *exp = (void *)test->output;
+ struct btf *targ_btf = btf__parse(test->btf_src_file, NULL);
+ int err;
+
+ err = setup_type_id_case_local(test);
+ if (err)
+ return err;
+
+ targ_btf = btf__parse(test->btf_src_file, NULL);
+
+ exp->targ_struct = find_btf_type(targ_btf, "a_struct", BTF_KIND_STRUCT);
+ exp->targ_union = find_btf_type(targ_btf, "a_union", BTF_KIND_UNION);
+ exp->targ_enum = find_btf_type(targ_btf, "an_enum", BTF_KIND_ENUM);
+ exp->targ_int = find_btf_type(targ_btf, "int", BTF_KIND_INT);
+ exp->targ_struct_typedef = find_btf_type(targ_btf, "named_struct_typedef", BTF_KIND_TYPEDEF);
+ exp->targ_func_proto_typedef = find_btf_type(targ_btf, "func_proto_typedef", BTF_KIND_TYPEDEF);
+ exp->targ_arr_typedef = find_btf_type(targ_btf, "arr_typedef", BTF_KIND_TYPEDEF);
+
+ btf__free(targ_btf);
+ return 0;
+}
+
+static int setup_type_id_case_failure(struct core_reloc_test_case *test)
+{
+ struct core_reloc_type_id_output *exp = (void *)test->output;
+ int err;
+
+ err = setup_type_id_case_local(test);
+ if (err)
+ return err;
+
+ exp->targ_struct = 0;
+ exp->targ_union = 0;
+ exp->targ_enum = 0;
+ exp->targ_int = 0;
+ exp->targ_struct_typedef = 0;
+ exp->targ_func_proto_typedef = 0;
+ exp->targ_arr_typedef = 0;
+
+ return 0;
+}
+
static struct core_reloc_test_case test_cases[] = {
/* validate we can find kernel image and use its BTF for relocs */
{
@@ -530,6 +682,10 @@ static struct core_reloc_test_case test_cases[] = {
.struct_exists = 1,
.struct_sz = sizeof(struct a_struct),
}),
+
+ /* BTF_TYPE_ID_LOCAL/BTF_TYPE_ID_TARGET tests */
+ TYPE_ID_CASE(type_id, setup_type_id_case_success),
+ TYPE_ID_CASE(type_id___missing_targets, setup_type_id_case_failure),
};
struct data {
@@ -551,7 +707,7 @@ void test_core_reloc(void)
struct bpf_object_load_attr load_attr = {};
struct core_reloc_test_case *test_case;
const char *tp_name, *probe_name;
- int err, duration = 0, i, equal;
+ int err, i, equal;
struct bpf_link *link = NULL;
struct bpf_map *data_map;
struct bpf_program *prog;
@@ -567,11 +723,13 @@ void test_core_reloc(void)
if (!test__start_subtest(test_case->case_name))
continue;
- DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts,
- .relaxed_core_relocs = test_case->relaxed_core_relocs,
- );
+ if (test_case->setup) {
+ err = test_case->setup(test_case);
+ if (CHECK(err, "test_setup", "test #%d setup failed: %d\n", i, err))
+ continue;
+ }
- obj = bpf_object__open_file(test_case->bpf_obj_file, &opts);
+ obj = bpf_object__open_file(test_case->bpf_obj_file, NULL);
if (CHECK(IS_ERR(obj), "obj_open", "failed to open '%s': %ld\n",
test_case->bpf_obj_file, PTR_ERR(obj)))
continue;
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_type_id.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_type_id.c
new file mode 100644
index 000000000000..abbe5bddcefd
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_type_id.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_type_id x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_type_id___missing_targets.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_type_id___missing_targets.c
new file mode 100644
index 000000000000..24e7caf4f013
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_type_id___missing_targets.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_type_id___missing_targets x) {}
diff --git a/tools/testing/selftests/bpf/progs/core_reloc_types.h b/tools/testing/selftests/bpf/progs/core_reloc_types.h
index d998537867a2..10afcc5f219f 100644
--- a/tools/testing/selftests/bpf/progs/core_reloc_types.h
+++ b/tools/testing/selftests/bpf/progs/core_reloc_types.h
@@ -1034,3 +1034,44 @@ struct core_reloc_type_based___fn_wrong_args {
func_proto_typedef___fn_wrong_arg_cnt1 f6;
func_proto_typedef___fn_wrong_arg_cnt2 f7;
};
+
+/*
+ * TYPE ID MAPPING (LOCAL AND TARGET)
+ */
+struct core_reloc_type_id_output {
+ int local_anon_struct;
+ int local_anon_union;
+ int local_anon_enum;
+ int local_anon_func_proto_ptr;
+ int local_anon_void_ptr;
+ int local_anon_arr;
+
+ int local_struct;
+ int local_union;
+ int local_enum;
+ int local_int;
+ int local_struct_typedef;
+ int local_func_proto_typedef;
+ int local_arr_typedef;
+
+ int targ_struct;
+ int targ_union;
+ int targ_enum;
+ int targ_int;
+ int targ_struct_typedef;
+ int targ_func_proto_typedef;
+ int targ_arr_typedef;
+};
+
+struct core_reloc_type_id {
+ struct a_struct f1;
+ union a_union f2;
+ enum an_enum f3;
+ named_struct_typedef f4;
+ func_proto_typedef f5;
+ arr_typedef f6;
+};
+
+struct core_reloc_type_id___missing_targets {
+ /* nothing */
+};
