From 046561981b948e07df096a8402f9efc80bc784d9 Mon Sep 17 00:00:00 2001 From: Jiong Wang Date: Fri, 24 May 2019 23:25:19 +0100 Subject: libbpf: add "prog_flags" to bpf_program/bpf_prog_load_attr/bpf_load_program_attr libbpf doesn't allow passing "prog_flags" during bpf program load in a couple of load related APIs, "bpf_load_program_xattr", "load_program" and "bpf_prog_load_xattr". It makes sense to allow passing "prog_flags" which is useful for customizing program loading. Reviewed-by: Jakub Kicinski Signed-off-by: Jiong Wang Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/libbpf.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 197b574406b3..ff149372b3c0 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -188,6 +188,7 @@ struct bpf_program { void *line_info; __u32 line_info_rec_size; __u32 line_info_cnt; + __u32 prog_flags; }; enum libbpf_map_type { @@ -2076,6 +2077,7 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, load_attr.line_info_rec_size = prog->line_info_rec_size; load_attr.line_info_cnt = prog->line_info_cnt; load_attr.log_level = prog->log_level; + load_attr.prog_flags = prog->prog_flags; if (!load_attr.insns || !load_attr.insns_cnt) return -EINVAL; @@ -3521,6 +3523,7 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, expected_attach_type); prog->log_level = attr->log_level; + prog->prog_flags = attr->prog_flags; if (!first_prog) first_prog = prog; } -- cgit v1.2.3 From d98363b510ce9938a19b07fe3c02357d8c65d52a Mon Sep 17 00:00:00 2001 From: Hariprasad Kelam Date: Sat, 25 May 2019 14:32:57 +0530 Subject: libbpf: fix warning that PTR_ERR_OR_ZERO can be used Fix below warning reported by coccicheck: /tools/lib/bpf/libbpf.c:3461:1-3: WARNING: PTR_ERR_OR_ZERO can be used Signed-off-by: Hariprasad Kelam Acked-by: Yonghong Song Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index ff149372b3c0..fd5905ac2ec3 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3460,9 +3460,7 @@ bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset) long libbpf_get_error(const void *ptr) { - if (IS_ERR(ptr)) - return PTR_ERR(ptr); - return 0; + return PTR_ERR_OR_ZERO(ptr); } int bpf_prog_load(const char *file, enum bpf_prog_type type, -- cgit v1.2.3 From 60276f9849988d3d3a54943c9ec27222c5819dae Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Fri, 24 May 2019 11:36:47 +0100 Subject: libbpf: add bpf_object__load_xattr() API function to pass log_level libbpf was recently made aware of the log_level attribute for programs, used to specify the level of information expected to be dumped by the verifier. Function bpf_prog_load_xattr() got support for this log_level parameter. But some applications using libbpf rely on another function to load programs, bpf_object__load(), which does accept any parameter for log level. Create an API function based on bpf_object__load(), but accepting an "attr" object as a parameter. Then add a log_level field to that object, so that applications calling the new bpf_object__load_xattr() can pick the desired log level. v3: - Rewrite commit log. v2: - We are in a new cycle, bump libbpf extraversion number. Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index fd5905ac2ec3..ca4432f5b067 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -2224,7 +2224,7 @@ static bool bpf_program__is_function_storage(struct bpf_program *prog, } static int -bpf_object__load_progs(struct bpf_object *obj) +bpf_object__load_progs(struct bpf_object *obj, int log_level) { size_t i; int err; @@ -2232,6 +2232,7 @@ bpf_object__load_progs(struct bpf_object *obj) for (i = 0; i < obj->nr_programs; i++) { if (bpf_program__is_function_storage(&obj->programs[i], obj)) continue; + obj->programs[i].log_level = log_level; err = bpf_program__load(&obj->programs[i], obj->license, obj->kern_version); @@ -2383,10 +2384,14 @@ int bpf_object__unload(struct bpf_object *obj) return 0; } -int bpf_object__load(struct bpf_object *obj) +int bpf_object__load_xattr(struct bpf_object_load_attr *attr) { + struct bpf_object *obj; int err; + if (!attr) + return -EINVAL; + obj = attr->obj; if (!obj) return -EINVAL; @@ -2399,7 +2404,7 @@ int bpf_object__load(struct bpf_object *obj) CHECK_ERR(bpf_object__create_maps(obj), err, out); CHECK_ERR(bpf_object__relocate(obj), err, out); - CHECK_ERR(bpf_object__load_progs(obj), err, out); + CHECK_ERR(bpf_object__load_progs(obj, attr->log_level), err, out); return 0; out: @@ -2408,6 +2413,15 @@ out: return err; } +int bpf_object__load(struct bpf_object *obj) +{ + struct bpf_object_load_attr attr = { + .obj = obj, + }; + + return bpf_object__load_xattr(&attr); +} + static int check_path(const char *path) { char *cp, errmsg[STRERR_BUFSIZE]; -- cgit v1.2.3 From 501b125a29f7cd8983960c5f3c80b337b1359cc3 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Wed, 29 May 2019 15:26:41 +0100 Subject: libbpf: prevent overwriting of log_level in bpf_object__load_progs() There are two functions in libbpf that support passing a log_level parameter for the verifier for loading programs: bpf_object__load_xattr() and bpf_prog_load_xattr(). Both accept an attribute object containing the log_level, and apply it to the programs to load. It turns out that to effectively load the programs, the latter function eventually relies on the former. This was not taken into account when adding support for log_level in bpf_object__load_xattr(), and the log_level passed to bpf_prog_load_xattr() later gets overwritten with a zero value, thus disabling verifier logs for the program in all cases: bpf_prog_load_xattr() // prog->log_level = attr1->log_level; -> bpf_object__load() // attr2->log_level = 0; -> bpf_object__load_xattr() // -> bpf_object__load_progs() // prog->log_level = attr2->log_level; Fix this by OR-ing the log_level in bpf_object__load_progs(), instead of overwriting it. v2: Fix commit log description (confusion on function names in v1). Fixes: 60276f984998 ("libbpf: add bpf_object__load_xattr() API function to pass log_level") Reported-by: Alexei Starovoitov Signed-off-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index ca4432f5b067..30cb08e2eb75 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -2232,7 +2232,7 @@ bpf_object__load_progs(struct bpf_object *obj, int log_level) for (i = 0; i < obj->nr_programs; i++) { if (bpf_program__is_function_storage(&obj->programs[i], obj)) continue; - obj->programs[i].log_level = log_level; + obj->programs[i].log_level |= log_level; err = bpf_program__load(&obj->programs[i], obj->license, obj->kern_version); -- cgit v1.2.3 From 8ca990ce0d402d5aaf05f7a33ff025fcbcbb5f93 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Wed, 29 May 2019 10:36:03 -0700 Subject: libbpf: fix detection of corrupted BPF instructions section Ensure that size of a section w/ BPF instruction is exactly a multiple of BPF instruction size. Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 30cb08e2eb75..c985a7916e35 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -349,8 +349,11 @@ static int bpf_program__init(void *data, size_t size, char *section_name, int idx, struct bpf_program *prog) { - if (size < sizeof(struct bpf_insn)) { - pr_warning("corrupted section '%s'\n", section_name); + const size_t bpf_insn_sz = sizeof(struct bpf_insn); + + if (size == 0 || size % bpf_insn_sz) { + pr_warning("corrupted section '%s', size: %zu\n", + section_name, size); return -EINVAL; } @@ -376,9 +379,8 @@ bpf_program__init(void *data, size_t size, char *section_name, int idx, section_name); goto errout; } - prog->insns_cnt = size / sizeof(struct bpf_insn); - memcpy(prog->insns, data, - prog->insns_cnt * sizeof(struct bpf_insn)); + prog->insns_cnt = size / bpf_insn_sz; + memcpy(prog->insns, data, size); prog->idx = idx; prog->instances.fds = NULL; prog->instances.nr = -1; -- cgit v1.2.3 From be5c5d4e9d8cbdd7fcdcbc45e86e34bc0bd1cefd Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Wed, 29 May 2019 10:36:04 -0700 Subject: libbpf: preserve errno before calling into user callback pr_warning ultimately may call into user-provided callback function, which can clobber errno value, so we need to save it before that. Acked-by: Song Liu Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index c985a7916e35..40690b7e500e 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -565,12 +565,12 @@ static int bpf_object__elf_init(struct bpf_object *obj) } else { obj->efile.fd = open(obj->path, O_RDONLY); if (obj->efile.fd < 0) { - char errmsg[STRERR_BUFSIZE]; - char *cp = libbpf_strerror_r(errno, errmsg, - sizeof(errmsg)); + char errmsg[STRERR_BUFSIZE], *cp; + err = -errno; + cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg)); pr_warning("failed to open %s: %s\n", obj->path, cp); - return -errno; + return err; } obj->efile.elf = elf_begin(obj->efile.fd, -- cgit v1.2.3 From 12ef5634a855eb642b4d28781526fbd830aa7f7a Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Wed, 29 May 2019 10:36:05 -0700 Subject: libbpf: simplify endianness check Rewrite endianness check to use "more canonical" way, using compiler-defined macros, similar to few other places in libbpf. It also is more obvious and shorter. Acked-by: Song Liu Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 37 ++++++++++++------------------------- 1 file changed, 12 insertions(+), 25 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 40690b7e500e..fb296eadc3f2 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -607,31 +607,18 @@ errout: return err; } -static int -bpf_object__check_endianness(struct bpf_object *obj) -{ - static unsigned int const endian = 1; - - switch (obj->efile.ehdr.e_ident[EI_DATA]) { - case ELFDATA2LSB: - /* We are big endian, BPF obj is little endian. */ - if (*(unsigned char const *)&endian != 1) - goto mismatch; - break; - - case ELFDATA2MSB: - /* We are little endian, BPF obj is big endian. */ - if (*(unsigned char const *)&endian != 0) - goto mismatch; - break; - default: - return -LIBBPF_ERRNO__ENDIAN; - } - - return 0; - -mismatch: - pr_warning("Error: endianness mismatch.\n"); +static int bpf_object__check_endianness(struct bpf_object *obj) +{ +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ + if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2LSB) + return 0; +#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ + if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2MSB) + return 0; +#else +# error "Unrecognized __BYTE_ORDER__" +#endif + pr_warning("endianness mismatch.\n"); return -LIBBPF_ERRNO__ENDIAN; } -- cgit v1.2.3 From c51829bb6e921337014d9ac3712b0b7e8cae9f3d Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Wed, 29 May 2019 10:36:06 -0700 Subject: libbpf: check map name retrieved from ELF Validate there was no error retrieving symbol name corresponding to a BPF map. Acked-by: Song Liu Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index fb296eadc3f2..60ec9694923a 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -920,6 +920,11 @@ bpf_object__init_maps(struct bpf_object *obj, int flags) map_name = elf_strptr(obj->efile.elf, obj->efile.strtabidx, sym.st_name); + if (!map_name) { + pr_warning("failed to get map #%d name sym string for obj %s\n", + map_idx, obj->path); + return -LIBBPF_ERRNO__FORMAT; + } obj->maps[map_idx].libbpf_type = LIBBPF_MAP_UNSPEC; obj->maps[map_idx].offset = sym.st_value; -- cgit v1.2.3 From f102154d3158c8fe9713f03bd3492f9cb8409a5e Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Wed, 29 May 2019 10:36:07 -0700 Subject: libbpf: fix error code returned on corrupted ELF All of libbpf errors are negative, except this one. Fix it. Acked-by: Song Liu Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 60ec9694923a..9f421206d3e7 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1221,7 +1221,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) if (!obj->efile.strtabidx || obj->efile.strtabidx >= idx) { pr_warning("Corrupted ELF file: index of strtab invalid\n"); - return LIBBPF_ERRNO__FORMAT; + return -LIBBPF_ERRNO__FORMAT; } if (btf_data) { obj->btf = btf__new(btf_data->d_buf, btf_data->d_size); -- cgit v1.2.3 From fba01a0689a98613f5ee3b1569fd9321f3fde7bd Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Wed, 29 May 2019 10:36:08 -0700 Subject: libbpf: use negative fd to specify missing BTF 0 is a valid FD, so it's better to initialize it to -1, as is done in other places. Also, technically, BTF type ID 0 is valid (it's a VOID type), so it's more reliable to check btf_fd, instead of btf_key_type_id, to determine if there is any BTF associated with a map. Acked-by: Song Liu Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 9f421206d3e7..b43913fc8b1b 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1751,7 +1751,7 @@ bpf_object__create_maps(struct bpf_object *obj) create_attr.key_size = def->key_size; create_attr.value_size = def->value_size; create_attr.max_entries = def->max_entries; - create_attr.btf_fd = 0; + create_attr.btf_fd = -1; create_attr.btf_key_type_id = 0; create_attr.btf_value_type_id = 0; if (bpf_map_type__is_map_in_map(def->type) && @@ -1765,11 +1765,11 @@ bpf_object__create_maps(struct bpf_object *obj) } *pfd = bpf_create_map_xattr(&create_attr); - if (*pfd < 0 && create_attr.btf_key_type_id) { + if (*pfd < 0 && create_attr.btf_fd >= 0) { cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); pr_warning("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n", map->name, cp, errno); - create_attr.btf_fd = 0; + create_attr.btf_fd = -1; create_attr.btf_key_type_id = 0; create_attr.btf_value_type_id = 0; map->btf_key_type_id = 0; @@ -2053,6 +2053,9 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, char *log_buf; int ret; + if (!insns || !insns_cnt) + return -EINVAL; + memset(&load_attr, 0, sizeof(struct bpf_load_program_attr)); load_attr.prog_type = prog->type; load_attr.expected_attach_type = prog->expected_attach_type; @@ -2063,7 +2066,7 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, load_attr.license = license; load_attr.kern_version = kern_version; load_attr.prog_ifindex = prog->prog_ifindex; - load_attr.prog_btf_fd = prog->btf_fd >= 0 ? prog->btf_fd : 0; + load_attr.prog_btf_fd = prog->btf_fd; load_attr.func_info = prog->func_info; load_attr.func_info_rec_size = prog->func_info_rec_size; load_attr.func_info_cnt = prog->func_info_cnt; @@ -2072,8 +2075,6 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, load_attr.line_info_cnt = prog->line_info_cnt; load_attr.log_level = prog->log_level; load_attr.prog_flags = prog->prog_flags; - if (!load_attr.insns || !load_attr.insns_cnt) - return -EINVAL; retry_load: log_buf = malloc(log_buf_size); -- cgit v1.2.3 From 7e8c328c4e96a0fc68d9f1264656683f7f1e12c1 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Wed, 29 May 2019 10:36:09 -0700 Subject: libbpf: simplify two pieces of logic Extra check for type is unnecessary in first case. Extra zeroing is unnecessary, as snprintf guarantees that it will zero-terminate string. Acked-by: Song Liu Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index b43913fc8b1b..33cd59bf9e72 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1430,8 +1430,7 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, if (maps[map_idx].libbpf_type != type) continue; if (type != LIBBPF_MAP_UNSPEC || - (type == LIBBPF_MAP_UNSPEC && - maps[map_idx].offset == sym.st_value)) { + maps[map_idx].offset == sym.st_value) { pr_debug("relocation: find map %zd (%s) for insn %u\n", map_idx, maps[map_idx].name, insn_idx); break; @@ -2354,7 +2353,6 @@ struct bpf_object *bpf_object__open_buffer(void *obj_buf, snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx", (unsigned long)obj_buf, (unsigned long)obj_buf_sz); - tmp_name[sizeof(tmp_name) - 1] = '\0'; name = tmp_name; } pr_debug("loading object '%s' from buffer\n", -- cgit v1.2.3 From 76e1022b9653b5b5254e2f99ac467354b9c08de6 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Wed, 29 May 2019 10:36:10 -0700 Subject: libbpf: typo and formatting fixes A bunch of typo and formatting fixes. Acked-by: Song Liu Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 33cd59bf9e72..a889925ecbcb 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -505,7 +505,7 @@ static struct bpf_object *bpf_object__new(const char *path, obj->efile.fd = -1; /* - * Caller of this function should also calls + * Caller of this function should also call * bpf_object__elf_finish() after data collection to return * obj_buf to user. If not, we should duplicate the buffer to * avoid user freeing them before elf finish. @@ -574,8 +574,7 @@ static int bpf_object__elf_init(struct bpf_object *obj) } obj->efile.elf = elf_begin(obj->efile.fd, - LIBBPF_ELF_C_READ_MMAP, - NULL); + LIBBPF_ELF_C_READ_MMAP, NULL); } if (!obj->efile.elf) { @@ -594,9 +593,9 @@ static int bpf_object__elf_init(struct bpf_object *obj) ep = &obj->efile.ehdr; /* Old LLVM set e_machine to EM_NONE */ - if ((ep->e_type != ET_REL) || (ep->e_machine && (ep->e_machine != EM_BPF))) { - pr_warning("%s is not an eBPF object file\n", - obj->path); + if (ep->e_type != ET_REL || + (ep->e_machine && ep->e_machine != EM_BPF)) { + pr_warning("%s is not an eBPF object file\n", obj->path); err = -LIBBPF_ERRNO__FORMAT; goto errout; } @@ -1438,7 +1437,7 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, } if (map_idx >= nr_maps) { - pr_warning("bpf relocation: map_idx %d large than %d\n", + pr_warning("bpf relocation: map_idx %d larger than %d\n", (int)map_idx, (int)nr_maps - 1); return -LIBBPF_ERRNO__RELOC; } @@ -1797,7 +1796,7 @@ err_out: } } - pr_debug("create map %s: fd=%d\n", map->name, *pfd); + pr_debug("created map %s: fd=%d\n", map->name, *pfd); } return 0; -- cgit v1.2.3 From 399dc65e9ca0c35c8ceea7130b25e7be8f229a52 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Wed, 29 May 2019 10:36:11 -0700 Subject: libbpf: reduce unnecessary line wrapping There are a bunch of lines of code or comments that are unnecessary wrapped into multi-lines. Fix that without violating any code guidelines. Acked-by: Song Liu Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 52 ++++++++++++++++---------------------------------- 1 file changed, 16 insertions(+), 36 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index a889925ecbcb..ba89d9727137 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -497,8 +497,7 @@ static struct bpf_object *bpf_object__new(const char *path, strcpy(obj->path, path); /* Using basename() GNU version which doesn't modify arg. */ - strncpy(obj->name, basename((void *)path), - sizeof(obj->name) - 1); + strncpy(obj->name, basename((void *)path), sizeof(obj->name) - 1); end = strchr(obj->name, '.'); if (end) *end = 0; @@ -578,15 +577,13 @@ static int bpf_object__elf_init(struct bpf_object *obj) } if (!obj->efile.elf) { - pr_warning("failed to open %s as ELF file\n", - obj->path); + pr_warning("failed to open %s as ELF file\n", obj->path); err = -LIBBPF_ERRNO__LIBELF; goto errout; } if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) { - pr_warning("failed to get EHDR from %s\n", - obj->path); + pr_warning("failed to get EHDR from %s\n", obj->path); err = -LIBBPF_ERRNO__FORMAT; goto errout; } @@ -622,18 +619,15 @@ static int bpf_object__check_endianness(struct bpf_object *obj) } static int -bpf_object__init_license(struct bpf_object *obj, - void *data, size_t size) +bpf_object__init_license(struct bpf_object *obj, void *data, size_t size) { - memcpy(obj->license, data, - min(size, sizeof(obj->license) - 1)); + memcpy(obj->license, data, min(size, sizeof(obj->license) - 1)); pr_debug("license of %s is %s\n", obj->path, obj->license); return 0; } static int -bpf_object__init_kversion(struct bpf_object *obj, - void *data, size_t size) +bpf_object__init_kversion(struct bpf_object *obj, void *data, size_t size) { __u32 kver; @@ -643,8 +637,7 @@ bpf_object__init_kversion(struct bpf_object *obj, } memcpy(&kver, data, sizeof(kver)); obj->kern_version = kver; - pr_debug("kernel version of %s is %x\n", obj->path, - obj->kern_version); + pr_debug("kernel version of %s is %x\n", obj->path, obj->kern_version); return 0; } @@ -800,8 +793,7 @@ bpf_object__init_internal_map(struct bpf_object *obj, struct bpf_map *map, def->key_size = sizeof(int); def->value_size = data->d_size; def->max_entries = 1; - def->map_flags = type == LIBBPF_MAP_RODATA ? - BPF_F_RDONLY_PROG : 0; + def->map_flags = type == LIBBPF_MAP_RODATA ? BPF_F_RDONLY_PROG : 0; if (data_buff) { *data_buff = malloc(data->d_size); if (!*data_buff) { @@ -816,8 +808,7 @@ bpf_object__init_internal_map(struct bpf_object *obj, struct bpf_map *map, return 0; } -static int -bpf_object__init_maps(struct bpf_object *obj, int flags) +static int bpf_object__init_maps(struct bpf_object *obj, int flags) { int i, map_idx, map_def_sz = 0, nr_syms, nr_maps = 0, nr_maps_glob = 0; bool strict = !(flags & MAPS_RELAX_COMPAT); @@ -1098,8 +1089,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) /* Elf is corrupted/truncated, avoid calling elf_strptr. */ if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) { - pr_warning("failed to get e_shstrndx from %s\n", - obj->path); + pr_warning("failed to get e_shstrndx from %s\n", obj->path); return -LIBBPF_ERRNO__FORMAT; } @@ -1340,8 +1330,7 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, size_t nr_maps = obj->nr_maps; int i, nrels; - pr_debug("collecting relocating info for: '%s'\n", - prog->section_name); + pr_debug("collecting relocating info for: '%s'\n", prog->section_name); nrels = shdr->sh_size / shdr->sh_entsize; prog->reloc_desc = malloc(sizeof(*prog->reloc_desc) * nrels); @@ -1366,9 +1355,7 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, return -LIBBPF_ERRNO__FORMAT; } - if (!gelf_getsym(symbols, - GELF_R_SYM(rel.r_info), - &sym)) { + if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) { pr_warning("relocation: symbol %"PRIx64" not found\n", GELF_R_SYM(rel.r_info)); return -LIBBPF_ERRNO__FORMAT; @@ -1817,18 +1804,14 @@ check_btf_ext_reloc_err(struct bpf_program *prog, int err, if (btf_prog_info) { /* * Some info has already been found but has problem - * in the last btf_ext reloc. Must have to error - * out. + * in the last btf_ext reloc. Must have to error out. */ pr_warning("Error in relocating %s for sec %s.\n", info_name, prog->section_name); return err; } - /* - * Have problem loading the very first info. Ignore - * the rest. - */ + /* Have problem loading the very first info. Ignore the rest. */ pr_warning("Cannot find %s for main program sec %s. Ignore all %s.\n", info_name, prog->section_name, info_name); return 0; @@ -2032,9 +2015,7 @@ static int bpf_object__collect_reloc(struct bpf_object *obj) return -LIBBPF_ERRNO__RELOC; } - err = bpf_program__collect_reloc(prog, - shdr, data, - obj); + err = bpf_program__collect_reloc(prog, shdr, data, obj); if (err) return err; } @@ -2354,8 +2335,7 @@ struct bpf_object *bpf_object__open_buffer(void *obj_buf, (unsigned long)obj_buf_sz); name = tmp_name; } - pr_debug("loading object '%s' from buffer\n", - name); + pr_debug("loading object '%s' from buffer\n", name); return __bpf_object__open(name, obj_buf, obj_buf_sz, true, true); } -- cgit v1.2.3 From 6446b3155521aab37f5a2b99ac264803ea7dced8 Mon Sep 17 00:00:00 2001 From: Hechao Li Date: Mon, 10 Jun 2019 17:56:50 -0700 Subject: bpf: add a new API libbpf_num_possible_cpus() Adding a new API libbpf_num_possible_cpus() that helps user with per-CPU map operations. Signed-off-by: Hechao Li Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index ba89d9727137..dd8b2cd5d3a7 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3827,3 +3827,60 @@ void bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear) desc->array_offset, addr); } } + +int libbpf_num_possible_cpus(void) +{ + static const char *fcpu = "/sys/devices/system/cpu/possible"; + int len = 0, n = 0, il = 0, ir = 0; + unsigned int start = 0, end = 0; + static int cpus; + char buf[128]; + int error = 0; + int fd = -1; + + if (cpus > 0) + return cpus; + + fd = open(fcpu, O_RDONLY); + if (fd < 0) { + error = errno; + pr_warning("Failed to open file %s: %s\n", + fcpu, strerror(error)); + return -error; + } + len = read(fd, buf, sizeof(buf)); + close(fd); + if (len <= 0) { + error = len ? errno : EINVAL; + pr_warning("Failed to read # of possible cpus from %s: %s\n", + fcpu, strerror(error)); + return -error; + } + if (len == sizeof(buf)) { + pr_warning("File %s size overflow\n", fcpu); + return -EOVERFLOW; + } + buf[len] = '\0'; + + for (ir = 0, cpus = 0; ir <= len; ir++) { + /* Each sub string separated by ',' has format \d+-\d+ or \d+ */ + if (buf[ir] == ',' || buf[ir] == '\0') { + buf[ir] = '\0'; + n = sscanf(&buf[il], "%u-%u", &start, &end); + if (n <= 0) { + pr_warning("Failed to get # CPUs from %s\n", + &buf[il]); + return -EINVAL; + } else if (n == 1) { + end = start; + } + cpus += end - start + 1; + il = ir + 1; + } + } + if (cpus <= 0) { + pr_warning("Invalid #CPUs %d from %s\n", cpus, fcpu); + return -EINVAL; + } + return cpus; +} -- cgit v1.2.3 From e55d54f43d3f11718d9e2800225097fda498e141 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Wed, 12 Jun 2019 22:04:57 -0700 Subject: libbpf: fix check for presence of associated BTF for map creation Kernel internally checks that either key or value type ID is specified, before using btf_fd. Do the same in libbpf's map creation code for determining when to retry map creation w/o BTF. Reported-by: Dan Carpenter Fixes: fba01a0689a9 ("libbpf: use negative fd to specify missing BTF") Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index dd8b2cd5d3a7..e725fa86b189 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1736,7 +1736,7 @@ bpf_object__create_maps(struct bpf_object *obj) create_attr.key_size = def->key_size; create_attr.value_size = def->value_size; create_attr.max_entries = def->max_entries; - create_attr.btf_fd = -1; + create_attr.btf_fd = 0; create_attr.btf_key_type_id = 0; create_attr.btf_value_type_id = 0; if (bpf_map_type__is_map_in_map(def->type) && @@ -1750,11 +1750,12 @@ bpf_object__create_maps(struct bpf_object *obj) } *pfd = bpf_create_map_xattr(&create_attr); - if (*pfd < 0 && create_attr.btf_fd >= 0) { + if (*pfd < 0 && (create_attr.btf_key_type_id || + create_attr.btf_value_type_id)) { cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); pr_warning("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n", map->name, cp, errno); - create_attr.btf_fd = -1; + create_attr.btf_fd = 0; create_attr.btf_key_type_id = 0; create_attr.btf_value_type_id = 0; map->btf_key_type_id = 0; @@ -2045,7 +2046,7 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, load_attr.license = license; load_attr.kern_version = kern_version; load_attr.prog_ifindex = prog->prog_ifindex; - load_attr.prog_btf_fd = prog->btf_fd; + load_attr.prog_btf_fd = prog->btf_fd >= 0 ? prog->btf_fd : 0; load_attr.func_info = prog->func_info; load_attr.func_info_rec_size = prog->func_info_rec_size; load_attr.func_info_cnt = prog->func_info_cnt; -- cgit v1.2.3 From 9c6660d0406f8c32d21957ca9853108513bea8b1 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 17 Jun 2019 12:26:51 -0700 Subject: libbpf: extract BTF loading logic As a preparation for adding BTF-based BPF map loading, extract .BTF and .BTF.ext loading logic. Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 93 +++++++++++++++++++++++++++++--------------------- 1 file changed, 55 insertions(+), 38 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index e725fa86b189..49d3a808e754 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1078,6 +1078,58 @@ static void bpf_object__sanitize_btf_ext(struct bpf_object *obj) } } +static int bpf_object__load_btf(struct bpf_object *obj, + Elf_Data *btf_data, + Elf_Data *btf_ext_data) +{ + int err = 0; + + if (btf_data) { + obj->btf = btf__new(btf_data->d_buf, btf_data->d_size); + if (IS_ERR(obj->btf)) { + pr_warning("Error loading ELF section %s: %d.\n", + BTF_ELF_SEC, err); + goto out; + } + err = btf__finalize_data(obj, obj->btf); + if (err) { + pr_warning("Error finalizing %s: %d.\n", + BTF_ELF_SEC, err); + goto out; + } + bpf_object__sanitize_btf(obj); + err = btf__load(obj->btf); + if (err) { + pr_warning("Error loading %s into kernel: %d.