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-rw-r--r--samples/bpf/tracex5_user.c98
1 files changed, 98 insertions, 0 deletions
diff --git a/samples/bpf/tracex5_user.c b/samples/bpf/tracex5_user.c
new file mode 100644
index 0000000000..7e2d8397fb
--- /dev/null
+++ b/samples/bpf/tracex5_user.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <linux/filter.h>
+#include <linux/seccomp.h>
+#include <sys/prctl.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "trace_helpers.h"
+#include "bpf_util.h"
+
+#ifdef __mips__
+#define MAX_ENTRIES 6000 /* MIPS n64 syscalls start at 5000 */
+#else
+#define MAX_ENTRIES 1024
+#endif
+
+/* install fake seccomp program to enable seccomp code path inside the kernel,
+ * so that our kprobe attached to seccomp_phase1() can be triggered
+ */
+static void install_accept_all_seccomp(void)
+{
+ struct sock_filter filter[] = {
+ BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW),
+ };
+ struct sock_fprog prog = {
+ .len = (unsigned short)ARRAY_SIZE(filter),
+ .filter = filter,
+ };
+ if (prctl(PR_SET_SECCOMP, 2, &prog))
+ perror("prctl");
+}
+
+int main(int ac, char **argv)
+{
+ struct bpf_link *link = NULL;
+ struct bpf_program *prog;
+ struct bpf_object *obj;
+ int key, fd, progs_fd;
+ const char *section;
+ char filename[256];
+ FILE *f;
+
+ snprintf(filename, sizeof(filename), "%s.bpf.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) {
+ printf("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;
+ }
+
+ link = bpf_program__attach(prog);
+ if (libbpf_get_error(link)) {
+ fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+ link = NULL;
+ goto cleanup;
+ }
+
+ progs_fd = bpf_object__find_map_fd_by_name(obj, "progs");
+ if (progs_fd < 0) {
+ fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+ goto cleanup;
+ }
+
+ bpf_object__for_each_program(prog, obj) {
+ section = bpf_program__section_name(prog);
+ /* register only syscalls to PROG_ARRAY */
+ if (sscanf(section, "kprobe/%d", &key) != 1)
+ continue;
+
+ fd = bpf_program__fd(prog);
+ bpf_map_update_elem(progs_fd, &key, &fd, BPF_ANY);
+ }
+
+ install_accept_all_seccomp();
+
+ f = popen("dd if=/dev/zero of=/dev/null count=5", "r");
+ (void) f;
+
+ read_trace_pipe();
+
+cleanup:
+ bpf_link__destroy(link);
+ bpf_object__close(obj);
+ return 0;
+}