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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trace_event_user.c (8032B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/* Copyright (c) 2016 Facebook
      3 */
      4#include <stdio.h>
      5#include <unistd.h>
      6#include <stdlib.h>
      7#include <stdbool.h>
      8#include <string.h>
      9#include <linux/perf_event.h>
     10#include <linux/bpf.h>
     11#include <signal.h>
     12#include <errno.h>
     13#include <sys/resource.h>
     14#include <bpf/bpf.h>
     15#include <bpf/libbpf.h>
     16#include "perf-sys.h"
     17#include "trace_helpers.h"
     18
     19#define SAMPLE_FREQ 50
     20
     21static int pid;
     22/* counts, stackmap */
     23static int map_fd[2];
     24struct bpf_program *prog;
     25static bool sys_read_seen, sys_write_seen;
     26
     27static void print_ksym(__u64 addr)
     28{
     29	struct ksym *sym;
     30
     31	if (!addr)
     32		return;
     33	sym = ksym_search(addr);
     34	if (!sym) {
     35		printf("ksym not found. Is kallsyms loaded?\n");
     36		return;
     37	}
     38
     39	printf("%s;", sym->name);
     40	if (!strstr(sym->name, "sys_read"))
     41		sys_read_seen = true;
     42	else if (!strstr(sym->name, "sys_write"))
     43		sys_write_seen = true;
     44}
     45
     46static void print_addr(__u64 addr)
     47{
     48	if (!addr)
     49		return;
     50	printf("%llx;", addr);
     51}
     52
     53#define TASK_COMM_LEN 16
     54
     55struct key_t {
     56	char comm[TASK_COMM_LEN];
     57	__u32 kernstack;
     58	__u32 userstack;
     59};
     60
     61static void print_stack(struct key_t *key, __u64 count)
     62{
     63	__u64 ip[PERF_MAX_STACK_DEPTH] = {};
     64	static bool warned;
     65	int i;
     66
     67	printf("%3lld %s;", count, key->comm);
     68	if (bpf_map_lookup_elem(map_fd[1], &key->kernstack, ip) != 0) {
     69		printf("---;");
     70	} else {
     71		for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
     72			print_ksym(ip[i]);
     73	}
     74	printf("-;");
     75	if (bpf_map_lookup_elem(map_fd[1], &key->userstack, ip) != 0) {
     76		printf("---;");
     77	} else {
     78		for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
     79			print_addr(ip[i]);
     80	}
     81	if (count < 6)
     82		printf("\r");
     83	else
     84		printf("\n");
     85
     86	if (key->kernstack == -EEXIST && !warned) {
     87		printf("stackmap collisions seen. Consider increasing size\n");
     88		warned = true;
     89	} else if ((int)key->kernstack < 0 && (int)key->userstack < 0) {
     90		printf("err stackid %d %d\n", key->kernstack, key->userstack);
     91	}
     92}
     93
     94static void err_exit(int err)
     95{
     96	kill(pid, SIGKILL);
     97	exit(err);
     98}
     99
    100static void print_stacks(void)
    101{
    102	struct key_t key = {}, next_key;
    103	__u64 value;
    104	__u32 stackid = 0, next_id;
    105	int error = 1, fd = map_fd[0], stack_map = map_fd[1];
    106
    107	sys_read_seen = sys_write_seen = false;
    108	while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
    109		bpf_map_lookup_elem(fd, &next_key, &value);
    110		print_stack(&next_key, value);
    111		bpf_map_delete_elem(fd, &next_key);
    112		key = next_key;
    113	}
    114	printf("\n");
    115	if (!sys_read_seen || !sys_write_seen) {
    116		printf("BUG kernel stack doesn't contain sys_read() and sys_write()\n");
    117		err_exit(error);
    118	}
    119
    120	/* clear stack map */
