From 3d208f4ca111a614903f49d5a77b93ddc6de294e Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 13 Dec 2019 17:43:30 -0800 Subject: libbpf: Expose btf__align_of() API Expose BTF API that calculates type alignment requirements. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20191214014341.3442258-7-andriin@fb.com --- tools/lib/bpf/btf_dump.c | 47 ++++++----------------------------------------- 1 file changed, 6 insertions(+), 41 deletions(-) (limited to 'tools/lib/bpf/btf_dump.c') diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c index cb126d8fcf75..53393026d085 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -752,41 +752,6 @@ static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id) } } -static int btf_align_of(const struct btf *btf, __u32 id) -{ - const struct btf_type *t = btf__type_by_id(btf, id); - __u16 kind = btf_kind(t); - - switch (kind) { - case BTF_KIND_INT: - case BTF_KIND_ENUM: - return min(sizeof(void *), t->size); - case BTF_KIND_PTR: - return sizeof(void *); - case BTF_KIND_TYPEDEF: - case BTF_KIND_VOLATILE: - case BTF_KIND_CONST: - case BTF_KIND_RESTRICT: - return btf_align_of(btf, t->type); - case BTF_KIND_ARRAY: - return btf_align_of(btf, btf_array(t)->type); - case BTF_KIND_STRUCT: - case BTF_KIND_UNION: { - const struct btf_member *m = btf_members(t); - __u16 vlen = btf_vlen(t); - int i, align = 1; - - for (i = 0; i < vlen; i++, m++) - align = max(align, btf_align_of(btf, m->type)); - - return align; - } - default: - pr_warn("unsupported BTF_KIND:%u\n", btf_kind(t)); - return 1; - } -} - static bool btf_is_struct_packed(const struct btf *btf, __u32 id, const struct btf_type *t) { @@ -794,18 +759,18 @@ static bool btf_is_struct_packed(const struct btf *btf, __u32 id, int align, i, bit_sz; __u16 vlen; - align = btf_align_of(btf, id); + align = btf__align_of(btf, id); /* size of a non-packed struct has to be a multiple of its alignment*/ - if (t->size % align) + if (align && t->size % align) return true; m = btf_members(t); vlen = btf_vlen(t); /* all non-bitfield fields have to be naturally aligned */ for (i = 0; i < vlen; i++, m++) { - align = btf_align_of(btf, m->type); + align = btf__align_of(btf, m->type); bit_sz = btf_member_bitfield_size(t, i); - if (bit_sz == 0 && m->offset % (8 * align) != 0) + if (align && bit_sz == 0 && m->offset % (8 * align) != 0) return true; } @@ -889,7 +854,7 @@ static void btf_dump_emit_struct_def(struct btf_dump *d, fname = btf_name_of(d, m->name_off); m_sz = btf_member_bitfield_size(t, i); m_off = btf_member_bit_offset(t, i); - align = packed ? 1 : btf_align_of(d->btf, m->type); + align = packed ? 1 : btf__align_of(d->btf, m->type); btf_dump_emit_bit_padding(d, off, m_off, m_sz, align, lvl + 1); btf_dump_printf(d, "\n%s", pfx(lvl + 1)); @@ -907,7 +872,7 @@ static void btf_dump_emit_struct_def(struct btf_dump *d, /* pad at the end, if necessary */ if (is_struct) { - align = packed ? 1 : btf_align_of(d->btf, id); + align = packed ? 1 : btf__align_of(d->btf, id); btf_dump_emit_bit_padding(d, off, t->size * 8, 0, align, lvl + 1); } -- cgit From 9f81654eebe8de7e0db15534816d8f6c84b2e1e5 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 13 Dec 2019 17:43:31 -0800 Subject: libbpf: Expose BTF-to-C type declaration emitting API Expose API that allows to emit type declaration and field/variable definition (if optional field name is specified) in valid C syntax for any provided BTF type. This is going to be used by bpftool when emitting data section layout as a struct. As part of making this API useful in a stand-alone fashion, move initialization of some of the internal btf_dump state to earlier phase. