From 8461ef8b7ef286212ca954d8b82dac3ceecb219d Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Fri, 1 Feb 2019 16:14:14 -0800 Subject: tools/bpf: move libbpf pr_* debug print functions to headers A global function libbpf_print, which is invisible outside the shared library, is defined to print based on levels. The pr_warning, pr_info and pr_debug macros are moved into the newly created header common.h. So any .c file including common.h can use these macros directly. Currently btf__new and btf_ext__new API has an argument getting __pr_debug function pointer into btf.c so the debugging information can be printed there. This patch removed this parameter from btf__new and btf_ext__new and directly using pr_debug in btf.c. Another global function libbpf_print_level_available, also invisible outside the shared library, can test whether a particular level debug printing is available or not. It is used in btf.c to test whether DEBUG level debug printing is availabl or not, based on which the log buffer will be allocated when loading btf to the kernel. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/libbpf.c | 46 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 32 insertions(+), 14 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 03bc01ca2577..eeba77b695ad 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -42,6 +42,7 @@ #include "bpf.h" #include "btf.h" #include "str_error.h" +#include "libbpf_util.h" #ifndef EM_BPF #define EM_BPF 247 @@ -69,16 +70,6 @@ static __printf(1, 2) libbpf_print_fn_t __pr_warning = __base_pr; static __printf(1, 2) libbpf_print_fn_t __pr_info = __base_pr; static __printf(1, 2) libbpf_print_fn_t __pr_debug; -#define __pr(func, fmt, ...) \ -do { \ - if ((func)) \ - (func)("libbpf: " fmt, ##__VA_ARGS__); \ -} while (0) - -#define pr_warning(fmt, ...) __pr(__pr_warning, fmt, ##__VA_ARGS__) -#define pr_info(fmt, ...) __pr(__pr_info, fmt, ##__VA_ARGS__) -#define pr_debug(fmt, ...) __pr(__pr_debug, fmt, ##__VA_ARGS__) - void libbpf_set_print(libbpf_print_fn_t warn, libbpf_print_fn_t info, libbpf_print_fn_t debug) @@ -88,6 +79,35 @@ void libbpf_set_print(libbpf_print_fn_t warn, __pr_debug = debug; } +__printf(2, 3) +void libbpf_print(enum libbpf_print_level level, const char *format, ...) +{ + va_list args; + + va_start(args, format); + if (level == LIBBPF_WARN) { + if (__pr_warning) + __pr_warning(format, args); + } else if (level == LIBBPF_INFO) { + if (__pr_info) + __pr_info(format, args); + } else { + if (__pr_debug) + __pr_debug(format, args); + } + va_end(args); +} + +bool libbpf_print_level_available(enum libbpf_print_level level) +{ + if (level == LIBBPF_WARN) + return !!__pr_warning; + else if (level == LIBBPF_INFO) + return !!__pr_info; + else + return !!__pr_debug; +} + #define STRERR_BUFSIZE 128 #define CHECK_ERR(action, err, out) do { \ @@ -839,8 +859,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) else if (strcmp(name, "maps") == 0) obj->efile.maps_shndx = idx; else if (strcmp(name, BTF_ELF_SEC) == 0) { - obj->btf = btf__new(data->d_buf, data->d_size, - __pr_debug); + obj->btf = btf__new(data->d_buf, data->d_size); if (IS_ERR(obj->btf)) { pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n", BTF_ELF_SEC, PTR_ERR(obj->btf)); @@ -915,8 +934,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) BTF_EXT_ELF_SEC, BTF_ELF_SEC); } else { obj->btf_ext = btf_ext__new(btf_ext_data->d_buf, - btf_ext_data->d_size, - __pr_debug); + btf_ext_data->d_size); if (IS_ERR(obj->btf_ext)) { pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n", BTF_EXT_ELF_SEC, -- cgit v1.2.2 From 9d100a19ffa519b17a0e998918337da5386e47fb Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Fri, 1 Feb 2019 16:14:15 -0800 Subject: tools/bpf: print out btf log at LIBBPF_WARN level Currently, the btf log is allocated and printed out in case of error at LIBBPF_DEBUG level. Such logs from kernel are very important for debugging. For example, bpf syscall BPF_PROG_LOAD command can get verifier logs back to user space. In function load_program() of libbpf.c, the log buffer is allocated unconditionally and printed out at pr_warning() level. Let us do the similar thing here for btf. Allocate buffer unconditionally and print out error logs at pr_warning() level. This can reduce one global function and optimize for common situations where pr_warning() is activated either by default or by user supplied debug output function. