138 lines · c
1// SPDX-License-Identifier: GPL-2.02#define _GNU_SOURCE3 4#include <test_progs.h>5#include "test_perf_skip.skel.h"6#include <linux/compiler.h>7#include <linux/hw_breakpoint.h>8#include <sys/mman.h>9 10#ifndef TRAP_PERF11#define TRAP_PERF 612#endif13 14int sigio_count, sigtrap_count;15 16static void handle_sigio(int sig __always_unused)17{18 ++sigio_count;19}20 21static void handle_sigtrap(int signum __always_unused,22 siginfo_t *info,23 void *ucontext __always_unused)24{25 ASSERT_EQ(info->si_code, TRAP_PERF, "si_code");26 ++sigtrap_count;27}28 29static noinline int test_function(void)30{31 asm volatile ("");32 return 0;33}34 35void serial_test_perf_skip(void)36{37 struct sigaction action = {};38 struct sigaction previous_sigtrap;39 sighandler_t previous_sigio = SIG_ERR;40 struct test_perf_skip *skel = NULL;41 struct perf_event_attr attr = {};42 int perf_fd = -1;43 int err;44 struct f_owner_ex owner;45 struct bpf_link *prog_link = NULL;46 47 action.sa_flags = SA_SIGINFO | SA_NODEFER;48 action.sa_sigaction = handle_sigtrap;49 sigemptyset(&action.sa_mask);50 if (!ASSERT_OK(sigaction(SIGTRAP, &action, &previous_sigtrap), "sigaction"))51 return;52 53 previous_sigio = signal(SIGIO, handle_sigio);54 if (!ASSERT_NEQ(previous_sigio, SIG_ERR, "signal"))55 goto cleanup;56 57 skel = test_perf_skip__open_and_load();58 if (!ASSERT_OK_PTR(skel, "skel_load"))59 goto cleanup;60 61 attr.type = PERF_TYPE_BREAKPOINT;62 attr.size = sizeof(attr);63 attr.bp_type = HW_BREAKPOINT_X;64 attr.bp_addr = (uintptr_t)test_function;65 attr.bp_len = sizeof(long);66 attr.sample_period = 1;67 attr.sample_type = PERF_SAMPLE_IP;68 attr.pinned = 1;69 attr.exclude_kernel = 1;70 attr.exclude_hv = 1;71 attr.precise_ip = 3;72 attr.sigtrap = 1;73 attr.remove_on_exec = 1;74 75 perf_fd = syscall(__NR_perf_event_open, &attr, 0, -1, -1, 0);76 if (perf_fd < 0 && (errno == ENOENT || errno == EOPNOTSUPP)) {77 printf("SKIP:no PERF_TYPE_BREAKPOINT/HW_BREAKPOINT_X\n");78 test__skip();79 goto cleanup;80 }81 if (!ASSERT_OK(perf_fd < 0, "perf_event_open"))82 goto cleanup;83 84 /* Configure the perf event to signal on sample. */85 err = fcntl(perf_fd, F_SETFL, O_ASYNC);86 if (!ASSERT_OK(err, "fcntl(F_SETFL, O_ASYNC)"))87 goto cleanup;88 89 owner.type = F_OWNER_TID;90 owner.pid = syscall(__NR_gettid);91 err = fcntl(perf_fd, F_SETOWN_EX, &owner);92 if (!ASSERT_OK(err, "fcntl(F_SETOWN_EX)"))93 goto cleanup;94 95 /* Allow at most one sample. A sample rejected by bpf should96 * not count against this.97 */98 err = ioctl(perf_fd, PERF_EVENT_IOC_REFRESH, 1);99 if (!ASSERT_OK(err, "ioctl(PERF_EVENT_IOC_REFRESH)"))100 goto cleanup;101 102 prog_link = bpf_program__attach_perf_event(skel->progs.handler, perf_fd);103 if (!ASSERT_OK_PTR(prog_link, "bpf_program__attach_perf_event"))104 goto cleanup;105 106 /* Configure the bpf program to suppress the sample. */107 skel->bss->ip = (uintptr_t)test_function;108 test_function();109 110 ASSERT_EQ(sigio_count, 0, "sigio_count");111 ASSERT_EQ(sigtrap_count, 0, "sigtrap_count");112 113 /* Configure the bpf program to allow the sample. */114 skel->bss->ip = 0;115 test_function();116 117 ASSERT_EQ(sigio_count, 1, "sigio_count");118 ASSERT_EQ(sigtrap_count, 1, "sigtrap_count");119 120 /* Test that the sample above is the only one allowed (by perf, not121 * by bpf)122 */123 test_function();124 125 ASSERT_EQ(sigio_count, 1, "sigio_count");126 ASSERT_EQ(sigtrap_count, 1, "sigtrap_count");127 128cleanup:129 bpf_link__destroy(prog_link);130 if (perf_fd >= 0)131 close(perf_fd);132 test_perf_skip__destroy(skel);133 134 if (previous_sigio != SIG_ERR)135 signal(SIGIO, previous_sigio);136 sigaction(SIGTRAP, &previous_sigtrap, NULL);137}138