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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task-exit.c (3641B)

      1// SPDX-License-Identifier: GPL-2.0
      2#include "debug.h"
      3#include "evlist.h"
      4#include "evsel.h"
      5#include "target.h"
      6#include "thread_map.h"
      7#include "tests.h"
      8#include "util/mmap.h"
      9
     10#include <errno.h>
     11#include <signal.h>
     12#include <linux/string.h>
     13#include <perf/cpumap.h>
     14#include <perf/evlist.h>
     15#include <perf/mmap.h>
     16
     17static int exited;
     18static int nr_exit;
     19
     20static void sig_handler(int sig __maybe_unused)
     21{
     22	exited = 1;
     23}
     24
     25/*
     26 * evlist__prepare_workload will send a SIGUSR1 if the fork fails, since
     27 * we asked by setting its exec_error to this handler.
     28 */
     29static void workload_exec_failed_signal(int signo __maybe_unused,
     30					siginfo_t *info __maybe_unused,
     31					void *ucontext __maybe_unused)
     32{
     33	exited	= 1;
     34	nr_exit = -1;
     35}
     36
     37/*
     38 * This test will start a workload that does nothing then it checks
     39 * if the number of exit event reported by the kernel is 1 or not
     40 * in order to check the kernel returns correct number of event.
     41 */
     42static int test__task_exit(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
     43{
     44	int err = -1;
     45	union perf_event *event;
     46	struct evsel *evsel;
     47	struct evlist *evlist;
     48	struct target target = {
     49		.uid		= UINT_MAX,
     50		.uses_mmap	= true,
     51	};
     52	const char *argv[] = { "true", NULL };
     53	char sbuf[STRERR_BUFSIZE];
     54	struct perf_cpu_map *cpus;
     55	struct perf_thread_map *threads;
     56	struct mmap *md;
     57	int retry_count = 0;
     58
     59	signal(SIGCHLD, sig_handler);
     60
     61	evlist = evlist__new_default();
     62	if (evlist == NULL) {
     63		pr_debug("evlist__new_default\n");
     64		return -1;
     65	}
     66
     67	/*
     68	 * Create maps of threads and cpus to monitor. In this case
     69	 * we start with all threads and cpus (-1, -1) but then in
     70	 * evlist__prepare_workload we'll fill in the only thread
     71	 * we're monitoring, the one forked there.
     72	 */
     73	cpus = perf_cpu_map__dummy_new();
     74	threads = thread_map__new_by_tid(-1);
     75	if (!cpus || !threads) {
     76		err = -ENOMEM;
     77		pr_debug("Not enough memory to create thread/cpu maps\n");
     78		goto out_delete_evlist;
     79	}
     80
     81	perf_evlist__set_maps(&evlist->core, cpus, threads);
     82
     83	err = evlist__prepare_workload(evlist, &target, argv, false, workload_exec_failed_signal);
     84	if (err < 0) {
     85		pr_debug("Couldn't run the workload!\n");
     86		goto out_delete_evlist;
     87	}
     88
     89	evsel = evlist__first(evlist);
     90	evsel->core.attr.task = 1;
     91#ifdef __s390x__
     92	evsel->core.attr.sample_freq = 1000000;
     93#else
     94	evsel->core.attr.sample_freq = 1;
     95#endif
     96	evsel->core.attr.inherit = 0;
     97	evsel->core.attr.watermark = 0;
     98	evsel->core.attr.wakeup_events = 1;
     99	evsel->core.attr.exclude_kernel = 1;
    100
    101	err = evlist__open(evlist);
    102	if (err < 0) {
    103		pr_debug("Couldn't open the evlist: %s\n",
    104			 str_error_r(-err, sbuf, sizeof(sbuf)));
    105		goto out_delete_evlist;
    106	}
    107
    108	if (evlist__mmap(evlist, 128) < 0) {
    109		pr_debug("failed to mmap events: %d (%s)\n", errno,
    110			 str_error_r(errno, sbuf, sizeof(sbuf)));
    111		err = -1;
    112		goto out_delete_evlist;
    113	}
    114
    115	evlist__start_workload(evlist);
    116
    117retry:
    118	md = &evlist->mmap[0];
    119	if (perf_mmap__read_init(&md->core) < 0)
    120		goto out_init;
    121
    122	while ((event = perf_mmap__read_event(&md->core)) != NULL) {
    123		if (event->header.type == PERF_RECORD_EXIT)
    124			nr_exit++;
    125
    126		perf_mmap__consume(&md->core);
    127	}
    128	perf_mmap__read_done(&md->core);
    129
    130out_init:
    131	if (!exited || !nr_exit) {
    132		evlist__poll(evlist, -1);
    133
    134		if (retry_count++ > 1000) {
    135			pr_debug("Failed after retrying 1000 times\n");
    136			err = -1;
    137			goto out_delete_evlist;
    138		}
    139
    140		goto retry;
    141	}
    142
    143	if (nr_exit != 1) {
    144		pr_debug("received %d EXIT records\n", nr_exit);
    145		err = -1;
    146	}
    147
    148out_delete_evlist:
    149	perf_cpu_map__put(cpus);
    150	perf_thread_map__put(threads);
    151	evlist__delete(evlist);
    152	return err;
    153}
    154
    155DEFINE_SUITE("Number of exit events of a simple workload", task_exit);