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/libbpf.c | 10 ---------- 1 file changed, 10 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index eeba77b695ad..0354af03b038 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -98,16 +98,6 @@ void libbpf_print(enum libbpf_print_level level, const char *format, ...) va_end(args); } -bool libbpf_print_level_available(enum libbpf_print_level level) -{ - if (level == LIBBPF_WARN) - return !!__pr_warning; - else if (level == LIBBPF_INFO) - return !!__pr_info; - else - return !!__pr_debug; -} - #define STRERR_BUFSIZE 128 #define CHECK_ERR(action, err, out) do { \ -- cgit v1.2.2 From 6f1ae8b6628b9e054d3a8c959cf472234944a578 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Fri, 1 Feb 2019 16:14:17 -0800 Subject: tools/bpf: simplify libbpf API function libbpf_set_print() Currently, the libbpf API function libbpf_set_print() takes three function pointer parameters for warning, info and debug printout respectively. This patch changes the API to have just one function pointer parameter and the function pointer has one additional parameter "debugging level". So if in the future, if the debug level is increased, the function signature won't change. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/libbpf.c | 33 ++++++++++++--------------------- 1 file changed, 12 insertions(+), 21 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 0354af03b038..ce209ab9a1a2 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -54,29 +54,26 @@ #define __printf(a, b) __attribute__((format(printf, a, b))) -__printf(1, 2) -static int __base_pr(const char *format, ...) +__printf(2, 3) +static int __base_pr(enum libbpf_print_level level, const char *format, ...) { va_list args; int err; + if (level == LIBBPF_DEBUG) + return 0; + va_start(args, format); err = vfprintf(stderr, format, args); va_end(args); return err; } -static __printf(1, 2) libbpf_print_fn_t __pr_warning = __base_pr; -static __printf(1, 2) libbpf_print_fn_t __pr_info = __base_pr; -static __printf(1, 2) libbpf_print_fn_t __pr_debug; +static __printf(2, 3) libbpf_print_fn_t __libbpf_pr = __base_pr; -void libbpf_set_print(libbpf_print_fn_t warn, - libbpf_print_fn_t info, - libbpf_print_fn_t debug) +void libbpf_set_print(libbpf_print_fn_t fn) { - __pr_warning = warn; - __pr_info = info; - __pr_debug = debug; + __libbpf_pr = fn; } __printf(2, 3) @@ -84,17 +81,11 @@ void libbpf_print(enum libbpf_print_level level, const char *format, ...) { va_list args; + if (!__libbpf_pr) + return; + va_start(args, format); - if (level == LIBBPF_WARN) { - if (__pr_warning) - __pr_warning(format, args); - } else if (level == LIBBPF_INFO) { - if (__pr_info) - __pr_info(format, args); - } else { - if (__pr_debug) - __pr_debug(format, args); - } + __libbpf_pr(level, format, args); va_end(args); } -- cgit v1.2.2 From 96408c43447aff5091a6938f29d8b6f2d0aa2064 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 4 Feb 2019 11:00:58 -0800 Subject: tools/bpf: implement libbpf btf__get_map_kv_tids() API function Currently, to get map key/value type id's, the macro BPF_ANNOTATE_KV_PAIR(, , ) needs to be defined in the bpf program for the corresponding map. During program/map loading time, the local static function bpf_map_find_btf_info() in libbpf.c is implemented to retrieve the key/value type ids given the map name. The patch refactored function bpf_map_find_btf_info() to create an API btf__get_map_kv_tids() which includes the bulk of implementation for the original function. The API btf__get_map_kv_tids() can be used by bcc, a JIT based bpf compilation system, which uses the same BPF_ANNOTATE_KV_PAIR to record map key/value types. Acked-by: Martin KaFai Lau Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/libbpf.c | 72 +++++++------------------------------------------- 1 file changed, 9 insertions(+), 63 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index ce209ab9a1a2..84ca6c2bea91 