cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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link_pinning.c (2779B)

      1// SPDX-License-Identifier: GPL-2.0
      2/* Copyright (c) 2020 Facebook */
      3
      4#include <test_progs.h>
      5#include <sys/stat.h>
      6
      7#include "test_link_pinning.skel.h"
      8
      9static int duration = 0;
     10
     11void test_link_pinning_subtest(struct bpf_program *prog,
     12			       struct test_link_pinning__bss *bss)
     13{
     14	const char *link_pin_path = "/sys/fs/bpf/pinned_link_test";
     15	struct stat statbuf = {};
     16	struct bpf_link *link;
     17	int err, i;
     18
     19	link = bpf_program__attach(prog);
     20	if (!ASSERT_OK_PTR(link, "link_attach"))
     21		goto cleanup;
     22
     23	bss->in = 1;
     24	usleep(1);
     25	CHECK(bss->out != 1, "res_check1", "exp %d, got %d\n", 1, bss->out);
     26
     27	/* pin link */
     28	err = bpf_link__pin(link, link_pin_path);
     29	if (CHECK(err, "link_pin", "err: %d\n", err))
     30		goto cleanup;
     31
     32	CHECK(strcmp(link_pin_path, bpf_link__pin_path(link)), "pin_path1",
     33	      "exp %s, got %s\n", link_pin_path, bpf_link__pin_path(link));
     34
     35	/* check that link was pinned */
     36	err = stat(link_pin_path, &statbuf);
     37	if (CHECK(err, "stat_link", "err %d errno %d\n", err, errno))
     38		goto cleanup;
     39
     40	bss->in = 2;
     41	usleep(1);
     42	CHECK(bss->out != 2, "res_check2", "exp %d, got %d\n", 2, bss->out);
     43
     44	/* destroy link, pinned link should keep program attached */
     45	bpf_link__destroy(link);
     46	link = NULL;
     47
     48	bss->in = 3;
     49	usleep(1);
     50	CHECK(bss->out != 3, "res_check3", "exp %d, got %d\n", 3, bss->out);
     51
     52	/* re-open link from BPFFS */
     53	link = bpf_link__open(link_pin_path);
     54	if (!ASSERT_OK_PTR(link, "link_open"))
     55		goto cleanup;
     56
     57	CHECK(strcmp(link_pin_path, bpf_link__pin_path(link)), "pin_path2",
     58	      "exp %s, got %s\n", link_pin_path, bpf_link__pin_path(link));
     59
     60	/* unpin link from BPFFS, program still attached */
     61	err = bpf_link__unpin(link);
     62	if (CHECK(err, "link_unpin", "err: %d\n", err))
     63		goto cleanup;
     64
     65	/* still active, as we have FD open now */
     66	bss->in = 4;
     67	usleep(1);
     68	CHECK(bss->out != 4, "res_check4", "exp %d, got %d\n", 4, bss->out);
     69
     70	bpf_link__destroy(link);
     71	link = NULL;
     72
     73	/* Validate it's finally detached.
     74	 * Actual detachment might get delayed a bit, so there is no reliable
     75	 * way to validate it immediately here, let's count up for long enough
     76	 * and see if eventually output stops being updated
     77	 */
     78	for (i = 5; i < 10000; i++) {
     79		bss->in = i;
     80		usleep(1);
     81		if (bss->out == i - 1)
     82			break;
     83	}
     84	CHECK(i == 10000, "link_attached", "got to iteration #%d\n", i);
     85
     86cleanup:
     87	bpf_link__destroy(link);
     88}
     89
     90void test_link_pinning(void)
     91{
     92	struct test_link_pinning* skel;
     93
     94	skel = test_link_pinning__open_and_load();
     95	if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
     96		return;
     97
     98	if (test__start_subtest("pin_raw_tp"))
     99		test_link_pinning_subtest(skel->progs.raw_tp_prog, skel->bss);
    100	if (test__start_subtest("pin_tp_btf"))
    101		test_link_pinning_subtest(skel->progs.tp_btf_prog, skel->bss);
    102
    103	test_link_pinning__destroy(skel);
    104}