From 63841bc0833623ecd4f758ec055b543cf1bc56ba Mon Sep 17 00:00:00 2001 From: "Daniel T. Lee" Date: Sat, 16 May 2020 13:06:05 +0900 Subject: samples, bpf: Refactor kprobe tracing user progs with libbpf Currently, the kprobe BPF program attachment method for bpf_load is quite old. The implementation of bpf_load "directly" controls and manages(create, delete) the kprobe events of DEBUGFS. On the other hand, using using the libbpf automatically manages the kprobe event. (under bpf_link interface) By calling bpf_program__attach(_kprobe) in libbpf, the corresponding kprobe is created and the BPF program will be attached to this kprobe. To remove this, by simply invoking bpf_link__destroy will clean up the event. This commit refactors kprobe tracing programs (tracex{1~7}_user.c) with libbpf using bpf_link interface and bpf_program__attach. tracex2_kern.c, which tracks system calls (sys_*), has been modified to append prefix depending on architecture. Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200516040608.1377876-3-danieltimlee@gmail.com --- samples/bpf/Makefile | 12 ++++----- samples/bpf/trace_common.h | 13 ++++++++++ samples/bpf/tracex1_user.c | 37 ++++++++++++++++++++++------ samples/bpf/tracex2_kern.c | 3 ++- samples/bpf/tracex2_user.c | 51 +++++++++++++++++++++++++++++++------- samples/bpf/tracex3_user.c | 61 ++++++++++++++++++++++++++++++++++------------ samples/bpf/tracex4_user.c | 51 +++++++++++++++++++++++++++++--------- samples/bpf/tracex6_user.c | 49 ++++++++++++++++++++++++++++++++----- samples/bpf/tracex7_user.c | 39 +++++++++++++++++++++++------ 9 files changed, 252 insertions(+), 64 deletions(-) create mode 100644 samples/bpf/trace_common.h (limited to 'samples') diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 424f6fe7ce38..4c91e5914329 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -64,13 +64,13 @@ fds_example-objs := fds_example.o sockex1-objs := sockex1_user.o sockex2-objs := sockex2_user.o sockex3-objs := bpf_load.o sockex3_user.o -tracex1-objs := bpf_load.o tracex1_user.o $(TRACE_HELPERS) -tracex2-objs := bpf_load.o tracex2_user.o -tracex3-objs := bpf_load.o tracex3_user.o -tracex4-objs := bpf_load.o tracex4_user.o +tracex1-objs := tracex1_user.o $(TRACE_HELPERS) +tracex2-objs := tracex2_user.o +tracex3-objs := tracex3_user.o +tracex4-objs := tracex4_user.o tracex5-objs := bpf_load.o tracex5_user.o $(TRACE_HELPERS) -tracex6-objs := bpf_load.o tracex6_user.o -tracex7-objs := bpf_load.o tracex7_user.o +tracex6-objs := tracex6_user.o +tracex7-objs := tracex7_user.o test_probe_write_user-objs := bpf_load.o test_probe_write_user_user.o trace_output-objs := bpf_load.o trace_output_user.o $(TRACE_HELPERS) lathist-objs := bpf_load.o lathist_user.o diff --git a/samples/bpf/trace_common.h b/samples/bpf/trace_common.h new file mode 100644 index 000000000000..8cb5400aed1f --- /dev/null +++ b/samples/bpf/trace_common.h @@ -0,0 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef __TRACE_COMMON_H +#define __TRACE_COMMON_H + +#ifdef __x86_64__ +#define SYSCALL(SYS) "__x64_" __stringify(SYS) +#elif defined(__s390x__) +#define SYSCALL(SYS) "__s390x_" __stringify(SYS) +#else +#define SYSCALL(SYS) __stringify(SYS) +#endif + +#endif diff --git a/samples/bpf/tracex1_user.c b/samples/bpf/tracex1_user.c index 55fddbd08702..9d4adb7fd834 100644 --- a/samples/bpf/tracex1_user.c +++ b/samples/bpf/tracex1_user.c @@ -1,21 +1,41 @@ // SPDX-License-Identifier: GPL-2.0 #include -#include #include -#include -#include "bpf_load.h" +#include #include "trace_helpers.h" int main(int ac, char **argv) { - FILE *f; + struct bpf_link *link = NULL; + struct bpf_program *prog; + struct bpf_object *obj; char filename[256]; + FILE *f; snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + obj = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + return 0; + } + + prog = bpf_object__find_program_by_name(obj, "bpf_prog1"); + if (!prog) { + fprintf(stderr, "ERROR: finding a prog in obj file failed\n"); + goto cleanup; + } + + /* load BPF program */ + if (bpf_object__load(obj)) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + goto cleanup; + } - if (load_bpf_file(filename)) { - printf("%s", bpf_log_buf); - return 1; + link = bpf_program__attach(prog); + if (libbpf_get_error(link)) { + fprintf(stderr, "ERROR: bpf_program__attach failed\n"); + link = NULL; + goto cleanup; } f = popen("taskset 1 ping -c5 localhost", "r"); @@ -23,5 +43,8 @@ int main(int ac, char **argv) read_trace_pipe(); +cleanup: + bpf_link__destroy(link); + bpf_object__close(obj); return 0; } diff --git a/samples/bpf/tracex2_kern.c b/samples/bpf/tracex2_kern.c index d865bb309bcb..cc5f94c098f8 100644 --- a/samples/bpf/tracex2_kern.c +++ b/samples/bpf/tracex2_kern.c @@ -10,6 +10,7 @@ #include #include #include +#include "trace_common.h" struct bpf_map_def SEC("maps") my_map = { .type = BPF_MAP_TYPE_HASH, @@ -77,7 +78,7 @@ struct bpf_map_def SEC("maps") my_hist_map = { .max_entries = 1024, }; -SEC("kprobe/sys_write") +SEC("kprobe/" SYSCALL(sys_write)) int bpf_prog3(struct pt_regs *ctx) { long write_size = PT_REGS_PARM3(ctx); diff --git a/samples/bpf/tracex2_user.c b/samples/bpf/tracex2_user.c index c9544a4ce61a..3e36b3e4e3ef 100644 --- a/samples/bpf/tracex2_user.c +++ b/samples/bpf/tracex2_user.c @@ -3,17 +3,19 @@ #include #include #include -#include #include #include #include -#include "bpf_load.h" +#include #include "bpf_util.h" #define MAX_INDEX 64 #define MAX_STARS 38 +/* my_map, my_hist_map */ +static int map_fd[2]; + static void stars(char *str, long val, long max, int width) { int i; @@ -115,18 +117,39 @@ static void int_exit(int sig) int main(int ac, char **argv) { struct rlimit r = {1024*1024, RLIM_INFINITY}; - char filename[256]; long key, next_key, value; + struct bpf_link *links[2]; + struct bpf_program *prog; + struct bpf_object *obj; + char filename[256]; + int i, j = 0; FILE *f; - int i; - - snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); if (setrlimit(RLIMIT_MEMLOCK, &r)) { perror("setrlimit(RLIMIT_MEMLOCK)"); return 1; } + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + obj = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + return 0; + } + + /* load BPF program */ + if (bpf_object__load(obj)) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + goto cleanup; + } + + map_fd[0] = bpf_object__find_map_fd_by_name(obj, "my_map"); + map_fd[1] = bpf_object__find_map_fd_by_name(obj, "my_hist_map"); + if (map_fd[0] < 0 || map_fd[1] < 0) { + fprintf(stderr, "ERROR: finding a map in obj file failed\n"); + goto cleanup; + } + signal(SIGINT, int_exit); signal(SIGTERM, int_exit); @@ -138,9 +161,14 @@ int main(int ac, char **argv) f = popen("dd if=/dev/zero of=/dev/null count=5000000", "r"); (void) f; - if (load_bpf_file(filename)) { - printf("%s", bpf_log_buf); - return 1; + bpf_object__for_each_program(prog, obj) { + links[j] = bpf_program__attach(prog); + if (libbpf_get_error(links[j])) { + fprintf(stderr, "ERROR: bpf_program__attach failed\n"); + links[j] = NULL; + goto cleanup; + } + j++; } for (i = 0; i < 5; i++) { @@ -156,5 +184,10 @@ int main(int ac, char **argv) } print_hist(map_fd[1]); +cleanup: + for (j--; j >= 0; j--) + bpf_link__destroy(links[j]); + + bpf_object__close(obj); return 0; } diff --git a/samples/bpf/tracex3_user.c b/samples/bpf/tracex3_user.c index cf8fedc773f2..70e987775c15 