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 /* attach point */ 9 static void method(void) { 10 return ; 11 } 12 13 void test_attach_probe(void) 14 { 15 DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts); 16 int duration = 0; 17 struct bpf_link *kprobe_link, *kretprobe_link; 18 struct bpf_link *uprobe_link, *uretprobe_link; 19 struct test_attach_probe* skel; 20 size_t uprobe_offset; 21 ssize_t base_addr, ref_ctr_offset; 22 bool legacy; 23 24 /* Check if new-style kprobe/uprobe API is supported. 25 * Kernels that support new FD-based kprobe and uprobe BPF attachment 26 * through perf_event_open() syscall expose 27 * /sys/bus/event_source/devices/kprobe/type and 28 * /sys/bus/event_source/devices/uprobe/type files, respectively. They 29 * contain magic numbers that are passed as "type" field of 30 * perf_event_attr. Lack of such file in the system indicates legacy 31 * kernel with old-style kprobe/uprobe attach interface through 32 * creating per-probe event through tracefs. For such cases 33 * ref_ctr_offset feature is not supported, so we don't test it. 34 */ 35 legacy = access("/sys/bus/event_source/devices/kprobe/type", F_OK) != 0; 36 37 base_addr = get_base_addr(); 38 if (CHECK(base_addr < 0, "get_base_addr", 39 "failed to find base addr: %zd", base_addr)) 40 return; 41 uprobe_offset = get_uprobe_offset(&method, base_addr); 42 43 ref_ctr_offset = get_rel_offset((uintptr_t)&uprobe_ref_ctr); 44 if (!ASSERT_GE(ref_ctr_offset, 0, "ref_ctr_offset")) 45 return; 46 47 skel = test_attach_probe__open_and_load(); 48 if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) 49 return; 50 if (CHECK(!skel->bss, "check_bss", ".bss wasn't mmap()-ed\n")) 51 goto cleanup; 52 53 kprobe_link = bpf_program__attach_kprobe(skel->progs.handle_kprobe, 54 false /* retprobe */, 55 SYS_NANOSLEEP_KPROBE_NAME); 56 if (!ASSERT_OK_PTR(kprobe_link, "attach_kprobe")) 57 goto cleanup; 58 skel->links.handle_kprobe = kprobe_link; 59 60 kretprobe_link = bpf_program__attach_kprobe(skel->progs.handle_kretprobe, 61 true /* retprobe */, 62 SYS_NANOSLEEP_KPROBE_NAME); 63 if (!ASSERT_OK_PTR(kretprobe_link, "attach_kretprobe")) 64 goto cleanup; 65 skel->links.handle_kretprobe = kretprobe_link; 66 67 if (!legacy) 68 ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_before"); 69 70 uprobe_opts.retprobe = false; 71 uprobe_opts.ref_ctr_offset = legacy ? 0 : ref_ctr_offset; 72 uprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe, 73 0 /* self pid */, 74 "/proc/self/exe", 75 uprobe_offset, 76 &uprobe_opts); 77 if (!ASSERT_OK_PTR(uprobe_link, "attach_uprobe")) 78 goto cleanup; 79 skel->links.handle_uprobe = uprobe_link; 80 81 if (!legacy) 82 ASSERT_GT(uprobe_ref_ctr, 0, "uprobe_ref_ctr_after"); 83 84 /* if uprobe uses ref_ctr, uretprobe has to use ref_ctr as well */ 85 uprobe_opts.retprobe = true; 86 uprobe_opts.ref_ctr_offset = legacy ? 0 : ref_ctr_offset; 87 uretprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe, 88 -1 /* any pid */, 89 "/proc/self/exe", 90 uprobe_offset, &uprobe_opts); 91 if (!ASSERT_OK_PTR(uretprobe_link, "attach_uretprobe")) 92 goto cleanup; 93 skel->links.handle_uretprobe = uretprobe_link; 94 95 /* trigger & validate kprobe && kretprobe */ 96 usleep(1); 97 98 if (CHECK(skel->bss->kprobe_res != 1, "check_kprobe_res", 99 "wrong kprobe res: %d\n", skel->bss->kprobe_res)) 100 goto cleanup; 101 if (CHECK(skel->bss->kretprobe_res != 2, "check_kretprobe_res", 102 "wrong kretprobe res: %d\n", skel->bss->kretprobe_res)) 103 goto cleanup; 104 105 /* trigger & validate uprobe & uretprobe */ 106 method(); 107 108 if (CHECK(skel->bss->uprobe_res != 3, "check_uprobe_res", 109 "wrong uprobe res: %d\n", skel->bss->uprobe_res)) 110 goto cleanup; 111 if (CHECK(skel->bss->uretprobe_res != 4, "check_uretprobe_res", 112 "wrong uretprobe res: %d\n", skel->bss->uretprobe_res)) 113 goto cleanup; 114 115 cleanup: 116 test_attach_probe__destroy(skel); 117 ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_cleanup"); 118 } 119