diff options
author | Andrii Nakryiko <andrii@kernel.org> | 2022-07-05 20:24:13 -0700 |
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committer | Andrii Nakryiko <andrii@kernel.org> | 2022-07-05 21:15:20 -0700 |
commit | f6b9f6d57e5c765b5ff358af1d7749df5e30334c (patch) | |
tree | 5000fbb43fba0126f39d3ead0375fd00c558eae7 | |
parent | cfb5a2dbf1413a0086e987d99ad591b91fc9cf5c (diff) | |
parent | 950b347787224e62f59c099e3e3f3f6ecc720d61 (diff) | |
download | linux-f6b9f6d57e5c765b5ff358af1d7749df5e30334c.tar.gz linux-f6b9f6d57e5c765b5ff358af1d7749df5e30334c.tar.bz2 linux-f6b9f6d57e5c765b5ff358af1d7749df5e30334c.zip |
Merge branch 'Introduce type match support'
Daniel Müller says:
====================
This patch set proposes the addition of a new way for performing type queries to
BPF. It introduces the "type matches" relation, similar to what is already
present with "type exists" (in the form of bpf_core_type_exists).
"type exists" performs fairly superficial checking, mostly concerned with
whether a type exists in the kernel and is of the same kind (enum/struct/...).
Notably, compatibility checks for members of composite types is lacking.
The newly introduced "type matches" (bpf_core_type_matches) fills this gap in
that it performs stricter checks: compatibility of members and existence of
similarly named enum variants is checked as well. E.g., given these definitions:
struct task_struct___og { int pid; int tgid; };
struct task_struct___foo { int foo; }
'task_struct___og' would "match" the kernel type 'task_struct', because the
members match up, while 'task_struct___foo' would not match, because the
kernel's 'task_struct' has no member named 'foo'.
More precisely, the "type match" relation is defined as follows (copied from
source):
- modifiers and typedefs are stripped (and, hence, effectively ignored)
- generally speaking types need to be of same kind (struct vs. struct, union
vs. union, etc.)
- exceptions are struct/union behind a pointer which could also match a
forward declaration of a struct or union, respectively, and enum vs.
enum64 (see below)
Then, depending on type:
- integers:
- match if size and signedness match
- arrays & pointers:
- target types are recursively matched
- structs & unions:
- local members need to exist in target with the same name
- for each member we recursively check match unless it is already behind a
pointer, in which case we only check matching names and compatible kind
- enums:
- local variants have to have a match in target by symbolic name (but not
numeric value)
- size has to match (but enum may match enum64 and vice versa)
- function pointers:
- number and position of arguments in local type has to match target
- for each argument and the return value we recursively check match
Enabling this feature requires a new relocation to be made known to the
compiler. This is being taken care of for LLVM as part of
https://reviews.llvm.org/D126838.
If applied, among other things, usage of this functionality could have helped
flag issues such as the one discussed here
https://lore.kernel.org/all/93a20759600c05b6d9e4359a1517c88e06b44834.camel@fb.com/
earlier.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
---
Changelog:
v2 -> v3:
- renamed btfgen_mark_types_match
- covered BTF_KIND_RESTRICT in type match marking logic
- used bpf_core_names_match in more places
- reworked "behind pointer" logic
- added test using live task_struct
v1 -> v2:
- deduplicated and moved core algorithm into relo_core.c
- adjusted bpf_core_names_match to get btf_type passed in
- removed some length equality checks before strncmp usage
- correctly use kflag from targ_t instead of local_t
- added comment for meaning of kflag w/ FWD kind
- __u32 -> u32
- handle BTF_KIND_FWD properly in bpftool marking logic
- rebased
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
-rw-r--r-- | include/uapi/linux/bpf.h | 1 | ||||
-rw-r--r-- | kernel/bpf/btf.c | 9 | ||||
-rw-r--r-- | tools/bpf/bpftool/gen.c | 108 | ||||
-rw-r--r-- | tools/include/uapi/linux/bpf.h | 1 | ||||
-rw-r--r-- | tools/lib/bpf/bpf_core_read.h | 11 | ||||
-rw-r--r-- | tools/lib/bpf/libbpf.c | 6 | ||||
-rw-r--r-- | tools/lib/bpf/relo_core.c | 279 | ||||
