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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */
#include <test_progs.h>
#include "testing_helpers.h"
#include "livepatch_trampoline.skel.h"
static int load_livepatch(void)
{
char path[4096];
/* CI will set KBUILD_OUTPUT */
snprintf(path, sizeof(path), "%s/samples/livepatch/livepatch-sample.ko",
getenv("KBUILD_OUTPUT") ? : "../../../..");
return load_module(path, env_verbosity > VERBOSE_NONE);
}
static void unload_livepatch(void)
{
/* Disable the livepatch before unloading the module */
system("echo 0 > /sys/kernel/livepatch/livepatch_sample/enabled");
unload_module("livepatch_sample", env_verbosity > VERBOSE_NONE);
}
static void read_proc_cmdline(void)
{
char buf[4096];
int fd, ret;
fd = open("/proc/cmdline", O_RDONLY);
if (!ASSERT_OK_FD(fd, "open /proc/cmdline"))
return;
ret = read(fd, buf, sizeof(buf));
if (!ASSERT_GT(ret, 0, "read /proc/cmdline"))
goto out;
ASSERT_OK(strncmp(buf, "this has been live patched", 26), "strncmp");
out:
close(fd);
}
static void __test_livepatch_trampoline(bool fexit_first)
{
struct livepatch_trampoline *skel = NULL;
int err;
skel = livepatch_trampoline__open_and_load();
if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
goto out;
skel->bss->my_pid = getpid();
if (!fexit_first) {
/* fentry program is loaded first by default */
err = livepatch_trampoline__attach(skel);
if (!ASSERT_OK(err, "skel_attach"))
goto out;
} else {
/* Manually load fexit program first. */
skel->links.fexit_cmdline = bpf_program__attach(skel->progs.fexit_cmdline);
if (!ASSERT_OK_PTR(skel->links.fexit_cmdline, "attach_fexit"))
goto out;
skel->links.fentry_cmdline = bpf_program__attach(skel->progs.fentry_cmdline);
if (!ASSERT_OK_PTR(skel->links.fentry_cmdline, "attach_fentry"))
goto out;
}
read_proc_cmdline();
ASSERT_EQ(skel->bss->fentry_hit, 1, "fentry_hit");
ASSERT_EQ(skel->bss->fexit_hit, 1, "fexit_hit");
out:
livepatch_trampoline__destroy(skel);
}
void test_livepatch_trampoline(void)
{
int retry_cnt = 0;
retry:
if (load_livepatch()) {
if (retry_cnt) {
ASSERT_OK(1, "load_livepatch");
goto out;
}
/*
* Something else (previous run of the same test?) loaded
* the KLP module. Unload the KLP module and retry.
*/
unload_livepatch();
retry_cnt++;
goto retry;
}
if (test__start_subtest("fentry_first"))
__test_livepatch_trampoline(false);
if (test__start_subtest("fexit_first"))
__test_livepatch_trampoline(true);
out:
unload_livepatch();
}
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