100644 --- a/samples/bpf/tracex3_user.c +++ b/samples/bpf/tracex3_user.c @@ -7,11 +7,10 @@ #include #include #include -#include #include #include -#include "bpf_load.h" +#include #include "bpf_util.h" #define SLOTS 100 @@ -109,20 +108,11 @@ static void print_hist(int fd) int main(int ac, char **argv) { struct rlimit r = {1024*1024, RLIM_INFINITY}; + struct bpf_link *links[2]; + struct bpf_program *prog; + struct bpf_object *obj; char filename[256]; - int i; - - snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); - - if (setrlimit(RLIMIT_MEMLOCK, &r)) { - perror("setrlimit(RLIMIT_MEMLOCK)"); - return 1; - } - - if (load_bpf_file(filename)) { - printf("%s", bpf_log_buf); - return 1; - } + int map_fd, i, j = 0; for (i = 1; i < ac; i++) { if (strcmp(argv[i], "-a") == 0) { @@ -137,6 +127,40 @@ int main(int ac, char **argv) } } + if (setrlimit(RLIMIT_MEMLOCK, &r)) { + perror("setrlimit(RLIMIT_MEMLOCK)"); + return 1; + } + + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + obj = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + return 0; + } + + /* load BPF program */ + if (bpf_object__load(obj)) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + goto cleanup; + } + + map_fd = bpf_object__find_map_fd_by_name(obj, "lat_map"); + if (map_fd < 0) { + fprintf(stderr, "ERROR: finding a map in obj file failed\n"); + goto cleanup; + } + + bpf_object__for_each_program(prog, obj) { + links[j] = bpf_program__attach(prog); + if (libbpf_get_error(links[j])) { + fprintf(stderr, "ERROR: bpf_program__attach failed\n"); + links[j] = NULL; + goto cleanup; + } + j++; + } + printf(" heatmap of IO latency\n"); if (text_only) printf(" %s", sym[num_colors - 1]); @@ -153,9 +177,14 @@ int main(int ac, char **argv) for (i = 0; ; i++) { if (i % 20 == 0) print_banner(); - print_hist(map_fd[1]); + print_hist(map_fd); sleep(2); } +cleanup: + for (j--; j >= 0; j--) + bpf_link__destroy(links[j]); + + bpf_object__close(obj); return 0; } diff --git a/samples/bpf/tracex4_user.c b/samples/bpf/tracex4_user.c index ec52203fce39..e8faf8f184ae 100644 --- a/samples/bpf/tracex4_user.c +++ b/samples/bpf/tracex4_user.c @@ -8,11 +8,10 @@ #include #include #include -#include #include #include -#include "bpf_load.h" +#include struct pair { long long val; @@ -36,8 +35,8 @@ static void print_old_objects(int fd) key = write(1, "\e[1;1H\e[2J", 12); /* clear screen */ key = -1; - while (bpf_map_get_next_key(map_fd[0], &key, &next_key) == 0) { - bpf_map_lookup_elem(map_fd[0], &next_key, &v); + while (bpf_map_get_next_key(fd, &key, &next_key) == 0) { + bpf_map_lookup_elem(fd, &next_key, &v); key = next_key; if (val - v.val < 1000000000ll) /* object was allocated more then 1 sec ago */ @@ -50,25 +49,55 @@ static void print_old_objects(int fd) int main(int ac, char **argv) { struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY}; + struct bpf_link *links[2]; + struct bpf_program *prog; + struct bpf_object *obj; char filename[256]; - int i; - - snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + int map_fd, i, j = 0; if (setrlimit(RLIMIT_MEMLOCK, &r)) { perror("setrlimit(RLIMIT_MEMLOCK, RLIM_INFINITY)"); return 1; } - if (load_bpf_file(filename)) { - printf("%s", bpf_log_buf); - return 1; + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + obj = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + return 0; + } + + /* load BPF program */ + if (bpf_object__load(obj)) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + goto cleanup; + } + + map_fd = bpf_object__find_map_fd_by_name(obj, "my_map"); + if (map_fd < 0) { + fprintf(stderr, "ERROR: finding a map in obj file failed\n"); + goto