-rw-r--r-- | tools/lib/bpf/relo_core.h | 4 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/prog_tests/core_reloc.c | 73 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___diff.c | 3 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/progs/core_reloc_types.h | 108 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c | 19 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/progs/test_core_reloc_type_based.c | 44 |
13 files changed, 648 insertions, 18 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index ad9e7311c4cf..379e68fb866f 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -6786,6 +6786,7 @@ enum bpf_core_relo_kind { BPF_CORE_TYPE_SIZE = 9, /* type size in bytes */ BPF_CORE_ENUMVAL_EXISTS = 10, /* enum value existence in target kernel */ BPF_CORE_ENUMVAL_VALUE = 11, /* enum value integer value */ + BPF_CORE_TYPE_MATCHES = 12, /* type match in target kernel */ }; /* diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 8d3c7ab8af46..4f2408a4df08 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -7443,6 +7443,15 @@ int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, MAX_TYPES_ARE_COMPAT_DEPTH); } +#define MAX_TYPES_MATCH_DEPTH 2 + +int bpf_core_types_match(const struct btf *local_btf, u32 local_id, + const struct btf *targ_btf, u32 targ_id) +{ + return __bpf_core_types_match(local_btf, local_id, targ_btf, targ_id, false, + MAX_TYPES_MATCH_DEPTH); +} + static bool bpf_core_is_flavor_sep(const char *s) { /* check X___Y name pattern, where X and Y are not underscores */ diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c index 480cbd859359..3d35fbc5fe16 100644 --- a/tools/bpf/bpftool/gen.c +++ b/tools/bpf/bpftool/gen.c @@ -1856,6 +1856,112 @@ static int btfgen_record_field_relo(struct btfgen_info *info, struct bpf_core_sp return 0; } +/* Mark types, members, and member types. Compared to btfgen_record_field_relo, + * this function does not rely on the target spec for inferring members, but + * uses the associated BTF. + * + * The `behind_ptr` argument is used to stop marking of composite types reached + * through a pointer. This way, we can keep BTF size in check while providing + * reasonable match semantics. + */ +static int btfgen_mark_type_match(struct btfgen_info *info, __u32 type_id, bool behind_ptr) +{ + const struct btf_type *btf_type; + struct btf *btf = info->src_btf; + struct btf_type *cloned_type; + int i, err; + + if (type_id == 0) + return 0; + + btf_type = btf__type_by_id(btf, type_id); + /* mark type on cloned BTF as used */ + cloned_type = (struct btf_type *)btf__type_by_id(info->marked_btf, type_id); + cloned_type->name_off = MARKED; + + switch (btf_kind(btf_type)) { + case BTF_KIND_UNKN: + case BTF_KIND_INT: + case BTF_KIND_FLOAT: + case BTF_KIND_ENUM: + case BTF_KIND_ENUM64: + break; + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: { + struct btf_member *m = btf_members(btf_type); + __u16 vlen = btf_vlen(btf_type); + + if (behind_ptr) + break; + + for (i = 0; i < vlen; i++, m++) { + /* mark member */ + btfgen_mark_member(info, type_id, i); + + /* mark member's type */ + err = btfgen_mark_type_match(info, m->type, false); + if (err) + return err; + } + break; + } + case BTF_KIND_CONST: + case BTF_KIND_FWD: + case BTF_KIND_RESTRICT: + case BTF_KIND_TYPEDEF: + case BTF_KIND_VOLATILE: + return btfgen_mark_type_match(info, btf_type->type, behind_ptr); + case BTF_KIND_PTR: + return btfgen_mark_type_match(info, btf_type->type, true); + case BTF_KIND_ARRAY: { + struct btf_array *array; + + array = btf_array(btf_type); + /* mark array type */ + err = btfgen_mark_type_match(info, array->type, false); + /* mark array's index type */ + err = err ? : btfgen_mark_type_match(info, array->index_type, false); + if (err) + return err; + break; + } + case BTF_KIND_FUNC_PROTO: { + __u16 vlen = btf_vlen(btf_type); + struct btf_param *param; + + /* mark ret type */ + err = btfgen_mark_type_match(info, btf_type->type, false); + if (err) + return err; + + /* mark parameters types */ + param = btf_params(btf_type); + for (i = 0; i < vlen; i++) { + err = btfgen_mark_type_match(info, param->type, false); + if (err) + return err; + param++; + } + break; + } + /* tells