From f38a1f0a5a5710b14c0e899628c815522c6111cf Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 8 Mar 2019 15:58:20 -0800 Subject: libbpf: handle BTF parsing and loading properly This patch splits and cleans up error handling logic for loading BTF data. Previously, if BTF data was parsed successfully, but failed to load into kernel, we'd report nonsensical error code, instead of error returned from btf__load(). Now btf__new() and btf__load() are handled separately with proper cleanup and warning reporting. Fixes: d29d87f7e612 ("btf: separate btf creation and loading") Reported-by: Martin KaFai Lau Signed-off-by: Andrii Nakryiko Acked-by: Martin KaFai Lau Acked-by: Yonghong Song Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'tools/lib') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index d5b830d60601..5e977d2688da 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -835,12 +835,19 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) obj->efile.maps_shndx = idx; else if (strcmp(name, BTF_ELF_SEC) == 0) { obj->btf = btf__new(data->d_buf, data->d_size); - if (IS_ERR(obj->btf) || btf__load(obj->btf)) { + if (IS_ERR(obj->btf)) { pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n", BTF_ELF_SEC, PTR_ERR(obj->btf)); - if (!IS_ERR(obj->btf)) - btf__free(obj->btf); obj->btf = NULL; + continue; + } + err = btf__load(obj->btf); + if (err) { + pr_warning("Error loading %s into kernel: %d. Ignored and continue.\n", + BTF_ELF_SEC, err); + btf__free(obj->btf); + obj->btf = NULL; + err = 0; } } else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) { btf_ext_data = data; -- cgit v1.2.3 From 6bf21b54a596d60905cfc7e8af8e2fe16d9fe7e9 Mon Sep 17 00:00:00 2001 From: Magnus Karlsson Date: Tue, 12 Mar 2019 09:59:45 +0100 Subject: libbpf: fix to reject unknown flags in xsk_socket__create() In xsk_socket__create(), the libbpf_flags field was not checked for setting currently unused/unknown flags. This patch fixes that by returning -EINVAL if the user has set any flag that is not in use at this point in time. Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets") Signed-off-by: Magnus Karlsson Reviewed-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann --- tools/lib/bpf/xsk.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'tools/lib') diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index f98ac82c9aea..8d0078b65486 100644 --- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -126,8 +126,8 @@ static void xsk_set_umem_config(struct xsk_umem_config *cfg, cfg->frame_headroom = usr_cfg->frame_headroom; } -static void xsk_set_xdp_socket_config(struct xsk_socket_config *cfg, - const struct xsk_socket_config *usr_cfg) +static int xsk_set_xdp_socket_config(struct xsk_socket_config *cfg, + const struct xsk_socket_config *usr_cfg) { if (!usr_cfg) { cfg->rx_size = XSK_RING_CONS__DEFAULT_NUM_DESCS; @@ -135,14 +135,19 @@ static void xsk_set_xdp_socket_config(struct xsk_socket_config *cfg, cfg->libbpf_flags = 0; cfg->xdp_flags = 0; cfg->bind_flags = 0; - return; + return 0; } + if (usr_cfg->libbpf_flags & ~XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD) + return -EINVAL; + cfg->rx_size = usr_cfg->rx_size; cfg->tx_size = usr_cfg->tx_size; cfg->libbpf_flags = usr_cfg->libbpf_flags; cfg->xdp_flags = usr_cfg->xdp_flags; cfg->bind_flags = usr_cfg->bind_flags; + + return 0; } int xsk_umem__create(struct xsk_umem **umem_ptr, void *umem_area, __u64 size, @@ -557,7 +562,9 