| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Powerpc needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select |
| * 'int-ll64.h' and avoid compile warnings when printing __u64 with %llu. |
| */ |
| #define __SANE_USERSPACE_TYPES__ |
| |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <unistd.h> |
| #include <string.h> |
| #include <sys/ioctl.h> |
| #include <time.h> |
| #include <fcntl.h> |
| #include <signal.h> |
| #include <sys/mman.h> |
| #include <linux/compiler.h> |
| #include <linux/hw_breakpoint.h> |
| |
| #include "tests.h" |
| #include "debug.h" |
| #include "event.h" |
| #include "../perf-sys.h" |
| #include "cloexec.h" |
| |
| static volatile long the_var; |
| |
| static noinline int test_function(void) |
| { |
| return 0; |
| } |
| |
| static int __event(bool is_x, void *addr, struct perf_event_attr *attr) |
| { |
| int fd; |
| |
| memset(attr, 0, sizeof(struct perf_event_attr)); |
| attr->type = PERF_TYPE_BREAKPOINT; |
| attr->size = sizeof(struct perf_event_attr); |
| |
| attr->config = 0; |
| attr->bp_type = is_x ? HW_BREAKPOINT_X : HW_BREAKPOINT_W; |
| attr->bp_addr = (unsigned long) addr; |
| attr->bp_len = sizeof(long); |
| |
| attr->sample_period = 1; |
| attr->sample_type = PERF_SAMPLE_IP; |
| |
| attr->exclude_kernel = 1; |
| attr->exclude_hv = 1; |
| |
| fd = sys_perf_event_open(attr, -1, 0, -1, |
| perf_event_open_cloexec_flag()); |
| if (fd < 0) { |
| pr_debug("failed opening event %llx\n", attr->config); |
| return TEST_FAIL; |
| } |
| |
| return fd; |
| } |
| |
| static int wp_event(void *addr, struct perf_event_attr *attr) |
| { |
| return __event(false, addr, attr); |
| } |
| |
| static int bp_event(void *addr, struct perf_event_attr *attr) |
| { |
| return __event(true, addr, attr); |
| } |
| |
| static int bp_accounting(int wp_cnt, int share) |
| { |
| struct perf_event_attr attr, attr_mod, attr_new; |
| int i, fd[wp_cnt], fd_wp, ret; |
| |
| for (i = 0; i < wp_cnt; i++) { |
| fd[i] = wp_event((void *)&the_var, &attr); |
| TEST_ASSERT_VAL("failed to create wp\n", fd[i] != -1); |
| pr_debug("wp %d created\n", i); |
| } |
| |
| attr_mod = attr; |
| attr_mod.bp_type = HW_BREAKPOINT_X; |
| attr_mod.bp_addr = (unsigned long) test_function; |
| |
| ret = ioctl(fd[0], PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &attr_mod); |
| TEST_ASSERT_VAL("failed to modify wp\n", ret == 0); |
| |
| pr_debug("wp 0 modified to bp\n"); |
| |
| if (!share) { |
| fd_wp = wp_event((void *)&the_var, &attr_new); |
| TEST_ASSERT_VAL("failed to create max wp\n", fd_wp != -1); |
| pr_debug("wp max created\n"); |
| } |
| |
| for (i = 0; i < wp_cnt; i++) |
| close(fd[i]); |
| |
| return 0; |
| } |
| |
| static int detect_cnt(bool is_x) |
| { |
| struct perf_event_attr attr; |
| void *addr = is_x ? (void *)test_function : (void *)&the_var; |
| int fd[100], cnt = 0, i; |
| |
| while (1) { |
| if (cnt == 100) { |
| pr_debug("way too many debug registers, fix the test\n"); |
| return 0; |
| } |
| fd[cnt] = __event(is_x, addr, &attr); |
| |
| if (fd[cnt] < 0) |
| break; |
| cnt++; |
| } |
| |
| for (i = 0; i < cnt; i++) |
| close(fd[i]); |
| |
| return cnt; |
| } |
| |
| static int detect_ioctl(void) |
| { |
| struct perf_event_attr attr; |
| int fd, ret = 1; |
| |
| fd = wp_event((void *) &the_var, &attr); |
| if (fd > 0) { |
| ret = ioctl(fd, PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &attr); |
| close(fd); |
| } |
| |
| return ret ? 0 : 1; |
| } |
| |
| static int detect_share(int wp_cnt, int bp_cnt) |
| { |
| struct perf_event_attr attr; |
| int i, fd[wp_cnt + bp_cnt], ret; |
| |
| for (i = 0; i < wp_cnt; i++) { |
| fd[i] = wp_event((void *)&the_var, &attr); |
| TEST_ASSERT_VAL("failed to create wp\n", fd[i] != -1); |
| } |
| |
| for (; i < (bp_cnt + wp_cnt); i++) { |
| fd[i] = bp_event((void *)test_function, &attr); |
| if (fd[i] == -1) |
| break; |
| } |
| |
| ret = i != (bp_cnt + wp_cnt); |
| |
| while (i--) |
| close(fd[i]); |
| |
| return ret; |
| } |
| |
| /* |
| * This test does following: |
| * - detects the number of watch/break-points, |
| * skip test if any is missing |
| * - detects PERF_EVENT_IOC_MODIFY_ATTRIBUTES ioctl, |
| * skip test if it's missing |
| * - detects if watchpoints and breakpoints share |
| * same slots |
| * - create all possible watchpoints on cpu 0 |
| * - change one of it to breakpoint |
| * - in case wp and bp do not share slots, |
| * we create another watchpoint to ensure |
| * the slot accounting is correct |
| */ |
| int test__bp_accounting(struct test *test __maybe_unused, int subtest __maybe_unused) |
| { |
| int has_ioctl = detect_ioctl(); |
| int wp_cnt = detect_cnt(false); |
| int bp_cnt = detect_cnt(true); |
| int share = detect_share(wp_cnt, bp_cnt); |
| |
| pr_debug("watchpoints count %d, breakpoints count %d, has_ioctl %d, share %d\n", |
| wp_cnt, bp_cnt, has_ioctl, share); |
| |
| if (!wp_cnt || !bp_cnt || !has_ioctl) |
| return TEST_SKIP; |
| |
| return bp_accounting(wp_cnt, share); |
| } |