diff --git a/tools/testing/selftests/bpf/progs/test_core_reloc_type_based.c b/tools/testing/selftests/bpf/progs/test_core_reloc_type_based.c
index 6ab259d02dc0..fb60f8195c53 100644
--- a/tools/testing/selftests/bpf/progs/test_core_reloc_type_based.c
+++ b/tools/testing/selftests/bpf/progs/test_core_reloc_type_based.c
@@ -48,20 +48,6 @@ typedef int (*func_proto_typedef)(long);
typedef char arr_typedef[20];
-struct core_reloc_type_based {
- struct a_struct f1;
- union a_union f2;
- enum an_enum f3;
- named_struct_typedef f4;
- anon_struct_typedef f5;
- struct_ptr_typedef f6;
- int_typedef f7;
- enum_typedef f8;
- void_ptr_typedef f9;
- func_proto_typedef f10;
- arr_typedef f11;
-};
-
struct core_reloc_type_based_output {
bool struct_exists;
bool union_exists;
diff --git a/tools/testing/selftests/bpf/progs/test_core_reloc_type_id.c b/tools/testing/selftests/bpf/progs/test_core_reloc_type_id.c
new file mode 100644
index 000000000000..23e6e6bf276c
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_core_reloc_type_id.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2020 Facebook
+
+#include <linux/bpf.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_core_read.h>
+
+char _license[] SEC("license") = "GPL";
+
+struct {
+ char in[256];
+ char out[256];
+ bool skip;
+} data = {};
+
+/* some types are shared with test_core_reloc_type_based.c */
+struct a_struct {
+ int x;
+};
+
+union a_union {
+ int y;
+ int z;
+};
+
+enum an_enum {
+ AN_ENUM_VAL1 = 1,
+ AN_ENUM_VAL2 = 2,
+ AN_ENUM_VAL3 = 3,
+};
+
+typedef struct a_struct named_struct_typedef;
+
+typedef int (*func_proto_typedef)(long);
+
+typedef char arr_typedef[20];
+
+struct core_reloc_type_id_output {
+ int local_anon_struct;
+ int local_anon_union;
+ int local_anon_enum;
+ int local_anon_func_proto_ptr;
+ int local_anon_void_ptr;
+ int local_anon_arr;
+
+ int local_struct;
+ int local_union;
+ int local_enum;
+ int local_int;
+ int local_struct_typedef;
+ int local_func_proto_typedef;
+ int local_arr_typedef;
+
+ int targ_struct;
+ int targ_union;
+ int targ_enum;
+ int targ_int;
+ int targ_struct_typedef;
+ int targ_func_proto_typedef;
+ int targ_arr_typedef;
+};
+
+/* preserve types even if Clang doesn't support built-in */
+struct a_struct t1 = {};
+union a_union t2 = {};
+enum an_enum t3 = 0;
+named_struct_typedef t4 = {};
+func_proto_typedef t5 = 0;
+arr_typedef t6 = {};
+
+SEC("raw_tracepoint/sys_enter")
+int test_core_type_id(void *ctx)
+{
+ /* We use __builtin_btf_type_id() in this tests, but up until the time
+ * __builtin_preserve_type_info() was added it contained a bug that
+ * would make this test fail. The bug was fixed with addition of
+ * __builtin_preserve_type_info(), though, so that's what we are using
+ * to detect whether this test has to be executed, however strange
+ * that might look like.
+ */
+#if __has_builtin(__builtin_preserve_type_info)
+ struct core_reloc_type_id_output *out = (void *)&data.out;
+
+ out->local_anon_struct = bpf_core_type_id_local(struct { int marker_field; });
+ out->local_anon_union = bpf_core_type_id_local(union { int marker_field; });
+ out->local_anon_enum = bpf_core_type_id_local(enum { MARKER_ENUM_VAL = 123 });
+ out->local_anon_func_proto_ptr = bpf_core_type_id_local(_Bool(*)(int));
+ out->local_anon_void_ptr = bpf_core_type_id_local(void *);
+ out->local_anon_arr = bpf_core_type_id_local(_Bool[47]);
+
+ out->local_struct = bpf_core_type_id_local(struct a_struct);
+ out->local_union = bpf_core_type_id_local(union a_union);
+ out->local_enum = bpf_core_type_id_local(enum an_enum);
+ out->local_int = bpf_core_type_id_local(int);
+ out->local_struct_typedef = bpf_core_type_id_local(named_struct_typedef);
+ out->local_func_proto_typedef = bpf_core_type_id_local(func_proto_typedef);
+ out->local_arr_typedef = bpf_core_type_id_local(arr_typedef);
+
+ out->targ_struct = bpf_core_type_id_kernel(struct a_struct);
+ out->targ_union = bpf_core_type_id_kernel(union a_union);
+ out->targ_enum = bpf_core_type_id_kernel(enum an_enum);
+ out->targ_int = bpf_core_type_id_kernel(int);
+ out->targ_struct_typedef = bpf_core_type_id_kernel(named_struct_typedef);
+ out->targ_func_proto_typedef = bpf_core_type_id_kernel(func_proto_typedef);
+ out->targ_arr_typedef = bpf_core_type_id_kernel(arr_typedef);
+#else
+ data.skip = true;
+#endif
+
+ return 0;
+}
--
2.24.1
^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH v3 bpf-next 4/5] libbpf: implement enum value-based CO-RE relocations
2020-08-19 19:45 [PATCH v3 bpf-next 0/5] Add libbpf support for type- and enum value-based CO-RE relocations Andrii Nakryiko
` (2 preceding siblings ...)
