bpf/prog_tests/module_attach.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /* Copyright (c) 2020 Facebook */
0003
0004 #include <test_progs.h>
0005 #include <stdbool.h>
0006 #include "test_module_attach.skel.h"
0007
0008 static int duration;
0009
0010 static int trigger_module_test_writable(int *val)
0011 {
0012     int fd, err;
0013     char buf[65];
0014     ssize_t rd;
0015
0016     fd = open(BPF_TESTMOD_TEST_FILE, O_RDONLY);
0017     err = -errno;
0018     if (!ASSERT_GE(fd, 0, "testmode_file_open"))
0019         return err;
0020
0021     rd = read(fd, buf, sizeof(buf) - 1);
0022     err = -errno;
0023     if (!ASSERT_GT(rd, 0, "testmod_file_rd_val")) {
0024         close(fd);
0025         return err;
0026     }
0027
0028     buf[rd] = '\0';
0029     *val = strtol(buf, NULL, 0);
0030     close(fd);
0031
0032     return 0;
0033 }
0034
0035 static int delete_module(const char *name, int flags)
0036 {
0037     return syscall(__NR_delete_module, name, flags);
0038 }
0039
0040 void test_module_attach(void)
0041 {
0042     const int READ_SZ = 456;
0043     const int WRITE_SZ = 457;
0044     struct test_module_attach* skel;
0045     struct test_module_attach__bss *bss;
0046     struct bpf_link *link;
0047     int err;
0048     int writable_val = 0;
0049
0050     skel = test_module_attach__open();
0051     if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
0052         return;
0053
0054     err = bpf_program__set_attach_target(skel->progs.handle_fentry_manual,
0055                          0, "bpf_testmod_test_read");
0056     ASSERT_OK(err, "set_attach_target");
0057
0058     err = test_module_attach__load(skel);
0059     if (CHECK(err, "skel_load", "failed to load skeleton\n"))
0060         return;
0061
0062     bss = skel->bss;
0063
0064     err = test_module_attach__attach(skel);
0065     if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
0066         goto cleanup;
0067
0068     /* trigger tracepoint */
0069     ASSERT_OK(trigger_module_test_read(READ_SZ), "trigger_read");
0070     ASSERT_OK(trigger_module_test_write(WRITE_SZ), "trigger_write");
0071
0072     ASSERT_EQ(bss->raw_tp_read_sz, READ_SZ, "raw_tp");
0073     ASSERT_EQ(bss->raw_tp_bare_write_sz, WRITE_SZ, "raw_tp_bare");
0074     ASSERT_EQ(bss->tp_btf_read_sz, READ_SZ, "tp_btf");
0075     ASSERT_EQ(bss->fentry_read_sz, READ_SZ, "fentry");
0076     ASSERT_EQ(bss->fentry_manual_read_sz, READ_SZ, "fentry_manual");
0077     ASSERT_EQ(bss->fexit_read_sz, READ_SZ, "fexit");
0078     ASSERT_EQ(bss->fexit_ret, -EIO, "fexit_tet");
0079     ASSERT_EQ(bss->fmod_ret_read_sz, READ_SZ, "fmod_ret");
0080
0081     bss->raw_tp_writable_bare_early_ret = true;
0082     bss->raw_tp_writable_bare_out_val = 0xf1f2f3f4;
0083     ASSERT_OK(trigger_module_test_writable(&writable_val),
0084           "trigger_writable");
0085     ASSERT_EQ(bss->raw_tp_writable_bare_in_val, 1024, "writable_test_in");
0086     ASSERT_EQ(bss->raw_tp_writable_bare_out_val, writable_val,
0087           "writable_test_out");
0088
0089     test_module_attach__detach(skel);
0090
0091     /* attach fentry/fexit and make sure it get's module reference */
0092     link = bpf_program__attach(skel->progs.handle_fentry);
0093     if (!ASSERT_OK_PTR(link, "attach_fentry"))
0094         goto cleanup;
0095
0096     ASSERT_ERR(delete_module("bpf_testmod", 0), "delete_module");
0097     bpf_link__destroy(link);
0098
0099     link = bpf_program__attach(skel->progs.handle_fexit);
0100     if (!ASSERT_OK_PTR(link, "attach_fexit"))
0101         goto cleanup;
0102
0103     ASSERT_ERR(delete_module("bpf_testmod", 0), "delete_module");
0104     bpf_link__destroy(link);
0105
0106 cleanup:
0107     test_module_attach__destroy(skel);
0108 }