From 775bc8ada89b376b4bbbce31aba47f4117fe1d9c Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Fri, 24 May 2019 11:36:46 +0100 Subject: [PATCH 1/3] tools: bpftool: add -d option to get debug output from libbpf libbpf has three levels of priority for output messages: warn, info, debug. By default, debug output is not printed to the console. Add a new "--debug" (short name: "-d") option to bpftool to print libbpf logs for all three levels. Internally, we simply use the function provided by libbpf to replace the default printing function by one that prints logs regardless of their level. v2: - Remove the possibility to select the log-levels to use (v1 offered a combination of "warn", "info" and "debug"). - Rename option and offer a short name: -d|--debug. - Add option description to all bpftool manual pages (instead of bpftool-prog.rst only), as all commands use libbpf. Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- tools/bpf/bpftool/Documentation/bpftool-btf.rst | 4 ++++ tools/bpf/bpftool/Documentation/bpftool-cgroup.rst | 4 ++++ .../bpf/bpftool/Documentation/bpftool-feature.rst | 4 ++++ tools/bpf/bpftool/Documentation/bpftool-map.rst | 4 ++++ tools/bpf/bpftool/Documentation/bpftool-net.rst | 4 ++++ tools/bpf/bpftool/Documentation/bpftool-perf.rst | 4 ++++ tools/bpf/bpftool/Documentation/bpftool-prog.rst | 4 ++++ tools/bpf/bpftool/Documentation/bpftool.rst | 3 +++ tools/bpf/bpftool/bash-completion/bpftool | 2 +- tools/bpf/bpftool/main.c | 14 +++++++++++++- 10 files changed, 45 insertions(+), 2 deletions(-) diff --git a/tools/bpf/bpftool/Documentation/bpftool-btf.rst b/tools/bpf/bpftool/Documentation/bpftool-btf.rst index 3daed9eba766b..6694a0fc8f99d 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-btf.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-btf.rst @@ -72,6 +72,10 @@ OPTIONS -p, --pretty Generate human-readable JSON output. Implies **-j**. + -d, --debug + Print all logs available from libbpf, including debug-level + information. + EXAMPLES ======== **# bpftool btf dump id 1226** diff --git a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst index ac26876389c23..36807735e2a5e 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst @@ -113,6 +113,10 @@ OPTIONS -f, --bpffs Show file names of pinned programs. + -d, --debug + Print all logs available from libbpf, including debug-level + information. + EXAMPLES ======== | diff --git a/tools/bpf/bpftool/Documentation/bpftool-feature.rst b/tools/bpf/bpftool/Documentation/bpftool-feature.rst index 14180e8870824..4d08f35034a2e 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-feature.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-feature.rst @@ -73,6 +73,10 @@ OPTIONS -p, --pretty Generate human-readable JSON output. Implies **-j**. + -d, --debug + Print all logs available from libbpf, including debug-level + information. + SEE ALSO ======== **bpf**\ (2), diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst index 13ef27b39f200..490b4501cb6ee 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-map.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst @@ -152,6 +152,10 @@ OPTIONS Do not automatically attempt to mount any virtual file system (such as tracefs or BPF virtual file system) when necessary. + -d, --debug + Print all logs available from libbpf, including debug-level + information. + EXAMPLES ======== **# bpftool map show** diff --git a/tools/bpf/bpftool/Documentation/bpftool-net.rst b/tools/bpf/bpftool/Documentation/bpftool-net.rst index 934580850f42b..d8e5237a20859 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-net.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-net.rst @@ -65,6 +65,10 @@ OPTIONS -p, --pretty Generate human-readable JSON output. Implies **-j**. + -d, --debug + Print all logs available from libbpf, including debug-level + information. + EXAMPLES ======== diff --git a/tools/bpf/bpftool/Documentation/bpftool-perf.rst b/tools/bpf/bpftool/Documentation/bpftool-perf.rst index 0c7576523a217..e252bd0bc4343 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-perf.