2020-08-19 19:45 ` [PATCH v3 bpf-next 3/5] selftests/bpf: add CO-RE relo test for TYPE_ID_LOCAL/TYPE_ID_TARGET Andrii Nakryiko
@ 2020-08-19 19:45 ` Andrii Nakryiko
2020-08-19 19:45 ` [PATCH v3 bpf-next 5/5] selftests/bpf: add tests for ENUMVAL_EXISTS/ENUMVAL_VALUE relocations Andrii Nakryiko
2020-08-19 21:58 ` [PATCH v3 bpf-next 0/5] Add libbpf support for type- and enum value-based CO-RE relocations Alexei Starovoitov
5 siblings, 0 replies; 8+ messages in thread
From: Andrii Nakryiko @ 2020-08-19 19:45 UTC (permalink / raw)
To: bpf, netdev, ast, daniel
Cc: andrii.nakryiko, kernel-team, Andrii Nakryiko, Yonghong Song
Implement two relocations of a new enumerator value-based CO-RE relocation
kind: ENUMVAL_EXISTS and ENUMVAL_VALUE.
First, ENUMVAL_EXISTS, allows to detect the presence of a named enumerator
value in the target (kernel) BTF. This is useful to do BPF helper/map/program
type support detection from BPF program side. bpf_core_enum_value_exists()
macro helper is provided to simplify built-in usage.
Second, ENUMVAL_VALUE, allows to capture enumerator integer value and relocate
it according to the target BTF, if it changes. This is useful to have
a guarantee against intentional or accidental re-ordering/re-numbering of some
of the internal (non-UAPI) enumerations, where kernel developers don't care
about UAPI backwards compatiblity concerns. bpf_core_enum_value() allows to
capture this succinctly and use correct enum values in code.
LLVM uses ldimm64 instruction to capture enumerator value-based relocations,
so add support for ldimm64 instruction patching as well.
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
tools/lib/bpf/bpf_core_read.h | 28 ++++++
tools/lib/bpf/libbpf.c | 145 ++++++++++++++++++++++++++++++--
tools/lib/bpf/libbpf_internal.h | 2 +
3 files changed, 170 insertions(+), 5 deletions(-)
diff --git a/tools/lib/bpf/bpf_core_read.h b/tools/lib/bpf/bpf_core_read.h
index 684bfb86361a..bbcefb3ff5a5 100644
--- a/tools/lib/bpf/bpf_core_read.h
+++ b/tools/lib/bpf/bpf_core_read.h
@@ -31,6 +31,12 @@ enum bpf_type_info_kind {
BPF_TYPE_SIZE = 1, /* type size in target kernel */
};
+/* second argument to __builtin_preserve_enum_value() built-in */
+enum bpf_enum_value_kind {
+ BPF_ENUMVAL_EXISTS = 0, /* enum value existence in kernel */
+ BPF_ENUMVAL_VALUE = 1, /* enum value value relocation */
+};
+
#define __CORE_RELO(src, field, info) \
__builtin_preserve_field_info((src)->field, BPF_FIELD_##info)
@@ -150,6 +156,28 @@ enum bpf_type_info_kind {
#define bpf_core_type_size(type) \
__builtin_preserve_type_info(*(typeof(type) *)0, BPF_TYPE_SIZE)
+/*
+ * Convenience macro to check that provided enumerator value is defined in
+ * a target kernel.
+ * Returns:
+ * 1, if specified enum type and its enumerator value are present in target
+ * kernel's BTF;
+ * 0, if no matching enum and/or enum value within that enum is found.
+ */
+#define bpf_core_enum_value_exists(enum_type, enum_value) \
+ __builtin_preserve_enum_value(*(typeof(enum_type) *)enum_value, BPF_ENUMVAL_EXISTS)
+
+/*
+ * Convenience macro to get the integer value of an enumerator value in
+ * a target kernel.
+ * Returns:
+ * 64-bit value, if specified enum type and its enumerator value are
+ * present in target kernel's BTF;
+ * 0, if no matching enum and/or enum value within that enum is found.
+ */
+#define bpf_core_enum_value(enum_type, enum_value) \
+ __builtin_preserve_enum_value(*(typeof(enum_type) *)enum_value, BPF_ENUMVAL_VALUE)
+
/*
* bpf_core_read() abstracts away bpf_probe_read_kernel() call and captures
* offset relocation for source address using __builtin_preserve_access_index()
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 882759dfc33e..77d420c02094 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -4115,6 +4115,8 @@ static const char *core_relo_kind_str(enum bpf_core_relo_kind kind)
case BPF_TYPE_ID_TARGET: return "target_type_id";
case BPF_TYPE_EXISTS: return "type_exists";
case BPF_TYPE_SIZE: return "type_size";
+ case BPF_ENUMVAL_EXISTS: return "enumval_exists";
+ case BPF_ENUMVAL_VALUE: return "enumval_value";
default: return "unknown";
}
}
@@ -4147,6 +4149,17 @@ static bool core_relo_is_type_based(enum bpf_core_relo_kind kind)
}
}
+static bool core_relo_is_enumval_based(enum bpf_core_relo_kind kind)
+{
+ switch (kind) {
+ case BPF_ENUMVAL_EXISTS:
+ case BPF_ENUMVAL_VALUE:
+ return true;
+ default:
+ return false;
+ }
+}
+
/*
* Turn bpf_core_relo into a low- and high-level spec representation,
* validating correctness along the way, as well as calculating resulting
@@ -4180,6 +4193,9 @@ static bool core_relo_is_type_based(enum bpf_core_relo_kind kind)
* Type-based relocations (TYPE_EXISTS/TYPE_SIZE,
* TYPE_ID_LOCAL/TYPE_ID_TARGET) don't capture any field information. Their
* spec and raw_spec are kept empty.