\n", + BTF_ELF_SEC, err); + goto out; + } + } + if (btf_ext_data) { + if (!obj->btf) { + pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n", + BTF_EXT_ELF_SEC, BTF_ELF_SEC); + goto out; + } + obj->btf_ext = btf_ext__new(btf_ext_data->d_buf, + btf_ext_data->d_size); + if (IS_ERR(obj->btf_ext)) { + pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n", + BTF_EXT_ELF_SEC, PTR_ERR(obj->btf_ext)); + obj->btf_ext = NULL; + goto out; + } + bpf_object__sanitize_btf_ext(obj); + } +out: + if (err || IS_ERR(obj->btf)) { + if (!IS_ERR_OR_NULL(obj->btf)) + btf__free(obj->btf); + obj->btf = NULL; + } + return 0; +} + static int bpf_object__elf_collect(struct bpf_object *obj, int flags) { Elf *elf = obj->efile.elf; @@ -1212,44 +1264,9 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) pr_warning("Corrupted ELF file: index of strtab invalid\n"); return -LIBBPF_ERRNO__FORMAT; } - if (btf_data) { - obj->btf = btf__new(btf_data->d_buf, btf_data->d_size); - if (IS_ERR(obj->btf)) { - pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n", - BTF_ELF_SEC, PTR_ERR(obj->btf)); - obj->btf = NULL; - } else { - err = btf__finalize_data(obj, obj->btf); - if (!err) { - bpf_object__sanitize_btf(obj); - err = btf__load(obj->btf); - } - if (err) { - pr_warning("Error finalizing and loading %s into kernel: %d. Ignored and continue.\n", - BTF_ELF_SEC, err); - btf__free(obj->btf); - obj->btf = NULL; - err = 0; - } - } - } - if (btf_ext_data) { - if (!obj->btf) { - pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n", - BTF_EXT_ELF_SEC, BTF_ELF_SEC); - } else { - obj->btf_ext = btf_ext__new(btf_ext_data->d_buf, - btf_ext_data->d_size); - if (IS_ERR(obj->btf_ext)) { - pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n", - BTF_EXT_ELF_SEC, - PTR_ERR(obj->btf_ext)); - obj->btf_ext = NULL; - } else { - bpf_object__sanitize_btf_ext(obj); - } - } - } + err = bpf_object__load_btf(obj, btf_data, btf_ext_data); + if (err) + return err; if (bpf_object__has_maps(obj)) { err = bpf_object__init_maps(obj, flags); if (err) -- cgit v1.2.3 From 01b29d1dc9a06e2cdc6a0172d35605eb0300ecb2 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 17 Jun 2019 12:26:52 -0700 Subject: libbpf: streamline ELF parsing error-handling Simplify ELF parsing logic by exiting early, as there is no common clean up path to execute. That makes it unnecessary to track when err was set and when it was cleared. It also reduces nesting in some places. Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 44 ++++++++++++++++++++------------------------ 1 file changed, 20 insertions(+), 24 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 49d3a808e754..7ee44d8877c5 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1154,24 +1154,21 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) if (gelf_getshdr(scn, &sh) != &sh) { pr_warning("failed to get section(%d) header from %s\n", idx, obj->path); - err = -LIBBPF_ERRNO__FORMAT; - goto out; + return -LIBBPF_ERRNO__FORMAT; } name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name); if (!name) { pr_warning("failed to get section(%d) name from %s\n", idx, obj->path); - err = -LIBBPF_ERRNO__FORMAT; - goto out; + return -LIBBPF_ERRNO__FORMAT; } data = elf_getdata(scn, 0); if (!data) { pr_warning("failed to get section(%d) data from %s(%s)\n", idx, name, obj->path); - err = -LIBBPF_ERRNO__FORMAT; - goto out; + return -LIBBPF_ERRNO__FORMAT; } pr_debug("section(%d) %s, size %ld, link %d, flags %lx, type=%d\n", idx, name, (unsigned long)data->d_size, @@ -1182,10 +1179,14 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) err = bpf_object__init_license(obj, data->d_buf, data->d_size); + if (err) + return err; } else if (strcmp(name, "version") == 0) { err = bpf_object__init_kversion(obj, data->d_buf, data->d_size); + if (err) + return err; } else if (strcmp(name, "maps") == 0) { obj->efile.maps_shndx = idx; } else if (strcmp(name, BTF_ELF_SEC) == 0) { @@ -1196,11 +1197,10 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) if (obj->efile.symbols) { pr_warning("bpf: multiple SYMTAB in %s\n", obj->path); - err = -LIBBPF_ERRNO__FORMAT; - } else { - obj->efile.symbols = data; - obj->efile.strtabidx = sh.sh_link; + return -LIBBPF_ERRNO__FORMAT; } + obj->efile.symbols = data; + obj->efile.strtabidx = sh.sh_link; } else if (sh.sh_type == SHT_PROGBITS && data->d_size > 0) { if (sh.sh_flags & SHF_EXECINSTR) { if (strcmp(name, ".text") == 0) @@ -1214,6 +1214,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) pr_warning("failed to alloc program %s (%s): %s", name, obj->path, cp); + return err; } } else if (strcmp(name, ".data") == 0) { obj->efile.data = data; @@ -1225,8 +1226,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) pr_debug("skip section(%d) %s\n", idx, name); } } else if (sh.sh_type == SHT_REL) { + int nr_reloc = obj->efile.nr_reloc; void *reloc = obj->efile.reloc; - int nr_reloc = obj->efile.nr_reloc + 1; int sec = sh.sh_info; /* points to other section */ /* Only do relo for section with exec instructions */ @@ -1236,28 +1237,24 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) continue; } - reloc = reallocarray(reloc, nr_reloc, + reloc = reallocarray(reloc, nr_reloc + 1, sizeof(*obj->efile.reloc)); if (!reloc) { pr_warning("realloc failed\n"); - err = -ENOMEM; - } else { - int n = nr_reloc - 1; + return -ENOMEM; + } - obj->efile.reloc = reloc; - obj->efile.nr_reloc = nr_reloc; + obj->efile.reloc = reloc; + obj->efile.nr_reloc++; - obj->efile.reloc[n].shdr = sh; - obj->efile.reloc[n].data = data; - } + obj->efile.reloc[nr_reloc].shdr = sh; + obj->efile.reloc[nr_reloc].data = data; } else if (sh.sh_type == SHT_NOBITS && strcmp(name, ".bss") == 0) { obj->efile.bss = data; obj->efile.bss_shndx = idx; } else { pr_debug("skip section(%d) %s\n", idx, name); } - if (err) - goto out; } if (!obj->efile.strtabidx || obj->efile.strtabidx >= idx) { @@ -1270,10 +1267,9 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) if (bpf_object__has_maps(obj)) { err = bpf_object__init_maps(obj, flags); if (err) - goto out; + return err; } err = bpf_object__init_prog_names(obj); -out: return err; } -- cgit v1.2.3 From bf82927125dd25003d76ed5541da704df21de57a Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 17 Jun 2019 12:26:53 -0700 Subject: libbpf: refactor map initialization User and global data maps initialization has gotten pretty complicated and unnecessarily convoluted. This patch splits out the logic for global data map and user-defined map initialization. It also removes the restriction of pre-calculating how many maps will be initialized, instead allowing to keep adding new maps as they are discovered, which will be used later for BTF-defined map definitions. Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 247 ++++++++++++++++++++++++++----------------------- 1 file changed, 133 insertions(+), 114 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 7ee44d8877c5..88609dca4f7d 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -234,6 +234,7 @@ struct bpf_object { size_t nr_programs; struct bpf_map *maps; size_t nr_maps; + size_t maps_cap; struct bpf_secdata sections; bool loaded; @@ -763,21 +764,51 @@ int bpf_object__variable_offset(const struct bpf_object *obj, const char *name, return -ENOENT; } -static bool bpf_object__has_maps(const struct bpf_object *obj) +static struct bpf_map *bpf_object__add_map(struct bpf_object *obj) { - return obj->efile.maps_shndx >= 0 || - obj->efile.data_shndx >= 0 || - obj->efile.rodata_shndx >= 0 || - obj->efile.bss_shndx >= 0; + struct bpf_map *new_maps; + size_t new_cap; + int i; + + if (obj->nr_maps < obj->maps_cap) + return &obj->maps[obj->nr_maps++]; + + new_cap = max(4ul, obj->maps_cap * 3 / 2); + new_maps = realloc(obj->maps, new_cap * sizeof(*obj->maps)); + if (!new_maps) { + pr_warning("alloc maps for object failed\n"); + return ERR_PTR(-ENOMEM); + } + + obj->maps_cap = new_cap; + obj->maps = new_maps; + + /* zero out new maps */ + memset(obj->maps + obj->nr_maps, 0, + (obj->maps_cap - obj->nr_maps) * sizeof(*obj->maps)); + /* + * fill all fd with -1 so won't close incorrect fd (fd=0 is stdin) + * when failure (zclose won't close negative fd)). + */ + for (i = obj->nr_maps; i < obj->maps_cap; i++) { + obj->maps[i].fd = -1; + obj->maps[i].inner_map_fd = -1; + } + + return &obj->maps[obj->nr_maps++]; } static int -bpf_object__init_internal_map(struct bpf_object *obj, struct bpf_map *map, - enum libbpf_map_type type, Elf_Data *data, - void **data_buff) +bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type, + Elf_Data *data, void **data_buff) { - struct bpf_map_def *def = &map->def; char map_name[BPF_OBJ_NAME_LEN]; + struct bpf_map_def *def; + struct bpf_map *map; + + map = bpf_object__add_map(obj); + if (IS_ERR(map)) + return PTR_ERR(map); map->libbpf_type = type; map->offset = ~(typeof(map->offset))0; @@ -789,6 +820,7 @@ bpf_object__init_internal_map(struct bpf_object *obj, struct bpf_map *map, return -ENOMEM; } + def = &map->def; def->type = BPF_MAP_TYPE_ARRAY; def->key_size = sizeof(int); def->value_size = data->d_size; @@ -808,29 +840,58 @@ bpf_object__init_internal_map(struct bpf_object *obj, struct bpf_map *map, return 0; } -static int bpf_object__init_maps(struct bpf_object *obj, int flags) +static int bpf_object__init_global_data_maps(struct bpf_object *obj) +{ + int err; + + if (!obj->caps.global_data) + return 0; + /* + * Populate obj->maps with libbpf internal maps. + */ + if (obj->efile.data_shndx >= 0) { + err = bpf_object__init_internal_map(obj, LIBBPF_MAP_DATA, + obj->efile.data, + &obj->sections.data); + if (err) + return err; + } + if (obj->efile.rodata_shndx >= 0) { + err = bpf_object__init_internal_map(obj, LIBBPF_MAP_RODATA, + obj->efile.rodata, + &obj->sections.rodata); + if (err) + return err; + } + if (obj->efile.bss_shndx >= 0) { + err = bpf_object__init_internal_map(obj, LIBBPF_MAP_BSS, + obj->efile.bss, NULL); + if (err) + return err; + } + return 0; +} + +static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict) { - int i, map_idx, map_def_sz = 0, nr_syms, nr_maps = 0, nr_maps_glob = 0; - bool strict = !(flags & MAPS_RELAX_COMPAT); Elf_Data *symbols = obj->efile.symbols; + int i, map_def_sz = 0, nr_maps = 0, nr_syms; Elf_Data *data = NULL; - int ret = 0; + Elf_Scn *scn; + + if (obj->efile.maps_shndx < 0) + return 0; if (!symbols) return -EINVAL; - nr_syms = symbols->d_size / sizeof(GElf_Sym); - - if (obj->efile.maps_shndx >= 0) { - Elf_Scn *scn = elf_getscn(obj->efile.elf, - obj->efile.maps_shndx); - if (scn) - data = elf_getdata(scn, NULL); - if (!scn || !data) { - pr_warning("failed to get Elf_Data from map section %d\n", - obj->efile.maps_shndx); - return -EINVAL; - } + scn = elf_getscn(obj->efile.elf, obj->efile.maps_shndx); + if (scn) + data = elf_getdata(scn, NULL); + if (!scn || !data) { + pr_warning("failed to get Elf_Data from map section %d\n", + obj->efile.maps_shndx); + return -EINVAL; } /* @@ -840,16 +901,8 @@ static int bpf_object__init_maps(struct bpf_object *obj, int flags) * * TODO: Detect array of map and report error. */ - if (obj->caps.global_data) { - if (obj->efile.data_shndx >= 0) - nr_maps_glob++; - if (obj->efile.rodata_shndx >= 0) - nr_maps_glob++; - if (obj->efile.bss_shndx >= 0) - nr_maps_glob++; - } - - for (i = 0; data && i < nr_syms; i++) { + nr_syms = symbols->d_size / sizeof(GElf_Sym); + for (i = 0; i < nr_syms; i++) { GElf_Sym sym; if (!gelf_getsym(symbols, i, &sym)) @@ -858,79 +911,56 @@ static int bpf_object__init_maps(struct bpf_object *obj, int flags) continue; nr_maps++; } - - if (!nr_maps && !nr_maps_glob) - return 0; - /* Assume equally sized map definitions */ - if (data) { - pr_debug("maps in %s: %d maps in %zd bytes\n", obj->path, - nr_maps, data->d_size); - - map_def_sz = data->d_size / nr_maps; - if (!data->d_size || (data->d_size % nr_maps) != 0) { - pr_warning("unable to determine map definition size " - "section %s, %d maps in %zd bytes\n", - obj->path, nr_maps, data->d_size); - return -EINVAL; - } - } - - nr_maps += nr_maps_glob; - obj->maps = calloc(nr_maps, sizeof(obj->maps[0])); - if (!obj->maps) { - pr_warning("alloc maps for object failed\n"); - return -ENOMEM; - } - obj->nr_maps = nr_maps; - - for (i = 0; i < nr_maps; i++) { - /* - * fill all fd with -1 so won't close incorrect - * fd (fd=0 is stdin) when failure (zclose won't close - * negative fd)). - */ - obj->maps[i].fd = -1; - obj->maps[i].inner_map_fd = -1; + pr_debug("maps in %s: %d maps in %zd bytes\n", + obj->path, nr_maps, data->d_size); + + map_def_sz = data->d_size / nr_maps; + if (!data->d_size || (data->d_size % nr_maps) != 0) { + pr_warning("unable to determine map definition size " + "section %s, %d maps in %zd bytes\n", + obj->path, nr_maps, data->d_size); + return -EINVAL; } - /* - * Fill obj->maps using data in "maps" section. - */ - for (i = 0, map_idx = 0; data && i < nr_syms; i++) { + /* Fill obj->maps using data in "maps" section. */ + for (i = 0; i < nr_syms; i++) { GElf_Sym sym; const char *map_name; struct bpf_map_def *def; + struct bpf_map *map; if (!gelf_getsym(symbols, i, &sym)) continue; if (sym.st_shndx != obj->efile.maps_shndx) continue; - map_name = elf_strptr(obj->efile.elf, - obj->efile.strtabidx, + map = bpf_object__add_map(obj); + if (IS_ERR(map)) + return PTR_ERR(map); + + map_name = elf_strptr(obj->efile.elf, obj->efile.strtabidx, sym.st_name); if (!map_name) { pr_warning("failed to get map #%d name sym string for obj %s\n", - map_idx, obj->path); + i, obj->path); return -LIBBPF_ERRNO__FORMAT; } - obj->maps[map_idx].libbpf_type = LIBBPF_MAP_UNSPEC; - obj->maps[map_idx].offset = sym.st_value; + map->libbpf_type = LIBBPF_MAP_UNSPEC; + map->offset = sym.st_value; if (sym.st_value + map_def_sz > data->d_size) { pr_warning("corrupted maps section in %s: last map \"%s\" too small\n", obj->path, map_name); return -EINVAL; } - obj->maps[map_idx].name = strdup(map_name); - if (!obj->maps[map_idx].name) { + map->name = strdup(map_name); + if (!map->name) { pr_warning("failed to alloc map name\n"); return -ENOMEM; } - pr_debug("map %d is \"%s\"\n", map_idx, - obj->maps[map_idx].name); + pr_debug("map %d is \"%s\"\n", i, map->name); def = (struct bpf_map_def *)(data->d_buf + sym.st_value); /* * If the definition of the map in the object file fits in @@ -939,7 +969,7 @@ static int bpf_object__init_maps(struct bpf_object *obj, int flags) * calloc above. */ if (map_def_sz <= sizeof(struct bpf_map_def)) { - memcpy(&obj->maps[map_idx].def, def, map_def_sz); + memcpy(&map->def, def, map_def_sz); } else { /* * Here the map structure being read is bigger than what @@ -959,37 +989,30 @@ static int bpf_object__init_maps(struct bpf_object *obj, int flags) return -EINVAL; } } - memcpy(&obj->maps[map_idx].def, def, - sizeof(struct bpf_map_def)); + memcpy(&map->def, def, sizeof(struct bpf_map_def)); } - map_idx++; } + return 0; +} - if (!obj->caps.global_data) - goto finalize; +static int bpf_object__init_maps(struct bpf_object *obj, int flags) +{ + bool strict = !