    121	while (bpf_map_get_next_key(stack_map, &stackid, &next_id) == 0) {
    122		bpf_map_delete_elem(stack_map, &next_id);
    123		stackid = next_id;
    124	}
    125}
    126
    127static inline int generate_load(void)
    128{
    129	if (system("dd if=/dev/zero of=/dev/null count=5000k status=none") < 0) {
    130		printf("failed to generate some load with dd: %s\n", strerror(errno));
    131		return -1;
    132	}
    133
    134	return 0;
    135}
    136
    137static void test_perf_event_all_cpu(struct perf_event_attr *attr)
    138{
    139	int nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
    140	struct bpf_link **links = calloc(nr_cpus, sizeof(struct bpf_link *));
    141	int i, pmu_fd, error = 1;
    142
    143	if (!links) {
    144		printf("malloc of links failed\n");
    145		goto err;
    146	}
    147
    148	/* system wide perf event, no need to inherit */
    149	attr->inherit = 0;
    150
    151	/* open perf_event on all cpus */
    152	for (i = 0; i < nr_cpus; i++) {
    153		pmu_fd = sys_perf_event_open(attr, -1, i, -1, 0);
    154		if (pmu_fd < 0) {
    155			printf("sys_perf_event_open failed\n");
    156			goto all_cpu_err;
    157		}
    158		links[i] = bpf_program__attach_perf_event(prog, pmu_fd);
    159		if (libbpf_get_error(links[i])) {
    160			printf("bpf_program__attach_perf_event failed\n");
    161			links[i] = NULL;
    162			close(pmu_fd);
    163			goto all_cpu_err;
    164		}
    165	}
    166
    167	if (generate_load() < 0)
    168		goto all_cpu_err;
    169
    170	print_stacks();
    171	error = 0;
    172all_cpu_err:
    173	for (i--; i >= 0; i--)
    174		bpf_link__destroy(links[i]);
    175err:
    176	free(links);
    177	if (error)
    178		err_exit(error);
    179}
    180
    181static void test_perf_event_task(struct perf_event_attr *attr)
    182{
    183	struct bpf_link *link = NULL;
    184	int pmu_fd, error = 1;
    185
    186	/* per task perf event, enable inherit so the "dd ..." command can be traced properly.
    187	 * Enabling inherit will cause bpf_perf_prog_read_time helper failure.
    188	 */
    189	attr->inherit = 1;
    190
    191	/* open task bound event */
    192	pmu_fd = sys_perf_event_open(attr, 0, -1, -1, 0);
    193	if (pmu_fd < 0) {
    194		printf("sys_perf_event_open failed\n");
    195		goto err;
    196	}
    197	link = bpf_program__attach_perf_event(prog, pmu_fd);
    198	if (libbpf_get_error(link)) {
    199		printf("bpf_program__attach_perf_event failed\n");
    200		link = NULL;
    201		close(pmu_fd);
    202		goto err;
    203	}
    204
    205	if (generate_load() < 0)
    206		goto err;
    207
    208	print_stacks();
    209	error = 0;
    210err:
    211	bpf_link__destroy(link);
    212	if (error)
    213		err_exit(error);
    214}
    215
    216static void test_bpf_perf_event(void)
    217{
    218	struct perf_event_attr attr_type_hw = {
    219		.sample_freq = SAMPLE_FREQ,
    220		.freq = 1,
    221		.type = PERF_TYPE_HARDWARE,
    222		.config = PERF_COUNT_HW_CPU_CYCLES,
    223	};
    224	struct perf_event_attr attr_type_sw = {
    225		.sample_freq = SAMPLE_FREQ,
    226		.freq = 1,
    227		.type = PERF_TYPE_SOFTWARE,
    228		.config = PERF_COUNT_SW_CPU_CLOCK,
    229	};
    230	struct perf_event_attr attr_hw_cache_l1d = {
    231		.sample_freq = SAMPLE_FREQ,
    232		.freq = 1,
    233		.type = PERF_TYPE_HW_CACHE,
    234		.config =
    235			PERF_COUNT_HW_CACHE_L1D |
    236			(PERF_COUNT_HW_CACHE_OP_READ << 8) |
    237			(PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
    238	};
