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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openat-syscall-all-cpus.c (3537B)

      1// SPDX-License-Identifier: GPL-2.0
      2#include <errno.h>
      3#include <inttypes.h>
      4/* For the CPU_* macros */
      5#include <pthread.h>
      6
      7#include <sys/types.h>
      8#include <sys/stat.h>
      9#include <fcntl.h>
     10#include <api/fs/fs.h>
     11#include <linux/err.h>
     12#include <linux/string.h>
     13#include <api/fs/tracing_path.h>
     14#include "evsel.h"
     15#include "tests.h"
     16#include "thread_map.h"
     17#include <perf/cpumap.h>
     18#include "debug.h"
     19#include "stat.h"
     20#include "util/counts.h"
     21
     22static int test__openat_syscall_event_on_all_cpus(struct test_suite *test __maybe_unused,
     23						  int subtest __maybe_unused)
     24{
     25	int err = TEST_FAIL, fd, idx;
     26	struct perf_cpu cpu;
     27	struct perf_cpu_map *cpus;
     28	struct evsel *evsel;
     29	unsigned int nr_openat_calls = 111, i;
     30	cpu_set_t cpu_set;
     31	struct perf_thread_map *threads = thread_map__new(-1, getpid(), UINT_MAX);
     32	char sbuf[STRERR_BUFSIZE];
     33	char errbuf[BUFSIZ];
     34
     35	if (threads == NULL) {
     36		pr_debug("thread_map__new\n");
     37		return -1;
     38	}
     39
     40	cpus = perf_cpu_map__new(NULL);
     41	if (cpus == NULL) {
     42		pr_debug("perf_cpu_map__new\n");
     43		goto out_thread_map_delete;
     44	}
     45
     46	CPU_ZERO(&cpu_set);
     47
     48	evsel = evsel__newtp("syscalls", "sys_enter_openat");
     49	if (IS_ERR(evsel)) {
     50		tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), "syscalls", "sys_enter_openat");
     51		pr_debug("%s\n", errbuf);
     52		err = TEST_SKIP;
     53		goto out_cpu_map_delete;
     54	}
     55
     56	if (evsel__open(evsel, cpus, threads) < 0) {
     57		pr_debug("failed to open counter: %s, "
     58			 "tweak /proc/sys/kernel/perf_event_paranoid?\n",
     59			 str_error_r(errno, sbuf, sizeof(sbuf)));
     60		err = TEST_SKIP;
     61		goto out_evsel_delete;
     62	}
     63
     64	perf_cpu_map__for_each_cpu(cpu, idx, cpus) {
     65		unsigned int ncalls = nr_openat_calls + idx;
     66		/*
     67		 * XXX eventually lift this restriction in a way that
     68		 * keeps perf building on older glibc installations
     69		 * without CPU_ALLOC. 1024 cpus in 2010 still seems
     70		 * a reasonable upper limit tho :-)
     71		 */
     72		if (cpu.cpu >= CPU_SETSIZE) {
     73			pr_debug("Ignoring CPU %d\n", cpu.cpu);
     74			continue;
     75		}
     76
     77		CPU_SET(cpu.cpu, &cpu_set);
     78		if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
     79			pr_debug("sched_setaffinity() failed on CPU %d: %s ",
     80				 cpu.cpu,
     81				 str_error_r(errno, sbuf, sizeof(sbuf)));
     82			goto out_close_fd;
     83		}
     84		for (i = 0; i < ncalls; ++i) {
     85			fd = openat(0, "/etc/passwd", O_RDONLY);
     86			close(fd);
     87		}
     88		CPU_CLR(cpu.cpu, &cpu_set);
     89	}
     90
     91	evsel->core.cpus = perf_cpu_map__get(cpus);
     92
     93	err = TEST_OK;
     94
     95	perf_cpu_map__for_each_cpu(cpu, idx, cpus) {
     96		unsigned int expected;
     97
     98		if (cpu.cpu >= CPU_SETSIZE)
     99			continue;
    100
    101		if (evsel__read_on_cpu(evsel, idx, 0) < 0) {
    102			pr_debug("evsel__read_on_cpu\n");
    103			err = TEST_FAIL;
    104			break;
    105		}
    106
    107		expected = nr_openat_calls + idx;
    108		if (perf_counts(evsel->counts, idx, 0)->val != expected) {
    109			pr_debug("evsel__read_on_cpu: expected to intercept %d calls on cpu %d, got %" PRIu64 "\n",
    110				 expected, cpu.cpu, perf_counts(evsel->counts, idx, 0)->val);
    111			err = TEST_FAIL;
    112		}
    113	}
    114
    115	evsel__free_counts(evsel);
    116out_close_fd:
    117	perf_evsel__close_fd(&evsel->core);
    118out_evsel_delete:
    119	evsel__delete(evsel);
    120out_cpu_map_delete:
    121	perf_cpu_map__put(cpus);
    122out_thread_map_delete:
    123	perf_thread_map__put(threads);
    124	return err;
    125}
    126
    127
    128static struct test_case tests__openat_syscall_event_on_all_cpus[] = {
    129	TEST_CASE_REASON("Detect openat syscall event on all cpus",
    130			 openat_syscall_event_on_all_cpus,
    131			 "permissions"),
    132	{	.name = NULL, }
    133};
    134
    135struct test_suite suite__openat_syscall_event_on_all_cpus = {
    136	.desc = "Detect openat syscall event on all cpus",
    137	.test_cases = tests__openat_syscall_event_on_all_cpus,
    138};