(flags & MAPS_RELAX_COMPAT); + int err; - /* - * Populate rest of obj->maps with libbpf internal maps. - */ - if (obj->efile.data_shndx >= 0) - ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++], - LIBBPF_MAP_DATA, - obj->efile.data, - &obj->sections.data); - if (!ret && obj->efile.rodata_shndx >= 0) - ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++], - LIBBPF_MAP_RODATA, - obj->efile.rodata, - &obj->sections.rodata); - if (!ret && obj->efile.bss_shndx >= 0) - ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++], - LIBBPF_MAP_BSS, - obj->efile.bss, NULL); -finalize: - if (!ret) + err = bpf_object__init_user_maps(obj, strict); + if (err) + return err; + + err = bpf_object__init_global_data_maps(obj); + if (err) + return err; + + if (obj->nr_maps) { qsort(obj->maps, obj->nr_maps, sizeof(obj->maps[0]), compare_bpf_map); - return ret; + } + return 0; } static bool section_have_execinstr(struct bpf_object *obj, int idx) @@ -1262,14 +1285,10 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) return -LIBBPF_ERRNO__FORMAT; } err = bpf_object__load_btf(obj, btf_data, btf_ext_data); - if (err) - return err; - if (bpf_object__has_maps(obj)) { + if (!err) err = bpf_object__init_maps(obj, flags); - if (err) - return err; - } - err = bpf_object__init_prog_names(obj); + if (!err) + err = bpf_object__init_prog_names(obj); return err; } -- cgit v1.2.3 From db48814bd2833ee231f48bd2030082369b88f9ef Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 17 Jun 2019 12:26:54 -0700 Subject: libbpf: identify maps by section index in addition to offset To support maps to be defined in multiple sections, it's important to identify map not just by offset within its section, but section index as well. This patch adds tracking of section index. For global data, we record section index of corresponding .data/.bss/.rodata ELF section for uniformity, and thus don't need a special value of offset for those maps. Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 40 +++++++++++++++++++++++++--------------- 1 file changed, 25 insertions(+), 15 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 88609dca4f7d..b1f3ab4b39b3 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -207,7 +207,8 @@ static const char * const libbpf_type_to_btf_name[] = { struct bpf_map { int fd; char *name; - size_t offset; + int sec_idx; + size_t sec_offset; int map_ifindex; int inner_map_fd; struct bpf_map_def def; @@ -647,7 +648,9 @@ static int compare_bpf_map(const void *_a, const void *_b) const struct bpf_map *a = _a; const struct bpf_map *b = _b; - return a->offset - b->offset; + if (a->sec_idx != b->sec_idx) + return a->sec_idx - b->sec_idx; + return a->sec_offset - b->sec_offset; } static bool bpf_map_type__is_map_in_map(enum bpf_map_type type) @@ -800,7 +803,7 @@ static struct bpf_map *bpf_object__add_map(struct bpf_object *obj) static int bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type, - Elf_Data *data, void **data_buff) + int sec_idx, Elf_Data *data, void **data_buff) { char map_name[BPF_OBJ_NAME_LEN]; struct bpf_map_def *def; @@ -811,7 +814,8 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type, return PTR_ERR(map); map->libbpf_type = type; - map->offset = ~(typeof(map->offset))0; + map->sec_idx = sec_idx; + map->sec_offset = 0; snprintf(map_name, sizeof(map_name), "%.8s%.7s", obj->name, libbpf_type_to_btf_name[type]); map->name = strdup(map_name); @@ -819,6 +823,8 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type, pr_warning("failed to alloc map name\n"); return -ENOMEM; } + pr_debug("map '%s' (global data): at sec_idx %d, offset %zu.\n", + map_name, map->sec_idx, map->sec_offset); def = &map->def; def->type = BPF_MAP_TYPE_ARRAY; @@ -851,6 +857,7 @@ static int bpf_object__init_global_data_maps(struct bpf_object *obj) */ if (obj->efile.data_shndx >= 0) { err = bpf_object__init_internal_map(obj, LIBBPF_MAP_DATA, + obj->efile.data_shndx, obj->efile.data, &obj->sections.data); if (err) @@ -858,6 +865,7 @@ static int bpf_object__init_global_data_maps(struct bpf_object *obj) } if (obj->efile.rodata_shndx >= 0) { err = bpf_object__init_internal_map(obj, LIBBPF_MAP_RODATA, + obj->efile.rodata_shndx, obj->efile.rodata, &obj->sections.rodata); if (err) @@ -865,6 +873,7 @@ static int bpf_object__init_global_data_maps(struct bpf_object *obj) } if (obj->efile.bss_shndx >= 0) { err = bpf_object__init_internal_map(obj, LIBBPF_MAP_BSS, + obj->efile.bss_shndx, obj->efile.bss, NULL); if (err) return err; @@ -948,7 +957,10 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict) } map->libbpf_type = LIBBPF_MAP_UNSPEC; - map->offset = sym.st_value; + map->sec_idx = sym.st_shndx; + map->sec_offset = sym.st_value; + pr_debug("map '%s' (legacy): at sec_idx %d, offset %zu.\n", + map_name, map->sec_idx, map->sec_offset); if (sym.st_value + map_def_sz > data->d_size) { pr_warning("corrupted maps section in %s: last map \"%s\" too small\n", obj->path, map_name); @@ -1448,9 +1460,13 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, if (maps[map_idx].libbpf_type != type) continue; if (type != LIBBPF_MAP_UNSPEC || - maps[map_idx].offset == sym.st_value) { - pr_debug("relocation: find map %zd (%s) for insn %u\n", - map_idx, maps[map_idx].name, insn_idx); + (maps[map_idx].sec_idx == sym.st_shndx && + maps[map_idx].sec_offset == sym.st_value)) { + pr_debug("relocation: found map %zd (%s, sec_idx %d, offset %zu) for insn %u\n", + map_idx, maps[map_idx].name, + maps[map_idx].sec_idx, + maps[map_idx].sec_offset, + insn_idx); break; } } @@ -3468,13 +3484,7 @@ bpf_object__find_map_fd_by_name(struct bpf_object *obj, const char *name) struct bpf_map * bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset) { - int i; - - for (i = 0; i < obj->nr_maps; i++) { - if (obj->maps[i].offset == offset) - return &obj->maps[i]; - } - return ERR_PTR(-ENOENT); + return ERR_PTR(-ENOTSUP); } long libbpf_get_error(const void *ptr) -- cgit v1.2.3 From 063183bf0486c7e61a2b454896bba2f7908b4ab0 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 17 Jun 2019 12:26:55 -0700 Subject: libbpf: split initialization and loading of BTF Libbpf does sanitization of BTF before loading it into kernel, if kernel doesn't support some of newer BTF features. This removes some of the important information from BTF (e.g., DATASEC and VAR description), which will be used for map construction. This patch splits BTF processing into initialization step, in which BTF is initialized from ELF and all the original data is still preserved; and sanitization/loading step, which ensures that BTF is safe to load into kernel. This allows to use full BTF information to construct maps, while still loading valid BTF into older kernels. Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 34 ++++++++++++++++++++++++---------- 1 file changed, 24 insertions(+), 10 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index b1f3ab4b39b3..da942ab2f06a 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1113,7 +1113,7 @@ static void bpf_object__sanitize_btf_ext(struct bpf_object *obj) } } -static int bpf_object__load_btf(struct bpf_object *obj, +static int bpf_object__init_btf(struct bpf_object *obj, Elf_Data *btf_data, Elf_Data *btf_ext_data) { @@ -1132,13 +1132,6 @@ static int bpf_object__load_btf(struct bpf_object *obj, BTF_ELF_SEC, err); goto out; } - bpf_object__sanitize_btf(obj); - err = btf__load(obj->btf); - if (err) { - pr_warning("Error loading %s into kernel: %d.\n", - BTF_ELF_SEC, err); - goto out; - } } if (btf_ext_data) { if (!obj->btf) { @@ -1154,7 +1147,6 @@ static int bpf_object__load_btf(struct bpf_object *obj, obj->btf_ext = NULL; goto out; } - bpf_object__sanitize_btf_ext(obj); } out: if (err || IS_ERR(obj->btf)) { @@ -1165,6 +1157,26 @@ out: return 0; } +static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj) +{ + int err = 0; + + if (!obj->btf) + return 0; + + bpf_object__sanitize_btf(obj); + bpf_object__sanitize_btf_ext(obj); + + err = btf__load(obj->btf); + if (err) { + pr_warning("Error loading %s into kernel: %d.\n", + BTF_ELF_SEC, err); + btf__free(obj->btf); + obj->btf = NULL; + } + return 0; +} + static int bpf_object__elf_collect(struct bpf_object *obj, int flags) { Elf *elf = obj->efile.elf; @@ -1296,9 +1308,11 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) pr_warning("Corrupted ELF file: index of strtab invalid\n"); return -LIBBPF_ERRNO__FORMAT; } - err = bpf_object__load_btf(obj, btf_data, btf_ext_data); + err = bpf_object__init_btf(obj, btf_data, btf_ext_data); if (!err) err = bpf_object__init_maps(obj, flags); + if (!err) + err = bpf_object__sanitize_and_load_btf(obj); if (!err) err = bpf_object__init_prog_names(obj); return err; -- cgit v1.2.3 From abd29c9314595b1ee5ec6c61d7c49a497ffb30a3 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 17 Jun 2019 12:26:56 -0700 Subject: libbpf: allow specifying map definitions using BTF This patch adds support for a new way to define BPF maps. It relies on BTF to describe mandatory and optional attributes of a map, as well as captures type information of key and value naturally. This eliminates the need for BPF_ANNOTATE_KV_PAIR hack and ensures key/value sizes are always in sync with the key/value type. Relying on BTF, this approach allows for both forward and backward compatibility w.r.t. extending supported map definition features. By default, any unrecognized attributes are treated as an error, but it's possible relax this using MAPS_RELAX_COMPAT flag. New attributes, added in the future will need to be optional. The outline of the new map definition (short, BTF-defined maps) is as follows: 1. All the maps should be defined in .maps ELF section. It's possible to have both "legacy" map definitions in `maps` sections and BTF-defined maps in .maps sections. Everything will still work transparently. 2. The map declaration and initialization is done through a global/static variable of a struct type with few mandatory and extra optional fields: - type field is mandatory and specified type of BPF map; - key/value fields are mandatory and capture key/value type/size information; - max_entries attribute is optional; if max_entries is not specified or initialized, it has to be provided in runtime through libbpf API before loading bpf_object; - map_flags is optional and if not defined, will be assumed to be 0. 3. Key/value fields should be **a pointer** to a type describing key/value. The pointee type is assumed (and will be recorded as such and used for size determination) to be a type describing key/value of the map. This is done to save excessive amounts of space allocated in corresponding ELF sections for key/value of big size. 4. As some maps disallow having BTF type ID associated with key/value, it's possible to specify key/value size explicitly without associating BTF type ID with it. Use key_size and value_size fields to do that (see example below). Here's an example of simple ARRAY map defintion: struct my_value { int x, y, z; }; struct { int type; int max_entries; int *key; struct my_value *value; } btf_map SEC(".maps") = { .type = BPF_MAP_TYPE_ARRAY, .max_entries = 16, }; This will define BPF ARRAY map 'btf_map' with 16 elements. The key will be of type int and thus key size will be 4 bytes. The value is struct my_value of size 12 bytes. This map can be used from C code exactly the same as with existing maps defined through struct bpf_map_def. Here's an example of STACKMAP definition (which currently disallows BTF type IDs for key/value): struct { __u32 type; __u32 max_entries; __u32 map_flags; __u32 key_size; __u32 value_size; } stackmap SEC(".maps") = { .type = BPF_MAP_TYPE_STACK_TRACE, .max_entries = 128, .map_flags = BPF_F_STACK_BUILD_ID, .key_size = sizeof(__u32), .value_size = PERF_MAX_STACK_DEPTH * sizeof(struct bpf_stack_build_id), }; This approach is naturally extended to support map-in-map, by making a value field to be another struct that describes inner map. This feature is not implemented yet. It's also possible to incrementally add features like pinning with full backwards and forward compatibility. Support for static initialization of BPF_MAP_TYPE_PROG_ARRAY using pointers to BPF programs is also on the roadmap. Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 353 +++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 344 insertions(+), 9 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index da942ab2f06a..585e3a2f1eb4 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -262,6 +262,7 @@ struct bpf_object { } *reloc; int nr_reloc; int maps_shndx; + int btf_maps_shndx; int text_shndx; int data_shndx; int rodata_shndx; @@ -514,6 +515,7 @@ static struct bpf_object *bpf_object__new(const char *path, obj->efile.obj_buf = obj_buf; obj->efile.obj_buf_sz = obj_buf_sz; obj->efile.maps_shndx = -1; + obj->efile.btf_maps_shndx = -1; obj->efile.data_shndx = -1; obj->efile.rodata_shndx = -1; obj->efile.bss_shndx = -1; @@ -1007,6 +1009,312 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict) return 0; } +static const struct btf_type *skip_mods_and_typedefs(const struct btf *btf, + __u32 id) +{ + const struct btf_type *t = btf__type_by_id(btf, id); + + while (true) { + switch (BTF_INFO_KIND(t->info)) { + case BTF_KIND_VOLATILE: + case BTF_KIND_CONST: + case BTF_KIND_RESTRICT: + case BTF_KIND_TYPEDEF: + t = btf__type_by_id(btf, t->type); + break; + default: + return t; + } + } +} + +static bool get_map_field_int(const char *map_name, + const struct btf *btf, + const struct btf_type *def, + const struct btf_member *m, + const void *data, __u32 *res) { + const struct btf_type *t = skip_mods_and_typedefs(btf, m->type); + const char *name = btf__name_by_offset(btf, m->name_off); + __u32 int_info = *(const __u32 *)(const void *)(t + 1); + + if (BTF_INFO_KIND(t->info) != BTF_KIND_INT) { + pr_warning("map '%s': attr '%s': expected INT, got %u.\n", + map_name, name, BTF_INFO_KIND(t->info)); + return false; + } + if (t->size != 4 || BTF_INT_BITS(int_info) != 32 || + BTF_INT_OFFSET(int_info)) { + pr_warning("map '%s': attr '%s': expected 32-bit non-bitfield integer, " + "got %u-byte (%d-bit) one with bit offset %d.\n", + map_name, name, t->size, BTF_INT_BITS(int_info), + BTF_INT_OFFSET(int_info)); + return false; + } + if (BTF_INFO_KFLAG(def->info) && BTF_MEMBER_BITFIELD_SIZE(m->offset)) { + pr_warning("map '%s': attr '%s': bitfield is not supported.