diff options
27 files changed, 1252 insertions, 547 deletions
diff --git a/tools/bpf/bpftool/.gitignore b/tools/bpf/bpftool/.gitignore index 26cde83e1ca3..3e601bcfd461 100644 --- a/tools/bpf/bpftool/.gitignore +++ b/tools/bpf/bpftool/.gitignore @@ -1,10 +1,11 @@ # SPDX-License-Identifier: GPL-2.0-only *.d -/_bpftool +/bpftool-bootstrap /bpftool bpftool*.8 bpf-helpers.* FEATURE-DUMP.bpftool feature libbpf -profiler.skel.h +/*.skel.h +/vmlinux.h diff --git a/tools/bpf/bpftool/Documentation/bpftool-btf.rst b/tools/bpf/bpftool/Documentation/bpftool-btf.rst index ce3a724f50c1..896f4c6c2870 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-btf.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-btf.rst @@ -36,6 +36,11 @@ DESCRIPTION otherwise list all BTF objects currently loaded on the system. + Since Linux 5.8 bpftool is able to discover information about + processes that hold open file descriptors (FDs) against BTF + objects. On such kernels bpftool will automatically emit this + information as well. + **bpftool btf dump** *BTF_SRC* Dump BTF entries from a given *BTF_SRC*. diff --git a/tools/bpf/bpftool/Documentation/bpftool-link.rst b/tools/bpf/bpftool/Documentation/bpftool-link.rst index 0e43d7b06c11..38b0949a185b 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-link.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-link.rst @@ -37,6 +37,11 @@ DESCRIPTION zero or more named attributes, some of which depend on type of link. + Since Linux 5.8 bpftool is able to discover information about + processes that hold open file descriptors (FDs) against BPF + links. On such kernels bpftool will automatically emit this + information as well. + **bpftool link pin** *LINK* *FILE* Pin link *LINK* as *FILE*. @@ -82,6 +87,7 @@ EXAMPLES 10: cgroup prog 25 cgroup_id 614 attach_type egress + pids test_progs(223) **# bpftool --json --pretty link show** @@ -91,7 +97,12 @@ EXAMPLES "type": "cgroup", "prog_id": 25, "cgroup_id": 614, - "attach_type": "egress" + "attach_type": "egress", + "pids": [{ + "pid": 223, + "comm": "test_progs" + } + ] } ] diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst index 31101643e57c..5bc2123e9944 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-map.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst @@ -62,6 +62,11 @@ DESCRIPTION Output will start with map ID followed by map type and zero or more named attributes (depending on kernel version). + Since Linux 5.8 bpftool is able to discover information about + processes that hold open file descriptors (FDs) against BPF + maps. On such kernels bpftool will automatically emit this + information as well. + **bpftool map create** *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE* **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**dev** *NAME*] Create a new map with given parameters and pin it to *bpffs* as *FILE*. @@ -180,7 +185,8 @@ EXAMPLES :: 10: hash name some_map flags 0x0 - key 4B value 8B max_entries 2048 memlock 167936B + key 4B value 8B max_entries 2048 memlock 167936B + pids systemd(1) The following three commands are equivalent: diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst index 2b254959d488..412ea3d9bf7f 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst @@ -75,6 +75,11 @@ DESCRIPTION program run. Activation or deactivation of the feature is performed via the **kernel.bpf_stats_enabled** sysctl knob. + Since Linux 5.8 bpftool is able to discover information about + processes that hold open file descriptors (FDs) against BPF + programs. On such kernels bpftool will automatically emit this + information as well. + **bpftool prog dump xlated** *PROG* [{ **file** *FILE* | **opcodes** | **visual** | **linum** }] Dump eBPF instructions of the programs from the kernel. By default, eBPF will be disassembled and printed to standard @@ -243,6 +248,7 @@ EXAMPLES 10: xdp name some_prog tag 005a3d2123620c8b gpl run_time_ns 81632 run_cnt 10 loaded_at 2017-09-29T20:11:00+0000 uid 0 xlated 528B jited 370B memlock 4096B map_ids 10 + pids systemd(1) **# bpftool --json --pretty prog show** @@ -262,6 +268,11 @@ EXAMPLES "bytes_jited": 370, "bytes_memlock": 4096, "map_ids": [10 + ], + "pids": [{ + "pid": 1, + "comm": "systemd" + } ] } ] diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile index 9e85f101be85..06f436e8191a 100644 --- a/tools/bpf/bpftool/Makefile +++ b/tools/bpf/bpftool/Makefile @@ -42,6 +42,7 @@ CFLAGS += -O2 CFLAGS += -W -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers CFLAGS += $(filter-out -Wswitch-enum,$(EXTRA_WARNINGS)) CFLAGS += -DPACKAGE='"bpftool"' -D__EXPORTED_HEADERS__ \ + -I$(if $(OUTPUT),$(OUTPUT),.) \ -I$(srctree)/kernel/bpf/ \ -I$(srctree)/tools/include \ -I$(srctree)/tools/include/uapi \ @@ -61,9 +62,9 @@ CLANG ?= clang FEATURE_USER = .bpftool FEATURE_TESTS = libbfd disassembler-four-args reallocarray zlib libcap \ - clang-bpf-global-var + clang-bpf-co-re FEATURE_DISPLAY = libbfd disassembler-four-args zlib libcap \ - clang-bpf-global-var + clang-bpf-co-re check_feat := 1 NON_CHECK_FEAT_TARGETS := clean uninstall doc doc-clean doc-install doc-uninstall @@ -116,40 +117,56 @@ CFLAGS += -DHAVE_LIBBFD_SUPPORT SRCS += $(BFD_SRCS) endif +BPFTOOL_BOOTSTRAP := $(if $(OUTPUT),$(OUTPUT)bpftool-bootstrap,./bpftool-bootstrap) + +BOOTSTRAP_OBJS = $(addprefix $(OUTPUT),main.o common.o json_writer.o gen.o btf.o) OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o -_OBJS = $(filter-out $(OUTPUT)prog.o,$(OBJS)) $(OUTPUT)_prog.o -ifeq ($(feature-clang-bpf-global-var),1) - __OBJS = $(OBJS) -else - __OBJS = $(_OBJS) -endif +VMLINUX_BTF_PATHS := $(if $(O),$(O)/vmlinux) \ + $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \ + ../../../vmlinux \ + /sys/kernel/btf/vmlinux \ + /boot/vmlinux-$(shell uname -r) +VMLINUX_BTF := $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS)))) -$(OUTPUT)_prog.o: prog.c - $(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -DBPFTOOL_WITHOUT_SKELETONS -o $@ $< +ifneq ($(VMLINUX_BTF),) +ifeq ($(feature-clang-bpf-co-re),1) -$(OUTPUT)_bpftool: $(_OBJS) $(LIBBPF) - $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(_OBJS) $(LIBS) +BUILD_BPF_SKELS := 1 -skeleton/profiler.bpf.o: skeleton/profiler.bpf.c $(LIBBPF) +$(OUTPUT)vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL_BOOTSTRAP) + $(QUIET_GEN)$(BPFTOOL_BOOTSTRAP) btf dump file $< format c > $@ + +$(OUTPUT)%.bpf.o: skeleton/%.bpf.c $(OUTPUT)vmlinux.h $(LIBBPF) $(QUIET_CLANG)$(CLANG) \ + -I$(if $(OUTPUT),$(OUTPUT),.) \ -I$(srctree)/tools/include/uapi/ \ - -I$(LIBBPF_PATH) -I$(srctree)/tools/lib \ + -I$(LIBBPF_PATH) \ + -I$(srctree)/tools/lib \ -g -O2 -target bpf -c $< -o $@ -profiler.skel.h: $(OUTPUT)_bpftool skeleton/profiler.bpf.o - $(QUIET_GEN)$(OUTPUT)./_bpftool gen skeleton skeleton/profiler.bpf.o > $@ +$(OUTPUT)%.skel.h: $(OUTPUT)%.bpf.o $(BPFTOOL_BOOTSTRAP) + $(QUIET_GEN)$(BPFTOOL_BOOTSTRAP) gen skeleton $< > $@ -$(OUTPUT)prog.o: prog.c profiler.skel.h - $(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -o $@ $< +$(OUTPUT)prog.o: $(OUTPUT)profiler.skel.h + +$(OUTPUT)pids.o: $(OUTPUT)pid_iter.skel.h + +endif +endif + +CFLAGS += $(if BUILD_BPF_SKELS,,-DBPFTOOL_WITHOUT_SKELETONS) $(OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c $(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -o $@ $< $(OUTPUT)feature.o: | zdep -$(OUTPUT)bpftool: $(__OBJS) $(LIBBPF) - $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(__OBJS) $(LIBS) +$(BPFTOOL_BOOTSTRAP): $(BOOTSTRAP_OBJS) $(LIBBPF) + $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(BOOTSTRAP_OBJS) $(LIBS) + +$(OUTPUT)bpftool: $(OBJS) $(LIBBPF) + $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(OBJS) $(LIBS) $(OUTPUT)%.o: %.c $(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -o $@ $< @@ -157,7 +174,7 @@ $(OUTPUT)%.o: %.c clean: $(LIBBPF)-clean $(call QUIET_CLEAN, bpftool) $(Q)$(RM) -- $(OUTPUT)bpftool $(OUTPUT)*.o $(OUTPUT)*.d - $(Q)$(RM) -- $(OUTPUT)_bpftool profiler.skel.h skeleton/profiler.bpf.o + $(Q)$(RM) -- $(BPFTOOL_BOOTSTRAP) $(OUTPUT)*.skel.h $(OUTPUT)vmlinux.h $(Q)$(RM) -r -- $(OUTPUT)libbpf/ $(call