selftests/bpf: Add uprobe session recursive test

Adding uprobe session test that verifies the cookie value is stored
properly when single uprobe-ed function is executed recursively.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241108134544.480660-9-jolsa@kernel.org
This commit is contained in:
Jiri Olsa 2024-11-08 14:45:39 +01:00 committed by Andrii Nakryiko
parent f6b45e352f
commit 8bcb9c62f0
2 changed files with 101 additions and 0 deletions

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@ -10,6 +10,7 @@
#include "uprobe_multi_pid_filter.skel.h"
#include "uprobe_multi_session.skel.h"
#include "uprobe_multi_session_cookie.skel.h"
#include "uprobe_multi_session_recursive.skel.h"
#include "bpf/libbpf_internal.h"
#include "testing_helpers.h"
#include "../sdt.h"
@ -36,6 +37,12 @@ noinline void usdt_trigger(void)
STAP_PROBE(test, pid_filter_usdt);
}
noinline void uprobe_session_recursive(int i)
{
if (i)
uprobe_session_recursive(i - 1);
}
struct child {
int go[2];
int c2p[2]; /* child -> parent channel */
@ -1091,6 +1098,54 @@ cleanup:
uprobe_multi_session_cookie__destroy(skel);
}
static void test_session_recursive_skel_api(void)
{
struct uprobe_multi_session_recursive *skel = NULL;
int i, err;
skel = uprobe_multi_session_recursive__open_and_load();
if (!ASSERT_OK_PTR(skel, "uprobe_multi_session_recursive__open_and_load"))
goto cleanup;
skel->bss->pid = getpid();
err = uprobe_multi_session_recursive__attach(skel);
if (!ASSERT_OK(err, "uprobe_multi_session_recursive__attach"))
goto cleanup;
for (i = 0; i < ARRAY_SIZE(skel->bss->test_uprobe_cookie_entry); i++)
skel->bss->test_uprobe_cookie_entry[i] = i + 1;
uprobe_session_recursive(5);
/*
* entry uprobe:
* uprobe_session_recursive(5) { *cookie = 1, return 0
* uprobe_session_recursive(4) { *cookie = 2, return 1
* uprobe_session_recursive(3) { *cookie = 3, return 0
* uprobe_session_recursive(2) { *cookie = 4, return 1
* uprobe_session_recursive(1) { *cookie = 5, return 0
* uprobe_session_recursive(0) { *cookie = 6, return 1
* return uprobe:
* } i = 0 not executed
* } i = 1 test_uprobe_cookie_return[0] = 5
* } i = 2 not executed
* } i = 3 test_uprobe_cookie_return[1] = 3
* } i = 4 not executed
* } i = 5 test_uprobe_cookie_return[2] = 1
*/
ASSERT_EQ(skel->bss->idx_entry, 6, "idx_entry");
ASSERT_EQ(skel->bss->idx_return, 3, "idx_return");
ASSERT_EQ(skel->bss->test_uprobe_cookie_return[0], 5, "test_uprobe_cookie_return[0]");
ASSERT_EQ(skel->bss->test_uprobe_cookie_return[1], 3, "test_uprobe_cookie_return[1]");
ASSERT_EQ(skel->bss->test_uprobe_cookie_return[2], 1, "test_uprobe_cookie_return[2]");
cleanup:
uprobe_multi_session_recursive__destroy(skel);
}
static void test_bench_attach_uprobe(void)
{
long attach_start_ns = 0, attach_end_ns = 0;
@ -1191,4 +1246,6 @@ void test_uprobe_multi_test(void)
test_session_skel_api();
if (test__start_subtest("session_cookie"))
test_session_cookie_skel_api();
if (test__start_subtest("session_cookie_recursive"))
test_session_recursive_skel_api();
}

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@ -0,0 +1,44 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <stdbool.h>
#include "bpf_kfuncs.h"
#include "bpf_misc.h"
char _license[] SEC("license") = "GPL";
int pid = 0;
int idx_entry = 0;
int idx_return = 0;
__u64 test_uprobe_cookie_entry[6];
__u64 test_uprobe_cookie_return[3];
static int check_cookie(void)
{
__u64 *cookie = bpf_session_cookie();
if (bpf_session_is_return()) {
if (idx_return >= ARRAY_SIZE(test_uprobe_cookie_return))
return 1;
test_uprobe_cookie_return[idx_return++] = *cookie;
return 0;
}
if (idx_entry >= ARRAY_SIZE(test_uprobe_cookie_entry))
return 1;
*cookie = test_uprobe_cookie_entry[idx_entry];
return idx_entry++ % 2;
}
SEC("uprobe.session//proc/self/exe:uprobe_session_recursive")
int uprobe_recursive(struct pt_regs *ctx)
{
if (bpf_get_current_pid_tgid() >> 32 != pid)
return 1;
return check_cookie();
}