\n", + map_name, name); + return false; + } + if (m->offset % 32) { + pr_warning("map '%s': attr '%s': unaligned fields are not supported.\n", + map_name, name); + return false; + } + + *res = *(const __u32 *)(data + m->offset / 8); + return true; +} + +static int bpf_object__init_user_btf_map(struct bpf_object *obj, + const struct btf_type *sec, + int var_idx, int sec_idx, + const Elf_Data *data, bool strict) +{ + const struct btf_type *var, *def, *t; + const struct btf_var_secinfo *vi; + const struct btf_var *var_extra; + const struct btf_member *m; + const void *def_data; + const char *map_name; + struct bpf_map *map; + int vlen, i; + + vi = (const struct btf_var_secinfo *)(const void *)(sec + 1) + var_idx; + var = btf__type_by_id(obj->btf, vi->type); + var_extra = (const void *)(var + 1); + map_name = btf__name_by_offset(obj->btf, var->name_off); + vlen = BTF_INFO_VLEN(var->info); + + if (map_name == NULL || map_name[0] == '\0') { + pr_warning("map #%d: empty name.\n", var_idx); + return -EINVAL; + } + if ((__u64)vi->offset + vi->size > data->d_size) { + pr_warning("map '%s' BTF data is corrupted.\n", map_name); + return -EINVAL; + } + if (BTF_INFO_KIND(var->info) != BTF_KIND_VAR) { + pr_warning("map '%s': unexpected var kind %u.\n", + map_name, BTF_INFO_KIND(var->info)); + return -EINVAL; + } + if (var_extra->linkage != BTF_VAR_GLOBAL_ALLOCATED && + var_extra->linkage != BTF_VAR_STATIC) { + pr_warning("map '%s': unsupported var linkage %u.\n", + map_name, var_extra->linkage); + return -EOPNOTSUPP; + } + + def = skip_mods_and_typedefs(obj->btf, var->type); + if (BTF_INFO_KIND(def->info) != BTF_KIND_STRUCT) { + pr_warning("map '%s': unexpected def kind %u.\n", + map_name, BTF_INFO_KIND(var->info)); + return -EINVAL; + } + if (def->size > vi->size) { + pr_warning("map '%s': invalid def size.\n", map_name); + return -EINVAL; + } + + map = bpf_object__add_map(obj); + if (IS_ERR(map)) + return PTR_ERR(map); + map->name = strdup(map_name); + if (!map->name) { + pr_warning("map '%s': failed to alloc map name.\n", map_name); + return -ENOMEM; + } + map->libbpf_type = LIBBPF_MAP_UNSPEC; + map->def.type = BPF_MAP_TYPE_UNSPEC; + map->sec_idx = sec_idx; + map->sec_offset = vi->offset; + pr_debug("map '%s': at sec_idx %d, offset %zu.\n", + map_name, map->sec_idx, map->sec_offset); + + def_data = data->d_buf + vi->offset; + vlen = BTF_INFO_VLEN(def->info); + m = (const void *)(def + 1); + for (i = 0; i < vlen; i++, m++) { + const char *name = btf__name_by_offset(obj->btf, m->name_off); + + if (!name) { + pr_warning("map '%s': invalid field #%d.\n", + map_name, i); + return -EINVAL; + } + if (strcmp(name, "type") == 0) { + if (!get_map_field_int(map_name, obj->btf, def, m, + def_data, &map->def.type)) + return -EINVAL; + pr_debug("map '%s': found type = %u.\n", + map_name, map->def.type); + } else if (strcmp(name, "max_entries") == 0) { + if (!get_map_field_int(map_name, obj->btf, def, m, + def_data, &map->def.max_entries)) + return -EINVAL; + pr_debug("map '%s': found max_entries = %u.\n", + map_name, map->def.max_entries); + } else if (strcmp(name, "map_flags") == 0) { + if (!get_map_field_int(map_name, obj->btf, def, m, + def_data, &map->def.map_flags)) + return -EINVAL; + pr_debug("map '%s': found map_flags = %u.\n", + map_name, map->def.map_flags); + } else if (strcmp(name, "key_size") == 0) { + __u32 sz; + + if (!get_map_field_int(map_name, obj->btf, def, m, + def_data, &sz)) + return -EINVAL; + pr_debug("map '%s': found key_size = %u.\n", + map_name, sz); + if (map->def.key_size && map->def.key_size != sz) { + pr_warning("map '%s': conflictling key size %u != %u.\n", + map_name, map->def.key_size, sz); + return -EINVAL; + } + map->def.key_size = sz; + } else if (strcmp(name, "key") == 0) { + __s64 sz; + + t = btf__type_by_id(obj->btf, m->type); + if (!t) { + pr_warning("map '%s': key type [%d] not found.\n", + map_name, m->type); + return -EINVAL; + } + if (BTF_INFO_KIND(t->info) != BTF_KIND_PTR) { + pr_warning("map '%s': key spec is not PTR: %u.\n", + map_name, BTF_INFO_KIND(t->info)); + return -EINVAL; + } + sz = btf__resolve_size(obj->btf, t->type); + if (sz < 0) { + pr_warning("map '%s': can't determine key size for type [%u]: %lld.\n", + map_name, t->type, sz); + return sz; + } + pr_debug("map '%s': found key [%u], sz = %lld.\n", + map_name, t->type, sz); + if (map->def.key_size && map->def.key_size != sz) { + pr_warning("map '%s': conflictling key size %u != %lld.\n", + map_name, map->def.key_size, sz); + return -EINVAL; + } + map->def.key_size = sz; + map->btf_key_type_id = t->type; + } else if (strcmp(name, "value_size") == 0) { + __u32 sz; + + if (!get_map_field_int(map_name, obj->btf, def, m, + def_data, &sz)) + return -EINVAL; + pr_debug("map '%s': found value_size = %u.\n", + map_name, sz); + if (map->def.value_size && map->def.value_size != sz) { + pr_warning("map '%s': conflictling value size %u != %u.\n", + map_name, map->def.value_size, sz); + return -EINVAL; + } + map->def.value_size = sz; + } else if (strcmp(name, "value") == 0) { + __s64 sz; + + t = btf__type_by_id(obj->btf, m->type); + if (!t) { + pr_warning("map '%s': value type [%d] not found.\n", + map_name, m->type); + return -EINVAL; + } + if (BTF_INFO_KIND(t->info) != BTF_KIND_PTR) { + pr_warning("map '%s': value spec is not PTR: %u.\n", + map_name, BTF_INFO_KIND(t->info)); + return -EINVAL; + } + sz = btf__resolve_size(obj->btf, t->type); + if (sz < 0) { + pr_warning("map '%s': can't determine value size for type [%u]: %lld.\n", + map_name, t->type, sz); + return sz; + } + pr_debug("map '%s': found value [%u], sz = %lld.\n", + map_name, t->type, sz); + if (map->def.value_size && map->def.value_size != sz) { + pr_warning("map '%s': conflictling value size %u != %lld.\n", + map_name, map->def.value_size, sz); + return -EINVAL; + } + map->def.value_size = sz; + map->btf_value_type_id = t->type; + } else { + if (strict) { + pr_warning("map '%s': unknown field '%s'.\n", + map_name, name); + return -ENOTSUP; + } + pr_debug("map '%s': ignoring unknown field '%s'.\n", + map_name, name); + } + } + + if (map->def.type == BPF_MAP_TYPE_UNSPEC) { + pr_warning("map '%s': map type isn't specified.\n", map_name); + return -EINVAL; + } + + return 0; +} + +static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict) +{ + const struct btf_type *sec = NULL; + int nr_types, i, vlen, err; + const struct btf_type *t; + const char *name; + Elf_Data *data; + Elf_Scn *scn; + + if (obj->efile.btf_maps_shndx < 0) + return 0; + + scn = elf_getscn(obj->efile.elf, obj->efile.btf_maps_shndx); + if (scn) + data = elf_getdata(scn, NULL); + if (!scn || !data) { + pr_warning("failed to get Elf_Data from map section %d (%s)\n", + obj->efile.maps_shndx, MAPS_ELF_SEC); + return -EINVAL; + } + + nr_types = btf__get_nr_types(obj->btf); + for (i = 1; i <= nr_types; i++) { + t = btf__type_by_id(obj->btf, i); + if (BTF_INFO_KIND(t->info) != BTF_KIND_DATASEC) + continue; + name = btf__name_by_offset(obj->btf, t->name_off); + if (strcmp(name, MAPS_ELF_SEC) == 0) { + sec = t; + break; + } + } + + if (!sec) { + pr_warning("DATASEC '%s' not found.\n", MAPS_ELF_SEC); + return -ENOENT; + } + + vlen = BTF_INFO_VLEN(sec->info); + for (i = 0; i < vlen; i++) { + err = bpf_object__init_user_btf_map(obj, sec, i, + obj->efile.btf_maps_shndx, + data, strict); + if (err) + return err; + } + + return 0; +} + static int bpf_object__init_maps(struct bpf_object *obj, int flags) { bool strict = !(flags & MAPS_RELAX_COMPAT); @@ -1016,6 +1324,10 @@ static int bpf_object__init_maps(struct bpf_object *obj, int flags) if (err) return err; + err = bpf_object__init_user_btf_maps(obj, strict); + if (err) + return err; + err = bpf_object__init_global_data_maps(obj); if (err) return err; @@ -1113,10 +1425,16 @@ static void bpf_object__sanitize_btf_ext(struct bpf_object *obj) } } +static bool bpf_object__is_btf_mandatory(const struct bpf_object *obj) +{ + return obj->efile.btf_maps_shndx >= 0; +} + static int bpf_object__init_btf(struct bpf_object *obj, Elf_Data *btf_data, Elf_Data *btf_ext_data) { + bool btf_required = bpf_object__is_btf_mandatory(obj); int err = 0; if (btf_data) { @@ -1150,10 +1468,18 @@ static int bpf_object__init_btf(struct bpf_object *obj, } out: if (err || IS_ERR(obj->btf)) { + if (btf_required) + err = err ? : PTR_ERR(obj->btf); + else + err = 0; if (!IS_ERR_OR_NULL(obj->btf)) btf__free(obj->btf); obj->btf = NULL; } + if (btf_required && !obj->btf) { + pr_warning("BTF is required, but is missing or corrupted.\n"); + return err == 0 ? -ENOENT : err; + } return 0; } @@ -1173,6 +1499,8 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj) BTF_ELF_SEC, err); btf__free(obj->btf); obj->btf = NULL; + if (bpf_object__is_btf_mandatory(obj)) + return err; } return 0; } @@ -1236,6 +1564,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) return err; } else if (strcmp(name, "maps") == 0) { obj->efile.maps_shndx = idx; + } else if (strcmp(name, MAPS_ELF_SEC) == 0) { + obj->efile.btf_maps_shndx = idx; } else if (strcmp(name, BTF_ELF_SEC) == 0) { btf_data = data; } else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) { @@ -1355,7 +1685,8 @@ static bool bpf_object__shndx_is_data(const struct bpf_object *obj, static bool bpf_object__shndx_is_maps(const struct bpf_object *obj, int shndx) { - return shndx == obj->efile.maps_shndx; + return shndx == obj->efile.maps_shndx || + shndx == obj->efile.btf_maps_shndx; } static bool bpf_object__relo_in_known_section(const struct bpf_object *obj, @@ -1399,14 +1730,14 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, prog->nr_reloc = nrels; for (i = 0; i < nrels; i++) { - GElf_Sym sym; - GElf_Rel rel; - unsigned int insn_idx; - unsigned int shdr_idx; struct bpf_insn *insns = prog->insns; enum libbpf_map_type type; + unsigned int insn_idx; + unsigned int shdr_idx; const char *name; size_t map_idx; + GElf_Sym sym; + GElf_Rel rel; if (!gelf_getrel(data, i, &rel)) { pr_warning("relocation: failed to get %d reloc\n", i); @@ -1500,14 +1831,18 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, return 0; } -static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf) +static int bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map) { struct bpf_map_def *def = &map->def; __u32 key_type_id = 0, value_type_id = 0; int ret; + /* if it's BTF-defined map, we don't need to search for type IDs */ + if (map->sec_idx == obj->efile.btf_maps_shndx) + return 0; + if (!bpf_map__is_internal(map)) { - ret = btf__get_map_kv_tids(btf, map->name, def->key_size, + ret = btf__get_map_kv_tids(obj->btf, map->name, def->key_size, def->value_size, &key_type_id, &value_type_id); } else { @@ -1515,7 +1850,7 @@ static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf) * LLVM annotates global data differently in BTF, that is, * only as '.data', '.bss' or '.rodata'. */ - ret = btf__find_by_name(btf, + ret = btf__find_by_name(obj->btf, libbpf_type_to_btf_name[map->libbpf_type]); } if (ret < 0) @@ -1805,7 +2140,7 @@ bpf_object__create_maps(struct bpf_object *obj) map->inner_map_fd >= 0) create_attr.inner_map_fd = map->inner_map_fd; - if (obj->btf && !bpf_map_find_btf_info(map, obj->btf)) { + if (obj->btf && !bpf_map_find_btf_info(obj, map)) { create_attr.btf_fd = btf__fd(obj->btf); create_attr.btf_key_type_id = map->btf_key_type_id; create_attr.btf_value_type_id = map->btf_value_type_id; -- cgit v1.2.3 From a324aae32fa9bfdd03e89078e20ebcbd7737fda5 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 17 Jun 2019 15:48:58 -0700 Subject: libbpf: constify getter APIs Add const qualifiers to bpf_object/bpf_program/bpf_map arguments for getter APIs. There is no need for them to not be const pointers. Verified that make -C tools/lib/bpf make -C tools/testing/selftests/bpf make -C tools/perf all build without warnings. Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 80 ++++++++++++++++++++++++++------------------------ 1 file changed, 41 insertions(+), 39 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 585e3a2f1eb4..8ce3beba8551 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1663,7 +1663,8 @@ bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx) } struct bpf_program * -bpf_object__find_program_by_title(struct bpf_object *obj, const char *title) +bpf_object__find_program_by_title(const struct bpf_object *obj, + const char *title) { struct bpf_program *pos; @@ -2589,8 +2590,8 @@ out: return err; } -static bool bpf_program__is_function_storage(struct bpf_program *prog, - struct bpf_object *obj) +static bool bpf_program__is_function_storage(const struct bpf_program *prog, + const struct bpf_object *obj) { return prog->idx == obj->efile.text_shndx && obj->has_pseudo_calls; } @@ -3296,17 +3297,17 @@ bpf_object__next(struct bpf_object *prev) return next; } -const char *bpf_object__name(struct bpf_object *obj) +const char *bpf_object__name(const struct bpf_object *obj) { return obj ? obj->path : ERR_PTR(-EINVAL); } -unsigned int bpf_object__kversion(struct bpf_object *obj) +unsigned int bpf_object__kversion(const struct bpf_object *obj) { return obj ? obj->kern_version : 0; } -struct btf *bpf_object__btf(struct bpf_object *obj) +struct btf *bpf_object__btf(const struct bpf_object *obj) { return obj ? obj->btf : NULL; } @@ -3327,13 +3328,14 @@ int bpf_object__set_priv(struct bpf_object *obj, void *priv, return 0; } -void *bpf_object__priv(struct bpf_object *obj) +void *bpf_object__priv(const struct bpf_object *obj) { return obj ? obj->priv : ERR_PTR(-EINVAL); } static struct bpf_program * -__bpf_program__iter(struct bpf_program *p, struct bpf_object *obj, bool forward) +__bpf_program__iter(const struct bpf_program *p, const struct bpf_object *obj, + bool forward) { size_t nr_programs = obj->nr_programs; ssize_t idx; @@ -3358,7 +3360,7 @@ __bpf_program__iter(struct bpf_program *p, struct bpf_object *obj, bool forward) } struct bpf_program * -bpf_program__next(struct bpf_program *prev, struct bpf_object *obj) +bpf_program__next(struct bpf_program *prev, const struct bpf_object *obj) { struct bpf_program *prog = prev; @@ -3370,7 +3372,7 @@ bpf_program__next(struct bpf_program *prev, struct bpf_object *obj) } struct bpf_program * -bpf_program__prev(struct bpf_program *next, struct bpf_object *obj) +bpf_program__prev(struct bpf_program *next, const struct bpf_object *obj) { struct bpf_program *prog = next; @@ -3392,7 +3394,7 @@ int bpf_program__set_priv(struct bpf_program *prog, void *priv, return 0; } -void *bpf_program__priv(struct bpf_program *prog) +void *bpf_program__priv(const struct bpf_program *prog) { return prog ? prog->priv : ERR_PTR(-EINVAL); } @@ -3402,7 +3404,7 @@ void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex) prog->prog_ifindex = ifindex; } -const char *bpf_program__title(struct bpf_program *prog, bool needs_copy) +const char *bpf_program__title(const struct bpf_program *prog, bool needs_copy) { const char *title; @@ -3418,7 +3420,7 @@ const char *bpf_program__title(struct bpf_program *prog, bool needs_copy) return title; } -int bpf_program__fd(struct bpf_program *prog) +int bpf_program__fd(const struct bpf_program *prog) { return bpf_program__nth_fd(prog, 0); } @@ -3451,7 +3453,7 @@ int bpf_program__set_prep(struct bpf_program *prog, int nr_instances, return 0; } -int bpf_program__nth_fd(struct bpf_program *prog, int n) +int bpf_program__nth_fd(const struct bpf_program *prog, int n) { int fd; @@ -3479,25 +3481,25 @@ void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type) prog->type = type; } -static bool bpf_program__is_type(struct bpf_program *prog, +static bool bpf_program__is_type(const struct bpf_program *prog, enum bpf_prog_type type) { return prog ? (prog->type == type) : false; } -#define BPF_PROG_TYPE_FNS(NAME, TYPE) \ -int bpf_program__set_##NAME(struct bpf_program *prog) \ -{ \ - if (!prog) \ - return -EINVAL; \ - bpf_program__set_type(prog, TYPE); \ - return 0; \ -} \ - \ -bool bpf_program__is_##NAME(struct bpf_program *prog) \ -{ \ - return bpf_program__is_type(prog, TYPE); \ -} \ +#define BPF_PROG_TYPE_FNS(NAME, TYPE) \ +int bpf_program__set_##NAME(struct bpf_program *prog) \ +{ \ + if (!prog) \ + return -EINVAL; \ + bpf_program__set_type(prog, TYPE); \ + return 0; \ +} \ + \ +bool bpf_program__is_##NAME(const struct bpf_program *prog) \ +{ \ + return bpf_program__is_type(prog, TYPE); \ +} \ BPF_PROG_TYPE_FNS(socket_filter, BPF_PROG_TYPE_SOCKET_FILTER); BPF_PROG_TYPE_FNS(kprobe, BPF_PROG_TYPE_KPROBE); @@ -3692,17 +3694,17 @@ bpf_program__identify_section(struct bpf_program *prog, expected_attach_type); } -int bpf_map__fd(struct bpf_map *map) +int bpf_map__fd(const struct bpf_map *map) { return map ? map->fd : -EINVAL; } -const struct bpf_map_def *bpf_map__def(struct bpf_map *map) +const struct bpf_map_def *bpf_map__def(const struct bpf_map *map) { return map ? &map->def : ERR_PTR(-EINVAL); } -const char *bpf_map__name(struct bpf_map *map) +const char *bpf_map__name(const struct bpf_map *map) { return map ? map->name : NULL; } @@ -3733,17 +3735,17 @@ int bpf_map__set_priv(struct bpf_map *map, void *priv, return 0; } -void *bpf_map__priv(struct bpf_map *map) +void *bpf_map__priv(const struct bpf_map *map) { return map ? map->priv : ERR_PTR(-EINVAL); } -bool bpf_map__is_offload_neutral(struct bpf_map *map) +bool bpf_map__is_offload_neutral(const struct bpf_map *map) { return map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY; } -bool bpf_map__is_internal(struct bpf_map *map) +bool bpf_map__is_internal(const struct bpf_map *map) { return map->libbpf_type != LIBBPF_MAP_UNSPEC; } @@ -3768,7 +3770,7 @@ int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd) } static struct bpf_map * -__bpf_map__iter(struct bpf_map *m, struct bpf_object *obj, int i) +__bpf_map__iter(const struct bpf_map *m, const struct bpf_object *obj, int i) { ssize_t idx; struct bpf_map *s, *e; @@ -3792,7 +3794,7 @@ __bpf_map__iter(struct bpf_map *m, struct bpf_object *obj, int i) } struct bpf_map * -bpf_map__next(struct bpf_map *prev, struct bpf_object *obj) +bpf_map__next(const struct bpf_map *prev, const struct bpf_object *obj) { if (prev == NULL) return obj->maps; @@ -3801,7 +3803,7 @@ bpf_map__next(struct bpf_map *prev, struct bpf_object *obj) } struct bpf_map * -bpf_map__prev(struct bpf_map *next, struct bpf_object *obj) +bpf_map__prev(const struct bpf_map *next, const struct bpf_object *obj) { if (next == NULL) { if (!obj->nr_maps) @@ -3813,7 +3815,7 @@ bpf_map__prev(struct bpf_map *next, struct bpf_object *obj) } struct bpf_map * -bpf_object__find_map_by_name(struct bpf_object *obj, const char *name) +bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name) { struct bpf_map *pos; @@ -3825,7 +3827,7 @@ bpf_object__find_map_by_name(struct bpf_object *obj, const char *name) } int -bpf_object__find_map_fd_by_name(struct bpf_object *obj, const char *name) +bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name) { return bpf_map__fd(bpf_object__find_map_by_name(obj, name)); } -- cgit v1.2.3 From 900de4ac4953fcf5e25ea45bea5bb28e797b1420 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Wed, 19 Jun 2019 17:27:42 +0100 Subject: libbpf: fix spelling mistake "conflictling" -> "conflicting" There are several spelling mistakes in pr_warning messages. Fix these. Signed-off-by: Colin Ian King Acked-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/libbpf.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 4259c9f0cfe7..68f45a96769f 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1169,7 +1169,7 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj, pr_debug("map '%s': found key_size = %u.\n", map_name, sz); if (map->def.key_size && map->def.key_size != sz) { - pr_warning("map '%s': conflictling key size %u != %u.\n", + pr_warning("map '%s': conflicting key size %u != %u.\n", map_name, map->def.key_size, sz); return -EINVAL; } @@ -1197,7 +1197,7 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj, pr_debug("map '%s': found key [%u], sz = %lld.\n", map_name, t->type, sz); if (map->def.key_size && map->def.key_size != sz) { - pr_warning("map '%s': conflictling key size %u != %lld.\n", + pr_warning("map '%s': conflicting key size %u != %lld.\n", map_name, map->def.key_size, sz); return -EINVAL; } @@ -1212,7 +1212,7 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj, pr_debug("map '%s': found value_size = %u.\n", map_name, sz); if (map->def.value_size && map->def.value_size != sz) { - pr_warning("map '%s': conflictling value size %u != %u.\n", + pr_warning("map '%s': conflicting value size %u != %u.\n", map_name, map->def.value_size, sz); return -EINVAL; } @@ -1240,7 +1240,7 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj, pr_debug("map '%s': found value [%u], sz = %lld.\n", map_name, t->type, sz); if (map->def.value_size && map->def.value_size != sz) { - pr_warning("map '%s': conflictling value size %u != %lld.\n", + pr_warning("map '%s': conflicting value size %u != %lld.\n", map_name, map->def.value_size, sz); return -EINVAL; } -- cgit v1.2.3 From 950649791b8366a4b89f570053d37bba1eb21c02 Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Wed, 26 Jun 2019 13:38:37 +0300 Subject: libbpf: fix max() type mismatch for 32bit It fixes build error for 32bit caused by type mismatch size_t/unsigned long. Fixes: bf82927125dd ("libbpf: refactor map initialization") Acked-by: Song Liu Acked-by: Andrii Nakryiko Signed-off-by: Ivan Khoronzhuk Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 68f45a96769f..5186b7710430 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -778,7 +778,7 @@ static struct bpf_map *bpf_object__add_map(struct bpf_object *obj) if (obj->nr_maps < obj->maps_cap) return &obj->maps[obj->nr_maps++]; - new_cap = max(4ul, obj->maps_cap * 3 / 2); + new_cap = max((size_t)4, obj->maps_cap * 3 / 2); new_maps = realloc(obj->maps, new_cap * sizeof(*obj->maps)); if (!new_maps) { pr_warning("alloc maps for object failed\n"); -- cgit v1.2.3 From 4cdbfb59c44a0df58ab321e4ddd9710cd0823584 Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Thu, 27 Jun 2019 13:38:49 -0700 Subject: libbpf: support sockopt hooks Make libbpf aware of new sockopt hooks so it can derive prog type and hook point from the section names. Cc: Andrii Nakryiko Cc: Martin Lau Signed-off-by: Stanislav Fomichev Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/libbpf.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 5186b7710430..6e6ebef11ba3 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -2646,6 +2646,7 @@ static bool bpf_prog_type__needs_kver(enum bpf_prog_type type) case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: case BPF_PROG_TYPE_PERF_EVENT: case BPF_PROG_TYPE_CGROUP_SYSCTL: + case BPF_PROG_TYPE_CGROUP_SOCKOPT: return false; case BPF_PROG_TYPE_KPROBE: default: @@ -3604,6 +3605,10 @@ static const struct { BPF_CGROUP_UDP6_RECVMSG), BPF_EAPROG_SEC("cgroup/sysctl", BPF_PROG_TYPE_CGROUP_SYSCTL, BPF_CGROUP_SYSCTL), + BPF_EAPROG_SEC("cgroup/getsockopt", BPF_PROG_TYPE_CGROUP_SOCKOPT, + BPF_CGROUP_GETSOCKOPT), + BPF_EAPROG_SEC("cgroup/setsockopt", BPF_PROG_TYPE_CGROUP_SOCKOPT, + BPF_CGROUP_SETSOCKOPT), }; #undef BPF_PROG_SEC_IMPL -- cgit v1.2.3 From 33bae185f74d49a0d7b1bfaafb8e959efce0f243 Mon Sep 17 00:00:00 2001 From: Leo Yan Date: Tue, 2 Jul 2019 18:25:31 +0800 Subject: bpf, libbpf, smatch: Fix potential NULL pointer dereference Based on the following report from Smatch, fix the potential NULL pointer dereference check: tools/lib/bpf/libbpf.c:3493 bpf_prog_load_xattr() warn: variable dereferenced before check 'attr' (see line 3483) 3479 int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, 3480 struct bpf_object **pobj, int *prog_fd) 3481 { 3482 struct bpf_object_open_attr open_attr = { 3483 .file = attr->file, 3484 .prog_type = attr->prog_type, ^^^^^^ 3485 }; At the head of function, it directly access 'attr' without checking if it's NULL pointer. This patch moves the values assignment after validating 'attr' and 'attr->file'. Signed-off-by: Leo Yan Acked-by: Yonghong Song Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 6e6ebef11ba3..4907997289e9 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3872,10 +3872,7 @@ int bpf_prog_load(const char *file, enum bpf_prog_type type, int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, struct bpf_object **pobj, int *prog_fd) { - struct bpf_object_open_attr open_attr = { - .file = attr->file, - .prog_type = attr->prog_type, - }; + struct bpf_object_open_attr open_attr = {}; struct bpf_program *prog, *first_prog = NULL; enum bpf_attach_type expected_attach_type; enum bpf_prog_type prog_type; @@ -3888,6 +3885,9 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, if (!attr->file) return -EINVAL; + open_attr.file = attr->file; + open_attr.prog_type = attr->prog_type; + obj = bpf_object__open_xattr(&open_attr); if (IS_ERR_OR_NULL(obj)) return -ENOENT; -- cgit v1.2.3 From 1c2e9efc26f389effc86e9b4d41f85d101f17629 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 1 Jul 2019 16:58:56 -0700 Subject: libbpf: introduce concept of bpf_link bpf_link is an abstraction of an association of a BPF program and one of many possible BPF attachment points (hooks). This allows to have uniform interface for detaching BPF programs regardless of the nature of link and how it was created. Details of creation and setting up of a specific bpf_link is handled by corresponding attachment methods (bpf_program__attach_xxx) added in subsequent commits. Once successfully created, bpf_link has to be eventually destroyed with bpf_link__destroy(), at which point BPF program is disassociated from a hook and all the relevant resources are freed. Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Reviewed-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 4907997289e9..f308690abd50 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3941,6 +3941,23 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, return 0; } +struct bpf_link { + int (*destroy)(struct bpf_link *link); +}; + +int bpf_link__destroy(struct bpf_link *link) +{ + int err; + + if (!link) + return 0; + + err = link->destroy(link); + free(link); + + return err; +} + enum bpf_perf_event_ret bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size, void **copy_mem, size_t *copy_size, -- cgit v1.2.3 From 63f2f5ee856ba9db751123bc5519be099a3849a7 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 1 Jul 2019 16:58:57 -0700 Subject: libbpf: add ability to attach/detach BPF program to perf event bpf_program__attach_perf_event allows to attach BPF program to existing perf event hook, providing most generic and most low-level way to attach BPF programs. It returns struct bpf_link, which should be passed to bpf_link__destroy to detach and free resources, associated with a link. Signed-off-by: Andrii Nakryiko Reviewed-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index f308690abd50..54ce22f9f777 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include #include @@ -3958,6 +3959,68 @@ int bpf_link__destroy(struct bpf_link *link) return err; } +struct bpf_link_fd { + struct bpf_link link; /* has to be at the top of struct */ + int fd; /* hook FD */ +}; + +static int bpf_link__destroy_perf_event(struct bpf_link *link) +{ + struct bpf_link_fd *l = (void *)link; + int err; + + err = ioctl(l->fd, PERF_EVENT_IOC_DISABLE, 0); + if (err) + err = -errno; + + close(l->fd); + return err; +} + +struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog, + int pfd) +{ + char errmsg[STRERR_BUFSIZE]; + struct bpf_link_fd *link; + int prog_fd, err; + + if (pfd < 0) { + pr_warning("program '%s': invalid perf event FD %d\n", + bpf_program__title(prog, false), pfd); + return ERR_PTR(-EINVAL); + } + prog_fd = bpf_program__fd(prog); + if (prog_fd < 0) { + pr_warning("program '%s': can't attach BPF program w/o FD (did you load it?)