QUIET_CLEAN, core-gen) $(Q)$(RM) -- $(OUTPUT)FEATURE-DUMP.bpftool @@ -192,6 +209,7 @@ FORCE: zdep: @if [ "$(feature-zlib)" != "1" ]; then echo "No zlib found"; exit 1 ; fi +.SECONDARY: .PHONY: all FORCE clean install uninstall zdep .PHONY: doc doc-clean doc-install doc-uninstall .DEFAULT_GOAL := all diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c index faac8189b285..fc9bc7a23db6 100644 --- a/tools/bpf/bpftool/btf.c +++ b/tools/bpf/bpftool/btf.c @@ -809,6 +809,7 @@ show_btf_plain(struct bpf_btf_info *info, int fd, printf("%s%u", n++ == 0 ? " map_ids " : ",", obj->obj_id); } + emit_obj_refs_plain(&refs_table, info->id, "\n\tpids "); printf("\n"); } @@ -841,6 +842,9 @@ show_btf_json(struct bpf_btf_info *info, int fd, jsonw_uint(json_wtr, obj->obj_id); } jsonw_end_array(json_wtr); /* map_ids */ + + emit_obj_refs_json(&refs_table, info->id, json_wtr); /* pids */ + jsonw_end_object(json_wtr); /* btf object */ } @@ -893,6 +897,7 @@ static int do_show(int argc, char **argv) close(fd); return err; } + build_obj_refs_table(&refs_table, BPF_OBJ_BTF); if (fd >= 0) { err = show_btf(fd, &btf_prog_table, &btf_map_table); @@ -939,6 +944,7 @@ static int do_show(int argc, char **argv) exit_free: delete_btf_table(&btf_prog_table); delete_btf_table(&btf_map_table); + delete_obj_refs_table(&refs_table); return err; } diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c index c47bdc65de8e..6c864c3683fc 100644 --- a/tools/bpf/bpftool/common.c +++ b/tools/bpf/bpftool/common.c @@ -581,3 +581,311 @@ print_all_levels(__maybe_unused enum libbpf_print_level level, { return vfprintf(stderr, format, args); } + +static int prog_fd_by_nametag(void *nametag, int **fds, bool tag) +{ + unsigned int id = 0; + int fd, nb_fds = 0; + void *tmp; + int err; + + while (true) { + struct bpf_prog_info info = {}; + __u32 len = sizeof(info); + + err = bpf_prog_get_next_id(id, &id); + if (err) { + if (errno != ENOENT) { + p_err("%s", strerror(errno)); + goto err_close_fds; + } + return nb_fds; + } + + fd = bpf_prog_get_fd_by_id(id); + if (fd < 0) { + p_err("can't get prog by id (%u): %s", + id, strerror(errno)); + goto err_close_fds; + } + + err = bpf_obj_get_info_by_fd(fd, &info, &len); + if (err) { + p_err("can't get prog info (%u): %s", + id, strerror(errno)); + goto err_close_fd; + } + + if ((tag && memcmp(nametag, info.tag, BPF_TAG_SIZE)) || + (!tag && strncmp(nametag, info.name, BPF_OBJ_NAME_LEN))) { + close(fd); + continue; + } + + if (nb_fds > 0) { + tmp = realloc(*fds, (nb_fds + 1) * sizeof(int)); + if (!tmp) { + p_err("failed to realloc"); + goto err_close_fd; + } + *fds = tmp; + } + (*fds)[nb_fds++] = fd; + } + +err_close_fd: + close(fd); +err_close_fds: + while (--nb_fds >= 0) + close((*fds)[nb_fds]); + return -1; +} + +int prog_parse_fds(int *argc, char ***argv, int **fds) +{ + if (is_prefix(**argv, "id")) { + unsigned int id; + char *endptr; + + NEXT_ARGP(); + + id = strtoul(**argv, &endptr, 0); + if (*endptr) { + p_err("can't parse %s as ID", **argv); + return -1; + } + NEXT_ARGP(); + + (*fds)[0] = bpf_prog_get_fd_by_id(id); + if ((*fds)[0] < 0) { + p_err("get by id (%u): %s", id, strerror(errno)); + return -1; + } + return 1; + } else if (is_prefix(**argv, "tag")) { + unsigned char tag[BPF_TAG_SIZE]; + + NEXT_ARGP(); + + if (sscanf(**argv, BPF_TAG_FMT, tag, tag + 1, tag + 2, + tag + 3, tag + 4, tag + 5, tag + 6, tag + 7) + != BPF_TAG_SIZE) { + p_err("can't parse tag"); + return -1; + } + NEXT_ARGP(); + + return prog_fd_by_nametag(tag, fds, true); + } else if (is_prefix(**argv, "name")) { + char *name; + + NEXT_ARGP(); + + name = **argv; + if (strlen(name) > BPF_OBJ_NAME_LEN - 1) { + p_err("can't parse name"); + return -1; + } + NEXT_ARGP(); + + return prog_fd_by_nametag(name, fds, false); + } else if (is_prefix(**argv, "pinned")) { + char *path; + + NEXT_ARGP(); + + path = **argv; + NEXT_ARGP(); + + (*fds)[0] = open_obj_pinned_any(path, BPF_OBJ_PROG); + if ((*fds)[0] < 0) + return -1; + return 1; + } + + p_err("expected 'id', 'tag', 'name' or 'pinned', got: '%s'?", **argv); + return -1; +} + +int prog_parse_fd(int *argc, char ***argv) +{ + int *fds = NULL; + int nb_fds, fd; + + fds = malloc(sizeof(int)); + if (!fds) { + p_err("mem alloc failed"); + return -1; + } + nb_fds = prog_parse_fds(argc, argv, &fds); + if (nb_fds != 1) { + if (nb_fds > 1) { + p_err("several programs match this handle"); + while (nb_fds--) + close(fds[nb_fds]); + } + fd = -1; + goto exit_free; + } + + fd = fds[0]; +exit_free: + free(fds); + return fd; +} + +static int map_fd_by_name(char *name, int **fds) +{ + unsigned int id = 0; + int fd, nb_fds = 0; + void *tmp; + int err; + + while (true) { + struct bpf_map_info info = {}; + __u32 len = sizeof(info); + + err = bpf_map_get_next_id(id, &id); + if (err) { + if (errno != ENOENT) { + p_err("%s", strerror(errno)); + goto err_close_fds; + } + return nb_fds; + } + + fd = bpf_map_get_fd_by_id(id); + if (fd < 0) { + p_err("can't get map by id (%u): %s", + id, strerror(errno)); + goto err_close_fds; + } + + err = bpf_obj_get_info_by_fd(fd, &info, &len); + if (err) { + p_err("can't get map info (%u): %s", + id, strerror(errno)); + goto err_close_fd; + } + + if (strncmp(name, info.name, BPF_OBJ_NAME_LEN)) { + close(fd); + continue; + } + + if (nb_fds > 0) { + tmp = realloc(*fds, (nb_fds + 1) * sizeof(int)); + if (!tmp) { + p_err("failed to realloc"); + goto err_close_fd; + } + *fds = tmp; + } + (*fds)[nb_fds++] = fd; + } + +err_close_fd: + close(fd); +err_close_fds: + while (--nb_fds >= 0) + close((*fds)[nb_fds]); + return -1; +} + +int map_parse_fds(int *argc, char ***argv, int **fds) +{ + if (is_prefix(**argv, "id")) { + unsigned int id; + char *endptr; + + NEXT_ARGP(); + + id = strtoul(**argv, &endptr, 0); + if (*endptr) { + p_err("can't parse %s as ID", **argv); + return -1; + } + NEXT_ARGP(); + + (*fds)[0] = bpf_map_get_fd_by_id(id); + if ((*fds)[0] < 0) { + p_err("get map by id (%u): %s", id, strerror(errno)); + return -1; + } + return 1; + } else if (is_prefix(**argv, "name")) { + char *name; + + NEXT_ARGP(); + + name = **argv; + if (strlen(name) > BPF_OBJ_NAME_LEN - 1) { + p_err("can't parse name"); + return -1; + } + NEXT_ARGP(); + + return map_fd_by_name(name, fds); + } else if (is_prefix(**argv, "pinned")) { + char *path; + + NEXT_ARGP(); + + path = **argv; + NEXT_ARGP(); + + (*fds)[0] = open_obj_pinned_any(path, BPF_OBJ_MAP); + if ((*fds)[0] < 0) + return -1; + return 1; + } + + p_err("expected 'id', 'name' or 'pinned', got: '%s'?", **argv); + return -1; +} + +int map_parse_fd(int *argc, char ***argv) +{ + int *fds = NULL; + int nb_fds, fd; + + fds = malloc(sizeof(int)); + if (!fds) { + p_err("mem alloc failed"); + return -1; + } + nb_fds = map_parse_fds(argc, argv, &fds); + if (nb_fds != 1) { + if (nb_fds > 1) { + p_err("several maps match this handle"); + while (nb_fds--) + close(fds[nb_fds]); + } + fd = -1; + goto exit_free; + } + + fd = fds[0]; +exit_free: + free(fds); + return fd; +} + +int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len) +{ + int err; + int fd; + + fd = map_parse_fd(argc, argv); + if (fd < 0) + return -1; + + err = bpf_obj_get_info_by_fd(fd, info, info_len); + if (err) { + p_err("can't get map info: %s", strerror(errno)); + close(fd); + return err; + } + + return fd; +} diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c index fca57ee8fafe..7329f3134283 100644 --- a/tools/bpf/bpftool/link.c +++ b/tools/bpf/bpftool/link.c @@ -143,6 +143,9 @@ static int show_link_close_json(int fd, struct bpf_link_info *info) } jsonw_end_array(json_wtr); } + + emit_obj_refs_json(&refs_table, info->id, json_wtr); + jsonw_end_object(json_wtr); return 0; @@ -212,6 +215,7 @@ static int show_link_close_plain(int fd, struct bpf_link_info *info) printf("\n\tpinned %s", obj->path); } } + emit_obj_refs_plain(&refs_table, info->id, "\n\tpids "); printf("\n"); @@ -257,6 +261,7 @@ static int do_show(int argc, char **argv) if (show_pinned) build_pinned_obj_table(&link_table, BPF_OBJ_LINK); + build_obj_refs_table(&refs_table, BPF_OBJ_LINK); if (argc == 2) { fd = link_parse_fd(&argc, &argv); @@ -296,6 +301,8 @@ static int do_show(int argc, char **argv) if (json_output) jsonw_end_array(json_wtr); + delete_obj_refs_table(&refs_table); + return errno == ENOENT ? 