+ *
+ * Enum value-based relocations (ENUMVAL_EXISTS/ENUMVAL_VALUE) use access
+ * string to specify enumerator's value index that need to be relocated.
*/
static int bpf_core_parse_spec(const struct btf *btf,
__u32 type_id,
@@ -4224,16 +4240,25 @@ static int bpf_core_parse_spec(const struct btf *btf,
if (spec->raw_len == 0)
return -EINVAL;
- /* first spec value is always reloc type array index */
t = skip_mods_and_typedefs(btf, type_id, &id);
if (!t)
return -EINVAL;
access_idx = spec->raw_spec[0];
- spec->spec[0].type_id = id;
- spec->spec[0].idx = access_idx;
+ acc = &spec->spec[0];
+ acc->type_id = id;
+ acc->idx = access_idx;
spec->len++;
+ if (core_relo_is_enumval_based(relo_kind)) {
+ if (!btf_is_enum(t) || spec->raw_len > 1 || access_idx >= btf_vlen(t))
+ return -EINVAL;
+
+ /* record enumerator name in a first accessor */
+ acc->name = btf__name_by_offset(btf, btf_enum(t)[access_idx].name_off);
+ return 0;
+ }
+
if (!core_relo_is_field_based(relo_kind))
return -EINVAL;
@@ -4676,6 +4701,39 @@ static int bpf_core_spec_match(struct bpf_core_spec *local_spec,
local_acc = &local_spec->spec[0];
targ_acc = &targ_spec->spec[0];
+ if (core_relo_is_enumval_based(local_spec->relo_kind)) {
+ size_t local_essent_len, targ_essent_len;
+ const struct btf_enum *e;
+ const char *targ_name;
+
+ /* has to resolve to an enum */
+ targ_type = skip_mods_and_typedefs(targ_spec->btf, targ_id, &targ_id);
+ if (!btf_is_enum(targ_type))
+ return 0;
+
+ local_essent_len = bpf_core_essential_name_len(local_acc->name);
+
+ for (i = 0, e = btf_enum(targ_type); i < btf_vlen(targ_type); i++, e++) {
+ targ_name = btf__name_by_offset(targ_spec->btf, e->name_off);
+ targ_essent_len = bpf_core_essential_name_len(targ_name);
+ if (targ_essent_len != local_essent_len)
+ continue;
+ if (strncmp(local_acc->name, targ_name, local_essent_len) == 0) {
+ targ_acc->type_id = targ_id;
+ targ_acc->idx = i;
+ targ_acc->name = targ_name;
+ targ_spec->len++;
+ targ_spec->raw_spec[targ_spec->raw_len] = targ_acc->idx;
+ targ_spec->raw_len++;
+ return 1;
+ }
+ }
+ return 0;
+ }
+
+ if (!core_relo_is_field_based(local_spec->relo_kind))
+ return -EINVAL;
+
for (i = 0; i < local_spec->len; i++, local_acc++, targ_acc++) {
targ_type = skip_mods_and_typedefs(targ_spec->btf, targ_id,
&targ_id);
@@ -4880,6 +4938,31 @@ static int bpf_core_calc_type_relo(const struct bpf_core_relo *relo,
return 0;
}
+static int bpf_core_calc_enumval_relo(const struct bpf_core_relo *relo,
+ const struct bpf_core_spec *spec,
+ __u32 *val)
+{
+ const struct btf_type *t;
+ const struct btf_enum *e;
+
+ switch (relo->kind) {
+ case BPF_ENUMVAL_EXISTS:
+ *val = spec ? 1 : 0;
+ break;
+ case BPF_ENUMVAL_VALUE:
+ if (!spec)
+ return -EUCLEAN; /* request instruction poisoning */
+ t = btf__type_by_id(spec->btf, spec->spec[0].type_id);
+ e = btf_enum(t) + spec->spec[0].idx;
+ *val = e->val;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
struct bpf_core_relo_res
{
/* expected value in the instruction, unless validate == false */
@@ -4918,6 +5001,9 @@ static int bpf_core_calc_relo(const struct bpf_program *prog,
} else if (core_relo_is_type_based(relo->kind)) {
err = bpf_core_calc_type_relo(relo, local_spec, &res->orig_val);
err = err ?: bpf_core_calc_type_relo(relo, targ_spec, &res->new_val);
+ } else if (core_relo_is_enumval_based(relo->kind)) {
+ err = bpf_core_calc_enumval_relo(relo, local_spec, &res->orig_val);
+ err = err ?: bpf_core_calc_enumval_relo(relo, targ_spec, &res->new_val);
}
if (err == -EUCLEAN) {
@@ -4954,6 +5040,11 @@ static void bpf_core_poison_insn(struct bpf_program *prog, int relo_idx,
insn->imm = 195896080; /* => 0xbad2310 => "bad relo" */
}
+static bool is_ldimm64(struct bpf_insn *insn)
+{
+ return insn->code == (BPF_LD | BPF_IMM | BPF_DW);
+}
+
/*
* Patch relocatable BPF instruction.