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname, } strncpy(xsk->ifname, ifname, IFNAMSIZ); - xsk_set_xdp_socket_config(&xsk->config, usr_config); + err = xsk_set_xdp_socket_config(&xsk->config, usr_config); + if (err) + goto out_socket; if (rx) { err = setsockopt(xsk->fd, SOL_XDP, XDP_RX_RING, -- cgit v1.2.3 From 9768095ba97ce946838e8210f0b44f2fd36ec31d Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Sun, 10 Mar 2019 17:44:09 -0700 Subject: btf: resolve enum fwds in btf_dedup GCC and clang support enum forward declarations as an extension. Such forward-declared enums will be represented as normal BTF_KIND_ENUM types with vlen=0. This patch adds ability to resolve such enums to their corresponding fully defined enums. This helps to avoid duplicated BTF type graphs which only differ by some types referencing forward-declared enum vs full enum. One such example in kernel is enum irqchip_irq_state, defined in include/linux/interrupt.h and forward-declared in include/linux/irq.h. This causes entire struct task_struct and all referenced types to be duplicated in btf_dedup output. This patch eliminates such duplication cases. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/btf.c | 51 ++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 38 insertions(+), 13 deletions(-) (limited to 'tools/lib') diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 1b8d8cdd3575..87e3020ac1bc 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -1602,16 +1602,12 @@ static bool btf_equal_int(struct btf_type *t1, struct btf_type *t2) /* Calculate type signature hash of ENUM. */ static __u32 btf_hash_enum(struct btf_type *t) { - struct btf_enum *member = (struct btf_enum *)(t + 1); - __u32 vlen = BTF_INFO_VLEN(t->info); - __u32 h = btf_hash_common(t); - int i; + __u32 h; - for (i = 0; i < vlen; i++) { - h = hash_combine(h, member->name_off); - h = hash_combine(h, member->val); - member++; - } + /* don't hash vlen and enum members to support enum fwd resolving */ + h = hash_combine(0, t->name_off); + h = hash_combine(h, t->info & ~0xffff); + h = hash_combine(h, t->size); return h; } @@ -1637,6 +1633,22 @@ static bool btf_equal_enum(struct btf_type *t1, struct btf_type *t2) return true; } +static inline bool btf_is_enum_fwd(struct btf_type *t) +{ + return BTF_INFO_KIND(t->info) == BTF_KIND_ENUM && + BTF_INFO_VLEN(t->info) == 0; +} + +static bool btf_compat_enum(struct btf_type *t1, struct btf_type *t2) +{ + if (!btf_is_enum_fwd(t1) && !btf_is_enum_fwd(t2)) + return btf_equal_enum(t1, t2); + /* ignore vlen when comparing */ + return t1->name_off == t2->name_off && + (t1->info & ~0xffff) == (t2->info & ~0xffff) && + t1->size == t2->size; +} + /* * Calculate type signature hash of STRUCT/UNION, ignoring referenced type IDs, * as referenced type IDs equivalence is established separately during type @@ -1860,6 +1872,17 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id) new_id = cand_node->type_id; break; } + if (d->opts.dont_resolve_fwds) + continue; + if (btf_compat_enum(t, cand)) { + if (btf_is_enum_fwd(t)) { + /* resolve fwd to full enum */ + new_id = cand_node->type_id; + break; + } + /* resolve canonical enum fwd to full enum */ + d->map[cand_node->type_id] = type_id; + } } break; @@ -2084,15 +2107,15 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id, return fwd_kind == real_kind; } - if (cand_type->info != canon_type->info) - return 0; - switch (cand_kind) { case BTF_KIND_INT: return btf_equal_int(cand_type, canon_type); case