0 : -1; } diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c index 46bd716a9d86..4a191fcbeb82 100644 --- a/tools/bpf/bpftool/main.c +++ b/tools/bpf/bpftool/main.c @@ -31,6 +31,7 @@ bool relaxed_maps; struct pinned_obj_table prog_table; struct pinned_obj_table map_table; struct pinned_obj_table link_table; +struct obj_refs_table refs_table; static void __noreturn clean_and_exit(int i) { @@ -92,9 +93,16 @@ int cmd_select(const struct cmd *cmds, int argc, char **argv, if (argc < 1 && cmds[0].func) return cmds[0].func(argc, argv); - for (i = 0; cmds[i].func; i++) - if (is_prefix(*argv, cmds[i].cmd)) + for (i = 0; cmds[i].cmd; i++) { + if (is_prefix(*argv, cmds[i].cmd)) { + if (!cmds[i].func) { + p_err("command '%s' is not supported in bootstrap mode", + cmds[i].cmd); + return -1; + } return cmds[i].func(argc - 1, argv + 1); + } + } help(argc - 1, argv + 1); diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index 5cdf0bc049bd..ce26271e5f0c 100644 --- a/tools/bpf/bpftool/main.h +++ b/tools/bpf/bpftool/main.h @@ -127,11 +127,13 @@ static const char * const attach_type_name[__MAX_BPF_ATTACH_TYPE] = { extern const char * const map_type_name[]; extern const size_t map_type_name_size; +/* keep in sync with the definition in skeleton/pid_iter.bpf.c */ enum bpf_obj_type { BPF_OBJ_UNKNOWN, BPF_OBJ_PROG, BPF_OBJ_MAP, BPF_OBJ_LINK, + BPF_OBJ_BTF, }; extern const char *bin_name; @@ -139,12 +141,14 @@ extern const char *bin_name; extern json_writer_t *json_wtr; extern bool json_output; extern bool show_pinned; +extern bool show_pids; extern bool block_mount; extern bool verifier_logs; extern bool relaxed_maps; extern struct pinned_obj_table prog_table; extern struct pinned_obj_table map_table; extern struct pinned_obj_table link_table; +extern struct obj_refs_table refs_table; void __printf(1, 2) p_err(const char *fmt, ...); void __printf(1, 2) p_info(const char *fmt, ...); @@ -168,12 +172,35 @@ struct pinned_obj { struct hlist_node hash; }; +struct obj_refs_table { + DECLARE_HASHTABLE(table, 16); +}; + +struct obj_ref { + int pid; + char comm[16]; +}; + +struct obj_refs { + struct hlist_node node; + __u32 id; + int ref_cnt; + struct obj_ref *refs; +}; + struct btf; struct bpf_line_info; int build_pinned_obj_table(struct pinned_obj_table *table, enum bpf_obj_type type); void delete_pinned_obj_table(struct pinned_obj_table *tab); +__weak int build_obj_refs_table(struct obj_refs_table *table, + enum bpf_obj_type type); +__weak void delete_obj_refs_table(struct obj_refs_table *table); +__weak void emit_obj_refs_json(struct obj_refs_table *table, __u32 id, + json_writer_t *json_wtr); +__weak void emit_obj_refs_plain(struct obj_refs_table *table, __u32 id, + const char *prefix); void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode); void print_dev_json(__u32 ifindex, __u64 ns_dev, __u64 ns_inode); @@ -194,23 +221,28 @@ int mount_bpffs_for_pin(const char *name); int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(int *, char ***)); int do_pin_fd(int fd, const char *name); -int do_prog(int argc, char **arg); -int do_map(int argc, char **arg); -int do_link(int argc, char **arg); -int do_event_pipe(int argc, char **argv); -int do_cgroup(int argc, char **arg); -int do_perf(int argc, char **arg); -int do_net(int argc, char **arg); -int do_tracelog(int argc, char **arg); -int do_feature(int argc, char **argv); -int do_btf(int argc, char **argv); +/* commands available in bootstrap mode */ int do_gen(int argc, char **argv); -int do_struct_ops(int argc, char **argv); -int do_iter(int argc, char **argv); +int do_btf(int argc, char **argv); + +/* non-bootstrap only commands */ +int do_prog(int argc, char **arg) __weak; +int do_map(int argc, char **arg) __weak; +int do_link(int argc, char **arg) __weak; +int do_event_pipe(int argc, char **argv) __weak; +int do_cgroup(int argc, char **arg) __weak; +int do_perf(int argc, char **arg) __weak; +int do_net(int argc, char **arg) __weak; +int do_tracelog(int argc, char **arg) __weak; +int do_feature(int argc, char **argv) __weak; +int do_struct_ops(int argc, char **argv) __weak; +int do_iter(int argc, char **argv) __weak; int parse_u32_arg(int *argc, char ***argv, __u32 *val, const char *what); int prog_parse_fd(int *argc, char ***argv); +int prog_parse_fds(int *argc, char ***argv, int **fds); int map_parse_fd(int *argc, char ***argv); +int map_parse_fds(int *argc, char ***argv, int **fds); int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len); struct bpf_prog_linfo; diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index c5fac8068ba1..0a6a5d82d380 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -92,162 +92,6 @@ static void *alloc_value(struct bpf_map_info *info) return malloc(info->value_size); } -static int map_fd_by_name(char *name, int **fds) -{ - unsigned int id = 0; - int fd, nb_fds = 0; - void *tmp; - int err; - - while (true) { - struct bpf_map_info info = {}; - __u32 len = sizeof(info); - - err = bpf_map_get_next_id(id, &id); - if (err) { - if (errno != ENOENT) { - p_err("%s", strerror(errno)); - goto err_close_fds; - } - return nb_fds; - } - - fd = bpf_map_get_fd_by_id(id); - if (fd < 0) { - p_err("can't get map by id (%u): %s", - id, strerror(errno)); - goto err_close_fds; - } - - err = bpf_obj_get_info_by_fd(fd, &info, &len); - if (err) { - p_err("can't get map info (%u): %s", - id, strerror(errno)); - goto err_close_fd; - } - - if (strncmp(name, info.name, BPF_OBJ_NAME_LEN)) { - close(fd); - continue; - } - - if (nb_fds > 0) { - tmp = realloc(*fds, (nb_fds + 1) * sizeof(int)); - if (!tmp) { - p_err("failed to realloc"); - goto err_close_fd; - } - *fds = tmp; - } - (*fds)[nb_fds++] = fd; - } - -err_close_fd: - close(fd); -err_close_fds: - while (--nb_fds >= 0) - close((*fds)[nb_fds]); - return -1; -} - -static int map_parse_fds(int *argc, char ***argv, int **fds) -{ - if (is_prefix(**argv, "id")) { - unsigned int id; - char *endptr; - - NEXT_ARGP(); - - id = strtoul(**argv, &endptr, 0); - if (*endptr) { - p_err("can't parse %s as ID", **argv); - return -1; - } - NEXT_ARGP(); - - (*fds)[0] = bpf_map_get_fd_by_id(id); - if ((*fds)[0] < 0) { - p_err("get map by id (%u): %s", id, strerror(errno)); - return -1; - } - return 1; - } else if (is_prefix(**argv, "name")) { - char *name; - - NEXT_ARGP(); - - name = **argv; - if (strlen(name) > BPF_OBJ_NAME_LEN - 1) { - p_err("can't parse name"); - return -1; - } - NEXT_ARGP(); - - return map_fd_by_name(name, fds); - } else if (is_prefix(**argv, "pinned")) { - char *path; - - NEXT_ARGP(); - - path = **argv; - NEXT_ARGP(); - - (*fds)[0] = open_obj_pinned_any(path, BPF_OBJ_MAP); - if ((*fds)[0] < 0) - return -1; - return 1; - } - - p_err("expected 'id', 'name' or 'pinned', got: '%s'?", **argv); - return -1; -} - -int map_parse_fd(int *argc, char ***argv) -{ - int *fds = NULL; - int nb_fds, fd; - - fds = malloc(sizeof(int)); - if (!fds) { - p_err("mem alloc failed"); - return -1; - } - nb_fds = map_parse_fds(argc, argv, &fds); - if (nb_fds != 1) { - if (nb_fds > 1) { - p_err("several maps match this handle"); - while (nb_fds--) - close(fds[nb_fds]); - } - fd = -1; - goto exit_free; - } - - fd = fds[0]; -exit_free: - free(fds); - return fd; -} - -int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len) -{ - int err; - int fd; - - fd = map_parse_fd(argc, argv); - if (fd < 0) - return -1; - - err = bpf_obj_get_info_by_fd(fd, info, info_len); - if (err) { - p_err("can't get map info: %s", strerror(errno)); - close(fd); - return err; - } - - return fd; -} - static int do_dump_btf(const struct btf_dumper *d, struct bpf_map_info *map_info, void *key, void *value) @@ -665,6 +509,8 @@ static int show_map_close_json(int fd, struct bpf_map_info *info) jsonw_end_array(json_wtr); } + emit_obj_refs_json(&refs_table, info->id, json_wtr); + jsonw_end_object(json_wtr); return 0; @@ -752,6 +598,8 @@ static int show_map_close_plain(int fd, struct bpf_map_info *info) if (frozen) printf("%sfrozen", info->btf_id ? " " : ""); + emit_obj_refs_plain(&refs_table, info->id, "\n\tpids "); + printf("\n"); return 0; } @@ -810,6 +658,7 @@ static int do_show(int argc, char **argv) if (show_pinned) build_pinned_obj_table(&map_table, BPF_OBJ_MAP); + build_obj_refs_table(&refs_table, BPF_OBJ_MAP); if (argc == 2) return do_show_subset(argc, argv); @@ -853,6 +702,8 @@ static int do_show(int argc, char **argv) if (json_output) jsonw_end_array(json_wtr); + delete_obj_refs_table(&refs_table); + return errno == ENOENT ? 