*
@@ -4966,6 +5057,7 @@ static void bpf_core_poison_insn(struct bpf_program *prog, int relo_idx,
* 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 = <imm64> (load with 64-bit immediate value).
*/
static int bpf_core_patch_insn(struct bpf_program *prog,
const struct bpf_core_relo *relo,
@@ -4984,6 +5076,11 @@ static int bpf_core_patch_insn(struct bpf_program *prog,
class = BPF_CLASS(insn->code);
if (res->poison) {
+ /* poison second part of ldimm64 to avoid confusing error from
+ * verifier about "unknown opcode 00"
+ */
+ if (is_ldimm64(insn))
+ bpf_core_poison_insn(prog, relo_idx, insn_idx + 1, insn + 1);
bpf_core_poison_insn(prog, relo_idx, insn_idx, insn);
return 0;
}
@@ -5012,7 +5109,7 @@ static int bpf_core_patch_insn(struct bpf_program *prog,
case BPF_ST:
case BPF_STX:
if (res->validate && insn->off != orig_val) {
- pr_warn("prog '%s': relo #%d: unexpected insn #%d (LD/LDX/ST/STX) value: got %u, exp %u -> %u\n",
+ pr_warn("prog '%s': relo #%d: unexpected insn #%d (LDX/ST/STX) value: got %u, exp %u -> %u\n",
bpf_program__title(prog, false), relo_idx,
insn_idx, insn->off, orig_val, new_val);
return -EINVAL;
@@ -5029,8 +5126,36 @@ static int bpf_core_patch_insn(struct bpf_program *prog,
bpf_program__title(prog, false), relo_idx, insn_idx,
orig_val, new_val);
break;
+ case BPF_LD: {
+ __u64 imm;
+
+ if (!is_ldimm64(insn) ||
+ insn[0].src_reg != 0 || insn[0].off != 0 ||
+ insn_idx + 1 >= prog->insns_cnt ||
+ insn[1].code != 0 || insn[1].dst_reg != 0 ||
+ insn[1].src_reg != 0 || insn[1].off != 0) {
+ pr_warn("prog '%s': relo #%d: insn #%d (LDIMM64) has unexpected form\n",
+ bpf_program__title(prog, false), relo_idx, insn_idx);
+ return -EINVAL;
+ }
+
+ imm = insn[0].imm + ((__u64)insn[1].imm << 32);
+ if (res->validate && imm != orig_val) {
+ pr_warn("prog '%s': relo #%d: unexpected insn #%d (LDIMM64) value: got %llu, exp %u -> %u\n",
+ bpf_program__title(prog, false), relo_idx,
+ insn_idx, imm, orig_val, new_val);
+ return -EINVAL;
+ }
+
+ insn[0].imm = new_val;
+ insn[1].imm = 0; /* currently only 32-bit values are supported */
+ pr_debug("prog '%s': relo #%d: patched insn #%d (LDIMM64) imm64 %llu -> %u\n",
+ bpf_program__title(prog, false), relo_idx, insn_idx,
+ imm, new_val);
+ break;
+ }
default:
- pr_warn("prog '%s': relo #%d: trying to relocate unrecognized insn #%d, code:%x, src:%x, dst:%x, off:%x, imm:%x\n",
+ pr_warn("prog '%s': relo #%d: trying to relocate unrecognized insn #%d, code:0x%x, src:0x%x, dst:0x%x, off:0x%x, imm:0x%x\n",
bpf_program__title(prog, false), relo_idx,
insn_idx, insn->code, insn->src_reg, insn->dst_reg,
insn->off, insn->imm);
@@ -5047,6 +5172,7 @@ static int bpf_core_patch_insn(struct bpf_program *prog,
static void bpf_core_dump_spec(int level, const struct bpf_core_spec *spec)
{
const struct btf_type *t;
+ const struct btf_enum *e;
const char *s;
__u32 type_id;
int i;
@@ -5060,6 +5186,15 @@ static void bpf_core_dump_spec(int level, const struct bpf_core_spec *spec)
if (core_relo_is_type_based(spec->relo_kind))
return;
+ if (core_relo_is_enumval_based(spec->relo_kind)) {
+ t = skip_mods_and_typedefs(spec->btf, type_id, NULL);
+ e = btf_enum(t) + spec->raw_spec[0];
+ s = btf__name_by_offset(spec->btf, e->name_off);
+
+ libbpf_print(level, "::%s = %u", s, e->val);
+ return;
+ }
+
if (core_relo_is_field_based(spec->relo_kind)) {
for (i = 0; i < spec->len; i++) {
if (spec->spec[i].name)
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index edd3511aa242..61dff515a2f0 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -242,6 +242,8 @@ enum bpf_core_relo_kind {
BPF_TYPE_ID_TARGET = 7, /* type ID in target kernel */
BPF_TYPE_EXISTS = 8, /* type existence in target kernel */
BPF_TYPE_SIZE = 9, /* type size in bytes */
+ BPF_ENUMVAL_EXISTS = 10, /* enum value existence in target kernel */
+ BPF_ENUMVAL_VALUE = 11, /* enum value integer value */
};
/* The minimum bpf_core_relo checked by the loader
--
2.24.1
^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH v3 bpf-next 5/5] selftests/bpf: add tests for ENUMVAL_EXISTS/ENUMVAL_VALUE relocations
2020-08-19 19:45 [PATCH v3 bpf-next 0/5] Add libbpf support for type- and enum value-based CO-RE relocations Andrii Nakryiko
` (3 preceding siblings ...)