BTF_KIND_ENUM: - return btf_equal_enum(cand_type, canon_type); + if (d->opts.dont_resolve_fwds) + return btf_equal_enum(cand_type, canon_type); + else + return btf_compat_enum(cand_type, canon_type); case BTF_KIND_FWD: return btf_equal_common(cand_type, canon_type); @@ -2103,6 +2126,8 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id, case BTF_KIND_PTR: case BTF_KIND_TYPEDEF: case BTF_KIND_FUNC: + if (cand_type->info != canon_type->info) + return 0; return btf_dedup_is_equiv(d, cand_type->type, canon_type->type); case BTF_KIND_ARRAY: { -- cgit v1.2.3 From 1d382264d911d91a8be5dbed1f0e053eb3245d81 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Sat, 23 Mar 2019 01:49:10 +0100 Subject: bpf, libbpf: fix version info and add it to shared object Even though libbpf's versioning script for the linker (libbpf.map) is pointing to 0.0.2, the BPF_EXTRAVERSION in the Makefile has not been updated along with it and is therefore still on 0.0.1. While fixing up, I also noticed that the generated shared object versioning information is missing, typical convention is to have a linker name (libbpf.so), soname (libbpf.so.0) and real name (libbpf.so.0.0.2) for library management. This is based upon the LIBBPF_VERSION as well. The build will then produce the following bpf libraries: # ll libbpf* libbpf.a libbpf.so -> libbpf.so.0.0.2 libbpf.so.0 -> libbpf.so.0.0.2 libbpf.so.0.0.2 # readelf -d libbpf.so.0.0.2 | grep SONAME 0x000000000000000e (SONAME) Library soname: [libbpf.so.0] And install them accordingly: # rm -rf /tmp/bld; mkdir /tmp/bld; make -j$(nproc) O=/tmp/bld install Auto-detecting system features: ... libelf: [ on ] ... bpf: [ on ] CC /tmp/bld/libbpf.o CC /tmp/bld/bpf.o CC /tmp/bld/nlattr.o CC /tmp/bld/btf.o CC /tmp/bld/libbpf_errno.o CC /tmp/bld/str_error.o CC /tmp/bld/netlink.o CC /tmp/bld/bpf_prog_linfo.o CC /tmp/bld/libbpf_probes.o CC /tmp/bld/xsk.o LD /tmp/bld/libbpf-in.o LINK /tmp/bld/libbpf.a LINK /tmp/bld/libbpf.so.0.0.2 LINK /tmp/bld/test_libbpf INSTALL /tmp/bld/libbpf.a INSTALL /tmp/bld/libbpf.so.0.0.2 # ll /usr/local/lib64/libbpf.* /usr/local/lib64/libbpf.a /usr/local/lib64/libbpf.so -> libbpf.so.0.0.2 /usr/local/lib64/libbpf.so.0 -> libbpf.so.0.0.2 /usr/local/lib64/libbpf.so.0.0.2 Fixes: 1bf4b05810fe ("tools: bpftool: add probes for eBPF program types") Fixes: 1b76c13e4b36 ("bpf tools: Introduce 'bpf' library and add bpf feature check") Reported-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/Makefile | 42 ++++++++++++++++++++++++++++-------------- 1 file changed, 28 insertions(+), 14 deletions(-) (limited to 'tools/lib') diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index 61aaacf0cfa1..5bf8e52c41fc 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -3,7 +3,7 @@ BPF_VERSION = 0 BPF_PATCHLEVEL = 0 -BPF_EXTRAVERSION = 1 +BPF_EXTRAVERSION = 2 MAKEFLAGS += --no-print-directory @@ -79,8 +79,6 @@ export prefix libdir src obj libdir_SQ = $(subst ','\'',$(libdir)) libdir_relative_SQ = $(subst ','\'',$(libdir_relative)) -LIB_FILE = libbpf.a libbpf.so - VERSION = $(BPF_VERSION) PATCHLEVEL = $(BPF_PATCHLEVEL) EXTRAVERSION = $(BPF_EXTRAVERSION) @@ -88,7 +86,10 @@ EXTRAVERSION = $(BPF_EXTRAVERSION) OBJ = $@ N = -LIBBPF_VERSION = $(BPF_VERSION).$(BPF_PATCHLEVEL).$(BPF_EXTRAVERSION) +LIBBPF_VERSION = $(BPF_VERSION).$(BPF_PATCHLEVEL).$(BPF_EXTRAVERSION) + +LIB_TARGET = libbpf.a libbpf.so.