>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_<type>().
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 <danieltimlee@xxxxxxxxx>
---
Changes in v2:
- program section match with bpf_program__is_<type> instead of strncmp
- refactor pointer array initialization
- error code cleanup
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 0cee2aa8970f..ac9175705b2f 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;
--
2.25.1
|