2020-08-19 19:45 ` [PATCH v3 bpf-next 4/5] libbpf: implement enum value-based CO-RE relocations Andrii Nakryiko
@ 2020-08-19 19:45 ` Andrii Nakryiko
2020-08-19 21:58 ` [PATCH v3 bpf-next 0/5] Add libbpf support for type- and enum value-based CO-RE relocations Alexei Starovoitov
5 siblings, 0 replies; 8+ messages in thread
From: Andrii Nakryiko @ 2020-08-19 19:45 UTC (permalink / raw)
To: bpf, netdev, ast, daniel
Cc: andrii.nakryiko, kernel-team, Andrii Nakryiko, Yonghong Song
Add tests validating existence and value relocations for enum value-based
relocations. If __builtin_preserve_enum_value() built-in is not supported,
skip tests.
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
.../selftests/bpf/prog_tests/core_reloc.c | 56 +++++++++++++
.../bpf/progs/btf__core_reloc_enumval.c | 3 +
.../progs/btf__core_reloc_enumval___diff.c | 3 +
.../btf__core_reloc_enumval___err_missing.c | 3 +
.../btf__core_reloc_enumval___val3_missing.c | 3 +
.../selftests/bpf/progs/core_reloc_types.h | 84 +++++++++++++++++++
.../bpf/progs/test_core_reloc_enumval.c | 72 ++++++++++++++++
7 files changed, 224 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_enumval.c
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_enumval___diff.c
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_enumval___err_missing.c
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_enumval___val3_missing.c
create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_enumval.c
diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
index ad550510ef69..30e40ff4b0d8 100644
--- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c
+++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
@@ -289,6 +289,23 @@ static int duration = 0;
.fails = true, \
}
+#define ENUMVAL_CASE_COMMON(name) \
+ .case_name = #name, \
+ .bpf_obj_file = "test_core_reloc_enumval.o", \
+ .btf_src_file = "btf__core_reloc_" #name ".o" \
+
+#define ENUMVAL_CASE(name, ...) { \
+ ENUMVAL_CASE_COMMON(name), \
+ .output = STRUCT_TO_CHAR_PTR(core_reloc_enumval_output) \
+ __VA_ARGS__, \
+ .output_len = sizeof(struct core_reloc_enumval_output), \
+}
+
+#define ENUMVAL_ERR_CASE(name) { \
+ ENUMVAL_CASE_COMMON(name), \
+ .fails = true, \
+}
+
struct core_reloc_test_case;
typedef int (*setup_test_fn)(struct core_reloc_test_case *test);
@@ -686,6 +703,45 @@ static struct core_reloc_test_case test_cases[] = {
/* BTF_TYPE_ID_LOCAL/BTF_TYPE_ID_TARGET tests */
TYPE_ID_CASE(type_id, setup_type_id_case_success),
TYPE_ID_CASE(type_id___missing_targets, setup_type_id_case_failure),
+
+ /* Enumerator value existence and value relocations */
+ ENUMVAL_CASE(enumval, {
+ .named_val1_exists = true,
+ .named_val2_exists = true,
+ .named_val3_exists = true,
+ .anon_val1_exists = true,
+ .anon_val2_exists = true,
+ .anon_val3_exists = true,
+ .named_val1 = 1,
+ .named_val2 = 2,
+ .anon_val1 = 0x10,
+ .anon_val2 = 0x20,
+ }),
+ ENUMVAL_CASE(enumval___diff, {
+ .named_val1_exists = true,
+ .named_val2_exists = true,
+ .named_val3_exists = true,
+ .anon_val1_exists = true,
+ .anon_val2_exists = true,
+ .anon_val3_exists = true,
+ .named_val1 = 101,
+ .named_val2 = 202,
+ .anon_val1 = 0x11,
+ .anon_val2 = 0x22,
+ }),
+ ENUMVAL_CASE(enumval___val3_missing, {
+ .named_val1_exists = true,
+ .named_val2_exists = true,
+ .named_val3_exists = false,
+ .anon_val1_exists = true,
+ .anon_val2_exists = true,
+ .anon_val3_exists = false,
+ .named_val1 = 111,
+ .named_val2 = 222,
+ .anon_val1 = 0x111,
+ .anon_val2 = 0x222,
+ }),
+ ENUMVAL_ERR_CASE(enumval___err_missing),
};
struct data {
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_enumval.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_enumval.c
new file mode 100644
index 000000000000..48e62f3f074f
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_enumval.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_enumval x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_enumval___diff.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_enumval___diff.c
new file mode 100644
index 000000000000..53e5e5a76888
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_enumval___diff.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_enumval___diff x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_enumval___err_missing.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_enumval___err_missing.c
new file mode 100644
index 000000000000..d024fb2ac06e
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_enumval___err_missing.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_enumval___err_missing x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_enumval___val3_missing.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_enumval___val3_missing.c
new file mode 100644
index 000000000000..9de6595d250c
