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// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
#include "test_attach_probe.skel.h"
/* this is how USDT semaphore is actually defined, except volatile modifier */
volatile unsigned short uprobe_ref_ctr __attribute__((unused)) __attribute((section(".probes")));
/* attach point */
static void method(void) {
return ;
}
void test_attach_probe(void)
{
DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
int duration = 0;
struct bpf_link *kprobe_link, *kretprobe_link;
struct bpf_link *uprobe_link, *uretprobe_link;
struct test_attach_probe* skel;
size_t uprobe_offset;
ssize_t base_addr, ref_ctr_offset;
bool legacy;
/* Check if new-style kprobe/uprobe API is supported.
* Kernels that support new FD-based kprobe and uprobe BPF attachment
* through perf_event_open() syscall expose
* /sys/bus/event_source/devices/kprobe/type and
* /sys/bus/event_source/devices/uprobe/type files, respectively. They
* contain magic numbers that are passed as "type" field of
* perf_event_attr. Lack of such file in the system indicates legacy
* kernel with old-style kprobe/uprobe attach interface through
* creating per-probe event through tracefs. For such cases
* ref_ctr_offset feature is not supported, so we don't test it.
*/
legacy = access("/sys/bus/event_source/devices/kprobe/type", F_OK) != 0;
base_addr = get_base_addr();
if (CHECK(base_addr < 0, "get_base_addr",
"failed to find base addr: %zd", base_addr))
return;
uprobe_offset = get_uprobe_offset(&method, base_addr);
ref_ctr_offset = get_rel_offset((uintptr_t)&uprobe_ref_ctr);
if (!ASSERT_GE(ref_ctr_offset, 0, "ref_ctr_offset"))
return;
skel = test_attach_probe__open_and_load();
if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
return;
if (CHECK(!skel->bss, "check_bss", ".bss wasn't mmap()-ed\n"))
goto cleanup;
kprobe_link = bpf_program__attach_kprobe(skel->progs.handle_kprobe,
false /* retprobe */,
SYS_NANOSLEEP_KPROBE_NAME);
if (!ASSERT_OK_PTR(kprobe_link, "attach_kprobe"))
goto cleanup;
skel->links.handle_kprobe = kprobe_link;
kretprobe_link = bpf_program__attach_kprobe(skel->progs.handle_kretprobe,
true /* retprobe */,
SYS_NANOSLEEP_KPROBE_NAME);
if (!ASSERT_OK_PTR(kretprobe_link, "attach_kretprobe"))
goto cleanup;
skel->links.handle_kretprobe = kretprobe_link;
if (!legacy)
ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_before");
uprobe_opts.retprobe = false;
uprobe_opts.ref_ctr_offset = legacy ? 0 : ref_ctr_offset;
uprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe,
0 /* self pid */,
"/proc/self/exe",
uprobe_offset,
&uprobe_opts);
if (!ASSERT_OK_PTR(uprobe_link, "attach_uprobe"))
goto cleanup;
skel->links.handle_uprobe = uprobe_link;
if (!legacy)
ASSERT_GT(uprobe_ref_ctr, 0, "uprobe_ref_ctr_after");
/* if uprobe uses ref_ctr, uretprobe has to use ref_ctr as well */
uprobe_opts.retprobe = true;
uprobe_opts.ref_ctr_offset = legacy ? 0 : ref_ctr_offset;
uretprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe,
-1 /* any pid */,
"/proc/self/exe",
uprobe_offset, &uprobe_opts);
if (!ASSERT_OK_PTR(uretprobe_link, "attach_uretprobe"))
goto cleanup;
skel->links.handle_uretprobe = uretprobe_link;
/* trigger & validate kprobe && kretprobe */
usleep(1);
if (CHECK(skel->bss->kprobe_res != 1, "check_kprobe_res",
"wrong kprobe res: %d\n", skel->bss->kprobe_res))
goto cleanup;
if (CHECK(skel->bss->kretprobe_res != 2, "check_kretprobe_res",
"wrong kretprobe res: %d\n", skel->bss->kretprobe_res))
goto cleanup;
/* trigger & validate uprobe & uretprobe */
method();
if (CHECK(skel->bss->uprobe_res != 3, "check_uprobe_res",
"wrong uprobe res: %d\n", skel->bss->uprobe_res))
goto cleanup;
if (CHECK(skel->bss->uretprobe_res != 4, "check_uretprobe_res",
"wrong uretprobe res: %d\n", skel->bss->uretprobe_res))
goto cleanup;
cleanup:
test_attach_probe__destroy(skel);
ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_cleanup");
}
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