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// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#include <test_progs.h>
#include "test_perf_skip.skel.h"
#include <linux/compiler.h>
#include <linux/hw_breakpoint.h>
#include <sys/mman.h>
#ifndef TRAP_PERF
#define TRAP_PERF 6
#endif
int sigio_count, sigtrap_count;
static void handle_sigio(int sig __always_unused)
{
++sigio_count;
}
static void handle_sigtrap(int signum __always_unused,
siginfo_t *info,
void *ucontext __always_unused)
{
ASSERT_EQ(info->si_code, TRAP_PERF, "si_code");
++sigtrap_count;
}
static noinline int test_function(void)
{
asm volatile ("");
return 0;
}
void serial_test_perf_skip(void)
{
struct sigaction action = {};
struct sigaction previous_sigtrap;
sighandler_t previous_sigio = SIG_ERR;
struct test_perf_skip *skel = NULL;
struct perf_event_attr attr = {};
int perf_fd = -1;
int err;
struct f_owner_ex owner;
struct bpf_link *prog_link = NULL;
action.sa_flags = SA_SIGINFO | SA_NODEFER;
action.sa_sigaction = handle_sigtrap;
sigemptyset(&action.sa_mask);
if (!ASSERT_OK(sigaction(SIGTRAP, &action, &previous_sigtrap), "sigaction"))
return;
previous_sigio = signal(SIGIO, handle_sigio);
if (!ASSERT_NEQ(previous_sigio, SIG_ERR, "signal"))
goto cleanup;
skel = test_perf_skip__open_and_load();
if (!ASSERT_OK_PTR(skel, "skel_load"))
goto cleanup;
attr.type = PERF_TYPE_BREAKPOINT;
attr.size = sizeof(attr);
attr.bp_type = HW_BREAKPOINT_X;
attr.bp_addr = (uintptr_t)test_function;
attr.bp_len = sizeof(long);
attr.sample_period = 1;
attr.sample_type = PERF_SAMPLE_IP;
attr.pinned = 1;
attr.exclude_kernel = 1;
attr.exclude_hv = 1;
attr.precise_ip = 3;
attr.sigtrap = 1;
attr.remove_on_exec = 1;
perf_fd = syscall(__NR_perf_event_open, &attr, 0, -1, -1, 0);
if (perf_fd < 0 && (errno == ENOENT || errno == EOPNOTSUPP)) {
printf("SKIP:no PERF_TYPE_BREAKPOINT/HW_BREAKPOINT_X\n");
test__skip();
goto cleanup;
}
if (!ASSERT_OK(perf_fd < 0, "perf_event_open"))
goto cleanup;
/* Configure the perf event to signal on sample. */
err = fcntl(perf_fd, F_SETFL, O_ASYNC);
if (!ASSERT_OK(err, "fcntl(F_SETFL, O_ASYNC)"))
goto cleanup;
owner.type = F_OWNER_TID;
owner.pid = syscall(__NR_gettid);
err = fcntl(perf_fd, F_SETOWN_EX, &owner);
if (!ASSERT_OK(err, "fcntl(F_SETOWN_EX)"))
goto cleanup;
/* Allow at most one sample. A sample rejected by bpf should
* not count against this.
*/
err = ioctl(perf_fd, PERF_EVENT_IOC_REFRESH, 1);
if (!ASSERT_OK(err, "ioctl(PERF_EVENT_IOC_REFRESH)"))
goto cleanup;
prog_link = bpf_program__attach_perf_event(skel->progs.handler, perf_fd);
if (!ASSERT_OK_PTR(prog_link, "bpf_program__attach_perf_event"))
goto cleanup;
/* Configure the bpf program to suppress the sample. */
skel->bss->ip = (uintptr_t)test_function;
test_function();
ASSERT_EQ(sigio_count, 0, "sigio_count");
ASSERT_EQ(sigtrap_count, 0, "sigtrap_count");
/* Configure the bpf program to allow the sample. */
skel->bss->ip = 0;
test_function();
ASSERT_EQ(sigio_count, 1, "sigio_count");
ASSERT_EQ(sigtrap_count, 1, "sigtrap_count");
/* Test that the sample above is the only one allowed (by perf, not
* by bpf)
*/
test_function();
ASSERT_EQ(sigio_count, 1, "sigio_count");
ASSERT_EQ(sigtrap_count, 1, "sigtrap_count");
cleanup:
bpf_link__destroy(prog_link);
if (perf_fd >= 0)
close(perf_fd);
test_perf_skip__destroy(skel);
if (previous_sigio != SIG_ERR)
signal(SIGIO, previous_sigio);
sigaction(SIGTRAP, &previous_sigtrap, NULL);
}
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