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_enumval___val3_missing.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_enumval___val3_missing x) {}
diff --git a/tools/testing/selftests/bpf/progs/core_reloc_types.h b/tools/testing/selftests/bpf/progs/core_reloc_types.h
index 10afcc5f219f..e6e616cb7bc9 100644
--- a/tools/testing/selftests/bpf/progs/core_reloc_types.h
+++ b/tools/testing/selftests/bpf/progs/core_reloc_types.h
@@ -1075,3 +1075,87 @@ struct core_reloc_type_id {
struct core_reloc_type_id___missing_targets {
/* nothing */
};
+
+/*
+ * ENUMERATOR VALUE EXISTENCE AND VALUE RELOCATION
+ */
+struct core_reloc_enumval_output {
+ bool named_val1_exists;
+ bool named_val2_exists;
+ bool named_val3_exists;
+ bool anon_val1_exists;
+ bool anon_val2_exists;
+ bool anon_val3_exists;
+
+ int named_val1;
+ int named_val2;
+ int anon_val1;
+ int anon_val2;
+};
+
+enum named_enum {
+ NAMED_ENUM_VAL1 = 1,
+ NAMED_ENUM_VAL2 = 2,
+ NAMED_ENUM_VAL3 = 3,
+};
+
+typedef enum {
+ ANON_ENUM_VAL1 = 0x10,
+ ANON_ENUM_VAL2 = 0x20,
+ ANON_ENUM_VAL3 = 0x30,
+} anon_enum;
+
+struct core_reloc_enumval {
+ enum named_enum f1;
+ anon_enum f2;
+};
+
+/* differing enumerator values */
+enum named_enum___diff {
+ NAMED_ENUM_VAL1___diff = 101,
+ NAMED_ENUM_VAL2___diff = 202,
+ NAMED_ENUM_VAL3___diff = 303,
+};
+
+typedef enum {
+ ANON_ENUM_VAL1___diff = 0x11,
+ ANON_ENUM_VAL2___diff = 0x22,
+ ANON_ENUM_VAL3___diff = 0x33,
+} anon_enum___diff;
+
+struct core_reloc_enumval___diff {
+ enum named_enum___diff f1;
+ anon_enum___diff f2;
+};
+
+/* missing (optional) third enum value */
+enum named_enum___val3_missing {
+ NAMED_ENUM_VAL1___val3_missing = 111,
+ NAMED_ENUM_VAL2___val3_missing = 222,
+};
+
+typedef enum {
+ ANON_ENUM_VAL1___val3_missing = 0x111,
+ ANON_ENUM_VAL2___val3_missing = 0x222,
+} anon_enum___val3_missing;
+
+struct core_reloc_enumval___val3_missing {
+ enum named_enum___val3_missing f1;
+ anon_enum___val3_missing f2;
+};
+
+/* missing (mandatory) second enum value, should fail */
+enum named_enum___err_missing {
+ NAMED_ENUM_VAL1___err_missing = 1,
+ NAMED_ENUM_VAL3___err_missing = 3,
+};
+
+typedef enum {
+ ANON_ENUM_VAL1___err_missing = 0x111,
+ ANON_ENUM_VAL3___err_missing = 0x222,
+} anon_enum___err_missing;
+
+struct core_reloc_enumval___err_missing {
+ enum named_enum___err_missing f1;
+ anon_enum___err_missing f2;
+};
diff --git a/tools/testing/selftests/bpf/progs/test_core_reloc_enumval.c b/tools/testing/selftests/bpf/progs/test_core_reloc_enumval.c
new file mode 100644
index 000000000000..e7ef3dada2bf
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_core_reloc_enumval.c
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2020 Facebook
+
+#include <linux/bpf.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_core_read.h>
+
+char _license[] SEC("license") = "GPL";
+
+struct {
+ char in[256];
+ char out[256];
+ bool skip;
+} data = {};
+
+enum named_enum {
+ NAMED_ENUM_VAL1 = 1,
+ NAMED_ENUM_VAL2 = 2,
+ NAMED_ENUM_VAL3 = 3,
+};
+
+typedef enum {
+ ANON_ENUM_VAL1 = 0x10,
+ ANON_ENUM_VAL2 = 0x20,
+ ANON_ENUM_VAL3 = 0x30,
+} anon_enum;
+
+struct core_reloc_enumval_output {
+ bool named_val1_exists;
+ bool named_val2_exists;
+ bool named_val3_exists;
+ bool anon_val1_exists;
+ bool anon_val2_exists;
+ bool anon_val3_exists;
+
+ int named_val1;
+ int named_val2;
+ int anon_val1;
+ int anon_val2;
+};
+
+SEC("raw_tracepoint/sys_enter")
+int test_core_enumval(void *ctx)
+{
+#if __has_builtin(__builtin_preserve_enum_value)
+ struct core_reloc_enumval_output *out = (void *)&data.out;
+ enum named_enum named = 0;
+ anon_enum anon = 0;
+
+ out->named_val1_exists = bpf_core_enum_value_exists(named, NAMED_ENUM_VAL1);
+ out->named_val2_exists = bpf_core_enum_value_exists(enum named_enum, NAMED_ENUM_VAL2);
+ out->named_val3_exists = bpf_core_enum_value_exists(enum named_enum, NAMED_ENUM_VAL3);
+
+ out->anon_val1_exists = bpf_core_enum_value_exists(anon, ANON_ENUM_VAL1);
+ out->anon_val2_exists = bpf_core_enum_value_exists(anon_enum, ANON_ENUM_VAL2);
+ out->anon_val3_exists = bpf_core_enum_value_exists(anon_enum, ANON_ENUM_VAL3);
+
+ out->named_val1 = bpf_core_enum_value(named, NAMED_ENUM_VAL1);
+ out->named_val2 = bpf_core_enum_value(named, NAMED_ENUM_VAL2);
+ /* NAMED_ENUM_VAL3 value is optional */
+
+ out->anon_val1 = bpf_core_enum_value(anon, ANON_ENUM_VAL1);
+ out->anon_val2 = bpf_core_enum_value(anon, ANON_ENUM_VAL2);
+ /* ANON_ENUM_VAL3 value is optional */
+#else
+ data.skip = true;
+#endif
+
+ return 0;
+}
--
2.24.1
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH v3 bpf-next 0/5] Add libbpf support for type- and enum value-based CO-RE relocations
2020-08-19 19:45 [PATCH v3 bpf-next 0/5] Add libbpf support for type- and enum value-based CO-RE relocations Andrii Nakryiko
` (4 preceding siblings ...)