\n", + bpf_program__title(prog, false)); + return ERR_PTR(-EINVAL); + } + + link = malloc(sizeof(*link)); + if (!link) + return ERR_PTR(-ENOMEM); + link->link.destroy = &bpf_link__destroy_perf_event; + link->fd = pfd; + + if (ioctl(pfd, PERF_EVENT_IOC_SET_BPF, prog_fd) < 0) { + err = -errno; + free(link); + pr_warning("program '%s': failed to attach to pfd %d: %s\n", + bpf_program__title(prog, false), pfd, + libbpf_strerror_r(err, errmsg, sizeof(errmsg))); + return ERR_PTR(err); + } + if (ioctl(pfd, PERF_EVENT_IOC_ENABLE, 0) < 0) { + err = -errno; + free(link); + pr_warning("program '%s': failed to enable pfd %d: %s\n", + bpf_program__title(prog, false), pfd, + libbpf_strerror_r(err, errmsg, sizeof(errmsg))); + return ERR_PTR(err); + } + return (struct bpf_link *)link; +} + enum bpf_perf_event_ret bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size, void **copy_mem, size_t *copy_size, -- cgit v1.2.3 From b26500274767bacbe571c75926fee2489f91ba28 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 1 Jul 2019 16:58:58 -0700 Subject: libbpf: add kprobe/uprobe attach API Add ability to attach to kernel and user probes and retprobes. Implementation depends on perf event support for kprobes/uprobes. Signed-off-by: Andrii Nakryiko Reviewed-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 169 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 169 insertions(+) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 54ce22f9f777..b5b49ddb152f 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4021,6 +4021,175 @@ struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog, return (struct bpf_link *)link; } +/* + * this function is expected to parse integer in the range of [0, 2^31-1] from + * given file using scanf format string fmt. If actual parsed value is + * negative, the result might be indistinguishable from error + */ +static int parse_uint_from_file(const char *file, const char *fmt) +{ + char buf[STRERR_BUFSIZE]; + int err, ret; + FILE *f; + + f = fopen(file, "r"); + if (!f) { + err = -errno; + pr_debug("failed to open '%s': %s\n", file, + libbpf_strerror_r(err, buf, sizeof(buf))); + return err; + } + err = fscanf(f, fmt, &ret); + if (err != 1) { + err = err == EOF ? -EIO : -errno; + pr_debug("failed to parse '%s': %s\n", file, + libbpf_strerror_r(err, buf, sizeof(buf))); + fclose(f); + return err; + } + fclose(f); + return ret; +} + +static int determine_kprobe_perf_type(void) +{ + const char *file = "/sys/bus/event_source/devices/kprobe/type"; + + return parse_uint_from_file(file, "%d\n"); +} + +static int determine_uprobe_perf_type(void) +{ + const char *file = "/sys/bus/event_source/devices/uprobe/type"; + + return parse_uint_from_file(file, "%d\n"); +} + +static int determine_kprobe_retprobe_bit(void) +{ + const char *file = "/sys/bus/event_source/devices/kprobe/format/retprobe"; + + return parse_uint_from_file(file, "config:%d\n"); +} + +static int determine_uprobe_retprobe_bit(void) +{ + const char *file = "/sys/bus/event_source/devices/uprobe/format/retprobe"; + + return parse_uint_from_file(file, "config:%d\n"); +} + +static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name, + uint64_t offset, int pid) +{ + struct perf_event_attr attr = {}; + char errmsg[STRERR_BUFSIZE]; + int type, pfd, err; + + type = uprobe ? determine_uprobe_perf_type() + : determine_kprobe_perf_type(); + if (type < 0) { + pr_warning("failed to determine %s perf type: %s\n", + uprobe ? "uprobe" : "kprobe", + libbpf_strerror_r(type, errmsg, sizeof(errmsg))); + return type; + } + if (retprobe) { + int bit = uprobe ? determine_uprobe_retprobe_bit() + : determine_kprobe_retprobe_bit(); + + if (bit < 0) { + pr_warning("failed to determine %s retprobe bit: %s\n", + uprobe ? "uprobe" : "kprobe", + libbpf_strerror_r(bit, errmsg, + sizeof(errmsg))); + return bit; + } + attr.config |= 1 << bit; + } + attr.size = sizeof(attr); + attr.type = type; + attr.config1 = (uint64_t)(void *)name; /* kprobe_func or uprobe_path */ + attr.config2 = offset; /* kprobe_addr or probe_offset */ + + /* pid filter is meaningful only for uprobes */ + pfd = syscall(__NR_perf_event_open, &attr, + pid < 0 ? -1 : pid /* pid */, + pid == -1 ? 0 : -1 /* cpu */, + -1 /* group_fd */, PERF_FLAG_FD_CLOEXEC); + if (pfd < 0) { + err = -errno; + pr_warning("%s perf_event_open() failed: %s\n", + uprobe ? "uprobe" : "kprobe", + libbpf_strerror_r(err, errmsg, sizeof(errmsg))); + return err; + } + return pfd; +} + +struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog, + bool retprobe, + const char *func_name) +{ + char errmsg[STRERR_BUFSIZE]; + struct bpf_link *link; + int pfd, err; + + pfd = perf_event_open_probe(false /* uprobe */, retprobe, func_name, + 0 /* offset */, -1 /* pid */); + if (pfd < 0) { + pr_warning("program '%s': failed to create %s '%s' perf event: %s\n", + bpf_program__title(prog, false), + retprobe ? "kretprobe" : "kprobe", func_name, + libbpf_strerror_r(pfd, errmsg, sizeof(errmsg))); + return ERR_PTR(pfd); + } + link = bpf_program__attach_perf_event(prog, pfd); + if (IS_ERR(link)) { + close(pfd); + err = PTR_ERR(link); + pr_warning("program '%s': failed to attach to %s '%s': %s\n", + bpf_program__title(prog, false), + retprobe ? "kretprobe" : "kprobe", func_name, + libbpf_strerror_r(err, errmsg, sizeof(errmsg))); + return link; + } + return link; +} + +struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog, + bool retprobe, pid_t pid, + const char *binary_path, + size_t func_offset) +{ + char errmsg[STRERR_BUFSIZE]; + struct bpf_link *link; + int pfd, err; + + pfd = perf_event_open_probe(true /* uprobe */, retprobe, + binary_path, func_offset, pid); + if (pfd < 0) { + pr_warning("program '%s': failed to create %s '%s:0x%zx' perf event: %s\n", + bpf_program__title(prog, false), + retprobe ? "uretprobe" : "uprobe", + binary_path, func_offset, + libbpf_strerror_r(pfd, errmsg, sizeof(errmsg))); + return ERR_PTR(pfd); + } + link = bpf_program__attach_perf_event(prog, pfd); + if (IS_ERR(link)) { + close(pfd); + err = PTR_ERR(link); + pr_warning("program '%s': failed to attach to %s '%s:0x%zx': %s\n", + bpf_program__title(prog, false), + retprobe ? "uretprobe" : "uprobe", + binary_path, func_offset, + libbpf_strerror_r(err, errmsg, sizeof(errmsg))); + return link; + } + return link; +} + enum bpf_perf_event_ret bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size, void **copy_mem, size_t *copy_size, -- cgit v1.2.3 From f6de59c17f111b3efc701c95b438e46245c4aeb1 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 1 Jul 2019 16:58:59 -0700 Subject: libbpf: add tracepoint attach API Allow attaching BPF programs to kernel tracepoint BPF hooks specified by category and name. Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Reviewed-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index b5b49ddb152f..85174fcd99e0 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4190,6 +4190,85 @@ struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog, return link; } +static int determine_tracepoint_id(const char *tp_category, + const char *tp_name) +{ + char file[PATH_MAX]; + int ret; + + ret = snprintf(file, sizeof(file), + "/sys/kernel/debug/tracing/events/%s/%s/id", + tp_category, tp_name); + if (ret < 0) + return -errno; + if (ret >= sizeof(file)) { + pr_debug("tracepoint %s/%s path is too long\n", + tp_category, tp_name); + return -E2BIG; + } + return parse_uint_from_file(file, "%d\n"); +} + +static int perf_event_open_tracepoint(const char *tp_category, + const char *tp_name) +{ + struct perf_event_attr attr = {}; + char errmsg[STRERR_BUFSIZE]; + int tp_id, pfd, err; + + tp_id = determine_tracepoint_id(tp_category, tp_name); + if (tp_id < 0) { + pr_warning("failed to determine tracepoint '%s/%s' perf event ID: %s\n", + tp_category, tp_name, + libbpf_strerror_r(tp_id, errmsg, sizeof(errmsg))); + return tp_id; + } + + attr.type = PERF_TYPE_TRACEPOINT; + attr.size = sizeof(attr); + attr.config = tp_id; + + pfd = syscall(__NR_perf_event_open, &attr, -1 /* pid */, 0 /* cpu */, + -1 /* group_fd */, PERF_FLAG_FD_CLOEXEC); + if (pfd < 0) { + err = -errno; + pr_warning("tracepoint '%s/%s' perf_event_open() failed: %s\n", + tp_category, tp_name, + libbpf_strerror_r(err, errmsg, sizeof(errmsg))); + return err; + } + return pfd; +} + +struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog, + const char *tp_category, + const char *tp_name) +{ + char errmsg[STRERR_BUFSIZE]; + struct bpf_link *link; + int pfd, err; + + pfd = perf_event_open_tracepoint(tp_category, tp_name); + if (pfd < 0) { + pr_warning("program '%s': failed to create tracepoint '%s/%s' perf event: %s\n", + bpf_program__title(prog, false), + tp_category, tp_name, + libbpf_strerror_r(pfd, errmsg, sizeof(errmsg))); + return ERR_PTR(pfd); + } + link = bpf_program__attach_perf_event(prog, pfd); + if (IS_ERR(link)) { + close(pfd); + err = PTR_ERR(link); + pr_warning("program '%s': failed to attach to tracepoint '%s/%s': %s\n", + bpf_program__title(prog, false), + tp_category, tp_name, + libbpf_strerror_r(err, errmsg, sizeof(errmsg))); + return link; + } + return link; +} + enum bpf_perf_event_ret bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size, void **copy_mem, size_t *copy_size, -- cgit v1.2.3 From 84bf5e1f4f174fc4f06bc747dafa1a7cfa4e9a67 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 1 Jul 2019 16:59:00 -0700 Subject: libbpf: add raw tracepoint attach API Add a wrapper utilizing bpf_link "infrastructure" to allow attaching BPF programs to raw tracepoints. Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Reviewed-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 85174fcd99e0..981fb5c3c6c9 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4269,6 +4269,45 @@ struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog, return link; } +static int bpf_link__destroy_fd(struct bpf_link *link) +{ + struct bpf_link_fd *l = (void *)link; + + return close(l->fd); +} + +struct bpf_link *bpf_program__attach_raw_tracepoint(struct bpf_program *prog, + const char *tp_name) +{ + char errmsg[STRERR_BUFSIZE]; + struct bpf_link_fd *link; + int prog_fd, pfd; + + prog_fd = bpf_program__fd(prog); + if (prog_fd < 0) { + pr_warning("program '%s': can't attach before loaded\n", + bpf_program__title(prog, false)); + return ERR_PTR(-EINVAL); + } + + link = malloc(sizeof(*link)); + if (!link) + return ERR_PTR(-ENOMEM); + link->link.destroy = &bpf_link__destroy_fd; + + pfd = bpf_raw_tracepoint_open(tp_name, prog_fd); + if (pfd < 0) { + pfd = -errno; + free(link); + pr_warning("program '%s': failed to attach to raw tracepoint '%s': %s\n", + bpf_program__title(prog, false), tp_name, + libbpf_strerror_r(pfd, errmsg, sizeof(errmsg))); + return ERR_PTR(pfd); + } + link->fd = pfd; + return (struct bpf_link *)link; +} + enum bpf_perf_event_ret bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size, void **copy_mem, size_t *copy_size, -- cgit v1.2.3 From ef99b02b23ef4308057573f76750e661b5aea3e1 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 5 Jul 2019 08:50:09 -0700 Subject: libbpf: capture value in BTF type info for BTF-defined map defs Change BTF-defined map definitions to capture compile-time integer values as part of BTF type definition, to avoid split of key/value type information and actual type/size/flags initialization for maps. Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Acked-by: Yonghong Song Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 58 ++++++++++++++++++++++++-------------------------- 1 file changed, 28 insertions(+), 30 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 981fb5c3c6c9..2a08eb106221 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1029,40 +1029,40 @@ static const struct btf_type *skip_mods_and_typedefs(const struct btf *btf, } } -static bool get_map_field_int(const char *map_name, - const struct btf *btf, +/* + * Fetch integer attribute of BTF map definition. Such attributes are + * represented using a pointer to an array, in which dimensionality of array + * encodes specified integer value. E.g., int (*type)[BPF_MAP_TYPE_ARRAY]; + * encodes `type => BPF_MAP_TYPE_ARRAY` key/value pair completely using BTF + * type definition, while using only sizeof(void *) space in ELF data section. + */ +static bool get_map_field_int(const char *map_name, const struct btf *btf, const struct btf_type *def, - const struct btf_member *m, - const void *data, __u32 *res) { + const struct btf_member *m, __u32 *res) { const struct btf_type *t = skip_mods_and_typedefs(btf, m->type); const char *name = btf__name_by_offset(btf, m->name_off); - __u32 int_info = *(const __u32 *)(const void *)(t + 1); + const struct btf_array *arr_info; + const struct btf_type *arr_t; - if (BTF_INFO_KIND(t->info) != BTF_KIND_INT) { - pr_warning("map '%s': attr '%s': expected INT, got %u.\n", + if (BTF_INFO_KIND(t->info) != BTF_KIND_PTR) { + pr_warning("map '%s': attr '%s': expected PTR, got %u.\n", map_name, name, BTF_INFO_KIND(t->info)); return false; } - if (t->size != 4 || BTF_INT_BITS(int_info) != 32 || - BTF_INT_OFFSET(int_info)) { - pr_warning("map '%s': attr '%s': expected 32-bit non-bitfield integer, " - "got %u-byte (%d-bit) one with bit offset %d.\n", - map_name, name, t->size, BTF_INT_BITS(int_info), - BTF_INT_OFFSET(int_info)); - return false; - } - if (BTF_INFO_KFLAG(def->info) && BTF_MEMBER_BITFIELD_SIZE(m->offset)) { - pr_warning("map '%s': attr '%s': bitfield is not supported.\n", - map_name, name); + + arr_t = btf__type_by_id(btf, t->type); + if (!arr_t) { + pr_warning("map '%s': attr '%s': type [%u] not found.\n", + map_name, name, t->type); return false; } - if (m->offset % 32) { - pr_warning("map '%s': attr '%s': unaligned fields are not supported.\n", - map_name, name); + if (BTF_INFO_KIND(arr_t->info) != BTF_KIND_ARRAY) { + pr_warning("map '%s': attr '%s': expected ARRAY, got %u.\n", + map_name, name, BTF_INFO_KIND(arr_t->info)); return false; } - - *res = *(const __u32 *)(data + m->offset / 8); + arr_info = (const void *)(arr_t + 1); + *res = arr_info->nelems; return true; } @@ -1075,7 +1075,6 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj, const struct btf_var_secinfo *vi; const struct btf_var *var_extra; const struct btf_member *m; - const void *def_data; const char *map_name; struct bpf_map *map; int vlen, i; @@ -1132,7 +1131,6 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj, pr_debug("map '%s': at sec_idx %d, offset %zu.\n", map_name, map->sec_idx, map->sec_offset); - def_data = data->d_buf + vi->offset; vlen = BTF_INFO_VLEN(def->info); m = (const void *)(def + 1); for (i = 0; i < vlen; i++, m++) { @@ -1145,19 +1143,19 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj, } if (strcmp(name, "type") == 0) { if (!get_map_field_int(map_name, obj->btf, def, m, - def_data, &map->def.type)) + &map->def.type)) return -EINVAL; pr_debug("map '%s': found type = %u.\n", map_name, map->def.type); } else if (strcmp(name, "max_entries") == 0) { if (!get_map_field_int(map_name, obj->btf, def, m, - def_data, &map->def.max_entries)) + &map->def.max_entries)) return -EINVAL; pr_debug("map '%s': found max_entries = %u.\n", map_name, map->def.max_entries); } else if (strcmp(name, "map_flags") == 0) { if (!get_map_field_int(map_name, obj->btf, def, m, - def_data, &map->def.map_flags)) + &map->def.map_flags)) return -EINVAL; pr_debug("map '%s': found map_flags = %u.