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20191214014341.3442258-8-andriin@fb.com --- tools/lib/bpf/btf.h | 22 ++++++++++++++++ tools/lib/bpf/btf_dump.c | 68 ++++++++++++++++++++++++++++++------------------ tools/lib/bpf/libbpf.map | 1 + 3 files changed, 65 insertions(+), 26 deletions(-) (limited to 'tools/lib/bpf/btf_dump.c') diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index a114c8ef4f08..8d73f7f5551f 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -126,6 +126,28 @@ LIBBPF_API void btf_dump__free(struct btf_dump *d); LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id); +struct btf_dump_emit_type_decl_opts { + /* size of this struct, for forward/backward compatiblity */ + size_t sz; + /* optional field name for type declaration, e.g.: + * - struct my_struct + * - void (*)(int) + * - char (*)[123] + */ + const char *field_name; + /* extra indentation level (in number of tabs) to emit for multi-line + * type declarations (e.g., anonymous struct); applies for lines + * starting from the second one (first line is assumed to have + * necessary indentation already + */ + int indent_level; +}; +#define btf_dump_emit_type_decl_opts__last_field indent_level + +LIBBPF_API int +btf_dump__emit_type_decl(struct btf_dump *d, __u32 id, + const struct btf_dump_emit_type_decl_opts *opts); + /* * A set of helpers for easier BTF types handling */ diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c index 53393026d085..e95f7710f210 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -116,6 +116,8 @@ static void btf_dump_printf(const struct btf_dump *d, const char *fmt, ...) va_end(args); } +static int btf_dump_mark_referenced(struct btf_dump *d); + struct btf_dump *btf_dump__new(const struct btf *btf, const struct btf_ext *btf_ext, const struct btf_dump_opts *opts, @@ -137,18 +139,39 @@ struct btf_dump *btf_dump__new(const struct btf *btf, if (IS_ERR(d->type_names)) { err = PTR_ERR(d->type_names); d->type_names = NULL; - btf_dump__free(d); - return ERR_PTR(err); } d->ident_names = hashmap__new(str_hash_fn, str_equal_fn, NULL); if (IS_ERR(d->ident_names)) { err = PTR_ERR(d->ident_names); d->ident_names = NULL; - btf_dump__free(d); - return ERR_PTR(err); + goto err; + } + d->type_states = calloc(1 + btf__get_nr_types(d->btf), + sizeof(d->type_states[0])); + if (!d->type_states) { + err = -ENOMEM; + goto err; + } + d->cached_names = calloc(1 + btf__get_nr_types(d->btf), + sizeof(d->cached_names[0])); + if (!d->cached_names) { + err = -ENOMEM; + goto err; } + /* VOID is special */ + d->type_states[0].order_state = ORDERED; + d->type_states[0].emit_state = EMITTED; + + /* eagerly determine referenced types for anon enums */ + err = btf_dump_mark_referenced(d); + if (err) + goto err; + return d; +err: + btf_dump__free(d); + return ERR_PTR(err); } void btf_dump__free(struct btf_dump *d) @@ -175,7 +198,6 @@ void btf_dump__free(struct btf_dump *d) free(d); } -static int btf_dump_mark_referenced(struct btf_dump *d); static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr); static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id); @@ -202,27 +224,6 @@ int btf_dump__dump_type(struct btf_dump *d, __u32 id) if (id > btf__get_nr_types(d->btf)) return -EINVAL; - /* type states are lazily allocated, as they might not be needed */ - if (!d->type_states) { - d->type_states = calloc(1 + btf__get_nr_types(d->btf), - sizeof(d->type_states[0])); - if (!d->type_states) - return -ENOMEM; - d->cached_names = calloc(1 + btf__get_nr_types(d->btf), - sizeof(d->cached_names[0])); - if (!d->cached_names) - return -ENOMEM; - - /* VOID is special */ - d->type_states[0].order_state = ORDERED; - d->type_states[0].emit_state = EMITTED; - - /* eagerly determine referenced types for anon enums */ - err = btf_dump_mark_referenced(d); - if (err) - return err; - } - d->emit_queue_cnt = 0; err = btf_dump_order_type(d, id, false); if (err < 0) @@ -1016,6 +1017,21 @@ static int btf_dump_push_decl_stack_id(struct btf_dump *d, __u32 id) * of a stack frame. Some care is required to "pop" stack frames after * processing type declaration chain. */ +int btf_dump__emit_type_decl(struct btf_dump *d, __u32 id, + const struct btf_dump_emit_type_decl_opts *opts) +{ + const char *fname; + int lvl; + + if (!OPTS_VALID(opts, btf_dump_emit_type_decl_opts)) + return -EINVAL; + + fname = OPTS_GET(opts, field_name, NULL); + lvl = OPTS_GET(opts, indent_level, 0); + btf_dump_emit_type_decl(d, id, fname, lvl); + return 