if some other type needs to be handled */ + default: + p_err("unsupported kind: %s (%d)", btf_kind_str(btf_type), type_id); + return -EINVAL; + } + + return 0; +} + +/* Mark types, members, and member types. Compared to btfgen_record_field_relo, + * this function does not rely on the target spec for inferring members, but + * uses the associated BTF. + */ +static int btfgen_record_type_match_relo(struct btfgen_info *info, struct bpf_core_spec *targ_spec) +{ + return btfgen_mark_type_match(info, targ_spec->root_type_id, false); +} + static int btfgen_record_type_relo(struct btfgen_info *info, struct bpf_core_spec *targ_spec) { return btfgen_mark_type(info, targ_spec->root_type_id, true); @@ -1882,6 +1988,8 @@ static int btfgen_record_reloc(struct btfgen_info *info, struct bpf_core_spec *r case BPF_CORE_TYPE_EXISTS: case BPF_CORE_TYPE_SIZE: return btfgen_record_type_relo(info, res); + case BPF_CORE_TYPE_MATCHES: + return btfgen_record_type_match_relo(info, res); case BPF_CORE_ENUMVAL_EXISTS: case BPF_CORE_ENUMVAL_VALUE: return btfgen_record_enumval_relo(info, res); diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index ad9e7311c4cf..379e68fb866f 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -6786,6 +6786,7 @@ enum bpf_core_relo_kind { BPF_CORE_TYPE_SIZE = 9, /* type size in bytes */ BPF_CORE_ENUMVAL_EXISTS = 10, /* enum value existence in target kernel */ BPF_CORE_ENUMVAL_VALUE = 11, /* enum value integer value */ + BPF_CORE_TYPE_MATCHES = 12, /* type match in target kernel */ }; /* diff --git a/tools/lib/bpf/bpf_core_read.h b/tools/lib/bpf/bpf_core_read.h index fd48b1ff59ca..496e6a8ee0dc 100644 --- a/tools/lib/bpf/bpf_core_read.h +++ b/tools/lib/bpf/bpf_core_read.h @@ -29,6 +29,7 @@ enum bpf_type_id_kind { enum bpf_type_info_kind { BPF_TYPE_EXISTS = 0, /* type existence in target kernel */ BPF_TYPE_SIZE = 1, /* type size in target kernel */ + BPF_TYPE_MATCHES = 2, /* type match in target kernel */ }; /* second argument to __builtin_preserve_enum_value() built-in */ @@ -184,6 +185,16 @@ enum bpf_enum_value_kind { __builtin_preserve_type_info(*(typeof(type) *)0, BPF_TYPE_EXISTS) /* + * Convenience macro to check that provided named type + * (struct/union/enum/typedef) "matches" that in a target kernel. + * Returns: + * 1, if the type matches in the target kernel's BTF; + * 0, if the type does not match any in the target kernel + */ +#define bpf_core_type_matches(type) \ + __builtin_preserve_type_info(*(typeof(type) *)0, BPF_TYPE_MATCHES) + +/* * Convenience macro to get the byte size of a provided named type * (struct/union/enum/typedef) in a target kernel. * Returns: diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 8a45a84eb9b2..64c4cc6140d3 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -5470,6 +5470,12 @@ int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, return __bpf_core_types_are_compat(local_btf, local_id, targ_btf, targ_id, 32); } +int bpf_core_types_match(const struct btf *local_btf, __u32 local_id, + const struct btf *targ_btf, __u32 targ_id) +{ + return __bpf_core_types_match(local_btf, local_id, targ_btf, targ_id, false, 32); +} + static size_t bpf_core_hash_fn(const void *key, void *ctx) { return (size_t)key; diff --git a/tools/lib/bpf/relo_core.c b/tools/lib/bpf/relo_core.c index e070123332cd..fe2533022aa9 100644 --- a/tools/lib/bpf/relo_core.c +++ b/tools/lib/bpf/relo_core.c @@ -95,6 +95,7 @@ static const char *core_relo_kind_str(enum bpf_core_relo_kind kind) case BPF_CORE_TYPE_ID_LOCAL: return "local_type_id"; case BPF_CORE_TYPE_ID_TARGET: return "target_type_id"; case BPF_CORE_TYPE_EXISTS: return "type_exists"; + case BPF_CORE_TYPE_MATCHES: return "type_matches"; case BPF_CORE_TYPE_SIZE: return "type_size"; case BPF_CORE_ENUMVAL_EXISTS: return "enumval_exists"; case BPF_CORE_ENUMVAL_VALUE: return "enumval_value"; @@ -123,6 +124,7 @@ static bool core_relo_is_type_based(enum bpf_core_relo_kind kind) case BPF_CORE_TYPE_ID_LOCAL: case BPF_CORE_TYPE_ID_TARGET: case BPF_CORE_TYPE_EXISTS: + case BPF_CORE_TYPE_MATCHES: case BPF_CORE_TYPE_SIZE: return true; default: @@ -251,7 +253,7 @@ recur: * - 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-based