2020-08-19 19:45 ` [PATCH v3 bpf-next 5/5] selftests/bpf: add tests for ENUMVAL_EXISTS/ENUMVAL_VALUE relocations Andrii Nakryiko
@ 2020-08-19 21:58 ` Alexei Starovoitov
2020-08-19 22:37 ` Andrii Nakryiko
5 siblings, 1 reply; 8+ messages in thread
From: Alexei Starovoitov @ 2020-08-19 21:58 UTC (permalink / raw)
To: Andrii Nakryiko; +Cc: bpf, netdev, ast, daniel, andrii.nakryiko, kernel-team
On Wed, Aug 19, 2020 at 12:45:14PM -0700, Andrii Nakryiko wrote:
>
> Selftests are added for all the new features. Selftests utilizing new Clang
> built-ins are designed such that they will compile with older Clangs and will
> be skipped during test runs. So this shouldn't cause any build and test
> failures on systems with slightly outdated Clang compiler.
>
> LLVM patches adding these relocation in Clang:
> - __builtin_btf_type_id() ([0], [1], [2]);
> - __builtin_preserve_type_info(), __builtin_preserve_enum_value() ([3], [4]).
>
> [0] https://reviews.llvm.org/D74572
> [1] https://reviews.llvm.org/D74668
> [2] https://reviews.llvm.org/D85174
> [3] https://reviews.llvm.org/D83878
> [4] https://reviews.llvm.org/D83242
Applied.
Thank you for listing the above in the commit log, but please follow up with
corresponding update to README.rst and mention the same details there: the
symptoms of missing clang features, which tests are going to be skipped for
older clang, etc.
Also progs/test_core_reloc_type_id.c talks about some bug with
__builtin_preserve_type_info() please add llvm diff number that fixes
it to that .c file.
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH v3 bpf-next 0/5] Add libbpf support for type- and enum value-based CO-RE relocations
2020-08-19 21:58 ` [PATCH v3 bpf-next 0/5] Add libbpf support for type- and enum value-based CO-RE relocations Alexei Starovoitov
@ 2020-08-19 22:37 ` Andrii Nakryiko
0 siblings, 0 replies; 8+ messages in thread
From: Andrii Nakryiko @ 2020-08-19 22:37 UTC (permalink / raw)
To: Alexei Starovoitov
Cc: Andrii Nakryiko, bpf, Networking, Alexei Starovoitov,
Daniel Borkmann, Kernel Team
On Wed, Aug 19, 2020 at 2:58 PM Alexei Starovoitov
<alexei.starovoitov@gmail.com> wrote:
>
> On Wed, Aug 19, 2020 at 12:45:14PM -0700, Andrii Nakryiko wrote:
> >
> > Selftests are added for all the new features. Selftests utilizing new Clang
> > built-ins are designed such that they will compile with older Clangs and will
> > be skipped during test runs. So this shouldn't cause any build and test
> > failures on systems with slightly outdated Clang compiler.
> >
> > LLVM patches adding these relocation in Clang:
> > - __builtin_btf_type_id() ([0], [1], [2]);
> > - __builtin_preserve_type_info(), __builtin_preserve_enum_value() ([3], [4]).
> >
> > [0] https://reviews.llvm.org/D74572
> > [1] https://reviews.llvm.org/D74668
> > [2] https://reviews.llvm.org/D85174
> > [3] https://reviews.llvm.org/D83878
> > [4] https://reviews.llvm.org/D83242
>
> Applied.
Thanks!
> Thank you for listing the above in the commit log, but please follow up with
> corresponding update to README.rst and mention the same details there: the
> symptoms of missing clang features, which tests are going to be skipped for
> older clang, etc.
Ok, sure.
>
> Also progs/test_core_reloc_type_id.c talks about some bug with
> __builtin_preserve_type_info() please add llvm diff number that fixes
> it to that .c file.
Ok, that's [2] above.
^ permalink raw reply [flat|nested] 8+ messages in thread