1 // SPDX-License-Identifier: GPL-2.0 2 #include <test_progs.h> 3 #include "test_attach_probe.skel.h" 4 5 /* this is how USDT semaphore is actually defined, except volatile modifier */ 6 volatile unsigned short uprobe_ref_ctr __attribute__((unused)) __attribute((section(".probes"))); 7 8 void test_attach_probe(void) 9 { 10 DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts); 11 int duration = 0; 12 struct bpf_link *kprobe_link, *kretprobe_link; 13 struct bpf_link *uprobe_link, *uretprobe_link; 14 struct test_attach_probe* skel; 15 size_t uprobe_offset; 16 ssize_t base_addr, ref_ctr_offset; 17 bool legacy; 18 19 /* Check if new-style kprobe/uprobe API is supported. 20 * Kernels that support new FD-based kprobe and uprobe BPF attachment 21 * through perf_event_open() syscall expose 22 * /sys/bus/event_source/devices/kprobe/type and 23 * /sys/bus/event_source/devices/uprobe/type files, respectively. They 24 * contain magic numbers that are passed as "type" field of 25 * perf_event_attr. Lack of such file in the system indicates legacy 26 * kernel with old-style kprobe/uprobe attach interface through 27 * creating per-probe event through tracefs. For such cases 28 * ref_ctr_offset feature is not supported, so we don't test it. 29 */ 30 legacy = access("/sys/bus/event_source/devices/kprobe/type", F_OK) != 0; 31 32 base_addr = get_base_addr(); 33 if (CHECK(base_addr < 0, "get_base_addr", 34 "failed to find base addr: %zd", base_addr)) 35 return; 36 uprobe_offset = get_uprobe_offset(&get_base_addr, base_addr); 37 38 ref_ctr_offset = get_rel_offset((uintptr_t)&uprobe_ref_ctr); 39 if (!ASSERT_GE(ref_ctr_offset, 0, "ref_ctr_offset")) 40 return; 41 42 skel = test_attach_probe__open_and_load(); 43 if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) 44 return; 45 if (CHECK(!skel->bss, "check_bss", ".bss wasn't mmap()-ed\n")) 46 goto cleanup; 47 48 kprobe_link = bpf_program__attach_kprobe(skel->progs.handle_kprobe, 49 false /* retprobe */, 50 SYS_NANOSLEEP_KPROBE_NAME); 51 if (!ASSERT_OK_PTR(kprobe_link, "attach_kprobe")) 52 goto cleanup; 53 skel->links.handle_kprobe = kprobe_link; 54 55 kretprobe_link = bpf_program__attach_kprobe(skel->progs.handle_kretprobe, 56 true /* retprobe */, 57 SYS_NANOSLEEP_KPROBE_NAME); 58 if (!ASSERT_OK_PTR(kretprobe_link, "attach_kretprobe")) 59 goto cleanup; 60 skel->links.handle_kretprobe = kretprobe_link; 61 62 if (!legacy) 63 ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_before"); 64 65 uprobe_opts.retprobe = false; 66 uprobe_opts.ref_ctr_offset = legacy ? 0 : ref_ctr_offset; 67 uprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe, 68 0 /* self pid */, 69 "/proc/self/exe", 70 uprobe_offset, 71 &uprobe_opts); 72 if (!ASSERT_OK_PTR(uprobe_link, "attach_uprobe")) 73 goto cleanup; 74 skel->links.handle_uprobe = uprobe_link; 75 76 if (!legacy) 77 ASSERT_GT(uprobe_ref_ctr, 0, "uprobe_ref_ctr_after"); 78 79 /* if uprobe uses ref_ctr, uretprobe has to use ref_ctr as well */ 80 uprobe_opts.retprobe = true; 81 uprobe_opts.ref_ctr_offset = legacy ? 0 : ref_ctr_offset; 82 uretprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe, 83 -1 /* any pid */, 84 "/proc/self/exe", 85 uprobe_offset, &uprobe_opts); 86 if (!ASSERT_OK_PTR(uretprobe_link, "attach_uretprobe")) 87 goto cleanup; 88 skel->links.handle_uretprobe = uretprobe_link; 89 90 /* trigger & validate kprobe && kretprobe */ 91 usleep(1); 92 93 if (CHECK(skel->bss->kprobe_res != 1, "check_kprobe_res", 94 "wrong kprobe res: %d\n", skel->bss->kprobe_res)) 95 goto cleanup; 96 if (CHECK(skel->bss->kretprobe_res != 2, "check_kretprobe_res", 97 "wrong kretprobe res: %d\n", skel->bss->kretprobe_res)) 98 goto cleanup; 99 100 /* trigger & validate uprobe & uretprobe */ 101 get_base_addr(); 102 103 if (CHECK(skel->bss->uprobe_res != 3, "check_uprobe_res", 104 "wrong uprobe res: %d\n", skel->bss->uprobe_res)) 105 goto cleanup; 106 if (CHECK(skel->bss->uretprobe_res != 4, "check_uretprobe_res", 107 "wrong uretprobe res: %d\n", skel->bss->uretprobe_res)) 108 goto cleanup; 109 110 cleanup: 111 test_attach_probe__destroy(skel); 112 ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_cleanup"); 113 } 114