relocations (TYPE_EXISTS/TYPE_MATCHES/TYPE_SIZE, * TYPE_ID_LOCAL/TYPE_ID_TARGET) don't capture any field information. Their * spec and raw_spec are kept empty. * @@ -568,9 +570,14 @@ static int bpf_core_spec_match(struct bpf_core_spec *local_spec, 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); + if (local_spec->relo_kind == BPF_CORE_TYPE_MATCHES) + return bpf_core_types_match(local_spec->btf, + local_spec->root_type_id, + targ_btf, targ_id); + else + return bpf_core_types_are_compat(local_spec->btf, + local_spec->root_type_id, + targ_btf, targ_id); } local_acc = &local_spec->spec[0]; @@ -819,6 +826,7 @@ static int bpf_core_calc_type_relo(const struct bpf_core_relo *relo, *validate = false; break; case BPF_CORE_TYPE_EXISTS: + case BPF_CORE_TYPE_MATCHES: *val = 1; break; case BPF_CORE_TYPE_SIZE: @@ -1410,3 +1418,266 @@ int bpf_core_calc_relo_insn(const char *prog_name, return 0; } + +static bool bpf_core_names_match(const struct btf *local_btf, size_t local_name_off, + const struct btf *targ_btf, size_t targ_name_off) +{ + const char *local_n, *targ_n; + size_t local_len, targ_len; + + local_n = btf__name_by_offset(local_btf, local_name_off); + targ_n = btf__name_by_offset(targ_btf, targ_name_off); + + if (str_is_empty(targ_n)) + return str_is_empty(local_n); + + targ_len = bpf_core_essential_name_len(targ_n); + local_len = bpf_core_essential_name_len(local_n); + + return targ_len == local_len && strncmp(local_n, targ_n, local_len) == 0; +} + +static int bpf_core_enums_match(const struct btf *local_btf, const struct btf_type *local_t, + const struct btf *targ_btf, const struct btf_type *targ_t) +{ + __u16 local_vlen = btf_vlen(local_t); + __u16 targ_vlen = btf_vlen(targ_t); + int i, j; + + if (local_t->size != targ_t->size) + return 0; + + if (local_vlen > targ_vlen) + return 0; + + /* iterate over the local enum's variants and make sure each has + * a symbolic name correspondent in the target + */ + for (i = 0; i < local_vlen; i++) { + bool matched = false; + __u32 local_n_off, targ_n_off; + + local_n_off = btf_is_enum(local_t) ? btf_enum(local_t)[i].name_off : + btf_enum64(local_t)[i].name_off; + + for (j = 0; j < targ_vlen; j++) { + targ_n_off = btf_is_enum(targ_t) ? btf_enum(targ_t)[j].name_off : + btf_enum64(targ_t)[j].name_off; + + if (bpf_core_names_match(local_btf, local_n_off, targ_btf, targ_n_off)) { + matched = true; + break; + } + } + + if (!matched) + return 0; + } + return 1; +} + +static int bpf_core_composites_match(const struct btf *local_btf, const struct btf_type *local_t, + const struct btf *targ_btf, const struct btf_type *targ_t, + bool behind_ptr, int level) +{ + const struct btf_member *local_m = btf_members(local_t); + __u16 local_vlen = btf_vlen(local_t); + __u16 targ_vlen = btf_vlen(targ_t); + int i, j, err; + + if (local_vlen > targ_vlen) + return 0; + + /* check that all local members have a match in the target */ + for (i = 0; i < local_vlen; i++, local_m++) { + const struct btf_member *targ_m = btf_members(targ_t); + bool matched = false; + + for (j = 0; j < targ_vlen; j++, targ_m++) { + if (!bpf_core_names_match(local_btf, local_m->name_off, + targ_btf, targ_m->name_off)) + continue; + + err = __bpf_core_types_match(local_btf, local_m->type, targ_btf, + targ_m->type, behind_ptr, level - 1); + if (err > 0) { + matched = true; + break; + } + } + + if (!matched) + return 0; + } + return 1; +} + +/* Check that two types "match". + * + * The matching relation is defined as follows: + * - modifiers and typedefs are stripped (and, hence, effectively ignored) + * - generally speaking types need to be of same kind (struct vs. struct, union + * vs. union, etc.) + * - exceptions are struct/union behind a pointer which could also match a + * forward declaration of a struct or union, respectively, and enum vs. + * enum64 (see below) + * Then, depending on type: + * - integers: + * - match if size and signedness match + * - arrays & pointers: + * - target types are recursively matched + * - structs & unions: + * - local members need to exist in target with the same name + * - for each member we recursively check match unless it is already behind a + * pointer, in which case we only check