Adding support to retrieve buildid from elf's "buildid" section and passing it through to the load_program function to kernel bpf syscall. Fixing perf use of the bpf_load_program function and linking in the vsprintf.o into bpftool to have the scnprintf function in. Link: http://lkml.kernel.org/n/tip-2pafwtzbyosmf9ftuf0udn54@xxxxxxxxxxxxxx Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx> --- tools/bpf/bpftool/Makefile | 5 ++++- tools/lib/bpf/bpf.c | 6 ++++-- tools/lib/bpf/bpf.h | 5 +++-- tools/lib/bpf/libbpf.c | 46 ++++++++++++++++++++++++++++++++++++++++------ tools/perf/tests/bpf.c | 9 ++++++++- 5 files changed, 59 insertions(+), 12 deletions(-) diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile index 4e69782c4a79..9ac11ea5de1c 100644 --- a/tools/bpf/bpftool/Makefile +++ b/tools/bpf/bpftool/Makefile @@ -75,11 +75,14 @@ include $(wildcard $(OUTPUT)*.d) all: $(OUTPUT)bpftool SRCS = $(wildcard *.c) -OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o +OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o $(OUTPUT)vsprintf.o $(OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c $(QUIET_CC)$(COMPILE.c) -MMD -o $@ $< +$(OUTPUT)vsprintf.o: $(srctree)/tools/lib/vsprintf.c + $(QUIET_CC)$(COMPILE.c) -MMD -o $@ $< + $(OUTPUT)bpftool: $(OBJS) $(LIBBPF) $(QUIET_LINK)$(CC) $(CFLAGS) -o $@ $^ $(LIBS) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index acbb3f8b3bec..8e384db5bbbd 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -168,6 +168,7 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, attr.log_size = 0; attr.log_level = 0; attr.kern_version = load_attr->kern_version; + attr.kern_buildid = ptr_to_u64(load_attr->buildid); memcpy(attr.prog_name, load_attr->name, min(name_len, BPF_OBJ_NAME_LEN - 1)); @@ -185,8 +186,8 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns, size_t insns_cnt, const char *license, - __u32 kern_version, char *log_buf, - size_t log_buf_sz) + __u32 kern_version, const char *buildid, + char *log_buf, size_t log_buf_sz) { struct bpf_load_program_attr load_attr; @@ -198,6 +199,7 @@ int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns, load_attr.insns_cnt = insns_cnt; load_attr.license = license; load_attr.kern_version = kern_version; + load_attr.buildid = buildid; return bpf_load_program_xattr(&load_attr, log_buf, log_buf_sz); } diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 39f6a0d64a3b..b5ffb178ebdd 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -49,6 +49,7 @@ struct bpf_load_program_attr { size_t insns_cnt; const char *license; __u32 kern_version; + const char *buildid; }; /* Recommend log buffer size */ @@ -57,8 +58,8 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, char *log_buf, size_t log_buf_sz); int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns, size_t insns_cnt, const char *license, - __u32 kern_version, char *log_buf, - size_t log_buf_sz); + __u32 kern_version, const char *buildid, + char *log_buf, size_t log_buf_sz); int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns, size_t insns_cnt, int strict_alignment, const char *license, __u32 kern_version, diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 5922443063f0..421f2c2e0ebe 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -220,6 +220,7 @@ static LIST_HEAD(bpf_objects_list); struct bpf_object { char license[64]; + char buildid[64]; u32 kern_version; struct bpf_program *programs; @@ -599,6 +600,32 @@ bpf_object__init_kversion(struct bpf_object *obj, return 0; } +static void buildid_scnprint(char *buf, int n, char *buildid, int size) +{ + int i, ret = 0; + + for (i = 0; i < size; i++) { + ret += scnprintf(buf + ret, n - ret, "%x", + (unsigned