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-perf.rst @@ -53,6 +53,10 @@ OPTIONS -p, --pretty Generate human-readable JSON output. Implies **-j**. + -d, --debug + Print all logs available from libbpf, including debug-level + information. + EXAMPLES ======== diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst index e8118544d1182..9a92614569e64 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst @@ -174,6 +174,10 @@ OPTIONS Do not automatically attempt to mount any virtual file system (such as tracefs or BPF virtual file system) when necessary. + -d, --debug + Print all logs available from libbpf, including debug-level + information. + EXAMPLES ======== **# bpftool prog show** diff --git a/tools/bpf/bpftool/Documentation/bpftool.rst b/tools/bpf/bpftool/Documentation/bpftool.rst index 3e562d7fd56f9..43dba07179534 100644 --- a/tools/bpf/bpftool/Documentation/bpftool.rst +++ b/tools/bpf/bpftool/Documentation/bpftool.rst @@ -66,6 +66,9 @@ OPTIONS Do not automatically attempt to mount any virtual file system (such as tracefs or BPF virtual file system) when necessary. + -d, --debug + Print all logs available from libbpf, including debug-level + information. SEE ALSO ======== diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool index fbbad0ed8e823..2725e27dfa42e 100644 --- a/tools/bpf/bpftool/bash-completion/bpftool +++ b/tools/bpf/bpftool/bash-completion/bpftool @@ -187,7 +187,7 @@ _bpftool() # Deal with options if [[ ${words[cword]} == -* ]]; then - local c='--version --json --pretty --bpffs --mapcompat' + local c='--version --json --pretty --bpffs --mapcompat --debug' COMPREPLY=( $( compgen -W "$c" -- "$cur" ) ) return 0 fi diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c index 1ac1fc520e6ab..d74293938a05c 100644 --- a/tools/bpf/bpftool/main.c +++ b/tools/bpf/bpftool/main.c @@ -10,6 +10,7 @@ #include #include +#include #include "main.h" @@ -77,6 +78,13 @@ static int do_version(int argc, char **argv) return 0; } +static int __printf(2, 0) +print_all_levels(__maybe_unused enum libbpf_print_level level, + const char *format, va_list args) +{ + return vfprintf(stderr, format, args); +} + int cmd_select(const struct cmd *cmds, int argc, char **argv, int (*help)(int argc, char **argv)) { @@ -317,6 +325,7 @@ int main(int argc, char **argv) { "bpffs", no_argument, NULL, 'f' }, { "mapcompat", no_argument, NULL, 'm' }, { "nomount", no_argument, NULL, 'n' }, + { "debug", no_argument, NULL, 'd' }, { 0 } }; int opt, ret; @@ -332,7 +341,7 @@ int main(int argc, char **argv) hash_init(map_table.table); opterr = 0; - while ((opt = getopt_long(argc, argv, "Vhpjfmn", + while ((opt = getopt_long(argc, argv, "Vhpjfmnd", options, NULL)) >= 0) { switch (opt) { case 'V': @@ -362,6 +371,9 @@ int main(int argc, char **argv) case 'n': block_mount = true; break; + case 'd': + libbpf_set_print(print_all_levels); + break; default: p_err("unrecognized option '%s'", argv[optind - 1]); if (json_output) From 60276f9849988d3d3a54943c9ec27222c5819dae Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Fri, 24 May 2019 11:36:47 +0100 Subject: [PATCH 2/3] libbpf: add bpf_object__load_xattr() API function to pass log_level libbpf was recently made aware of the log_level attribute for programs, used to specify the level of information expected to be dumped by the verifier. Function bpf_prog_load_xattr() got support for this log_level parameter. But some applications using libbpf rely on another function to load programs, bpf_object__load(), which does accept any parameter for log level. Create an API function based on bpf_object__load(), but accepting an "attr" object as a parameter. Then add a log_level field to that object, so that applications calling the new bpf_object__load_xattr() can pick the desired log level. v3: - Rewrite commit log. v2: - We are in a new cycle, bump libbpf extraversion number. Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- tools/lib/bpf/Makefile | 2 +- tools/lib/bpf/libbpf.c | 20 +++++++++++++++++--- tools/lib/bpf/libbpf.h | 6 ++++++ tools/lib/bpf/libbpf.map | 1 + 4 files changed, 25 insertions(+), 4 deletions(-) diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index a2aceadf68db5..9312066a1ae38 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -3,7 +3,7 @@ BPF_VERSION = 0 BPF_PATCHLEVEL = 0 -BPF_EXTRAVERSION = 3 +BPF_EXTRAVERSION = 4 MAKEFLAGS += --no-print-directory diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index fd5905ac2ec37..ca4432f5b067e 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -2224,7 +2224,7 @@ static bool bpf_program__is_function_storage(struct bpf_program *prog, } static int -bpf_object__load_progs(struct bpf_object *obj) +bpf_object__load_progs(struct bpf_object *obj, int log_level) { size_t i; int err; @@ -2232,6 +2232,7 @@ bpf_object__load_progs(struct bpf_object *obj) for (i = 0; i < obj->nr_programs; i++) { if (bpf_program__is_function_storage(&obj->programs[i], obj)) continue; + obj->programs[i].log_level = log_level; err = bpf_program__load(&obj->programs[i], obj->license, obj->kern_version); @@ -2383,10 +2384,14 @@ int bpf_object__unload(struct bpf_object *obj) return 0; } -int bpf_object__load(struct bpf_object *obj) +int bpf_object__load_xattr(struct bpf_object_load_attr *attr) { + struct bpf_object *obj; int err; + if (!attr) + return -EINVAL; + obj = attr->obj; if (!obj) return -EINVAL; @@ -2399,7 +2404,7 @@ int bpf_object__load(struct bpf_object *obj) CHECK_ERR(bpf_object__create_maps(obj), err, out); CHECK_ERR(bpf_object__relocate(obj), err, out); - CHECK_ERR(bpf_object__load_progs(obj), err, out); + CHECK_ERR(bpf_object__load_progs(obj, attr->log_level), err, out); return 0; out: @@ -2408,6 +2413,15 @@ int bpf_object__load(struct bpf_object *obj) return err; } +int bpf_object__load(struct bpf_object *obj) +{ + struct bpf_object_load_attr attr = { + .obj = obj, + }; + + return bpf_object__load_xattr(&attr); +} + static int check_path(const char *path) { char *cp, errmsg[STRERR_BUFSIZE]; diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 5abc2375defd6..1af0d48178c8a 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -89,8 +89,14 @@ LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj, LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path); LIBBPF_API void bpf_object__close(struct bpf_object *object); +struct bpf_object_load_attr { + struct bpf_object *obj; + int log_level; +}; + /* Load/unload object into/from kernel */ LIBBPF_API int bpf_object__load(struct bpf_object *obj); +LIBBPF_API int bpf_object__load_xattr(struct bpf_object_load_attr *attr); LIBBPF_API int bpf_object__unload(struct bpf_object *obj); LIBBPF_API const char *bpf_object__name(struct bpf_object *obj); LIBBPF_API unsigned int bpf_object__kversion(struct bpf_object *obj); diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 8bf51d0a6072a..46dcda89df211 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -171,4 +171,5 @@ LIBBPF_0.0.4 { btf_dump__free; btf_dump__new; btf__parse_elf; + bpf_object__load_xattr; } LIBBPF_0.0.3; From 55d778076b0354b088a9a16d9ff584c887e17f42 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Fri, 24 May 2019 11:36:48 +0100 Subject: [PATCH 3/3] tools: bpftool: make -d option print debug output from verifier The "-d" option is used to require all logs available for bpftool. So far it meant telling libbpf to print even debug-level information. But there is another source of info that can be made more verbose: when we attemt to load programs with bpftool, we can pass a log_level parameter to the verifier in order to control the amount of information that is printed to the console. Reuse the "-d" option to print all information the verifier can tell. At this time, this means logs related to BPF_LOG_LEVEL1, BPF_LOG_LEVEL2 and BPF_LOG_STATS. As mentioned in the discussion on the first version of this set, these macros are internal to the kernel (include/linux/bpf_verifier.h) and are not meant to be part of the stable user API, therefore we simply use the related constants to print whatever we can at this time, without trying to tell users what is log_level1 or what is statistics. Verifier logs are only used when loading programs for now (In the future: for loading BTF objects with bpftool? Although libbpf does not currently offer to print verifier info at debug level if no error occurred when loading BTF objects), so bpftool.rst and bpftool-prog.rst are the only man pages to get the update. v3: - Add details on log level and BTF loading at the end of commit log. v2: - Remove the possibility to select the log levels to use (v1 offered a combination of "log_level1", "log_level2" and "stats"). - The macros from kernel header bpf_verifier.h are not used (and therefore not moved to UAPI header). - In v1 this was a distinct option, but is now merged in the only "-d" switch to activate libbpf and verifier debug-level logs all at the same time. Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- .../bpftool/Documentation/bpftool-prog.rst | 5 ++-- tools/bpf/bpftool/Documentation/bpftool.rst | 5 ++-- tools/bpf/bpftool/main.c | 2 ++ tools/bpf/bpftool/main.h | 1 + tools/bpf/bpftool/prog.c | 27 ++++++++++++------- 5 files changed, 26 insertions(+), 14 deletions(-) diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst index 9a92614569e64..228a5c863cc75 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst @@ -175,8 +175,9 @@ OPTIONS (such as tracefs or BPF virtual file system) when necessary. -d, --debug - Print all logs available from libbpf, including debug-level - information. + Print all logs available, even debug-level information. This + includes logs from libbpf as well as from the verifier, when + attempting to load programs. EXAMPLES ======== diff --git a/tools/bpf/bpftool/Documentation/bpftool.rst b/tools/bpf/bpftool/Documentation/bpftool.rst index 43dba07179534..6a9c52ef84a9e 100644 --- a/tools/bpf/bpftool/Documentation/bpftool.rst +++ b/tools/bpf/bpftool/Documentation/bpftool.rst @@ -67,8 +67,9 @@ OPTIONS (such as tracefs or BPF virtual file system) when necessary. -d, --debug - Print all logs available from libbpf, including debug-level - information. + Print all logs available, even debug-level information. This + includes logs from libbpf as well as from the verifier, when + attempting to load programs. SEE ALSO ======== diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c index d74293938a05c..4879f6395c7e2 100644 --- a/tools/bpf/bpftool/main.c +++ b/tools/bpf/bpftool/main.c @@ -26,6 +26,7 @@ bool pretty_output; bool json_output; bool show_pinned; bool block_mount; +bool verifier_logs; int bpf_flags; struct pinned_obj_table prog_table; struct pinned_obj_table map_table; @@ -373,6 +374,7 @@ int main(int argc, char **argv) break; case 'd': libbpf_set_print(print_all_levels); + verifier_logs = true; break; default: p_err("unrecognized option '%s'", argv[optind - 1]); diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index 3d63feb7f852f..28a2a5857e141 100644 --- a/tools/bpf/bpftool/main.h +++ b/tools/bpf/bpftool/main.h @@ -91,6 +91,7 @@ extern json_writer_t *json_wtr; extern bool json_output; extern bool show_pinned; extern bool block_mount; +extern bool verifier_logs; extern int bpf_flags; extern struct pinned_obj_table prog_table; extern struct pinned_obj_table map_table; diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index 26336bad04427..1f209c80d906e 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -750,10 +750,11 @@ static int do_detach(int argc, char **argv) static int load_with_options(int argc, char **argv, bool first_prog_only) { - enum bpf_attach_type expected_attach_type; - struct bpf_object_open_attr attr = { - .prog_type = BPF_PROG_TYPE_UNSPEC, + struct bpf_object_load_attr load_attr = { 0 }; + struct bpf_object_open_attr open_attr = { + .prog_type = BPF_PROG_TYPE_UNSPEC, }; + enum bpf_attach_type expected_attach_type; struct map_replace *map_replace = NULL; struct bpf_program *prog = NULL, *pos; unsigned int old_map_fds = 0; @@ -767,7 +768,7 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) if (!REQ_ARGS(2)) return -1; - attr.file = GET_ARG(); + open_attr.file = GET_ARG(); pinfile = GET_ARG(); while (argc) { @@ -776,7 +777,7 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) NEXT_ARG(); - if (attr.prog_type != BPF_PROG_TYPE_UNSPEC) { + if (open_attr.prog_type != BPF_PROG_TYPE_UNSPEC) { p_err("program type already specified"); goto err_free_reuse_maps; } @@ -793,7 +794,8 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) strcat(type, *argv); strcat(type, "/"); - err = libbpf_prog_type_by_name(type, &attr.prog_type, + err = libbpf_prog_type_by_name(type, + &open_attr.prog_type, &expected_attach_type); free(type); if (err < 0) @@ -881,16 +883,16 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) set_max_rlimit(); - obj = __bpf_object__open_xattr(&attr, bpf_flags); + obj = __bpf_object__open_xattr(&open_attr, bpf_flags); if (IS_ERR_OR_NULL(obj)) { p_err("failed to open object file"); goto err_free_reuse_maps; } bpf_object__for_each_program(pos, obj) { - enum bpf_prog_type prog_type = attr.prog_type; + enum bpf_prog_type prog_type = open_attr.prog_type; - if (attr.prog_type == BPF_PROG_TYPE_UNSPEC) { + if (open_attr.prog_type == BPF_PROG_TYPE_UNSPEC) { const char *sec_name = bpf_program__title(pos, false); err = libbpf_prog_type_by_name(sec_name, &prog_type, @@ -960,7 +962,12 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) goto err_close_obj; } - err = bpf_object__load(obj); + load_attr.obj = obj; + if (verifier_logs) + /* log_level1 + log_level2 + stats, but not stable UAPI */ + load_attr.log_level = 1 + 2 + 4; + + err = bpf_object__load_xattr(&load_attr); if (err) { p_err("failed to load object file"); goto err_close_obj;