matching names and compatible kind + * - enums: + * - local variants have to have a match in target by symbolic name (but not + * numeric value) + * - size has to match (but enum may match enum64 and vice versa) + * - function pointers: + * - number and position of arguments in local type has to match target + * - for each argument and the return value we recursively check match + */ +int __bpf_core_types_match(const struct btf *local_btf, __u32 local_id, const struct btf *targ_btf, + __u32 targ_id, bool behind_ptr, int level) +{ + const struct btf_type *local_t, *targ_t; + int depth = 32; /* max recursion depth */ + __u16 local_k, targ_k; + + if (level <= 0) + return -EINVAL; + + local_t = btf_type_by_id(local_btf, local_id); + targ_t = btf_type_by_id(targ_btf, targ_id); + +recur: + depth--; + if (depth < 0) + return -EINVAL; + + local_t = skip_mods_and_typedefs(local_btf, local_id, &local_id); + targ_t = skip_mods_and_typedefs(targ_btf, targ_id, &targ_id); + if (!local_t || !targ_t) + return -EINVAL; + + if (!bpf_core_names_match(local_btf, local_t->name_off, targ_btf, targ_t->name_off)) + return 0; + + local_k = btf_kind(local_t); + targ_k = btf_kind(targ_t); + + switch (local_k) { + case BTF_KIND_UNKN: + return local_k == targ_k; + case BTF_KIND_FWD: { + bool local_f = BTF_INFO_KFLAG(local_t->info); + + if (behind_ptr) { + if (local_k == targ_k) + return local_f == BTF_INFO_KFLAG(targ_t->info); + + /* for forward declarations kflag dictates whether the + * target is a struct (0) or union (1) + */ + return (targ_k == BTF_KIND_STRUCT && !local_f) || + (targ_k == BTF_KIND_UNION && local_f); + } else { + if (local_k != targ_k) + return 0; + + /* match if the forward declaration is for the same kind */ + return local_f == BTF_INFO_KFLAG(targ_t->info); + } + } + case BTF_KIND_ENUM: + case BTF_KIND_ENUM64: + if (!btf_is_any_enum(targ_t)) + return 0; + + return bpf_core_enums_match(local_btf, local_t, targ_btf, targ_t); + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: + if (behind_ptr) { + bool targ_f = BTF_INFO_KFLAG(targ_t->info); + + if (local_k == targ_k) + return 1; + + if (targ_k != BTF_KIND_FWD) + return 0; + + return (local_k == BTF_KIND_UNION) == targ_f; + } else { + if (local_k != targ_k) + return 0; + + return bpf_core_composites_match(local_btf, local_t, targ_btf, targ_t, + behind_ptr, level); + } + case BTF_KIND_INT: { + __u8 local_sgn; + __u8 targ_sgn; + + if (local_k != targ_k) + return 0; + + local_sgn = btf_int_encoding(local_t) & BTF_INT_SIGNED; + targ_sgn = btf_int_encoding(targ_t) & BTF_INT_SIGNED; + + return local_t->size == targ_t->size && local_sgn == targ_sgn; + } + case BTF_KIND_PTR: + if (local_k != targ_k) + return 0; + + behind_ptr = true; + + local_id = local_t->type; + targ_id = targ_t->type; + goto recur; + case BTF_KIND_ARRAY: { + const struct btf_array *local_array = btf_array(local_t); + const struct btf_array *targ_array = btf_array(targ_t); + + if (local_k != targ_k) + return 0; + + if (local_array->nelems != targ_array->nelems) + return 0; + + local_id = local_array->type; + targ_id = targ_array->type; + goto recur; + } + case BTF_KIND_FUNC_PROTO: { + struct btf_param *local_p = btf_params(local_t); + struct btf_param *targ_p = btf_params(targ_t); + __u16 local_vlen = btf_vlen(local_t); + __u16 targ_vlen = btf_vlen(targ_t); + int i, err; + + if (local_k != targ_k) + return 0; + + if (local_vlen != targ_vlen) + return 0; + + for (i = 0; i < local_vlen; i++, local_p++, targ_p++) { + err = __bpf_core_types_match(local_btf, local_p->type, targ_btf, + targ_p->type, behind_ptr, level - 1); + if (err <= 0) + return err; + } + + /* tail recurse for return type check */ + local_id = local_t->type; + targ_id = targ_t->type; + goto recur; + } + default: + pr_warn("unexpected kind %s relocated, local [%d], target [%d]\n", + btf_kind_str(local_t), local_id, targ_id); + return 0; + } +} diff --git a/tools/lib/bpf/relo_core.h b/tools/lib/bpf/relo_core.h index 3fd3842d4230..1c0566daf8e8 100644 --- a/tools/lib/bpf/relo_core.h +++ b/tools/lib/bpf/relo_core.h @@ -72,6 +72,10 @@ int __bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, const struct btf *targ_btf, __u32 targ_id, int