0; +} + static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id, const char *fname, int lvl) { diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index e7fcca36f186..990c7c0e2d9f 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -211,6 +211,7 @@ LIBBPF_0.0.6 { LIBBPF_0.0.7 { global: + btf_dump__emit_type_decl; bpf_program__attach; btf__align_of; } LIBBPF_0.0.6; -- cgit From 1d1a3bcffe360a56fd8cc287ed74d4c3066daf42 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 10 Jan 2020 10:19:16 -0800 Subject: libbpf: Poison kernel-only integer types It's been a recurring issue with types like u32 slipping into libbpf source code accidentally. This is not detected during builds inside kernel source tree, but becomes a compilation error in libbpf's Github repo. Libbpf is supposed to use only __{s,u}{8,16,32,64} typedefs, so poison {s,u}{8,16,32,64} explicitly in every .c file. Doing that in a bit more centralized way, e.g., inside libbpf_internal.h breaks selftests, which are both using kernel u32 and libbpf_internal.h. This patch also fixes a new u32 occurence in libbpf.c, added recently. Fixes: 590a00888250 ("bpf: libbpf: Add STRUCT_OPS support") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20200110181916.271446-1-andriin@fb.com --- tools/lib/bpf/bpf.c | 3 +++ tools/lib/bpf/bpf_prog_linfo.c | 3 +++ tools/lib/bpf/btf.c | 3 +++ tools/lib/bpf/btf_dump.c | 3 +++ tools/lib/bpf/hashmap.c | 3 +++ tools/lib/bpf/libbpf.c | 5 ++++- tools/lib/bpf/libbpf_errno.c | 3 +++ tools/lib/bpf/libbpf_probes.c | 3 +++ tools/lib/bpf/netlink.c | 3 +++ tools/lib/bpf/nlattr.c | 3 +++ tools/lib/bpf/str_error.c | 3 +++ tools/lib/bpf/xsk.c | 3 +++ 12 files changed, 37 insertions(+), 1 deletion(-) (limited to 'tools/lib/bpf/btf_dump.c') diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index b0ecbe9ef2d4..500afe478e94 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -32,6 +32,9 @@ #include "libbpf.h" #include "libbpf_internal.h" +/* make sure libbpf doesn't use kernel-only integer typedefs */ +#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 + /* * When building perf, unistd.h is overridden. __NR_bpf is * required to be defined explicitly. diff --git a/tools/lib/bpf/bpf_prog_linfo.c b/tools/lib/bpf/bpf_prog_linfo.c index 3ed1a27b5f7c..bafca49cb1e6 100644 --- a/tools/lib/bpf/bpf_prog_linfo.c +++ b/tools/lib/bpf/bpf_prog_linfo.c @@ -8,6 +8,9 @@ #include "libbpf.h" #include "libbpf_internal.h" +/* make sure libbpf doesn't use kernel-only integer typedefs */ +#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 + struct bpf_prog_linfo { void *raw_linfo; void *raw_jited_linfo; diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 5f04f56e1eb6..cfeb6a44480b 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -17,6 +17,9 @@ #include "libbpf_internal.h" #include "hashmap.h" +/* make sure libbpf doesn't use kernel-only integer typedefs */ +#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 + #define BTF_MAX_NR_TYPES 0x7fffffff #define BTF_MAX_STR_OFFSET 0x7fffffff diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c index e95f7710f210..885acebd4396 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -18,6 +18,9 @@ #include "libbpf.h" #include "libbpf_internal.h" +/* make sure libbpf doesn't use kernel-only integer typedefs */ +#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 + static const char PREFIXES[] = "\t\t\t\t\t\t\t\t\t\t\t\t\t"; static const size_t PREFIX_CNT = sizeof(PREFIXES) - 1; diff --git a/tools/lib/bpf/hashmap.c b/tools/lib/bpf/hashmap.c index 6122272943e6..54c30c802070 100644 --- a/tools/lib/bpf/hashmap.c +++ b/tools/lib/bpf/hashmap.c @@ -12,6 +12,9 @@ #include #include "hashmap.h" +/* make sure libbpf doesn't use kernel-only integer typedefs */ +#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 + /* start with 4 buckets */ #define HASHMAP_MIN_CAP_BITS 2 diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 3afd780b0f06..0c229f00a67e 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -55,6 +55,9 @@ #include "libbpf_internal.h" #include "hashmap.h" +/* make sure