$(LIBBPF_VERSION) +LIB_FILE = libbpf.a libbpf.so* # Set compile option CFLAGS ifdef EXTRA_CFLAGS @@ -128,16 +129,18 @@ all: export srctree OUTPUT CC LD CFLAGS V include $(srctree)/tools/build/Makefile.include -BPF_IN := $(OUTPUT)libbpf-in.o -LIB_FILE := $(addprefix $(OUTPUT),$(LIB_FILE)) -VERSION_SCRIPT := libbpf.map +BPF_IN := $(OUTPUT)libbpf-in.o +VERSION_SCRIPT := libbpf.map + +LIB_TARGET := $(addprefix $(OUTPUT),$(LIB_TARGET)) +LIB_FILE := $(addprefix $(OUTPUT),$(LIB_FILE)) GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN) | \ awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {s++} END{print s}') VERSIONED_SYM_COUNT = $(shell readelf -s --wide $(OUTPUT)libbpf.so | \ grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u | wc -l) -CMD_TARGETS = $(LIB_FILE) +CMD_TARGETS = $(LIB_TARGET) CXX_TEST_TARGET = $(OUTPUT)test_libbpf @@ -170,9 +173,13 @@ $(BPF_IN): force elfdep bpfdep echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/if_xdp.h' differs from latest version at 'include/uapi/linux/if_xdp.h'" >&2 )) || true $(Q)$(MAKE) $(build)=libbpf -$(OUTPUT)libbpf.so: $(BPF_IN) - $(QUIET_LINK)$(CC) --shared -Wl,--version-script=$(VERSION_SCRIPT) \ - $^ -o $@ +$(OUTPUT)libbpf.so: $(OUTPUT)libbpf.so.$(LIBBPF_VERSION) + +$(OUTPUT)libbpf.so.$(LIBBPF_VERSION): $(BPF_IN) + $(QUIET_LINK)$(CC) --shared -Wl,-soname,libbpf.so.$(VERSION) \ + -Wl,--version-script=$(VERSION_SCRIPT) $^ -o $@ + @ln -sf $(@F) $(OUTPUT)libbpf.so + @ln -sf $(@F) $(OUTPUT)libbpf.so.$(VERSION) $(OUTPUT)libbpf.a: $(BPF_IN) $(QUIET_LINK)$(RM) $@; $(AR) rcs $@ $^ @@ -192,6 +199,12 @@ check_abi: $(OUTPUT)libbpf.so exit 1; \ fi +define do_install_mkdir + if [ ! -d '$(DESTDIR_SQ)$1' ]; then \ + $(INSTALL) -d -m 755 '$(DESTDIR_SQ)$1'; \ + fi +endef + define do_install if [ ! -d '$(DESTDIR_SQ)$2' ]; then \ $(INSTALL) -d -m 755 '$(DESTDIR_SQ)$2'; \ @@ -200,8 +213,9 @@ define do_install endef install_lib: all_cmd - $(call QUIET_INSTALL, $(LIB_FILE)) \ - $(call do_install,$(LIB_FILE),$(libdir_SQ)) + $(call QUIET_INSTALL, $(LIB_TARGET)) \ + $(call do_install_mkdir,$(libdir_SQ)); \ + cp -fpR $(LIB_FILE) $(DESTDIR)$(libdir_SQ) install_headers: $(call QUIET_INSTALL, headers) \ @@ -219,7 +233,7 @@ config-clean: clean: $(call QUIET_CLEAN, libbpf) $(RM) $(TARGETS) $(CXX_TEST_TARGET) \ - *.o *~ *.a *.so .*.d .*.cmd LIBBPF-CFLAGS + *.o *~ *.a *.so *.so.$(VERSION) .*.d .*.cmd LIBBPF-CFLAGS $(call QUIET_CLEAN, core-gen) $(RM) $(OUTPUT)FEATURE-DUMP.libbpf -- cgit v1.2.3 From 63197f78bca2d86093126783b0ee6519bd652435 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Sat, 23 Mar 2019 01:49:11 +0100 Subject: bpf, libbpf: clarify bump in libbpf version info The current documentation suggests that we would need to bump the libbpf version on every change. Lets clarify this a bit more and reflect what we do today in practice, that is, bumping it once per development cycle. Fixes: 76d1b894c515 ("libbpf: Document API and ABI conventions") Reported-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/README.rst | 1 + 1 file changed, 1 insertion(+) (limited to 'tools/lib') diff --git a/tools/lib/bpf/README.rst b/tools/lib/bpf/README.rst index 5788479384ca..cef7b77eab69 100644 --- a/tools/lib/bpf/README.rst +++ b/tools/lib/bpf/README.rst @@ -111,6 +111,7 @@ starting from ``0.0.1``. Every time ABI is being changed, e.g. because a new symbol is added or semantic of existing symbol is changed, ABI version should be bumped. +This bump in ABI version is at most once per kernel development cycle. For example, if current state of ``libbpf.map`` is: -- cgit v1.2.3