level); int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, const struct btf *targ_btf, __u32 targ_id); +int __bpf_core_types_match(const struct btf *local_btf, __u32 local_id, const struct btf *targ_btf, + __u32 targ_id, bool behind_ptr, int level); +int bpf_core_types_match(const struct btf *local_btf, __u32 local_id, const struct btf *targ_btf, + __u32 targ_id); size_t bpf_core_essential_name_len(const char *name); diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c index 2f92feb809be..a6f65e2236f4 100644 --- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c +++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c @@ -543,7 +543,6 @@ static int __trigger_module_test_read(const struct core_reloc_test_case *test) return 0; } - static const struct core_reloc_test_case test_cases[] = { /* validate we can find kernel image and use its BTF for relocs */ { @@ -556,6 +555,7 @@ static const struct core_reloc_test_case test_cases[] = { .valid = { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, }, .comm = "test_progs", .comm_len = sizeof("test_progs"), + .local_task_struct_matches = true, }, .output_len = sizeof(struct core_reloc_kernel_output), .raw_tp_name = "sys_enter", @@ -752,9 +752,10 @@ static const struct core_reloc_test_case test_cases[] = { SIZE_CASE(size___diff_offs), SIZE_ERR_CASE(size___err_ambiguous), - /* validate type existence and size relocations */ + /* validate type existence, match, and size relocations */ TYPE_BASED_CASE(type_based, { .struct_exists = 1, + .complex_struct_exists = 1, .union_exists = 1, .enum_exists = 1, .typedef_named_struct_exists = 1, @@ -765,6 +766,20 @@ static const struct core_reloc_test_case test_cases[] = { .typedef_void_ptr_exists = 1, .typedef_func_proto_exists = 1, .typedef_arr_exists = 1, + + .struct_matches = 1, + .complex_struct_matches = 1, + .union_matches = 1, + .enum_matches = 1, + .typedef_named_struct_matches = 1, + .typedef_anon_struct_matches = 1, + .typedef_struct_ptr_matches = 1, + .typedef_int_matches = 1, + .typedef_enum_matches = 1, + .typedef_void_ptr_matches = 1, + .typedef_func_proto_matches = 1, + .typedef_arr_matches = 1, + .struct_sz = sizeof(struct a_struct), .union_sz = sizeof(union a_union), .enum_sz = sizeof(enum an_enum), @@ -780,6 +795,45 @@ static const struct core_reloc_test_case test_cases[] = { TYPE_BASED_CASE(type_based___all_missing, { /* all zeros */ }), + TYPE_BASED_CASE(type_based___diff, { + .struct_exists = 1, + .complex_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_matches = 1, + .complex_struct_matches = 1, + .union_matches = 1, + .enum_matches = 1, + .typedef_named_struct_matches = 1, + .typedef_anon_struct_matches = 1, + .typedef_struct_ptr_matches = 1, + .typedef_int_matches = 0, + .typedef_enum_matches = 1, + .typedef_void_ptr_matches = 1, + .typedef_func_proto_matches = 0, + .typedef_arr_matches = 0, + + .struct_sz = sizeof(struct a_struct___diff), + .union_sz = sizeof(union a_union___diff), + .enum_sz = sizeof(enum an_enum___diff), + .typedef_named_struct_sz = sizeof(named_struct_typedef___diff), + .typedef_anon_struct_sz = sizeof(anon_struct_typedef___diff), + .typedef_struct_ptr_sz = sizeof(struct_ptr_typedef___diff), + .typedef_int_sz = sizeof(int_typedef___diff), + .typedef_enum_sz = sizeof(enum_typedef___diff), + .typedef_void_ptr_sz = sizeof(void_ptr_typedef___diff), + .typedef_func_proto_sz = sizeof(func_proto_typedef___diff), + .typedef_arr_sz = sizeof(arr_typedef___diff), + }), TYPE_BASED_CASE(type_based___diff_sz, { .struct_exists = 1, .union_exists = 1, @@ -792,6 +846,19 @@ static const struct core_reloc_test_case test_cases[] = { .typedef_void_ptr_exists = 1, .typedef_func_proto_exists = 1, .typedef_arr_exists = 1, + + .struct_matches = 0, + .union_matches = 0, + .enum_matches = 0, + .typedef_named_struct_matches = 0, + .typedef_anon_struct_matches = 0, + .typedef_struct_ptr_matches = 1, + .typedef_int_matches = 0, + .typedef_enum_matches = 0, + .typedef_void_ptr_matches = 1, + .typedef_func_proto_matches = 0, + .typedef_arr_matches = 0, + .struct_sz = sizeof(struct a_struct___diff_sz), .union_sz = sizeof(union a_union___diff_sz), .enum_sz = sizeof(enum an_enum___diff_sz), @@ -806,10 +873,12 @@ static const struct core_reloc_test_case test_cases[] = { }), TYPE_BASED_CASE(type_based___incompat, { .enum_exists = 1, + .enum_matches = 1, .enum_sz = sizeof(enum an_enum), }), TYPE_BASED_CASE(type_based___fn_wrong_args, { .struct_exists = 1, + .struct_matches = 1, .struct_sz = sizeof(struct a_struct), }), diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___diff.