0 : -1; } diff --git a/tools/bpf/bpftool/pids.c b/tools/bpf/bpftool/pids.c new file mode 100644 index 000000000000..3474a91743ff --- /dev/null +++ b/tools/bpf/bpftool/pids.c @@ -0,0 +1,229 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +/* Copyright (C) 2020 Facebook */ +#include <errno.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <bpf/bpf.h> + +#include "main.h" +#include "skeleton/pid_iter.h" + +#ifdef BPFTOOL_WITHOUT_SKELETONS + +int build_obj_refs_table(struct obj_refs_table *table, enum bpf_obj_type type) +{ + p_err("bpftool built without PID iterator support"); + return -ENOTSUP; +} +void delete_obj_refs_table(struct obj_refs_table *table) {} + +#else /* BPFTOOL_WITHOUT_SKELETONS */ + +#include "pid_iter.skel.h" + +static void add_ref(struct obj_refs_table *table, struct pid_iter_entry *e) +{ + struct obj_refs *refs; + struct obj_ref *ref; + void *tmp; + int i; + + hash_for_each_possible(table->table, refs, node, e->id) { + if (refs->id != e->id) + continue; + + for (i = 0; i < refs->ref_cnt; i++) { + if (refs->refs[i].pid == e->pid) + return; + } + + tmp = realloc(refs->refs, (refs->ref_cnt + 1) * sizeof(*ref)); + if (!tmp) { + p_err("failed to re-alloc memory for ID %u, PID %d, COMM %s...", + e->id, e->pid, e->comm); + return; + } + refs->refs = tmp; + ref = &refs->refs[refs->ref_cnt]; + ref->pid = e->pid; + memcpy(ref->comm, e->comm, sizeof(ref->comm)); + refs->ref_cnt++; + + return; + } + + /* new ref */ + refs = calloc(1, sizeof(*refs)); + if (!refs) { + p_err("failed to alloc memory for ID %u, PID %d, COMM %s...", + e->id, e->pid, e->comm); + return; + } + + refs->id = e->id; + refs->refs = malloc(sizeof(*refs->refs)); + if (!refs->refs) { + free(refs); + p_err("failed to alloc memory for ID %u, PID %d, COMM %s...", + e->id, e->pid, e->comm); + return; + } + ref = &refs->refs[0]; + ref->pid = e->pid; + memcpy(ref->comm, e->comm, sizeof(ref->comm)); + refs->ref_cnt = 1; + hash_add(table->table, &refs->node, e->id); +} + +static int __printf(2, 0) +libbpf_print_none(__maybe_unused enum libbpf_print_level level, + __maybe_unused const char *format, + __maybe_unused va_list args) +{ + return 0; +} + +int build_obj_refs_table(struct obj_refs_table *table, enum bpf_obj_type type) +{ + char buf[4096]; + struct pid_iter_bpf *skel; + struct pid_iter_entry *e; + int err, ret, fd = -1, i; + libbpf_print_fn_t default_print; + + hash_init(table->table); + set_max_rlimit(); + + skel = pid_iter_bpf__open(); + if (!skel) { + p_err("failed to open PID iterator skeleton"); + return -1; + } + + skel->rodata->obj_type = type; + + /* we don't want output polluted with libbpf errors if bpf_iter is not + * supported + */ + default_print = libbpf_set_print(libbpf_print_none); + err = pid_iter_bpf__load(skel); + libbpf_set_print(default_print); + if (err) { + /* too bad, kernel doesn't support BPF iterators yet */ + err = 0; + goto out; + } + err = pid_iter_bpf__attach(skel); + if (err) { + /* if we loaded above successfully, attach has to succeed */ + p_err("failed to attach PID iterator: %d", err); + goto out; + } + + fd = bpf_iter_create(bpf_link__fd(skel->links.iter)); + if (fd < 0) { + err = -errno; + p_err("failed to create PID iterator session: %d", err); + goto out; + } + + while (true) { + ret = read(fd, buf, sizeof(buf)); + if (ret < 0) { + err = -errno; + p_err("failed to read PID iterator output: %d", err); + goto out; + } + if (ret == 0) + break; + if (ret % sizeof(*e)) { + err = -EINVAL; + p_err("invalid PID iterator output format"); + goto out; + } + ret /= sizeof(*e); + + e = (void *)buf; + for (i = 0; i < ret; i++, e++) { + add_ref(table, e); + } + } + err = 0; +out: + if (fd >= 0) + close(fd); + pid_iter_bpf__destroy(skel); + return err; +} + +void delete_obj_refs_table(struct obj_refs_table *table) +{ + struct obj_refs *refs; + struct hlist_node *tmp; + unsigned int bkt; + + hash_for_each_safe(table->table, bkt, tmp, refs, node) { + hash_del(&refs->node); + free(refs->refs); + free(refs); + } +} + +void emit_obj_refs_json(struct obj_refs_table *table, __u32 id, json_writer_t *json_wtr) +{ + struct obj_refs *refs; + struct obj_ref *ref; + int i; + + if (hash_empty(table->table)) + return; + + hash_for_each_possible(table->table, refs, node, id) { + if (refs->id != id) + continue; + if (refs->ref_cnt == 0) + break; + + jsonw_name(json_wtr, "pids"); + jsonw_start_array(json_wtr); + for (i = 0; i < refs->ref_cnt; i++) { + ref = &refs->refs[i]; + jsonw_start_object(json_wtr); + jsonw_int_field(json_wtr, "pid", ref->pid); + jsonw_string_field(json_wtr, "comm", ref->comm); + jsonw_end_object(json_wtr); + } + jsonw_end_array(json_wtr); + break; + } +} + +void emit_obj_refs_plain(struct obj_refs_table *table, __u32 id, const char *prefix) +{ + struct obj_refs *refs; + struct obj_ref *ref; + int i; + + if (hash_empty(table->table)) + return; + + hash_for_each_possible(table->table, refs, node, id) { + if (refs->id != id) + continue; + if (refs->ref_cnt == 0) + break; + + printf("%s", prefix); + for (i = 0; i < refs->ref_cnt; i++) { + ref = &refs->refs[i]; + printf("%s%s(%d)", i == 0 ? "" : ", ", ref->comm, ref->pid); + } + break; + } +} + + +#endif diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index a5eff83496f2..e21fa8ad2efa 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -86,158 +86,6 @@ static void print_boot_time(__u64 nsecs, char *buf, unsigned int size) strftime(buf, size, "%FT%T%z", &load_tm); } -static int prog_fd_by_nametag(void *nametag, int **fds, bool tag) -{ - unsigned int id = 0; - int fd, nb_fds = 0; - void *tmp; - int err; - - while (true) { - struct bpf_prog_info info = {}; - __u32 len = sizeof(info); - - err = bpf_prog_get_next_id(id, &id); - if (err) { - if (errno != ENOENT) { - p_err("%s", strerror(errno)); - goto err_close_fds; - } - return nb_fds; - } - - fd = bpf_prog_get_fd_by_id(id); - if (fd < 0) { - p_err("can't get prog by id (%u): %s", - id, strerror(errno)); - goto err_close_fds; - } - - err = bpf_obj_get_info_by_fd(fd, &info, &len); - if (err) { - p_err("can't get prog info (%u): %s", - id, strerror(errno)); - goto err_close_fd; - } - - if ((tag && memcmp(nametag, info.tag, BPF_TAG_SIZE)) || - (!tag && strncmp(nametag, info.name, BPF_OBJ_NAME_LEN))) { - close(fd); - continue; - } - - if (nb_fds > 0) { - tmp = realloc(*fds, (nb_fds + 1) * sizeof(int)); - if (!tmp) { - p_err("failed to realloc"); - goto err_close_fd; - } - *fds = tmp; - } - (*fds)[nb_fds++] = fd; - } - -err_close_fd: - close(fd); -err_close_fds: - while (--nb_fds >= 0) - close((*fds)[nb_fds]); - return -1; -} - -static int prog_parse_fds(int *argc, char ***argv, int **fds) -{ - if (is_prefix(**argv, "id")) { - unsigned int id; - char *endptr; - - NEXT_ARGP(); - - id = strtoul(**argv, &endptr, 0); - if (*endptr) { - p_err("can't parse %s as ID", **argv); - return -1; - } - NEXT_ARGP(); - - (*fds)[0] = bpf_prog_get_fd_by_id(id); - if ((*fds)[0] < 0) { - p_err("get by id (%u): %s", id, strerror(errno)); - return -1; - } - return 1; - } else if (is_prefix(**argv, "tag")) { - unsigned char tag[BPF_TAG_SIZE]; - - NEXT_ARGP(); - - if (sscanf(**argv, BPF_TAG_FMT, tag, tag + 1, tag + 2, - tag + 3, tag + 4, tag + 5, tag + 6, tag + 7) - != BPF_TAG_SIZE) { - p_err("can't parse tag"); - return -1; - } - NEXT_ARGP(); - - return prog_fd_by_nametag(tag, fds, true); - } else if (is_prefix(**argv, "name")) { - char *name; - - NEXT_ARGP(); - - name = **argv; - if (strlen(name) > BPF_OBJ_NAME_LEN - 1) { - p_err("can't parse name"); - return -1; - } - NEXT_ARGP(); - - return prog_fd_by_nametag(name, fds, false); - } else if (is_prefix(**argv, "pinned")) { - char *path; - - NEXT_ARGP(); - - path = **argv; - NEXT_ARGP(); - - (*fds)[0] = open_obj_pinned_any(path, BPF_OBJ_PROG); - if ((*fds)[0] < 0) - return -1; - return 1; - } - - p_err("expected 'id', 'tag', 'name' or 'pinned', got: '%s'?", **argv); - return -1; -} - -int prog_parse_fd(int *argc, char ***argv) -{ - int *fds = NULL; - int nb_fds, fd; - - fds = malloc(sizeof(int)); - if (!fds) { - p_err("mem alloc failed"); - return -1; - } - nb_fds = prog_parse_fds(argc, argv, &fds); - if (nb_fds != 1) { - if (nb_fds > 1) { - p_err("several programs match this handle"); - while (nb_fds--) - close(fds[nb_fds]); - } - fd = -1; - goto exit_free; - } - - fd = fds[0]; -exit_free: - free(fds); - return fd; -} - static void show_prog_maps(int fd, __u32 num_maps) { struct bpf_prog_info info = {}; @@ -342,6 +190,8 @@ static void print_prog_json(struct bpf_prog_info *info, int fd) jsonw_end_array(json_wtr); } + emit_obj_refs_json(&refs_table, info->id, json_wtr); + jsonw_end_object(json_wtr); } @@ -408,6 +258,8 @@ static void print_prog_plain(struct bpf_prog_info *info, int fd) if (info->btf_id) printf("\n\tbtf_id %d", info->btf_id); + emit_obj_refs_plain(&refs_table, info->id, "\n\tpids "); + printf("\n"); } @@ -473,6 +325,7 @@ static int do_show(int argc, char **argv) if (show_pinned) build_pinned_obj_table(&prog_table, BPF_OBJ_PROG); + build_obj_refs_table(&refs_table, BPF_OBJ_PROG); if (argc == 2) return do_show_subset(argc, argv); @@ -514,6 +367,8 @@ static int do_show(int argc, char **argv) if (json_output) jsonw_end_array(json_wtr); + delete_obj_refs_table(&refs_table); + return err; } diff --git a/tools/bpf/bpftool/skeleton/pid_iter.bpf.c b/tools/bpf/bpftool/skeleton/pid_iter.bpf.c new file mode 100644 index 000000000000..8468a608911e --- /dev/null +++ b/tools/bpf/bpftool/skeleton/pid_iter.bpf.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +/* Copyright (c) 2020 Facebook */ +#include <vmlinux.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_core_read.h> +#include <bpf/bpf_tracing.h> +#include "pid_iter.h" + +/* keep in sync with the definition in main.h */ +enum bpf_obj_type { + BPF_OBJ_UNKNOWN, + BPF_OBJ_PROG, + BPF_OBJ_MAP, + BPF_OBJ_LINK, + BPF_OBJ_BTF, +}; + +extern const void bpf_link_fops __ksym; +extern const void bpf_map_fops __ksym; +extern const void bpf_prog_fops __ksym; +extern const void btf_fops __ksym; + +const volatile enum bpf_obj_type obj_type = BPF_OBJ_UNKNOWN; + +static __always_inline __u32 get_obj_id(void *ent, enum bpf_obj_type type) +{ + switch (type) { + case BPF_OBJ_PROG: + return BPF_CORE_READ((struct bpf_prog *)ent, aux, id); + case BPF_OBJ_MAP: + return BPF_CORE_READ((struct bpf_map *)ent, id); + case BPF_OBJ_BTF: + return BPF_CORE_READ((struct btf *)ent, id); + case BPF_OBJ_LINK: + return BPF_CORE_READ((struct bpf_link *)ent, id); + default: + return 0; + } +} + +SEC("iter/task_file") +int iter(struct bpf_iter__task_file *ctx) +{ + struct file *file = ctx->file; + struct task_struct *task = ctx->task; + struct pid_iter_entry e; + const void *fops; + + if (!file || !task) + return 0; + + switch (obj_type) { + case BPF_OBJ_PROG: + fops = &bpf_prog_fops; + break; + case BPF_OBJ_MAP: + fops = &bpf_map_fops; + break; + case BPF_OBJ_BTF: + fops = &btf_fops; + break; + case BPF_OBJ_LINK: + fops = &bpf_link_fops; + break; + default: + return 0; + } + + if (file->f_op != fops) + return 0; + + e.pid = task->tgid; + e.id = get_obj_id(file->private_data, obj_type); + bpf_probe_read(&e.comm, sizeof(e.comm), task->group_leader->comm); + bpf_seq_write(ctx->meta->seq, &e, sizeof(e)); + + return 0; +} + +char LICENSE[] SEC("license") = "Dual BSD/GPL"; diff --git a/tools/bpf/bpftool/skeleton/pid_iter.h b/tools/bpf/bpftool/skeleton/pid_iter.h new file mode 100644 index 000000000000..5692cf257adb --- /dev/null +++ b/tools/bpf/bpftool/skeleton/pid_iter.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */ +/* Copyright (c) 2020 Facebook */ +#ifndef __PID_ITER_H +#define __PID_ITER_H + +struct pid_iter_entry { + __u32 id; + int pid; + char comm[16]; +}; + +#endif diff --git a/tools/bpf/bpftool/skeleton/profiler.bpf.c b/tools/bpf/bpftool/skeleton/profiler.bpf.c index c9d196ddb670..4e3512f700c0 100644 --- a/tools/bpf/bpftool/skeleton/profiler.bpf.c +++ b/tools/bpf/bpftool/skeleton/profiler.bpf.c @@ -1,7 +1,6 @@ // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) // Copyright (c) 2020 Facebook -#include "profiler.h" -#include <linux/bpf.h> +#include <vmlinux.h> #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> diff --git a/tools/bpf/bpftool/skeleton/profiler.h b/tools/bpf/bpftool/skeleton/profiler.h deleted file mode 100644 index 1f767e9510f7..000000000000 --- a/tools/bpf/bpftool/skeleton/profiler.h +++ /dev/null @@ -1,46 +0,0 @@ -/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ -#ifndef __PROFILER_H -#define __PROFILER_H - -/* useful typedefs from vmlinux.h */ - -typedef signed char __s8; -typedef unsigned char __u8; -typedef short int __s16; -typedef short unsigned int __u16; -typedef int __s32; -typedef unsigned int __u32; -typedef long long int __s64; -typedef long long unsigned int __u64; - -typedef __s8 s8; -typedef __u8 u8; -typedef __s16 s16; -typedef __u16 u16; -typedef __s32 s32; -typedef __u32 u32; -typedef __s64 s64; -typedef __u64 u64; - -enum { - false = 0, - true = 1, -}; - -#ifdef __CHECKER__ -#define __bitwise__ __attribute__((bitwise)) -#else -#define __bitwise__ -#endif - -typedef __u16 __bitwise__ __le16; -typedef __u16 __bitwise__ __be16; -typedef __u32 __bitwise__ __le32; -typedef __u32 __bitwise__ __be32; -typedef __u64 __bitwise__ __le64; -typedef __u64 __bitwise__ __be64; - -typedef __u16 __bitwise__ __sum16; -typedef __u32 __bitwise__ __wsum; - -#endif /* __PROFILER_H */ diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile index b1f0321180f5..88371f7f0369 100644 --- a/tools/build/feature/Makefile +++ b/tools/build/feature/Makefile @@ -68,7 +68,7 @@ FILES= \ test-llvm-version.bin \ test-libaio.bin \ test-libzstd.bin \ - test-clang-bpf-global-var.bin \ + test-clang-bpf-co-re.bin \ test-file-handle.bin \ test-libpfm4.bin @@ -325,7 +325,7 @@ $(OUTPUT)test-libaio.bin: $(OUTPUT)test-libzstd.bin: $(BUILD) -lzstd -$(OUTPUT)test-clang-bpf-global-var.bin: +$(OUTPUT)test-clang-bpf-co-re.bin: $(CLANG) -S -g -target bpf -o - $(patsubst %.bin,%.c,$(@F)) | \ grep BTF_KIND_VAR diff --git a/tools/build/feature/test-clang-bpf-co-re.c b/tools/build/feature/test-clang-bpf-co-re.c new file mode 100644 index 000000000000..cb5265bfdd83 --- /dev/null +++ b/tools/build/feature/test-clang-bpf-co-re.c @@ -0,0 +1,9 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2020 Facebook + +struct test { + int a; + int b; +} __attribute__((preserve_access_index)); + +volatile struct test global_value_for_test = {}; diff --git a/tools/build/feature/test-clang-bpf-global-var.c b/tools/build/feature/test-clang-bpf-global-var.c deleted file mode 100644 index 221f1481d52e..000000000000 --- a/tools/build/feature/test-clang-bpf-global-var.c +++ /dev/null @@ -1,4 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -// Copyright (c) 2020 Facebook - -volatile int global_value_for_test = 1; diff --git a/tools/lib/bpf/bpf_core_read.h b/tools/lib/bpf/bpf_core_read.h index 7009dc90e012..eae5cccff761 100644 --- a/tools/lib/bpf/bpf_core_read.h +++ b/tools/lib/bpf/bpf_core_read.h @@ -217,7 +217,7 @@ enum bpf_field_info_kind { */ #define BPF_CORE_READ_INTO(dst, src, a, ...) \ ({ \ - ___core_read(bpf_core_read, dst, src, a, ##__VA_ARGS__) \ + ___core_read(bpf_core_read, dst, (src), a, ##__VA_ARGS__) \ }) /* @@ -227,7 +227,7 @@ enum bpf_field_info_kind { */ #define BPF_CORE_READ_STR_INTO(dst, src, a, ...) \ ({ \ - ___core_read(bpf_core_read_str, dst, src, a, ##__VA_ARGS__) \ + ___core_read(bpf_core_read_str, dst, (src), a, ##__VA_ARGS__)\ }) /* @@ -254,8 +254,8 @@ enum bpf_field_info_kind { */ #define BPF_CORE_READ(src, a, ...) \ ({ \ - ___type(src, a, ##__VA_ARGS__) __r; \ - BPF_CORE_READ_INTO(&__r, src, a, ##__VA_ARGS__); \ + ___type((src), a, ##__VA_ARGS__) __r; \ + BPF_CORE_READ_INTO(&__r, (src), a, ##__VA_ARGS__); \ __r; \ }) diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h index f67dce2af802..a510d8ed716f 100644 --- a/tools/lib/bpf/bpf_helpers.h +++ b/tools/lib/bpf/bpf_helpers.h @@ -75,5 +75,6 @@ enum libbpf_tristate { }; #define __kconfig __attribute__((section(".kconfig"))) +#define __ksym __attribute__((section(".ksyms"))) #endif diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index 70c1b7ec2bd0..06cd1731c154 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -168,6 +168,11 @@ static inline bool btf_kflag(const struct btf_type *t) return BTF_INFO_KFLAG(t->info); } +static inline bool btf_is_void(const struct btf_type *t) +{ + return btf_kind(t) == BTF_KIND_UNKN; +} + static inline bool btf_is_int(const struct btf_type *t) { return btf_kind(t) == BTF_KIND_INT; diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 259a6360475f..18461deb1b19 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -285,6 +285,7 @@ struct bpf_struct_ops { #define BSS_SEC ".bss" #define RODATA_SEC ".rodata" #define KCONFIG_SEC ".kconfig" +#define KSYMS_SEC ".ksyms" #define STRUCT_OPS_SEC ".struct_ops" enum libbpf_map_type { @@ -330,24 +331,39 @@ struct bpf_map { enum extern_type { EXT_UNKNOWN, - EXT_CHAR, - EXT_BOOL, - EXT_INT, - EXT_TRISTATE, - EXT_CHAR_ARR, + EXT_KCFG, + EXT_KSYM, +}; + +enum kcfg_type { + KCFG_UNKNOWN, + KCFG_CHAR, + KCFG_BOOL, + KCFG_INT, + KCFG_TRISTATE, + KCFG_CHAR_ARR, }; struct extern_desc { - const char *name; + enum extern_type type; int sym_idx; int btf_id; - enum extern_type type; - int sz; - int align; - int data_off; - bool is_signed; - bool is_weak; + int sec_btf_id; + const char *name; bool is_set; + bool is_weak; + union { + struct { + enum kcfg_type type; + int sz; + int align; + int data_off; + bool is_signed; + } kcfg; + struct { + unsigned long long addr; + } ksym; + }; }; static LIST_HEAD(bpf_objects_list); @@ -1424,19 +1440,19 @@ static struct extern_desc *find_extern_by_name(const struct bpf_object *obj, return NULL; } -static int set_ext_value_tri(struct extern_desc *ext, void *ext_val, - char value) +static int set_kcfg_value_tri(struct extern_desc *ext, void *ext_val, + char value) { - switch (ext->type) { - case EXT_BOOL: + switch (ext->kcfg.type) { + case KCFG_BOOL: if (value == 'm') { - pr_warn("extern %s=%c should be tristate or char\n", + pr_warn("extern (kcfg) %s=%c should be tristate or char\n", ext->name, value); return -EINVAL; } *(bool *)ext_val = value == 'y' ? true : false; break; - case EXT_TRISTATE: + case KCFG_TRISTATE: if (value == 'y') *(enum libbpf_tristate *)ext_val = TRI_YES; else if (value == 'm') @@ -1444,14 +1460,14 @@ static int set_ext_value_tri(struct extern_desc *ext, void *ext_val, else /* value == 'n' */ *(enum libbpf_tristate *)ext_val = TRI_NO; break; - case EXT_CHAR: + case KCFG_CHAR: *(char *)ext_val = value; break; - case EXT_UNKNOWN: - case EXT_INT: - case EXT_CHAR_ARR: + case KCFG_UNKNOWN: + case KCFG_INT: + case KCFG_CHAR_ARR: default: - pr_warn("extern %s=%c should be bool, tristate, or char\n", + pr_warn("extern (kcfg) %s=%c should be bool, tristate, or char\n", ext->name, value); return -EINVAL; } @@ -1459,29 +1475,29 @@ static int set_ext_value_tri(struct extern_desc *ext, void *ext_val, return 0; } -static int set_ext_value_str(struct extern_desc *ext, char *ext_val, - const char *value) +static int set_kcfg_value_str(struct extern_desc *ext, char *ext_val, + const char *value) { size_t len; - if (ext->type != EXT_CHAR_ARR) { - pr_warn("extern %s=%s should char array\n", ext->name, value); + if (ext->kcfg.type != KCFG_CHAR_ARR) { + pr_warn("extern (kcfg) %s=%s should be char array\n", ext->name, value); return -EINVAL; } len = strlen(value); if (value[len - 1] != '"') { - pr_warn("extern '%s': invalid string config '%s'\n", + pr_warn("extern (kcfg) '%s': invalid string config '%s'\n", ext->name, value); return -EINVAL; } /* strip quotes */ len -= 2; - if (len >= ext->sz) { - pr_warn("extern '%s': long string config %s of (%zu bytes) truncated to %d bytes\n", - ext->name, value, len, ext->sz - 1); - len = ext->sz - 1; + if (len >= ext->kcfg.sz) { + pr_warn("extern (kcfg) '%s': long string config %s of (%zu bytes) truncated to %d bytes\n", + ext->name, value, len, ext->kcfg.sz - 1); + len = ext->kcfg.sz - 1; } memcpy(ext_val, value + 1, len); ext_val[len] = '\0'; @@ -1508,11 +1524,11 @@ static int parse_u64(const char *value, __u64 *res) return 0; } -static bool is_ext_value_in_range(const struct extern_desc *ext, __u64 v) +static bool is_kcfg_value_in_range(const struct extern_desc *ext, __u64 v) { - int bit_sz = ext->sz * 8; + int bit_sz = ext->kcfg.sz * 8; - if (ext->sz == 8) + if (ext->kcfg.sz == 8) return true; /* Validate that value stored in u64 fits in integer of `ext->sz` @@ -1527,26 +1543,26 @@ static bool is_ext_value_in_range(const struct extern_desc *ext, __u64 v) * For unsigned target integer, check that all the (64 - Y) bits are * zero. */ - if (ext->is_signed) + if (ext->kcfg.is_signed) return v + (1ULL << (bit_sz - 1)) < (1ULL << bit_sz); else return (v >> bit_sz) == 0; } -static int set_ext_value_num(struct extern_desc *ext, void *ext_val, - __u64 value) +static int set_kcfg_value_num(struct extern_desc *ext, void *ext_val, + __u64 value) { - if (ext->type != EXT_INT && ext->type != EXT_CHAR) { - pr_warn("extern %s=%llu should be integer\n", + if (ext->kcfg.type != KCFG_INT && ext->kcfg.type != KCFG_CHAR) { + pr_warn("extern (kcfg) %s=%llu should be integer\n", ext->name, (unsigned long long)value); return -EINVAL; } - if (!is_ext_value_in_range(ext, value)) { - pr_warn("extern %s=%llu value doesn't fit in %d bytes\n", - ext->name, (unsigned long long)value, ext->sz); + if (!is_kcfg_value_in_range(ext, value)) { + pr_warn("extern (kcfg) %s=%llu value doesn't fit in %d bytes\n", + ext->name, (unsigned long long)value, ext->kcfg.sz); return -ERANGE; } - switch (ext->sz) { + switch (ext->kcfg.sz) { case 1: *(__u8 *)ext_val = value; break; case 2: *(__u16 *)ext_val = value; break; case 4: *(__u32 *)ext_val = value; break; @@ -1592,30 +1608,30 @@ static int bpf_object__process_kconfig_line(struct bpf_object *obj, if (!ext || ext->is_set) return 0; - ext_val = data + ext->data_off; + ext_val = data + ext->kcfg.data_off; value = sep + 1; switch (*value) { case 'y': case 'n': case 'm': - err = set_ext_value_tri(ext, ext_val, *value); + err = set_kcfg_value_tri(ext, ext_val, *value); break; case '"': - err = set_ext_value_str(ext, ext_val, value); + err = set_kcfg_value_str(ext, ext_val, value); break; default: /* assume integer */ err = parse_u64(value, &num); if (err) { - pr_warn("extern %s=%s should be integer\n", + pr_warn("extern (kcfg) %s=%s should be integer\n", ext->name, value); return err; } - err = set_ext_value_num(ext, ext_val, num); + err = set_kcfg_value_num(ext, ext_val, num); break; } if (err) return err; - pr_debug("extern %s=%s\n", ext->name, value); + pr_debug("extern (kcfg) %s=%s\n", ext->name, value); return 0; } @@ -1686,16 +1702,20 @@ static int bpf_object__read_kconfig_mem(struct bpf_object *obj, static int bpf_object__init_kconfig_map(struct bpf_object *obj) { - struct extern_desc *last_ext; + struct extern_desc *last_ext = NULL, *ext; size_t map_sz; - int err; + int i, err; - if (obj->nr_extern == 0) - return 0; + for (i = 0; i < obj->nr_extern; i++) { + ext = &obj->externs[i]; + if (ext->type == EXT_KCFG) + last_ext = ext; + } - last_ext = &obj->externs[obj->nr_extern - 1]; - map_sz = last_ext->data_off + last_ext->sz; + if (!last_ext) + return 0; + map_sz = last_ext->kcfg.data_off + last_ext->kcfg.sz; err = bpf_object__init_internal_map(obj, LIBBPF_MAP_KCONFIG, obj->efile.symbols_shndx, NULL, map_sz); @@ -2714,8 +2734,33 @@ static int find_extern_btf_id(const struct btf *btf, const char *ext_name) return -ENOENT; } -static enum extern_type find_extern_type(const struct btf *btf, int id, - bool *is_signed) +static int find_extern_sec_btf_id(struct btf *btf, int ext_btf_id) { + const struct btf_var_secinfo *vs; + const struct btf_type *t; + int i, j, n; + + if (!btf) + return -ESRCH; + + n = btf__get_nr_types(btf); + for (i = 1; i <= n; i++) { + t = btf__type_by_id(btf, i); + + if (!btf_is_datasec(t)) + continue; + + vs = btf_var_secinfos(t); + for (j = 0; j < btf_vlen(t); j++, vs++) { + if (vs->type == ext_btf_id) + return i; + } + } + + return -ENOENT; +} + +static enum kcfg_type find_kcfg_type(const struct btf *btf, int id, + bool *is_signed) { const struct btf_type *t; const char *name; @@ -2730,29 +2775,29 @@ static enum extern_type find_extern_type(const struct btf *btf, int id, int enc = btf_int_encoding(t); if (enc & BTF_INT_BOOL) - return t->size == 1 ? EXT_BOOL : EXT_UNKNOWN; + return t->size == 1 ? KCFG_BOOL : KCFG_UNKNOWN; if (is_signed) *is_signed = enc & BTF_INT_SIGNED; if (t->size == 1) - return EXT_CHAR; + return KCFG_CHAR; if (t->size < 1 || t->size > 8 || (t->size & (t->size - 1))) - return EXT_UNKNOWN; - return EXT_INT; + return KCFG_UNKNOWN; + return KCFG_INT; } case BTF_KIND_ENUM: if (t->size != 4) - return EXT_UNKNOWN; + return KCFG_UNKNOWN; if (strcmp(name, "libbpf_tristate")) - return EXT_UNKNOWN; - return EXT_TRISTATE; + return KCFG_UNKNOWN; + return KCFG_TRISTATE; case BTF_KIND_ARRAY: if (btf_array(t)->nelems == 0) - return EXT_UNKNOWN; - if (find_extern_type(btf, btf_array(t)->type, NULL) != EXT_CHAR) - return EXT_UNKNOWN; - return EXT_CHAR_ARR; + return KCFG_UNKNOWN; + if (find_kcfg_type(btf, btf_array(t)->type, NULL) != KCFG_CHAR) + return KCFG_UNKNOWN; + return KCFG_CHAR_ARR; default: - return EXT_UNKNOWN; + return KCFG_UNKNOWN; } } @@ -2761,23 +2806,45 @@ static int cmp_externs(const void *_a, const void *_b) const struct extern_desc *a = _a; const struct extern_desc *b = _b; - /* descending order by alignment requirements */ - if (a->align != b->align) - return a->align > b->align ? -1 : 1; - /* ascending order by size, within same alignment class */ - if (a->sz != b->sz) - return a->sz < b->sz ? -1 : 1; + if (a->type != b->type) + return a->type < b->type ? -1 : 1; + + if (a->type == EXT_KCFG) { + /* descending order by alignment requirements */ + if (a->kcfg.align != b->kcfg.align) + return a->kcfg.align > b->kcfg.align ? -1 : 1; + /* ascending order by size, within same alignment class */ + if (a->kcfg.sz != b->kcfg.sz) + return a->kcfg.sz < b->kcfg.sz ? -1 : 1; + } + /* resolve ties by name */ return strcmp(a->name, b->name); } +static int find_int_btf_id(const struct btf *btf) +{ + const struct btf_type *t; + int i, n; + + n = btf__get_nr_types(btf); + for (i = 1; i <= n; i++) { + t = btf__type_by_id(btf, i); + + if (btf_is_int(t) && btf_int_bits(t) == 32) + return i; + } + + return 0; +} + static int bpf_object__collect_externs(struct bpf_object *obj) { + struct btf_type *sec, *kcfg_sec = NULL, *ksym_sec = NULL; const struct btf_type *t; struct extern_desc *ext; - int i, n, off, btf_id; - struct btf_type *sec; - const char *ext_name; + int i, n, off; + const char *ext_name, *sec_name; Elf_Scn *scn; GElf_Shdr sh; @@ -2823,22 +2890,50 @@ static int bpf_object__collect_externs(struct bpf_object *obj) ext->name = btf__name_by_offset(obj->btf, t->name_off); ext->sym_idx = i; ext->is_weak = GELF_ST_BIND(sym.st_info) == STB_WEAK; - ext->sz = btf__resolve_size(obj->btf, t->type); - if (ext->sz <= 0) { - pr_warn("failed to resolve size of extern '%s': %d\n", - ext_name, ext->sz); - return ext->sz; - } - ext->align = btf__align_of(obj->btf, t->type); - if (ext->align <= 0) { - pr_warn("failed to determine alignment of extern '%s': %d\n", - ext_name, ext->align); - return -EINVAL; - } - ext->type = find_extern_type(obj->btf, t->type, - &ext->is_signed); - if (ext->type == EXT_UNKNOWN) { - pr_warn("extern '%s' type is unsupported\n", ext_name); + + ext->sec_btf_id = find_extern_sec_btf_id(obj->btf, ext->btf_id); + if (ext->sec_btf_id <= 0) { + pr_warn("failed to find BTF for extern '%s' [%d] section: %d\n", + ext_name, ext->btf_id, ext->sec_btf_id); + return ext->sec_btf_id; + } + sec = (void *)btf__type_by_id(obj->btf, ext->sec_btf_id); + sec_name = btf__name_by_offset(obj->btf, sec->name_off); + + if (strcmp(sec_name, KCONFIG_SEC) == 0) { + kcfg_sec = sec; + ext->type = EXT_KCFG; + ext->kcfg.sz = btf__resolve_size(obj->btf, t->type); + if (ext->kcfg.sz <= 0) { + pr_warn("failed to resolve size of extern (kcfg) '%s': %d\n", + ext_name, ext->kcfg.sz); + return ext->kcfg.sz; + } + ext->kcfg.align = btf__align_of(obj->btf, t->type); + if (ext->kcfg.align <= 0) { + pr_warn("failed to determine alignment of extern (kcfg) '%s': %d\n", + ext_name, ext->kcfg.align); + return -EINVAL; + } + ext->kcfg.type = find_kcfg_type(obj->btf, t->type, + &ext->kcfg.is_signed); + if (ext->kcfg.type == KCFG_UNKNOWN) { + pr_warn("extern (kcfg) '%s' type is unsupported\n", ext_name); + return -ENOTSUP; + } + } else if (strcmp(sec_name, KSYMS_SEC) == 0) { + const struct btf_type *vt; + + ksym_sec = sec; + ext->type = EXT_KSYM; + + vt = skip_mods_and_typedefs(obj->btf, t->type, NULL); + if (!btf_is_void(vt)) { + pr_warn("extern (ksym) '%s' is not typeless (void)\n", ext_name); + return -ENOTSUP; + } + } else { + pr_warn("unrecognized extern section '%s'\n", sec_name); return -ENOTSUP; } } @@ -2847,42 +2942,80 @@ static int bpf_object__collect_externs(struct bpf_object *obj) if (!obj->nr_extern) return 0; - /* sort externs by (alignment, size, name) and calculate their offsets - * within a map */ + /* sort externs by type, for kcfg ones also by (align, size, name) */ qsort(obj->externs, obj->nr_extern, sizeof(*ext), cmp_externs); - off = 0; - for (i = 0; i < obj->nr_extern; i++) { - ext = &obj->externs[i]; - ext->data_off = roundup(off, ext->align); - off = ext->data_off + ext->sz; - pr_debug("extern #%d: symbol %d, off %u, name %s\n", - i, ext->sym_idx, ext->data_off, ext->name); - } - btf_id = btf__find_by_name(obj->btf, KCONFIG_SEC); - if (btf_id <= 0) { - pr_warn("no BTF info found for '%s' datasec\n", KCONFIG_SEC); - return -ESRCH; - } + /* for .ksyms section, we need to turn all externs into allocated + * variables in BTF to pass kernel verification; we do this by + * pretending that each extern is a 8-byte variable + */ + if (ksym_sec) { + /* find existing 4-byte integer type in BTF to use for fake + * extern variables in DATASEC + */ + int int_btf_id = find_int_btf_id(obj->btf); - sec = (struct btf_type *)btf__type_by_id(obj->btf, btf_id); - sec->size = off; - n = btf_vlen(sec); - for (i = 0; i < n; i++) { - struct btf_var_secinfo *vs = btf_var_secinfos(sec) + i; - - t = btf__type_by_id(obj->btf, vs->type); - ext_name = btf__name_by_offset(obj->btf, t->name_off); - ext = find_extern_by_name(obj, ext_name); - if (!ext) { - pr_warn("failed to find extern definition for BTF var '%s'\n", - ext_name); - return -ESRCH; + for (i = 0; i < obj->nr_extern; i++) { + ext = &obj->externs[i]; + if (ext->type != EXT_KSYM) + continue; + pr_debug("extern (ksym) #%d: symbol %d, name %s\n", + i, ext->sym_idx, ext->name); + } + + sec = ksym_sec; + n = btf_vlen(sec); + for (i = 0, off = 0; i < n; i++, off += sizeof(int)) { + struct btf_var_secinfo *vs = btf_var_secinfos(sec) + i; + struct btf_type *vt; + + vt = (void *)btf__type_by_id(obj->btf, vs->type); + ext_name = btf__name_by_offset(obj->btf, vt->name_off); + ext = find_extern_by_name(obj, ext_name); + if (!ext) { + pr_warn("failed to find extern definition for BTF var '%s'\n", + ext_name); + return -ESRCH; + } + btf_var(vt)->linkage = BTF_VAR_GLOBAL_ALLOCATED; + vt->type = int_btf_id; + vs->offset = off; + vs->size = sizeof(int); } - vs->offset = ext->data_off; - btf_var(t)->linkage = BTF_VAR_GLOBAL_ALLOCATED; + sec->size = off; } + if (kcfg_sec) { + sec = kcfg_sec; + /* for kcfg externs calculate their offsets within a .kconfig map */ + off = 0; + for (i = 0; i < obj->nr_extern; i++) { + ext = &obj->externs[i]; + if (ext->type != EXT_KCFG) + continue; + + ext->kcfg.data_off = roundup(off, ext->kcfg.align); + off = ext->kcfg.data_off + ext->kcfg.sz; + pr_debug("extern (kcfg) #%d: symbol %d, off %u, name %s\n", + i, ext->sym_idx, ext->kcfg.data_off, ext->name); + } + sec->size = off; + n = btf_vlen(sec); + for (i = 0; i < n; i++) { + struct btf_var_secinfo *vs = btf_var_secinfos(sec) + i; + + t = btf__type_by_id(obj->btf, vs->type); + ext_name = btf__name_by_offset(obj->btf, t->name_off); + ext = find_extern_by_name(obj, ext_name); + if (!ext) { + pr_warn("failed to find extern definition for BTF var '%s'\n", + ext_name); + return -ESRCH; + } + btf_var(t)->linkage = BTF_VAR_GLOBAL_ALLOCATED; + vs->offset = ext->kcfg.data_off; + } + } return 0; } @@ -3012,11 +3145,11 @@ static int bpf_program__record_reloc(struct bpf_program *prog, sym_idx); return -LIBBPF_ERRNO__RELOC; } - pr_debug("found extern #%d '%s' (sym %d, off %u) for insn %u\n", - i, ext->name, ext->sym_idx, ext->data_off, insn_idx); + pr_debug("found extern #%d '%s' (sym %d) for insn %u\n", + i, ext->name, ext->sym_idx, insn_idx); reloc_desc->type = RELO_EXTERN; reloc_desc->insn_idx = insn_idx; - reloc_desc->sym_off = ext->data_off; + reloc_desc->sym_off = i; /* sym_off stores extern index */ return 0; } @@ -4941,6 +5074,7 @@ bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj) for (i = 0; i < prog->nr_reloc; i++) { struct reloc_desc *relo = &prog->reloc_desc[i]; struct bpf_insn *insn = &prog->insns[relo->insn_idx]; + struct extern_desc *ext; if (relo->insn_idx + 1 >= (int)prog->insns_cnt) { pr_warn("relocation out of range: '%s'\n", @@ -4959,9 +5093,15 @@ bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj) insn[0].imm = obj->maps[relo->map_idx].fd; break; case RELO_EXTERN: - insn[0].src_reg = BPF_PSEUDO_MAP_VALUE; - insn[0].imm = obj->maps[obj->kconfig_map_idx].fd; - insn[1].imm = relo->sym_off; + ext = &obj->externs[relo->sym_off]; + if (ext->type == EXT_KCFG) { + insn[0].src_reg = BPF_PSEUDO_MAP_VALUE; + insn[0].imm = obj->maps[obj->kconfig_map_idx].fd; + insn[1].imm = ext->kcfg.data_off; + } else /* EXT_KSYM */ { + insn[0].imm = (__u32)ext->ksym.addr; + insn[1].imm = ext->ksym.addr >> 32; + } break; case RELO_CALL: err = bpf_program__reloc_text(prog, obj, relo); @@ -5580,56 +5720,114 @@ static int bpf_object__sanitize_maps(struct bpf_object *obj) return 0; } +static int bpf_object__read_kallsyms_file(struct bpf_object *obj) +{ + char sym_type, sym_name[500]; + unsigned long long sym_addr; + struct extern_desc *ext; + int ret, err = 0; + FILE *f; + + f = fopen("/proc/kallsyms", "r"); + if (!f) { + err = -errno; + pr_warn("failed to open /proc/kallsyms: %d\n", err); + return err; + } + + while (true) { + ret = fscanf(f, "%llx %c %499s%*[^\n]\n", + &sym_addr, &sym_type, sym_name); + if (ret == EOF && feof(f)) + break; + if (ret != 3) { + pr_warn("failed to read kallasyms entry: %d\n", ret); + err = -EINVAL; + goto out; + } + + ext = find_extern_by_name(obj, sym_name); + if (!ext || ext->type != EXT_KSYM) + continue; + + if (ext->is_set && ext->ksym.addr != sym_addr) { + pr_warn("extern (ksym) '%s' resolution is ambiguous: 0x%llx or 0x%llx\n", + sym_name, ext->ksym.addr, sym_addr); + err = -EINVAL; + goto out; + } + if (!ext->is_set) { + ext->is_set = true; + ext->ksym.addr = sym_addr; + pr_debug("extern (ksym) %s=0x%llx\n", sym_name, sym_addr); + } + } + +out: + fclose(f); + return err; +} + static int bpf_object__resolve_externs(struct bpf_object *obj, const char *extra_kconfig) { - bool need_config = false; + bool need_config = false, need_kallsyms = false; struct extern_desc *ext; + void *kcfg_data = NULL; int err, i; - void *data; if (obj->nr_extern == 0) return 0; - data = obj->maps[obj->kconfig_map_idx].mmaped; + if (obj->kconfig_map_idx >= 0) + kcfg_data = obj->maps[obj->kconfig_map_idx].mmaped; for (i = 0; i < obj->nr_extern; i++) { ext = &obj->externs[i]; - if (strcmp(ext->name, "LINUX_KERNEL_VERSION") == 0) { - void *ext_val = data + ext->data_off; + if (ext->type == EXT_KCFG && + strcmp(ext->name, "LINUX_KERNEL_VERSION") == 0) { + void *ext_val = kcfg_data + ext->kcfg.data_off; __u32 kver = get_kernel_version(); if (!kver) { pr_warn("failed to get kernel version\n"); return -EINVAL; } - err = set_ext_value_num(ext, ext_val, kver); + err = set_kcfg_value_num(ext, ext_val, kver); if (err) return err; - pr_debug("extern %s=0x%x\n", ext->name, kver); - } else if (strncmp(ext->name, "CONFIG_", 7) == 0) { + pr_debug("extern (kcfg) %s=0x%x\n", ext->name, kver); + } else if (ext->type == EXT_KCFG && + strncmp(ext->name, "CONFIG_", 7) == 0) { need_config = true; + } else if (ext->type == EXT_KSYM) { + need_kallsyms = true; } else { pr_warn("unrecognized extern '%s'\n", ext->name); return -EINVAL; } } if (need_config && extra_kconfig) { - err = bpf_object__read_kconfig_mem(obj, extra_kconfig, data); + err = bpf_object__read_kconfig_mem(obj, extra_kconfig, kcfg_data); if (err) return -EINVAL; need_config = false; for (i = 0; i < obj->nr_extern; i++) { ext = &obj->externs[i]; - if (!ext->is_set) { + if (ext->type == EXT_KCFG && !ext->is_set) { need_config = true; break; } } } if (need_config) { - err = bpf_object__read_kconfig_file(obj, data); + err = bpf_object__read_kconfig_file(obj, kcfg_data); + if (err) + return -EINVAL; + } + if (need_kallsyms) { + err = bpf_object__read_kallsyms_file(obj); if (err) return -EINVAL; } diff --git a/tools/testing/selftests/bpf/prog_tests/ksyms.c b/tools/testing/selftests/bpf/prog_tests/ksyms.c new file mode 100644 index 000000000000..e3d6777226a8 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/ksyms.c @@ -0,0 +1,71 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2019 Facebook */ + +#include <test_progs.h> +#include "test_ksyms.skel.h" +#include <sys/stat.h> + +static int duration; + +static __u64 kallsyms_find(const char *sym) +{ + char type, name[500]; + __u64 addr, res = 0; + FILE *f; + + f = fopen("/proc/kallsyms", "r"); + if (CHECK(!f, "kallsyms_fopen", "failed to open: %d\n", errno)) + return 0; + + while (fscanf(f, "%llx %c %499s%*[^\n]\n", &addr, &type, name) > 0) { + if (strcmp(name, sym) == 0) { + res = addr; + goto out; + } + } + + CHECK(false, "not_found", "symbol %s not found\n", sym); +out: + fclose(f); + return res; +} + +void test_ksyms(void) +{ + __u64 link_fops_addr = kallsyms_find("bpf_link_fops"); + const char *btf_path = "/sys/kernel/btf/vmlinux"; + struct test_ksyms *skel; + struct test_ksyms__data *data; + struct stat st; + __u64 btf_size; + int err; + + if (CHECK(stat(btf_path, &st), "stat_btf", "err %d\n", errno)) + return; + btf_size = st.st_size; + + skel = test_ksyms__open_and_load(); + if (CHECK(!skel, "skel_open", "failed to open and load skeleton\n")) + return; + + err = test_ksyms__attach(skel); + if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err)) + goto cleanup; + + /* trigger tracepoint */ + usleep(1); + + data = skel->data; + CHECK(data->out__bpf_link_fops != link_fops_addr, "bpf_link_fops", + "got 0x%llx, exp 0x%llx\n", + data->out__bpf_link_fops, link_fops_addr); + CHECK(data->out__bpf_link_fops1 != 0, "bpf_link_fops1", + "got %llu, exp %llu\n", data->out__bpf_link_fops1, (__u64)0); + CHECK(data->out__btf_size != btf_size, "btf_size", + "got %llu, exp %llu\n", data->out__btf_size, btf_size); + CHECK(data->out__per_cpu_start != 0, "__per_cpu_start", + "got %llu, exp %llu\n", data->out__per_cpu_start, (__u64)0); + +cleanup: + test_ksyms__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_ksyms.c b/tools/testing/selftests/bpf/progs/test_ksyms.c new file mode 100644 index 000000000000..6c9cbb5a3bdf --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_ksyms.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2019 Facebook */ + +#include <stdbool.h> +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> + +__u64 out__bpf_link_fops = -1; +__u64 out__bpf_link_fops1 = -1; +__u64 out__btf_size = -1; +__u64 out__per_cpu_start = -1; + +extern const void bpf_link_fops __ksym; +extern const void __start_BTF __ksym; +extern const void __stop_BTF __ksym; +extern const void __per_cpu_start __ksym; +/* non-existing symbol, weak, default to zero */ +extern const void bpf_link_fops1 __ksym __weak; + +SEC("raw_tp/sys_enter") +int handler(const void *ctx) +{ + out__bpf_link_fops = (__u64)&bpf_link_fops; + out__btf_size = (__u64)(&__stop_BTF - &__start_BTF); + out__per_cpu_start = (__u64)&__per_cpu_start; + + out__bpf_link_fops1 = (__u64)&bpf_link_fops1; + + return 0; +} + +char _license[] SEC("license") = "GPL"; |