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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backward-ring-buffer.c (3886B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Test backward bit in event attribute, read ring buffer from end to
      4 * beginning
      5 */
      6
      7#include <evlist.h>
      8#include <sys/prctl.h>
      9#include "record.h"
     10#include "tests.h"
     11#include "debug.h"
     12#include "parse-events.h"
     13#include "util/mmap.h"
     14#include <errno.h>
     15#include <linux/string.h>
     16#include <perf/mmap.h>
     17
     18#define NR_ITERS 111
     19
     20static void testcase(void)
     21{
     22	int i;
     23
     24	for (i = 0; i < NR_ITERS; i++) {
     25		char proc_name[15];
     26
     27		snprintf(proc_name, sizeof(proc_name), "p:%d\n", i);
     28		prctl(PR_SET_NAME, proc_name);
     29	}
     30}
     31
     32static int count_samples(struct evlist *evlist, int *sample_count,
     33			 int *comm_count)
     34{
     35	int i;
     36
     37	for (i = 0; i < evlist->core.nr_mmaps; i++) {
     38		struct mmap *map = &evlist->overwrite_mmap[i];
     39		union perf_event *event;
     40
     41		perf_mmap__read_init(&map->core);
     42		while ((event = perf_mmap__read_event(&map->core)) != NULL) {
     43			const u32 type = event->header.type;
     44
     45			switch (type) {
     46			case PERF_RECORD_SAMPLE:
     47				(*sample_count)++;
     48				break;
     49			case PERF_RECORD_COMM:
     50				(*comm_count)++;
     51				break;
     52			default:
     53				pr_err("Unexpected record of type %d\n", type);
     54				return TEST_FAIL;
     55			}
     56		}
     57		perf_mmap__read_done(&map->core);
     58	}
     59	return TEST_OK;
     60}
     61
     62static int do_test(struct evlist *evlist, int mmap_pages,
     63		   int *sample_count, int *comm_count)
     64{
     65	int err;
     66	char sbuf[STRERR_BUFSIZE];
     67
     68	err = evlist__mmap(evlist, mmap_pages);
     69	if (err < 0) {
     70		pr_debug("evlist__mmap: %s\n",
     71			 str_error_r(errno, sbuf, sizeof(sbuf)));
     72		return TEST_FAIL;
     73	}
     74
     75	evlist__enable(evlist);
     76	testcase();
     77	evlist__disable(evlist);
     78
     79	err = count_samples(evlist, sample_count, comm_count);
     80	evlist__munmap(evlist);
     81	return err;
     82}
     83
     84
     85static int test__backward_ring_buffer(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
     86{
     87	int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0;
     88	char pid[16], sbuf[STRERR_BUFSIZE];
     89	struct evlist *evlist;
     90	struct evsel *evsel __maybe_unused;
     91	struct parse_events_error parse_error;
     92	struct record_opts opts = {
     93		.target = {
     94			.uid = UINT_MAX,
     95			.uses_mmap = true,
     96		},
     97		.freq	      = 0,
     98		.mmap_pages   = 256,
     99		.default_interval = 1,
    100	};
    101
    102	snprintf(pid, sizeof(pid), "%d", getpid());
    103	pid[sizeof(pid) - 1] = '\0';
    104	opts.target.tid = opts.target.pid = pid;
    105
    106	evlist = evlist__new();
    107	if (!evlist) {
    108		pr_debug("Not enough memory to create evlist\n");
    109		return TEST_FAIL;
    110	}
    111
    112	err = evlist__create_maps(evlist, &opts.target);
    113	if (err < 0) {
    114		pr_debug("Not enough memory to create thread/cpu maps\n");
    115		goto out_delete_evlist;
    116	}
    117
    118	parse_events_error__init(&parse_error);
    119	/*
    120	 * Set backward bit, ring buffer should be writing from end. Record
    121	 * it in aux evlist
    122	 */
    123	err = parse_events(evlist, "syscalls:sys_enter_prctl/overwrite/", &parse_error);
    124	parse_events_error__exit(&parse_error);
    125	if (err) {
    126		pr_debug("Failed to parse tracepoint event, try use root\n");
    127		ret = TEST_SKIP;
    128		goto out_delete_evlist;
    129	}
    130
    131	evlist__config(evlist, &opts, NULL);
    132
    133	err = evlist__open(evlist);
    134	if (err < 0) {
    135		pr_debug("perf_evlist__open: %s\n",
    136			 str_error_r(errno, sbuf, sizeof(sbuf)));
    137		goto out_delete_evlist;
    138	}
    139
    140	ret = TEST_FAIL;
    141	err = do_test(evlist, opts.mmap_pages, &sample_count,
    142		      &comm_count);
    143	if (err != TEST_OK)
    144		goto out_delete_evlist;
    145
    146	if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) {
    147		pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n",
    148		       sample_count, comm_count);
    149		goto out_delete_evlist;
    150	}
    151
    152	evlist__close(evlist);
    153
    154	err = evlist__open(evlist);
    155	if (err < 0) {
    156		pr_debug("perf_evlist__open: %s\n",
    157			 str_error_r(errno, sbuf, sizeof(sbuf)));
    158		goto out_delete_evlist;
    159	}
    160
    161	err = do_test(evlist, 1, &sample_count, &comm_count);
    162	if (err != TEST_OK)
    163		goto out_delete_evlist;
    164
    165	ret = TEST_OK;
    166out_delete_evlist:
    167	evlist__delete(evlist);
    168	return ret;
    169}
    170
    171DEFINE_SUITE("Read backward ring buffer", backward_ring_buffer);