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___diff.c new file mode 100644 index 000000000000..57ae2c258928 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_type_based___diff.c @@ -0,0 +1,3 @@ +#include "core_reloc_types.h" + +void f(struct core_reloc_type_based___diff x) {} diff --git a/tools/testing/selftests/bpf/progs/core_reloc_types.h b/tools/testing/selftests/bpf/progs/core_reloc_types.h index 26e103302c05..7ef91d19c66e 100644 --- a/tools/testing/selftests/bpf/progs/core_reloc_types.h +++ b/tools/testing/selftests/bpf/progs/core_reloc_types.h @@ -13,6 +13,7 @@ struct core_reloc_kernel_output { int valid[10]; char comm[sizeof("test_progs")]; int comm_len; + bool local_task_struct_matches; }; /* @@ -860,10 +861,11 @@ struct core_reloc_size___err_ambiguous2 { }; /* - * TYPE EXISTENCE & SIZE + * TYPE EXISTENCE, MATCH & SIZE */ struct core_reloc_type_based_output { bool struct_exists; + bool complex_struct_exists; bool union_exists; bool enum_exists; bool typedef_named_struct_exists; @@ -875,6 +877,19 @@ struct core_reloc_type_based_output { bool typedef_func_proto_exists; bool typedef_arr_exists; + bool struct_matches; + bool complex_struct_matches; + bool union_matches; + bool enum_matches; + bool typedef_named_struct_matches; + bool typedef_anon_struct_matches; + bool typedef_struct_ptr_matches; + bool typedef_int_matches; + bool typedef_enum_matches; + bool typedef_void_ptr_matches; + bool typedef_func_proto_matches; + bool typedef_arr_matches; + int struct_sz; int union_sz; int enum_sz; @@ -892,6 +907,14 @@ struct a_struct { int x; }; +struct a_complex_struct { + union { + struct a_struct * restrict a; + void *b; + } x; + volatile long y; +}; + union a_union { int y; int z; @@ -923,22 +946,85 @@ 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 a_complex_struct f2; + union a_union f3; + enum an_enum f4; + named_struct_typedef f5; + anon_struct_typedef f6; + struct_ptr_typedef f7; + int_typedef f8; + enum_typedef f9; + void_ptr_typedef f10; + func_proto_typedef f11; + arr_typedef f12; }; /* no types in target */ struct core_reloc_type_based___all_missing { }; +/* different member orders, enum variant values, signedness, etc */ +struct a_struct___diff { + int x; + int a; +}; + +struct a_struct___forward; + +struct a_complex_struct___diff { + union { + struct a_struct___forward *a; + void *b; + } x; + volatile long y; +}; + +union a_union___diff { + int z; + int y; +}; + +typedef struct a_struct___diff named_struct_typedef___diff; + +typedef struct { int z, x, y; } anon_struct_typedef___diff; + +typedef struct { + int c; + int b; + int a; +} *struct_ptr_typedef___diff; + +enum an_enum___diff { + AN_ENUM_VAL2___diff = 0, + AN_ENUM_VAL1___diff = 42, + AN_ENUM_VAL3___diff = 1, +}; + +typedef unsigned int int_typedef___diff; + +typedef enum { TYPEDEF_ENUM_VAL2___diff, TYPEDEF_ENUM_VAL1___diff = 50 } enum_typedef___diff; + +typedef const void *void_ptr_typedef___diff; + +typedef int_typedef___diff (*func_proto_typedef___diff)(long); + +typedef char arr_typedef___diff[3]; + +struct core_reloc_type_based___diff { + struct a_struct___diff f1; + struct a_complex_struct___diff f2; + union a_union___diff f3; + enum an_enum___diff f4; + named_struct_typedef___diff f5; + anon_struct_typedef___diff f6; + struct_ptr_typedef___diff f7; + int_typedef___diff f8; + enum_typedef___diff f9; + void_ptr_typedef___diff f10; + func_proto_typedef___diff f11; + arr_typedef___diff f12; +}; + /* different type sizes, extra modifiers, anon vs named enums, etc */ struct a_struct___diff_sz { long x; 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 145028b52ad8..a17dd83eae67 100644 --- a/tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c +++ b/tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c @@ -21,6 +21,7 @@ struct core_reloc_kernel_output { /* we have test_progs[-flavor], so cut flavor part */ char comm[sizeof("test_progs")]; int comm_len; + bool local_task_struct_matches; }; struct task_struct { @@ -30,11 +31,25 @@ struct task_struct { struct task_struct *group_leader; }; +struct mm_struct___wrong { + int abc_whatever_should_not_exist; +}; + +struct task_struct___local { + int pid; + struct mm_struct___wrong *mm; +}; + #define CORE_READ(dst, src) bpf_core_read(dst, sizeof(*(dst)), src) SEC("raw_tracepoint/sys_enter") int test_core_kernel(void *ctx) { + /* Support for the BPF_TYPE_MATCHES argument to the + * __builtin_preserve_type_info builtin was added at some point during + * development of clang 15 and it's what we require for this test. + */ +#if __has_builtin(__builtin_preserve_type_info) && __clang_major__ >= 15 struct task_struct *task = (void *)bpf_get_current_task(); struct core_reloc_kernel_output *out = (void *)&data.out; uint64_t pid_tgid = bpf_get_current_pid_tgid(); @@ -93,6 +108,10 @@ int test_core_kernel(void *ctx) group_leader, group_leader, group_leader, group_leader, comm); + out->local_task_struct_matches = bpf_core_type_matches(struct task_struct___local); +#else + data.skip = true; +#endif return 0; } 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 fb60f8195c53..d95bc08b75c1 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 @@ -19,6 +19,14 @@ struct a_struct { int x; }; +struct a_complex_struct { + union { + struct a_struct *a; + void *b; + } x; + volatile long y; +}; + union a_union { int y; int z; @@ -50,6 +58,7 @@ typedef char arr_typedef[20]; struct core_reloc_type_based_output { bool struct_exists; + bool complex_struct_exists; bool union_exists; bool enum_exists; bool typedef_named_struct_exists; @@ -61,6 +70,19 @@ struct core_reloc_type_based_output { bool typedef_func_proto_exists; bool typedef_arr_exists; + bool struct_matches; + bool complex_struct_matches; + bool union_matches; + bool enum_matches; + bool typedef_named_struct_matches; + bool typedef_anon_struct_matches; + bool typedef_struct_ptr_matches; + bool typedef_int_matches; + bool typedef_enum_matches; + bool typedef_void_ptr_matches; + bool typedef_func_proto_matches; + bool typedef_arr_matches; + int struct_sz; int union_sz; int enum_sz; @@ -77,10 +99,17 @@ struct core_reloc_type_based_output { SEC("raw_tracepoint/sys_enter") int test_core_type_based(void *ctx) { -#if __has_builtin(__builtin_preserve_type_info) + /* Support for the BPF_TYPE_MATCHES argument to the + * __builtin_preserve_type_info builtin was added at some point during + * development of clang 15 and it's what we require for this test. Part of it + * could run with merely __builtin_preserve_type_info (which could be checked + * separately), but we have to find an upper bound. + */ +#if __has_builtin(__builtin_preserve_type_info) && __clang_major__ >= 15 struct core_reloc_type_based_output *out = (void *)&data.out; out->struct_exists = bpf_core_type_exists(struct a_struct); + out->complex_struct_exists = bpf_core_type_exists(struct a_complex_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); @@ -92,6 +121,19 @@ int test_core_type_based(void *ctx) out->typedef_func_proto_exists = bpf_core_type_exists(func_proto_typedef); out->typedef_arr_exists = bpf_core_type_exists(arr_typedef); + out->struct_matches = bpf_core_type_matches(struct a_struct); + out->complex_struct_matches = bpf_core_type_matches(struct a_complex_struct); + out->union_matches = bpf_core_type_matches(union a_union); + out->enum_matches = bpf_core_type_matches(enum an_enum); + out->typedef_named_struct_matches = bpf_core_type_matches(named_struct_typedef); + out->typedef_anon_struct_matches = bpf_core_type_matches(anon_struct_typedef); + out->typedef_struct_ptr_matches = bpf_core_type_matches(struct_ptr_typedef); + out->typedef_int_matches = bpf_core_type_matches(int_typedef); + out->typedef_enum_matches = bpf_core_type_matches(enum_typedef); + out->typedef_void_ptr_matches = bpf_core_type_matches(void_ptr_typedef); + out->typedef_func_proto_matches = bpf_core_type_matches(func_proto_typedef); + out->typedef_arr_matches = bpf_core_type_matches(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); |