From 151936bf51afcdd6db52b3b73e339d021064b0ea Mon Sep 17 00:00:00 2001 From: "Daniel T. Lee" Date: Sun, 11 Oct 2020 03:17:33 +0900 Subject: [PATCH] samples: bpf: Replace attach_tracepoint() to attach() in xdp_redirect_cpu >From commit d7a18ea7e8b6 ("libbpf: Add generic bpf_program__attach()"), for some BPF programs, it is now possible to attach BPF programs with __attach() instead of explicitly calling __attach_(). This commit refactors the __attach_tracepoint() with libbpf's generic __attach() method. In addition, this refactors the logic of setting the map FD to simplify the code. Also, the missing removal of bpf_load.o in Makefile has been fixed. Signed-off-by: Daniel T. Lee Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201010181734.1109-3-danieltimlee@gmail.com --- samples/bpf/Makefile | 2 +- samples/bpf/xdp_redirect_cpu_user.c | 153 +++++++++++++--------------- 2 files changed, 73 insertions(+), 82 deletions(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 50ad7e8b05bc..aeebf5d12f32 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -98,7 +98,7 @@ test_map_in_map-objs := test_map_in_map_user.o per_socket_stats_example-objs := cookie_uid_helper_example.o xdp_redirect-objs := xdp_redirect_user.o xdp_redirect_map-objs := xdp_redirect_map_user.o -xdp_redirect_cpu-objs := bpf_load.o xdp_redirect_cpu_user.o +xdp_redirect_cpu-objs := xdp_redirect_cpu_user.o xdp_monitor-objs := xdp_monitor_user.o xdp_rxq_info-objs := xdp_rxq_info_user.o syscall_tp-objs := syscall_tp_user.o diff --git a/samples/bpf/xdp_redirect_cpu_user.c b/samples/bpf/xdp_redirect_cpu_user.c index 3dd366e9474d..6fb8dbde62c5 100644 --- a/samples/bpf/xdp_redirect_cpu_user.c +++ b/samples/bpf/xdp_redirect_cpu_user.c @@ -37,18 +37,35 @@ static __u32 prog_id; static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST; static int n_cpus; -static int cpu_map_fd; -static int rx_cnt_map_fd; -static int redirect_err_cnt_map_fd; -static int cpumap_enqueue_cnt_map_fd; -static int cpumap_kthread_cnt_map_fd; -static int cpus_available_map_fd; -static int cpus_count_map_fd; -static int cpus_iterator_map_fd; -static int exception_cnt_map_fd; + +enum map_type { + CPU_MAP, + RX_CNT, + REDIRECT_ERR_CNT, + CPUMAP_ENQUEUE_CNT, + CPUMAP_KTHREAD_CNT, + CPUS_AVAILABLE, + CPUS_COUNT, + CPUS_ITERATOR, + EXCEPTION_CNT, +}; + +static const char *const map_type_strings[] = { + [CPU_MAP] = "cpu_map", + [RX_CNT] = "rx_cnt", + [REDIRECT_ERR_CNT] = "redirect_err_cnt", + [CPUMAP_ENQUEUE_CNT] = "cpumap_enqueue_cnt", + [CPUMAP_KTHREAD_CNT] = "cpumap_kthread_cnt", + [CPUS_AVAILABLE] = "cpus_available", + [CPUS_COUNT] = "cpus_count", + [CPUS_ITERATOR] = "cpus_iterator", + [EXCEPTION_CNT] = "exception_cnt", +}; #define NUM_TP 5 -struct bpf_link *tp_links[NUM_TP] = { 0 }; +#define NUM_MAP 9 +struct bpf_link *tp_links[NUM_TP] = {}; +static int map_fds[NUM_MAP]; static int tp_cnt = 0; /* Exit return codes */ @@ -527,20 +544,20 @@ static void stats_collect(struct stats_record *rec) { int fd, i; - fd = rx_cnt_map_fd; + fd = map_fds[RX_CNT]; map_collect_percpu(fd, 0, &rec->rx_cnt); - fd = redirect_err_cnt_map_fd; + fd = map_fds[REDIRECT_ERR_CNT]; map_collect_percpu(fd, 1, &rec->redir_err); - fd = cpumap_enqueue_cnt_map_fd; + fd = map_fds[CPUMAP_ENQUEUE_CNT]; for (i = 0; i < n_cpus; i++) map_collect_percpu(fd, i, &rec->enq[i]); - fd = cpumap_kthread_cnt_map_fd; + fd = map_fds[CPUMAP_KTHREAD_CNT]; map_collect_percpu(fd, 0, &rec->kthread); - fd = exception_cnt_map_fd; + fd = map_fds[EXCEPTION_CNT]; map_collect_percpu(fd, 0, &rec->exception); } @@ -565,7 +582,7 @@ static int create_cpu_entry(__u32 cpu, struct bpf_cpumap_val *value, /* Add a CPU entry to cpumap, as this allocate a cpu entry in * the kernel for the cpu. */ - ret = bpf_map_update_elem(cpu_map_fd, &cpu, value, 0); + ret = bpf_map_update_elem(map_fds[CPU_MAP], &cpu, value, 0); if (ret) { fprintf(stderr, "Create CPU entry failed (err:%d)\n", ret); exit(EXIT_FAIL_BPF); @@ -574,21 +591,21 @@ static int create_cpu_entry(__u32 cpu, struct bpf_cpumap_val *value, /* Inform bpf_prog's that a new CPU is available to select * from via some control maps. */ - ret = bpf_map_update_elem(cpus_available_map_fd, &avail_idx, &cpu, 0); + ret = bpf_map_update_elem(map_fds[CPUS_AVAILABLE], &avail_idx, &cpu, 0); if (ret) { fprintf(stderr, "Add to avail CPUs failed\n"); exit(EXIT_FAIL_BPF); } /* When not replacing/updating existing entry, bump the count */ - ret = bpf_map_lookup_elem(cpus_count_map_fd, &key, &curr_cpus_count); + ret = bpf_map_lookup_elem(map_fds[CPUS_COUNT], &key, &curr_cpus_count); if (ret) { fprintf(stderr, "Failed reading curr cpus_count\n"); exit(EXIT_FAIL_BPF); } if (new) { curr_cpus_count++; - ret = bpf_map_update_elem(cpus_count_map_fd, &key, + ret = bpf_map_update_elem(map_fds[CPUS_COUNT], &key, &curr_cpus_count, 0); if (ret) { fprintf(stderr, "Failed write curr cpus_count\n"); @@ -612,7 +629,7 @@ static void mark_cpus_unavailable(void) int ret, i; for (i = 0; i < n_cpus; i++) { - ret = bpf_map_update_elem(cpus_available_map_fd, &i, + ret = bpf_map_update_elem(map_fds[CPUS_AVAILABLE], &i, &invalid_cpu, 0); if (ret) { fprintf(stderr, "Failed marking CPU unavailable\n"); @@ -665,68 +682,37 @@ static void stats_poll(int interval, bool use_separators, char *prog_name, free_stats_record(prev); } -static struct bpf_link * attach_tp(struct bpf_object *obj, - const char *tp_category, - const char* tp_name) +static int init_tracepoints(struct bpf_object *obj) { struct bpf_program *prog; - struct bpf_link *link; - char sec_name[PATH_MAX]; - int len; - len = snprintf(sec_name, PATH_MAX, "tracepoint/%s/%s", - tp_category, tp_name); - if (len < 0) - exit(EXIT_FAIL); + bpf_object__for_each_program(prog, obj) { + if (bpf_program__is_tracepoint(prog) != true) + continue; - prog = bpf_object__find_program_by_title(obj, sec_name); - if (!prog) { - fprintf(stderr, "ERR: finding progsec: %s\n", sec_name); - exit(EXIT_FAIL_BPF); + tp_links[tp_cnt] = bpf_program__attach(prog); + if (libbpf_get_error(tp_links[tp_cnt])) { + tp_links[tp_cnt] = NULL; + return -EINVAL; + } + tp_cnt++; } - link = bpf_program__attach_tracepoint(prog, tp_category, tp_name); - if (libbpf_get_error(link)) - exit(EXIT_FAIL_BPF); - - return link; -} - -static void init_tracepoints(struct bpf_object *obj) { - tp_links[tp_cnt++] = attach_tp(obj, "xdp", "xdp_redirect_err"); - tp_links[tp_cnt++] = attach_tp(obj, "xdp", "xdp_redirect_map_err"); - tp_links[tp_cnt++] = attach_tp(obj, "xdp", "xdp_exception"); - tp_links[tp_cnt++] = attach_tp(obj, "xdp", "xdp_cpumap_enqueue"); - tp_links[tp_cnt++] = attach_tp(obj, "xdp", "xdp_cpumap_kthread"); + return 0; } static int init_map_fds(struct bpf_object *obj) { - /* Maps updated by tracepoints */ - redirect_err_cnt_map_fd = - bpf_object__find_map_fd_by_name(obj, "redirect_err_cnt"); - exception_cnt_map_fd = - bpf_object__find_map_fd_by_name(obj, "exception_cnt"); - cpumap_enqueue_cnt_map_fd = - bpf_object__find_map_fd_by_name(obj, "cpumap_enqueue_cnt"); - cpumap_kthread_cnt_map_fd = - bpf_object__find_map_fd_by_name(obj, "cpumap_kthread_cnt"); - - /* Maps used by XDP */ - rx_cnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rx_cnt"); - cpu_map_fd = bpf_object__find_map_fd_by_name(obj, "cpu_map"); - cpus_available_map_fd = - bpf_object__find_map_fd_by_name(obj, "cpus_available"); - cpus_count_map_fd = bpf_object__find_map_fd_by_name(obj, "cpus_count"); - cpus_iterator_map_fd = - bpf_object__find_map_fd_by_name(obj, "cpus_iterator"); - - if (cpu_map_fd < 0 || rx_cnt_map_fd < 0 || - redirect_err_cnt_map_fd < 0 || cpumap_enqueue_cnt_map_fd < 0 || - cpumap_kthread_cnt_map_fd < 0 || cpus_available_map_fd < 0 || - cpus_count_map_fd < 0 || cpus_iterator_map_fd < 0 || - exception_cnt_map_fd < 0) - return -ENOENT; + enum map_type type; + + for (type = 0; type < NUM_MAP; type++) { + map_fds[type] = + bpf_object__find_map_fd_by_name(obj, + map_type_strings[type]); + + if (map_fds[type] < 0) + return -ENOENT; + } return 0; } @@ -795,13 +781,13 @@ int main(int argc, char **argv) bool stress_mode = false; struct bpf_program *prog; struct bpf_object *obj; + int err = EXIT_FAIL; char filename[256]; int added_cpus = 0; int longindex = 0; int interval = 2; int add_cpu = -1; - int opt, err; - int prog_fd; + int opt, prog_fd; int *cpu, i; __u32 qsize; @@ -824,24 +810,29 @@ int main(int argc, char **argv) } if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd)) - return EXIT_FAIL; + return err; if (prog_fd < 0) { fprintf(stderr, "ERR: bpf_prog_load_xattr: %s\n", strerror(errno)); - return EXIT_FAIL; + return err; } - init_tracepoints(obj); + + if (init_tracepoints(obj) < 0) { + fprintf(stderr, "ERR: bpf_program__attach failed\n"); + return err; + } + if (init_map_fds(obj) < 0) { fprintf(stderr, "bpf_object__find_map_fd_by_name failed\n"); - return EXIT_FAIL; + return err; } mark_cpus_unavailable(); cpu = malloc(n_cpus * sizeof(int)); if (!cpu) { fprintf(stderr, "failed to allocate cpu array\n"); - return EXIT_FAIL; + return err; } memset(cpu, 0, n_cpus * sizeof(int)); @@ -960,14 +951,12 @@ int main(int argc, char **argv) prog = bpf_object__find_program_by_title(obj, prog_name); if (!prog) { fprintf(stderr, "bpf_object__find_program_by_title failed\n"); - err = EXIT_FAIL; goto out; } prog_fd = bpf_program__fd(prog); if (prog_fd < 0) { fprintf(stderr, "bpf_program__fd failed\n"); - err = EXIT_FAIL; goto out; } @@ -986,6 +975,8 @@ int main(int argc, char **argv) stats_poll(interval, use_separators, prog_name, mprog_name, &value, stress_mode); + + err = EXIT_OK; out: free(cpu); return err; -- 2.39.5