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 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 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