char) buildid[i]); + } +} + +static int +bpf_object__init_buildid(struct bpf_object *obj, + void *data, size_t size) +{ + char buf[64]; + + if (size > sizeof(obj->buildid)) + return -LIBBPF_ERRNO__FORMAT; + + memcpy(&obj->buildid, data, size); + + buildid_scnprint(buf, 64, obj->buildid, size); + pr_debug("kernel buildid of %s is: %s\n", obj->path, buf); + return 0; +} + static int compare_bpf_map(const void *_a, const void *_b) { const struct bpf_map *a = _a; @@ -817,6 +844,10 @@ static int bpf_object__elf_collect(struct bpf_object *obj) err = bpf_object__init_kversion(obj, data->d_buf, data->d_size); + else if (strcmp(name, "buildid") == 0) + err = bpf_object__init_buildid(obj, + data->d_buf, + data->d_size); else if (strcmp(name, "maps") == 0) obj->efile.maps_shndx = idx; else if (sh.sh_type == SHT_SYMTAB) { @@ -1166,7 +1197,7 @@ static int bpf_object__collect_reloc(struct bpf_object *obj) static int load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type, const char *name, struct bpf_insn *insns, int insns_cnt, - char *license, u32 kern_version, int *pfd) + char *license, u32 kern_version, const char *buildid, int *pfd) { struct bpf_load_program_attr load_attr; char *log_buf; @@ -1180,6 +1211,7 @@ load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type, load_attr.insns_cnt = insns_cnt; load_attr.license = license; load_attr.kern_version = kern_version; + load_attr.buildid = buildid; if (!load_attr.insns || !load_attr.insns_cnt) return -EINVAL; @@ -1189,7 +1221,6 @@ load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type, pr_warning("Alloc log buffer for bpf loader error, continue without log\n"); ret = bpf_load_program_xattr(&load_attr, log_buf, BPF_LOG_BUF_SIZE); - if (ret >= 0) { *pfd = ret; ret = 0; @@ -1234,7 +1265,8 @@ load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type, static int bpf_program__load(struct bpf_program *prog, - char *license, u32 kern_version) + char *license, u32 kern_version, + const char *buildid) { int err = 0, fd, i; @@ -1261,7 +1293,7 @@ bpf_program__load(struct bpf_program *prog, } err = load_program(prog->type, prog->expected_attach_type, prog->name, prog->insns, prog->insns_cnt, - license, kern_version, &fd); + license, kern_version, buildid, &fd); if (!err) prog->instances.fds[0] = fd; goto out; @@ -1292,7 +1324,8 @@ bpf_program__load(struct bpf_program *prog, err = load_program(prog->type, prog->expected_attach_type, prog->name, result.new_insn_ptr, result.new_insn_cnt, - license, kern_version, &fd); + license, kern_version, + buildid, &fd); if (err) { pr_warning("Loading the %dth instance of program '%s' failed\n", @@ -1324,7 +1357,8 @@ bpf_object__load_progs(struct bpf_object *obj) continue; err = bpf_program__load(&obj->programs[i], obj->license, - obj->kern_version); + obj->kern_version, + obj->buildid); if (err) return err; } diff --git a/tools/perf/tests/bpf.c b/tools/perf/tests/bpf.c index 79b54f8ddebf..2a738b7b743a 100644 --- a/tools/perf/tests/bpf.c +++ b/tools/perf/tests/bpf.c @@ -298,6 +298,7 @@ static int check_env(void) int err; unsigned int kver_int; char license[] = "GPL"; + char buildid[64]; struct bpf_insn insns[] = { BPF_MOV64_IMM(BPF_REG_0, 1), @@ -310,9 +311,15 @@ static int check_env(void) return err; } + err = fetch_kernel_buildid(buildid, sizeof(buildid)); + if (err) { + pr_debug("Unable to get kernel buildid\n"); + return err; + } + err = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns, sizeof(insns) / sizeof(insns[0]), - license, kver_int, NULL, 0); + license, kver_int, buildid, NULL, 0); if (err < 0) { pr_err("Missing basic BPF support, skip this test: %s\n", strerror(errno)); -- 2.13.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