\n", map_name, map->def.map_flags); @@ -1165,7 +1163,7 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj, __u32 sz; if (!get_map_field_int(map_name, obj->btf, def, m, - def_data, &sz)) + &sz)) return -EINVAL; pr_debug("map '%s': found key_size = %u.\n", map_name, sz); @@ -1208,7 +1206,7 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj, __u32 sz; if (!get_map_field_int(map_name, obj->btf, def, m, - def_data, &sz)) + &sz)) return -EINVAL; pr_debug("map '%s': found value_size = %u.\n", map_name, sz); -- cgit v1.2.3 From fb84b8224655309e7d38f989e426b82a4543f115 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Sat, 6 Jul 2019 11:06:24 -0700 Subject: libbpf: add perf buffer API BPF_MAP_TYPE_PERF_EVENT_ARRAY map is often used to send data from BPF program to user space for additional processing. libbpf already has very low-level API to read single CPU perf buffer, bpf_perf_event_read_simple(), but it's hard to use and requires a lot of code to set everything up. This patch adds perf_buffer abstraction on top of it, abstracting setting up and polling per-CPU logic into simple and convenient API, similar to what BCC provides. perf_buffer__new() sets up per-CPU ring buffers and updates corresponding BPF map entries. It accepts two user-provided callbacks: one for handling raw samples and one for get notifications of lost samples due to buffer overflow. perf_buffer__new_raw() is similar, but provides more control over how perf events are set up (by accepting user-provided perf_event_attr), how they are handled (perf_event_header pointer is passed directly to user-provided callback), and on which CPUs ring buffers are created (it's possible to provide a list of CPUs and corresponding map keys to update). This API allows advanced users fuller control. perf_buffer__poll() is used to fetch ring buffer data across all CPUs, utilizing epoll instance. perf_buffer__free() does corresponding clean up and unsets FDs from BPF map. All APIs are not thread-safe. User should ensure proper locking/coordination if used in multi-threaded set up. Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 366 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 366 insertions(+) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 2a08eb106221..ae569b50e2e0 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -32,7 +32,9 @@ #include #include #include +#include #include +#include #include #include #include @@ -4354,6 +4356,370 @@ bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size, return ret; } +struct perf_buffer; + +struct perf_buffer_params { + struct perf_event_attr *attr; + /* if event_cb is specified, it takes precendence */ + perf_buffer_event_fn event_cb; + /* sample_cb and lost_cb are higher-level common-case callbacks */ + perf_buffer_sample_fn sample_cb; + perf_buffer_lost_fn lost_cb; + void *ctx; + int cpu_cnt; + int *cpus; + int *map_keys; +}; + +struct perf_cpu_buf { + struct perf_buffer *pb; + void *base; /* mmap()'ed memory */ + void *buf; /* for reconstructing segmented data */ + size_t buf_size; + int fd; + int cpu; + int map_key; +}; + +struct perf_buffer { + perf_buffer_event_fn event_cb; + perf_buffer_sample_fn sample_cb; + perf_buffer_lost_fn lost_cb; + void *ctx; /* passed into callbacks */ + + size_t page_size; + size_t mmap_size; + struct perf_cpu_buf **cpu_bufs; + struct epoll_event *events; + int cpu_cnt; + int epoll_fd; /* perf event FD */ + int map_fd; /* BPF_MAP_TYPE_PERF_EVENT_ARRAY BPF map FD */ +}; + +static void perf_buffer__free_cpu_buf(struct perf_buffer *pb, + struct perf_cpu_buf *cpu_buf) +{ + if (!cpu_buf) + return; + if (cpu_buf->base && + munmap(cpu_buf->base, pb->mmap_size + pb->page_size)) + pr_warning("failed to munmap cpu_buf #%d\n", cpu_buf->cpu); + if (cpu_buf->fd >= 0) { + ioctl(cpu_buf->fd, PERF_EVENT_IOC_DISABLE, 0); + close(cpu_buf->fd); + } + free(cpu_buf->buf); + free(cpu_buf); +} + +void perf_buffer__free(struct perf_buffer *pb) +{ + int i; + + if (!pb) + return; + if (pb->cpu_bufs) { + for (i = 0; i < pb->cpu_cnt && pb->cpu_bufs[i]; i++) { + struct perf_cpu_buf *cpu_buf = pb->cpu_bufs[i]; + + bpf_map_delete_elem(pb->map_fd, &cpu_buf->map_key); + perf_buffer__free_cpu_buf(pb, cpu_buf); + } + free(pb->cpu_bufs); + } + if (pb->epoll_fd >= 0) + close(pb->epoll_fd); + free(pb->events); + free(pb); +} + +static struct perf_cpu_buf * +perf_buffer__open_cpu_buf(struct perf_buffer *pb, struct perf_event_attr *attr, + int cpu, int map_key) +{ + struct perf_cpu_buf *cpu_buf; + char msg[STRERR_BUFSIZE]; + int err; + + cpu_buf = calloc(1, sizeof(*cpu_buf)); + if (!cpu_buf) + return ERR_PTR(-ENOMEM); + + cpu_buf->pb = pb; + cpu_buf->cpu = cpu; + cpu_buf->map_key = map_key; + + cpu_buf->fd = syscall(__NR_perf_event_open, attr, -1 /* pid */, cpu, + -1, PERF_FLAG_FD_CLOEXEC); + if (cpu_buf->fd < 0) { + err = -errno; + pr_warning("failed to open perf buffer event on cpu #%d: %s\n", + cpu, libbpf_strerror_r(err, msg, sizeof(msg))); + goto error; + } + + cpu_buf->base = mmap(NULL, pb->mmap_size + pb->page_size, + PROT_READ | PROT_WRITE, MAP_SHARED, + cpu_buf->fd, 0); + if (cpu_buf->base == MAP_FAILED) { + cpu_buf->base = NULL; + err = -errno; + pr_warning("failed to mmap perf buffer on cpu #%d: %s\n", + cpu, libbpf_strerror_r(err, msg, sizeof(msg))); + goto error; + } + + if (ioctl(cpu_buf->fd, PERF_EVENT_IOC_ENABLE, 0) < 0) { + err = -errno; + pr_warning("failed to enable perf buffer event on cpu #%d: %s\n", + cpu, libbpf_strerror_r(err, msg, sizeof(msg))); + goto error; + } + + return cpu_buf; + +error: + perf_buffer__free_cpu_buf(pb, cpu_buf); + return (struct perf_cpu_buf *)ERR_PTR(err); +} + +static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt, + struct perf_buffer_params *p); + +struct perf_buffer *perf_buffer__new(int map_fd, size_t page_cnt, + const struct perf_buffer_opts *opts) +{ + struct perf_buffer_params p = {}; + struct perf_event_attr attr = { + .config = PERF_COUNT_SW_BPF_OUTPUT, + .type = PERF_TYPE_SOFTWARE, + .sample_type = PERF_SAMPLE_RAW, + .sample_period = 1, + .wakeup_events = 1, + }; + + p.attr = &attr; + p.sample_cb = opts ? opts->sample_cb : NULL; + p.lost_cb = opts ? opts->lost_cb : NULL; + p.ctx = opts ? opts->ctx : NULL; + + return __perf_buffer__new(map_fd, page_cnt, &p); +} + +struct perf_buffer * +perf_buffer__new_raw(int map_fd, size_t page_cnt, + const struct perf_buffer_raw_opts *opts) +{ + struct perf_buffer_params p = {}; + + p.attr = opts->attr; + p.event_cb = opts->event_cb; + p.ctx = opts->ctx; + p.cpu_cnt = opts->cpu_cnt; + p.cpus = opts->cpus; + p.map_keys = opts->map_keys; + + return __perf_buffer__new(map_fd, page_cnt, &p); +} + +static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt, + struct perf_buffer_params *p) +{ + struct bpf_map_info map = {}; + char msg[STRERR_BUFSIZE]; + struct perf_buffer *pb; + __u32 map_info_len; + int err, i; + + if (page_cnt & (page_cnt - 1)) { + pr_warning("page count should be power of two, but is %zu\n", + page_cnt); + return ERR_PTR(-EINVAL); + } + + map_info_len = sizeof(map); + err = bpf_obj_get_info_by_fd(map_fd, &map, &map_info_len); + if (err) { + err = -errno; + pr_warning("failed to get map info for map FD %d: %s\n", + map_fd, libbpf_strerror_r(err, msg, sizeof(msg))); + return ERR_PTR(err); + } + + if (map.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) { + pr_warning("map '%s' should be BPF_MAP_TYPE_PERF_EVENT_ARRAY\n", + map.name); + return ERR_PTR(-EINVAL); + } + + pb = calloc(1, sizeof(*pb)); + if (!pb) + return ERR_PTR(-ENOMEM); + + pb->event_cb = p->event_cb; + pb->sample_cb = p->sample_cb; + pb->lost_cb = p->lost_cb; + pb->ctx = p->ctx; + + pb->page_size = getpagesize(); + pb->mmap_size = pb->page_size * page_cnt; + pb->map_fd = map_fd; + + pb->epoll_fd = epoll_create1(EPOLL_CLOEXEC); + if (pb->epoll_fd < 0) { + err = -errno; + pr_warning("failed to create epoll instance: %s\n", + libbpf_strerror_r(err, msg, sizeof(msg))); + goto error; + } + + if (p->cpu_cnt > 0) { + pb->cpu_cnt = p->cpu_cnt; + } else { + pb->cpu_cnt = libbpf_num_possible_cpus(); + if (pb->cpu_cnt < 0) { + err = pb->cpu_cnt; + goto error; + } + if (map.max_entries < pb->cpu_cnt) + pb->cpu_cnt = map.max_entries; + } + + pb->events = calloc(pb->cpu_cnt, sizeof(*pb->events)); + if (!pb->events) { + err = -ENOMEM; + pr_warning("failed to allocate events: out of memory\n"); + goto error; + } + pb->cpu_bufs = calloc(pb->cpu_cnt, sizeof(*pb->cpu_bufs)); + if (!pb->cpu_bufs) { + err = -ENOMEM; + pr_warning("failed to allocate buffers: out of memory\n"); + goto error; + } + + for (i = 0; i < pb->cpu_cnt; i++) { + struct perf_cpu_buf *cpu_buf; + int cpu, map_key; + + cpu = p->cpu_cnt > 0 ? p->cpus[i] : i; + map_key = p->cpu_cnt > 0 ? p->map_keys[i] : i; + + cpu_buf = perf_buffer__open_cpu_buf(pb, p->attr, cpu, map_key); + if (IS_ERR(cpu_buf)) { + err = PTR_ERR(cpu_buf); + goto error; + } + + pb->cpu_bufs[i] = cpu_buf; + + err = bpf_map_update_elem(pb->map_fd, &map_key, + &cpu_buf->fd, 0); + if (err) { + err = -errno; + pr_warning("failed to set cpu #%d, key %d -> perf FD %d: %s\n", + cpu, map_key, cpu_buf->fd, + libbpf_strerror_r(err, msg, sizeof(msg))); + goto error; + } + + pb->events[i].events = EPOLLIN; + pb->events[i].data.ptr = cpu_buf; + if (epoll_ctl(pb->epoll_fd, EPOLL_CTL_ADD, cpu_buf->fd, + &pb->events[i]) < 0) { + err = -errno; + pr_warning("failed to epoll_ctl cpu #%d perf FD %d: %s\n", + cpu, cpu_buf->fd, + libbpf_strerror_r(err, msg, sizeof(msg))); + goto error; + } + } + + return pb; + +error: + if (pb) + perf_buffer__free(pb); + return ERR_PTR(err); +} + +struct perf_sample_raw { + struct perf_event_header header; + uint32_t size; + char data[0]; +}; + +struct perf_sample_lost { + struct perf_event_header header; + uint64_t id; + uint64_t lost; + uint64_t sample_id; +}; + +static enum bpf_perf_event_ret +perf_buffer__process_record(struct perf_event_header *e, void *ctx) +{ + struct perf_cpu_buf *cpu_buf = ctx; + struct perf_buffer *pb = cpu_buf->pb; + void *data = e; + + /* user wants full control over parsing perf event */ + if (pb->event_cb) + return pb->event_cb(pb->ctx, cpu_buf->cpu, e); + + switch (e->type) { + case PERF_RECORD_SAMPLE: { + struct perf_sample_raw *s = data; + + if (pb->sample_cb) + pb->sample_cb(pb->ctx, cpu_buf->cpu, s->data, s->size); + break; + } + case PERF_RECORD_LOST: { + struct perf_sample_lost *s = data; + + if (pb->lost_cb) + pb->lost_cb(pb->ctx, cpu_buf->cpu, s->lost); + break; + } + default: + pr_warning("unknown perf sample type %d\n", e->type); + return LIBBPF_PERF_EVENT_ERROR; + } + return LIBBPF_PERF_EVENT_CONT; +} + +static int perf_buffer__process_records(struct perf_buffer *pb, + struct perf_cpu_buf *cpu_buf) +{ + enum bpf_perf_event_ret ret; + + ret = bpf_perf_event_read_simple(cpu_buf->base, pb->mmap_size, + pb->page_size, &cpu_buf->buf, + &cpu_buf->buf_size, + perf_buffer__process_record, cpu_buf); + if (ret != LIBBPF_PERF_EVENT_CONT) + return ret; + return 0; +} + +int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms) +{ + int i, cnt, err; + + cnt = epoll_wait(pb->epoll_fd, pb->events, pb->cpu_cnt, timeout_ms); + for (i = 0; i < cnt; i++) { + struct perf_cpu_buf *cpu_buf = pb->events[i].data.ptr; + + err = perf_buffer__process_records(pb, cpu_buf); + if (err) { + pr_warning("error while processing records: %d\n", err); + return err; + } + } + return cnt < 0 ? -errno : cnt; +} + struct bpf_prog_info_array_desc { int array_offset; /* e.g. offset of jited_prog_insns */ int count_offset; /* e.g. offset of jited_prog_len */ -- cgit v1.2.3 From d7ff34d5fb5a2f6722786863c4afa79c51f8edf2 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Sat, 6 Jul 2019 11:06:25 -0700 Subject: libbpf: auto-set PERF_EVENT_ARRAY size to number of CPUs For BPF_MAP_TYPE_PERF_EVENT_ARRAY typically correct size is number of possible CPUs. This is impossible to specify at compilation time. This change adds automatic setting of PERF_EVENT_ARRAY size to number of system CPUs, unless non-zero size is specified explicitly. This allows to adjust size for advanced specific cases, while providing convenient and logical defaults. Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Acked-by: Yonghong Song Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index ae569b50e2e0..ed07789b3e62 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -2116,6 +2116,7 @@ static int bpf_object__create_maps(struct bpf_object *obj) { struct bpf_create_map_attr create_attr = {}; + int nr_cpus = 0; unsigned int i; int err; @@ -2138,7 +2139,22 @@ bpf_object__create_maps(struct bpf_object *obj) create_attr.map_flags = def->map_flags; create_attr.key_size = def->key_size; create_attr.value_size = def->value_size; - create_attr.max_entries = def->max_entries; + if (def->type == BPF_MAP_TYPE_PERF_EVENT_ARRAY && + !def->max_entries) { + if (!nr_cpus) + nr_cpus = libbpf_num_possible_cpus(); + if (nr_cpus < 0) { + pr_warning("failed to determine number of system CPUs: %d\n", + nr_cpus); + err = nr_cpus; + goto err_out; + } + pr_debug("map '%s': setting size to %d\n", + map->name, nr_cpus); + create_attr.max_entries = nr_cpus; + } else { + create_attr.max_entries = def->max_entries; + } create_attr.btf_fd = 0; create_attr.btf_key_type_id = 0; create_attr.btf_value_type_id = 0; @@ -2155,9 +2171,10 @@ bpf_object__create_maps(struct bpf_object *obj) *pfd = bpf_create_map_xattr(&create_attr); if (*pfd < 0 && (create_attr.btf_key_type_id || create_attr.btf_value_type_id)) { - cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); + err = -errno; + cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg)); pr_warning("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n", - map->name, cp, errno); + map->name, cp, err); create_attr.btf_fd = 0; create_attr.btf_key_type_id = 0; create_attr.btf_value_type_id = 0; @@ -2169,11 +2186,11 @@ bpf_object__create_maps(struct bpf_object *obj) if (*pfd < 0) { size_t j; - err = *pfd; + err = -errno; err_out: - cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); - pr_warning("failed to create map (name: '%s'): %s\n", - map->name, cp); + cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg)); + pr_warning("failed to create map (name: '%s'): %s(%d)\n", + map->name, cp, err); for (j = 0; j < i; j++) zclose(obj->maps[j].fd); return err; -- cgit v1.2.3