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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")));
/* uprobe attach point */
static noinline void trigger_func(void)
{
asm volatile ("");
}
/* attach point for byname uprobe */
static noinline void trigger_func2(void)
{
asm volatile ("");
}
/* attach point for byname sleepable uprobe */
static noinline void trigger_func3(void)
{
asm volatile ("");
}
static char test_data[] = "test_data";
void test_attach_probe(void)
{
DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
struct bpf_link *kprobe_link, *kretprobe_link;
struct bpf_link *uprobe_link, *uretprobe_link;
struct test_attach_probe* skel;
ssize_t uprobe_offset, ref_ctr_offset;
struct bpf_link *uprobe_err_link;
bool legacy;
char *mem;
/* 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;
uprobe_offset = get_uprobe_offset(&trigger_func);
if (!ASSERT_GE(uprobe_offset, 0, "uprobe_offset"))
return;
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();
if (!ASSERT_OK_PTR(skel, "skel_open"))
return;
/* sleepable kprobe test case needs flags set before loading */
if (!ASSERT_OK(bpf_program__set_flags(skel->progs.handle_kprobe_sleepable,
BPF_F_SLEEPABLE), "kprobe_sleepable_flags"))
goto cleanup;
if (!ASSERT_OK(test_attach_probe__load(skel), "skel_load"))
goto cleanup;
if (!ASSERT_OK_PTR(skel->bss, "check_bss"))
goto cleanup;
/* manual-attach kprobe/kretprobe */
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;
/* auto-attachable kprobe and kretprobe */
skel->links.handle_kprobe_auto = bpf_program__attach(skel->progs.handle_kprobe_auto);
ASSERT_OK_PTR(skel->links.handle_kprobe_auto, "attach_kprobe_auto");
skel->links.handle_kretprobe_auto = bpf_program__attach(skel->progs.handle_kretprobe_auto);
ASSERT_OK_PTR(skel->links.handle_kretprobe_auto, "attach_kretprobe_auto");
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;
/* verify auto-attach fails for old-style uprobe definition */
uprobe_err_link = bpf_program__attach(skel->progs.handle_uprobe_byname);
if (!ASSERT_EQ(libbpf_get_error(uprobe_err_link), -EOPNOTSUPP,
"auto-attach should fail for old-style name"))
goto cleanup;
uprobe_opts.func_name = "trigger_func2";
uprobe_opts.retprobe = false;
uprobe_opts.ref_ctr_offset = 0;
skel->links.handle_uprobe_byname =
bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname,
0 /* this pid */,
"/proc/self/exe",
0, &uprobe_opts);
if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname, "attach_uprobe_byname"))
goto cleanup;
/* verify auto-attach works */
skel->links.handle_uretprobe_byname =
bpf_program__attach(skel->progs.handle_uretprobe_byname);
if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname, "attach_uretprobe_byname"))
goto cleanup;
/* test attach by name for a library function, using the library
* as the binary argument. libc.so.6 will be resolved via dlopen()/dlinfo().
*/
uprobe_opts.func_name = "malloc";
uprobe_opts.retprobe = false;
skel->links.handle_uprobe_byname2 =
bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname2,
0 /* this pid */,
"libc.so.6",
0, &uprobe_opts);
if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname2, "attach_uprobe_byname2"))
goto cleanup;
uprobe_opts.func_name = "free";
uprobe_opts.retprobe = true;
skel->links.handle_uretprobe_byname2 =
bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe_byname2,
-1 /* any pid */,
"libc.so.6",
0, &uprobe_opts);
if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname2, "attach_uretprobe_byname2"))
goto cleanup;
/* sleepable kprobes should not attach successfully */
skel->links.handle_kprobe_sleepable = bpf_program__attach(skel->progs.handle_kprobe_sleepable);
if (!ASSERT_ERR_PTR(skel->links.handle_kprobe_sleepable, "attach_kprobe_sleepable"))
goto cleanup;
/* test sleepable uprobe and uretprobe variants */
skel->links.handle_uprobe_byname3_sleepable = bpf_program__attach(skel->progs.handle_uprobe_byname3_sleepable);
if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname3_sleepable, "attach_uprobe_byname3_sleepable"))
goto cleanup;
skel->links.handle_uprobe_byname3 = bpf_program__attach(skel->progs.handle_uprobe_byname3);
if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname3, "attach_uprobe_byname3"))
goto cleanup;
skel->links.handle_uretprobe_byname3_sleepable = bpf_program__attach(skel->progs.handle_uretprobe_byname3_sleepable);
if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname3_sleepable, "attach_uretprobe_byname3_sleepable"))
goto cleanup;
skel->links.handle_uretprobe_byname3 = bpf_program__attach(skel->progs.handle_uretprobe_byname3);
if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname3, "attach_uretprobe_byname3"))
goto cleanup;
skel->bss->user_ptr = test_data;
/* trigger & validate kprobe && kretprobe */
usleep(1);
/* trigger & validate shared library u[ret]probes attached by name */
mem = malloc(1);
free(mem);
/* trigger & validate uprobe & uretprobe */
trigger_func();
/* trigger & validate uprobe attached by name */
trigger_func2();
/* trigger & validate sleepable uprobe attached by name */
trigger_func3();
ASSERT_EQ(skel->bss->kprobe_res, 1, "check_kprobe_res");
ASSERT_EQ(skel->bss->kprobe2_res, 11, "check_kprobe_auto_res");
ASSERT_EQ(skel->bss->kretprobe_res, 2, "check_kretprobe_res");
ASSERT_EQ(skel->bss->kretprobe2_res, 22, "check_kretprobe_auto_res");
ASSERT_EQ(skel->bss->uprobe_res, 3, "check_uprobe_res");
ASSERT_EQ(skel->bss->uretprobe_res, 4, "check_uretprobe_res");
ASSERT_EQ(skel->bss->uprobe_byname_res, 5, "check_uprobe_byname_res");
ASSERT_EQ(skel->bss->uretprobe_byname_res, 6, "check_uretprobe_byname_res");
ASSERT_EQ(skel->bss->uprobe_byname2_res, 7, "check_uprobe_byname2_res");
ASSERT_EQ(skel->bss->uretprobe_byname2_res, 8, "check_uretprobe_byname2_res");
ASSERT_EQ(skel->bss->uprobe_byname3_sleepable_res, 9, "check_uprobe_byname3_sleepable_res");
ASSERT_EQ(skel->bss->uprobe_byname3_res, 10, "check_uprobe_byname3_res");
ASSERT_EQ(skel->bss->uretprobe_byname3_sleepable_res, 11, "check_uretprobe_byname3_sleepable_res");
ASSERT_EQ(skel->bss->uretprobe_byname3_res, 12, "check_uretprobe_byname3_res");
cleanup:
test_attach_probe__destroy(skel);
ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_cleanup");
}
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