libbpf doesn't use kernel-only integer typedefs */ +#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 + #ifndef EM_BPF #define EM_BPF 247 #endif @@ -6475,7 +6478,7 @@ static int bpf_object__collect_struct_ops_map_reloc(struct bpf_object *obj, Elf_Data *symbols; unsigned int moff; const char *name; - u32 member_idx; + __u32 member_idx; GElf_Sym sym; GElf_Rel rel; int i, nrels; diff --git a/tools/lib/bpf/libbpf_errno.c b/tools/lib/bpf/libbpf_errno.c index 4343e40588c6..0afb51f7a919 100644 --- a/tools/lib/bpf/libbpf_errno.c +++ b/tools/lib/bpf/libbpf_errno.c @@ -13,6 +13,9 @@ #include "libbpf.h" +/* make sure libbpf doesn't use kernel-only integer typedefs */ +#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 + #define ERRNO_OFFSET(e) ((e) - __LIBBPF_ERRNO__START) #define ERRCODE_OFFSET(c) ERRNO_OFFSET(LIBBPF_ERRNO__##c) #define NR_ERRNO (__LIBBPF_ERRNO__END - __LIBBPF_ERRNO__START) diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c index 320697f8e4c7..8cc992bc532a 100644 --- a/tools/lib/bpf/libbpf_probes.c +++ b/tools/lib/bpf/libbpf_probes.c @@ -17,6 +17,9 @@ #include "libbpf.h" #include "libbpf_internal.h" +/* make sure libbpf doesn't use kernel-only integer typedefs */ +#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 + static bool grep(const char *buffer, const char *pattern) { return !!strstr(buffer, pattern); diff --git a/tools/lib/bpf/netlink.c b/tools/lib/bpf/netlink.c index 5065c1aa1061..431bd25c6cdb 100644 --- a/tools/lib/bpf/netlink.c +++ b/tools/lib/bpf/netlink.c @@ -15,6 +15,9 @@ #include "libbpf_internal.h" #include "nlattr.h" +/* make sure libbpf doesn't use kernel-only integer typedefs */ +#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 + #ifndef SOL_NETLINK #define SOL_NETLINK 270 #endif diff --git a/tools/lib/bpf/nlattr.c b/tools/lib/bpf/nlattr.c index 8db44bbfc66d..0ad41dfea8eb 100644 --- a/tools/lib/bpf/nlattr.c +++ b/tools/lib/bpf/nlattr.c @@ -13,6 +13,9 @@ #include #include +/* make sure libbpf doesn't use kernel-only integer typedefs */ +#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 + static uint16_t nla_attr_minlen[LIBBPF_NLA_TYPE_MAX+1] = { [LIBBPF_NLA_U8] = sizeof(uint8_t), [LIBBPF_NLA_U16] = sizeof(uint16_t), diff --git a/tools/lib/bpf/str_error.c b/tools/lib/bpf/str_error.c index b8064eedc177..146da01979c7 100644 --- a/tools/lib/bpf/str_error.c +++ b/tools/lib/bpf/str_error.c @@ -4,6 +4,9 @@ #include #include "str_error.h" +/* make sure libbpf doesn't use kernel-only integer typedefs */ +#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 + /* * Wrapper to allow for building in non-GNU systems such as Alpine Linux's musl * libc, while checking strerror_r() return to avoid having to check this in diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index 8e0ffa800a71..9807903f121e 100644 --- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -32,6 +32,9 @@ #include "libbpf_internal.h" #include "xsk.h" +/* make sure libbpf doesn't use kernel-only integer typedefs */ +#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 + #ifndef SOL_XDP #define SOL_XDP 283 #endif -- cgit From bc0eb9a333918d2cc4f42f7f4cf09eaf029ac9de Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Thu, 16 Jan 2020 22:07:58 -0800 Subject: libbpf: Fix error handling bug in btf_dump__new Fix missing jump to error handling in btf_dump__new, found by Coverity static code analysis. Fixes: 9f81654eebe8 ("libbpf: Expose BTF-to-C type declaration emitting API") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200117060801.1311525-2-andriin@fb.com --- tools/lib/bpf/btf_dump.c | 1 + 1 file changed, 1 insertion(+) (limited to 'tools/lib/bpf/btf_dump.c') diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c index 885acebd4396..bd09ed1710f1 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -142,6 +142,7 @@ struct btf_dump *btf_dump__new(const struct btf *btf, if (IS_ERR(d->type_names)) { err = PTR_ERR(d->type_names); d->type_names = NULL; + goto err; } d->ident_names = hashmap__new(str_hash_fn, str_equal_fn, NULL); if (IS_ERR(d->ident_names)) { -- cgit