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1056,72 +1056,18 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf) { - const struct btf_type *container_type; - const struct btf_member *key, *value; struct bpf_map_def *def = &map->def; - const size_t max_name = 256; - char container_name[max_name]; - __s64 key_size, value_size; - __s32 container_id; - - if (snprintf(container_name, max_name, "____btf_map_%s", map->name) == - max_name) { - pr_warning("map:%s length of '____btf_map_%s' is too long\n", - map->name, map->name); - return -EINVAL; - } - - container_id = btf__find_by_name(btf, container_name); - if (container_id < 0) { - pr_debug("map:%s container_name:%s cannot be found in BTF. Missing BPF_ANNOTATE_KV_PAIR?\n", - map->name, container_name); - return container_id; - } - - container_type = btf__type_by_id(btf, container_id); - if (!container_type) { - pr_warning("map:%s cannot find BTF type for container_id:%u\n", - map->name, container_id); - return -EINVAL; - } - - if (BTF_INFO_KIND(container_type->info) != BTF_KIND_STRUCT || - BTF_INFO_VLEN(container_type->info) < 2) { - pr_warning("map:%s container_name:%s is an invalid container struct\n", - map->name, container_name); - return -EINVAL; - } - - key = (struct btf_member *)(container_type + 1); - value = key + 1; - - key_size = btf__resolve_size(btf, key->type); - if (key_size < 0) { - pr_warning("map:%s invalid BTF key_type_size\n", - map->name); - return key_size; - } - - if (def->key_size != key_size) { - pr_warning("map:%s btf_key_type_size:%u != map_def_key_size:%u\n", - map->name, (__u32)key_size, def->key_size); - return -EINVAL; - } - - value_size = btf__resolve_size(btf, value->type); - if (value_size < 0) { - pr_warning("map:%s invalid BTF value_type_size\n", map->name); - return value_size; - } + __u32 key_type_id, value_type_id; + int ret; - if (def->value_size != value_size) { - pr_warning("map:%s btf_value_type_size:%u != map_def_value_size:%u\n", - map->name, (__u32)value_size, def->value_size); - return -EINVAL; - } + ret = btf__get_map_kv_tids(btf, map->name, def->key_size, + def->value_size, &key_type_id, + &value_type_id); + if (ret) + return ret; - map->btf_key_type_id = key->type; - map->btf_value_type_id = value->type; + map->btf_key_type_id = key_type_id; + map->btf_value_type_id = value_type_id; return 0; } -- cgit v1.2.2 From a8a1f7d09cfc7e18874786c7634c9e71384fcd4e Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Mon, 4 Feb 2019 16:20:55 -0800 Subject: libbpf: fix libbpf_print With the recent print rework we now have the following problem: pr_{warning,info,debug} expand to __pr which calls libbpf_print. libbpf_print does va_start and calls __libbpf_pr with va_list argument. In __base_pr we again do va_start. Because the next argument is a va_list, we don't get correct pointer to the argument (and print noting in my case, I don't know why it doesn't crash tbh). Fix this by changing libbpf_print_fn_t signature to accept va_list and remove unneeded calls to va_start in the existing users. Alternatively, this can we solved by exporting __libbpf_pr and changing __pr macro to (and killing libbpf_print): { if (__libbpf_pr) __libbpf_pr(level, "libbpf: " fmt, ##__VA_ARGS__) } Signed-off-by: Stanislav Fomichev Acked-by: Yonghong Song Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/libbpf.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) (limited to 'tools/lib/bpf/libbpf.c') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 84ca6c2bea91..47969aa0faf8 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -54,22 +54,16 @@ #define __printf(a, b) __attribute__((format(printf, a, b))) -__printf(2, 3) -static int __base_pr(enum libbpf_print_level level, const char *format, ...) +static int __base_pr(enum libbpf_print_level level, const char *format, + va_list args) { - va_list args; - int err; - if (level == LIBBPF_DEBUG) return 0; - va_start(args, format); - err = vfprintf(stderr, format, args); - va_end(args); - return err; + return vfprintf(stderr, format, args); } -static __printf(2, 3) libbpf_print_fn_t __libbpf_pr = __base_pr; +static libbpf_print_fn_t __libbpf_pr = __base_pr; void libbpf_set_print(libbpf_print_fn_t fn) { -- cgit v1.2.2