131 lines
2.8 KiB
C
131 lines
2.8 KiB
C
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
|
/* Copyright (c) 2021 Facebook */
|
||
|
|
#include <test_progs.h>
|
||
|
|
#include "get_branch_snapshot.skel.h"
|
||
|
|
|
||
|
|
static int *pfd_array;
|
||
|
|
static int cpu_cnt;
|
||
|
|
|
||
|
|
static bool is_hypervisor(void)
|
||
|
|
{
|
||
|
|
char *line = NULL;
|
||
|
|
bool ret = false;
|
||
|
|
size_t len;
|
||
|
|
FILE *fp;
|
||
|
|
|
||
|
|
fp = fopen("/proc/cpuinfo", "r");
|
||
|
|
if (!fp)
|
||
|
|
return false;
|
||
|
|
|
||
|
|
while (getline(&line, &len, fp) != -1) {
|
||
|
|
if (!strncmp(line, "flags", 5)) {
|
||
|
|
if (strstr(line, "hypervisor") != NULL)
|
||
|
|
ret = true;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
free(line);
|
||
|
|
fclose(fp);
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int create_perf_events(void)
|
||
|
|
{
|
||
|
|
struct perf_event_attr attr = {0};
|
||
|
|
int cpu;
|
||
|
|
|
||
|
|
/* create perf event */
|
||
|
|
attr.size = sizeof(attr);
|
||
|
|
attr.type = PERF_TYPE_RAW;
|
||
|
|
attr.config = 0x1b00;
|
||
|
|
attr.sample_type = PERF_SAMPLE_BRANCH_STACK;
|
||
|
|
attr.branch_sample_type = PERF_SAMPLE_BRANCH_KERNEL |
|
||
|
|
PERF_SAMPLE_BRANCH_USER | PERF_SAMPLE_BRANCH_ANY;
|
||
|
|
|
||
|
|
cpu_cnt = libbpf_num_possible_cpus();
|
||
|
|
pfd_array = malloc(sizeof(int) * cpu_cnt);
|
||
|
|
if (!pfd_array) {
|
||
|
|
cpu_cnt = 0;
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
for (cpu = 0; cpu < cpu_cnt; cpu++) {
|
||
|
|
pfd_array[cpu] = syscall(__NR_perf_event_open, &attr,
|
||
|
|
-1, cpu, -1, PERF_FLAG_FD_CLOEXEC);
|
||
|
|
if (pfd_array[cpu] < 0)
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
return cpu == 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void close_perf_events(void)
|
||
|
|
{
|
||
|
|
int cpu, fd;
|
||
|
|
|
||
|
|
for (cpu = 0; cpu < cpu_cnt; cpu++) {
|
||
|
|
fd = pfd_array[cpu];
|
||
|
|
if (fd < 0)
|
||
|
|
break;
|
||
|
|
close(fd);
|
||
|
|
}
|
||
|
|
free(pfd_array);
|
||
|
|
}
|
||
|
|
|
||
|
|
void serial_test_get_branch_snapshot(void)
|
||
|
|
{
|
||
|
|
struct get_branch_snapshot *skel = NULL;
|
||
|
|
int err;
|
||
|
|
|
||
|
|
/* Skip the test before we fix LBR snapshot for hypervisor. */
|
||
|
|
if (is_hypervisor()) {
|
||
|
|
test__skip();
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (create_perf_events()) {
|
||
|
|
test__skip(); /* system doesn't support LBR */
|
||
|
|
goto cleanup;
|
||
|
|
}
|
||
|
|
|
||
|
|
skel = get_branch_snapshot__open_and_load();
|
||
|
|
if (!ASSERT_OK_PTR(skel, "get_branch_snapshot__open_and_load"))
|
||
|
|
goto cleanup;
|
||
|
|
|
||
|
|
err = kallsyms_find("bpf_testmod_loop_test", &skel->bss->address_low);
|
||
|
|
if (!ASSERT_OK(err, "kallsyms_find"))
|
||
|
|
goto cleanup;
|
||
|
|
|
||
|
|
/* Just a guess for the end of this function, as module functions
|
||
|
|
* in /proc/kallsyms could come in any order.
|
||
|
|
*/
|
||
|
|
skel->bss->address_high = skel->bss->address_low + 128;
|
||
|
|
|
||
|
|
err = get_branch_snapshot__attach(skel);
|
||
|
|
if (!ASSERT_OK(err, "get_branch_snapshot__attach"))
|
||
|
|
goto cleanup;
|
||
|
|
|
||
|
|
trigger_module_test_read(100);
|
||
|
|
|
||
|
|
if (skel->bss->total_entries < 16) {
|
||
|
|
/* too few entries for the hit/waste test */
|
||
|
|
test__skip();
|
||
|
|
goto cleanup;
|
||
|
|
}
|
||
|
|
|
||
|
|
ASSERT_GT(skel->bss->test1_hits, 6, "find_looptest_in_lbr");
|
||
|
|
|
||
|
|
/* Given we stop LBR in software, we will waste a few entries.
|
||
|
|
* But we should try to waste as few as possible entries. We are at
|
||
|
|
* about 7 on x86_64 systems.
|
||
|
|
* Add a check for < 10 so that we get heads-up when something
|
||
|
|
* changes and wastes too many entries.
|
||
|
|
*/
|
||
|
|
ASSERT_LT(skel->bss->wasted_entries, 10, "check_wasted_entries");
|
||
|
|
|
||
|
|
cleanup:
|
||
|
|
get_branch_snapshot__destroy(skel);
|
||
|
|
close_perf_events();
|
||
|
|
}
|