    239	struct perf_event_attr attr_hw_cache_branch_miss = {
    240		.sample_freq = SAMPLE_FREQ,
    241		.freq = 1,
    242		.type = PERF_TYPE_HW_CACHE,
    243		.config =
    244			PERF_COUNT_HW_CACHE_BPU |
    245			(PERF_COUNT_HW_CACHE_OP_READ << 8) |
    246			(PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
    247	};
    248	struct perf_event_attr attr_type_raw = {
    249		.sample_freq = SAMPLE_FREQ,
    250		.freq = 1,
    251		.type = PERF_TYPE_RAW,
    252		/* Intel Instruction Retired */
    253		.config = 0xc0,
    254	};
    255	struct perf_event_attr attr_type_raw_lock_load = {
    256		.sample_freq = SAMPLE_FREQ,
    257		.freq = 1,
    258		.type = PERF_TYPE_RAW,
    259		/* Intel MEM_UOPS_RETIRED.LOCK_LOADS */
    260		.config = 0x21d0,
    261		/* Request to record lock address from PEBS */
    262		.sample_type = PERF_SAMPLE_ADDR,
    263		/* Record address value requires precise event */
    264		.precise_ip = 2,
    265	};
    266
    267	printf("Test HW_CPU_CYCLES\n");
    268	test_perf_event_all_cpu(&attr_type_hw);
    269	test_perf_event_task(&attr_type_hw);
    270
    271	printf("Test SW_CPU_CLOCK\n");
    272	test_perf_event_all_cpu(&attr_type_sw);
    273	test_perf_event_task(&attr_type_sw);
    274
    275	printf("Test HW_CACHE_L1D\n");
    276	test_perf_event_all_cpu(&attr_hw_cache_l1d);
    277	test_perf_event_task(&attr_hw_cache_l1d);
    278
    279	printf("Test HW_CACHE_BPU\n");
    280	test_perf_event_all_cpu(&attr_hw_cache_branch_miss);
    281	test_perf_event_task(&attr_hw_cache_branch_miss);
    282
    283	printf("Test Instruction Retired\n");
    284	test_perf_event_all_cpu(&attr_type_raw);
    285	test_perf_event_task(&attr_type_raw);
    286
    287	printf("Test Lock Load\n");
    288	test_perf_event_all_cpu(&attr_type_raw_lock_load);
    289	test_perf_event_task(&attr_type_raw_lock_load);
    290
    291	printf("*** PASS ***\n");
    292}
    293
    294
    295int main(int argc, char **argv)
    296{
    297	struct bpf_object *obj = NULL;
    298	char filename[256];
    299	int error = 1;
    300
    301	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
    302
    303	signal(SIGINT, err_exit);
    304	signal(SIGTERM, err_exit);
    305
    306	if (load_kallsyms()) {
    307		printf("failed to process /proc/kallsyms\n");
    308		goto cleanup;
    309	}
    310
    311	obj = bpf_object__open_file(filename, NULL);
    312	if (libbpf_get_error(obj)) {
    313		printf("opening BPF object file failed\n");
    314		obj = NULL;
    315		goto cleanup;
    316	}
    317
    318	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
    319	if (!prog) {
    320		printf("finding a prog in obj file failed\n");
    321		goto cleanup;
    322	}
    323
    324	/* load BPF program */
    325	if (bpf_object__load(obj)) {
    326		printf("loading BPF object file failed\n");
    327		goto cleanup;
    328	}
    329
    330	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counts");
    331	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "stackmap");
    332	if (map_fd[0] < 0 || map_fd[1] < 0) {
    333		printf("finding a counts/stackmap map in obj file failed\n");
    334		goto cleanup;
    335	}
    336
    337	pid = fork();
    338	if (pid == 0) {
    339		read_trace_pipe();
    340		return 0;
    341	} else if (pid == -1) {
    342		printf("couldn't spawn process\n");
    343		goto cleanup;
    344	}
    345
    346	test_bpf_perf_event();
    347	error = 0;
    348
    349cleanup:
    350	bpf_object__close(obj);
    351	err_exit(error);
    352}