cleanup; + } + + bpf_object__for_each_program(prog, obj) { + links[j] = bpf_program__attach(prog); + if (libbpf_get_error(links[j])) { + fprintf(stderr, "ERROR: bpf_program__attach failed\n"); + links[j] = NULL; + goto cleanup; + } + j++; } for (i = 0; ; i++) { - print_old_objects(map_fd[1]); + print_old_objects(map_fd); sleep(1); } +cleanup: + for (j--; j >= 0; j--) + bpf_link__destroy(links[j]); + + bpf_object__close(obj); return 0; } diff --git a/samples/bpf/tracex6_user.c b/samples/bpf/tracex6_user.c index 4bb3c830adb2..33df9784775d 100644 --- a/samples/bpf/tracex6_user.c +++ b/samples/bpf/tracex6_user.c @@ -4,7 +4,6 @@ #include #include #include -#include #include #include #include @@ -15,12 +14,15 @@ #include #include -#include "bpf_load.h" #include +#include #include "perf-sys.h" #define SAMPLE_PERIOD 0x7fffffffffffffffULL +/* counters, values, values2 */ +static int map_fd[3]; + static void check_on_cpu(int cpu, struct perf_event_attr *attr) { struct bpf_perf_event_value value2; @@ -174,16 +176,51 @@ static void test_bpf_perf_event(void) int main(int argc, char **argv) { struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY}; + struct bpf_link *links[2]; + struct bpf_program *prog; + struct bpf_object *obj; char filename[256]; + int i = 0; + + setrlimit(RLIMIT_MEMLOCK, &r); snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + obj = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + return 0; + } - setrlimit(RLIMIT_MEMLOCK, &r); - if (load_bpf_file(filename)) { - printf("%s", bpf_log_buf); - return 1; + /* load BPF program */ + if (bpf_object__load(obj)) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + goto cleanup; + } + + map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counters"); + map_fd[1] = bpf_object__find_map_fd_by_name(obj, "values"); + map_fd[2] = bpf_object__find_map_fd_by_name(obj, "values2"); + if (map_fd[0] < 0 || map_fd[1] < 0 || map_fd[2] < 0) { + fprintf(stderr, "ERROR: finding a map in obj file failed\n"); + goto cleanup; + } + + bpf_object__for_each_program(prog, obj) { + links[i] = bpf_program__attach(prog); + if (libbpf_get_error(links[i])) { + fprintf(stderr, "ERROR: bpf_program__attach failed\n"); + links[i] = NULL; + goto cleanup; + } + i++; } test_bpf_perf_event(); + +cleanup: + for (i--; i >= 0; i--) + bpf_link__destroy(links[i]); + + bpf_object__close(obj); return 0; } diff --git a/samples/bpf/tracex7_user.c b/samples/bpf/tracex7_user.c index ea6dae78f0df..fdcd6580dd73 100644 --- a/samples/bpf/tracex7_user.c +++ b/samples/bpf/tracex7_user.c @@ -1,28 +1,51 @@ #define _GNU_SOURCE #include -#include #include -#include -#include "bpf_load.h" +#include int main(int argc, char **argv) { - FILE *f; + struct bpf_link *link = NULL; + struct bpf_program *prog; + struct bpf_object *obj; char filename[256]; char command[256]; - int ret; + int ret = 0; + FILE *f; snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + obj = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + return 0; + } + + prog = bpf_object__find_program_by_name(obj, "bpf_prog1"); + if (!prog) { + fprintf(stderr, "ERROR: finding a prog in obj file failed\n"); + goto cleanup; + } + + /* load BPF program */ + if (bpf_object__load(obj)) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + goto cleanup; + } - if (load_bpf_file(filename)) { - printf("%s", bpf_log_buf); - return 1; + link = bpf_program__attach(prog); + if (libbpf_get_error(link)) { + fprintf(stderr, "ERROR: bpf_program__attach failed\n"); + link = NULL; + goto cleanup; } snprintf(command, 256, "mount %s tmpmnt/", argv[1]); f = popen(command, "r"); ret = pclose(f); +cleanup: + bpf_link__destroy(link); + bpf_object__close(obj); return ret ? 0 : 1; } -- cgit v1.2.3