From a77f879ba1178437e5df87090165e5a45a91ba7f Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Thu, 21 Oct 2021 14:48:12 -0700 Subject: [PATCH 1/2] libbpf: Use func name when pinning programs with LIBBPF_STRICT_SEC_NAME We can't use section name anymore because they are not unique and pinning objects with multiple programs with the same progtype/secname will fail. [0] Closes: https://github.com/libbpf/libbpf/issues/273 Fixes: 33a2c75c55e2 ("libbpf: add internal pin_name") Signed-off-by: Stanislav Fomichev Signed-off-by: Andrii Nakryiko Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20211021214814.1236114-2-sdf@google.com --- tools/lib/bpf/libbpf.c | 13 +++++++++++-- tools/lib/bpf/libbpf_legacy.h | 3 +++ 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index eb102440a28a..604abe00785f 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -285,7 +285,7 @@ struct bpf_program { size_t sub_insn_off; char *name; - /* sec_name with / replaced by _; makes recursive pinning + /* name with / replaced by _; makes recursive pinning * in bpf_object__pin_programs easier */ char *pin_name; @@ -618,7 +618,16 @@ static char *__bpf_program__pin_name(struct bpf_program *prog) { char *name, *p; - name = p = strdup(prog->sec_name); + if (libbpf_mode & LIBBPF_STRICT_SEC_NAME) + name = strdup(prog->name); + else + name = strdup(prog->sec_name); + + if (!name) + return NULL; + + p = name; + while ((p = strchr(p, '/'))) *p = '_'; diff --git a/tools/lib/bpf/libbpf_legacy.h b/tools/lib/bpf/libbpf_legacy.h index 74e6f860f703..29ccafab11a8 100644 --- a/tools/lib/bpf/libbpf_legacy.h +++ b/tools/lib/bpf/libbpf_legacy.h @@ -52,6 +52,9 @@ enum libbpf_strict_mode { * allowed, with LIBBPF_STRICT_SEC_PREFIX this will become * unrecognized by libbpf and would have to be just SEC("xdp") and * SEC("xdp") and SEC("perf_event"). + * + * Note, in this mode the program pin path will be based on the + * function name instead of section name. */ LIBBPF_STRICT_SEC_NAME = 0x04, From d1321207b176b0a5a8004b371ade5a0d8dec7732 Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Thu, 21 Oct 2021 14:48:14 -0700 Subject: [PATCH 2/2] selftests/bpf: Fix flow dissector tests - update custom loader to search by name, not section name - update bpftool commands to use proper pin path Signed-off-by: Stanislav Fomichev Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211021214814.1236114-4-sdf@google.com --- .../selftests/bpf/flow_dissector_load.c | 18 +++++++++++------- .../selftests/bpf/flow_dissector_load.h | 10 ++-------- .../selftests/bpf/test_flow_dissector.sh | 10 +++++----- 3 files changed, 18 insertions(+), 20 deletions(-) diff --git a/tools/testing/selftests/bpf/flow_dissector_load.c b/tools/testing/selftests/bpf/flow_dissector_load.c index 3fd83b9dc1bf..87fd1aa323a9 100644 --- a/tools/testing/selftests/bpf/flow_dissector_load.c +++ b/tools/testing/selftests/bpf/flow_dissector_load.c @@ -17,7 +17,7 @@ const char *cfg_pin_path = "/sys/fs/bpf/flow_dissector"; const char *cfg_map_name = "jmp_table"; bool cfg_attach = true; -char *cfg_section_name; +char *cfg_prog_name; char *cfg_path_name; static void load_and_attach_program(void) @@ -25,7 +25,11 @@ static void load_and_attach_program(void) int prog_fd, ret; struct bpf_object *obj; - ret = bpf_flow_load(&obj, cfg_path_name, cfg_section_name, + ret = libbpf_set_strict_mode(LIBBPF_STRICT_ALL); + if (ret) + error(1, 0, "failed to enable libbpf strict mode: %d", ret); + + ret = bpf_flow_load(&obj, cfg_path_name, cfg_prog_name, cfg_map_name, NULL, &prog_fd, NULL); if (ret) error(1, 0, "bpf_flow_load %s", cfg_path_name); @@ -75,15 +79,15 @@ static void parse_opts(int argc, char **argv) break; case 'p': if (cfg_path_name) - error(1, 0, "only one prog name can be given"); + error(1, 0, "only one path can be given"); cfg_path_name = optarg; break; case 's': - if (cfg_section_name) - error(1, 0, "only one section can be given"); + if (cfg_prog_name) + error(1, 0, "only one prog can be given"); - cfg_section_name = optarg; + cfg_prog_name = optarg; break; } } @@ -94,7 +98,7 @@ static void parse_opts(int argc, char **argv) if (cfg_attach && !cfg_path_name) error(1, 0, "must provide a path to the BPF program"); - if (cfg_attach && !cfg_section_name) + if (cfg_attach && !cfg_prog_name) error(1, 0, "must provide a section name"); } diff --git a/tools/testing/selftests/bpf/flow_dissector_load.h b/tools/testing/selftests/bpf/flow_dissector_load.h index 7290401ec172..9d0acc2fc6cc 100644 --- a/tools/testing/selftests/bpf/flow_dissector_load.h +++ b/tools/testing/selftests/bpf/flow_dissector_load.h @@ -7,7 +7,7 @@ static inline int bpf_flow_load(struct bpf_object **obj, const char *path, - const char *section_name, + const char *prog_name, const char *map_name, const char *keys_map_name, int *prog_fd, @@ -23,13 +23,7 @@ static inline int bpf_flow_load(struct bpf_object **obj, if (ret) return ret; - main_prog = NULL; - bpf_object__for_each_program(prog, *obj) { - if (strcmp(section_name, bpf_program__section_name(prog)) == 0) { - main_prog = prog; - break; - } - } + main_prog = bpf_object__find_program_by_name(*obj, prog_name); if (!main_prog) return -1; diff --git a/tools/testing/selftests/bpf/test_flow_dissector.sh b/tools/testing/selftests/bpf/test_flow_dissector.sh index 174b72a64a4c..dbd91221727d 100755 --- a/tools/testing/selftests/bpf/test_flow_dissector.sh +++ b/tools/testing/selftests/bpf/test_flow_dissector.sh @@ -26,22 +26,22 @@ if [[ -z $(ip netns identify $$) ]]; then type flow_dissector if ! unshare --net $bpftool prog attach pinned \ - /sys/fs/bpf/flow/flow_dissector flow_dissector; then + /sys/fs/bpf/flow/_dissect flow_dissector; then echo "Unexpected unsuccessful attach in namespace" >&2 err=1 fi - $bpftool prog attach pinned /sys/fs/bpf/flow/flow_dissector \ + $bpftool prog attach pinned /sys/fs/bpf/flow/_dissect \ flow_dissector if unshare --net $bpftool prog attach pinned \ - /sys/fs/bpf/flow/flow_dissector flow_dissector; then + /sys/fs/bpf/flow/_dissect flow_dissector; then echo "Unexpected successful attach in namespace" >&2 err=1 fi if ! $bpftool prog detach pinned \ - /sys/fs/bpf/flow/flow_dissector flow_dissector; then + /sys/fs/bpf/flow/_dissect flow_dissector; then echo "Failed to detach flow dissector" >&2 err=1 fi @@ -95,7 +95,7 @@ else fi # Attach BPF program -./flow_dissector_load -p bpf_flow.o -s flow_dissector +./flow_dissector_load -p bpf_flow.o -s _dissect # Setup tc qdisc add dev lo ingress