| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Inspired by breakpoint overflow test done by |
| * Vince Weaver <vincent.weaver@maine.edu> for perf_event_tests |
| * (git://github.com/deater/perf_event_tests) |
| */ |
| |
| /* |
| * 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 int fd1; |
| static int fd2; |
| static int fd3; |
| static int overflows; |
| static int overflows_2; |
| |
| volatile long the_var; |
| |
| |
| /* |
| * Use ASM to ensure watchpoint and breakpoint can be triggered |
| * at one instruction. |
| */ |
| #if defined (__x86_64__) |
| extern void __test_function(volatile long *ptr); |
| asm ( |
| ".pushsection .text;" |
| ".globl __test_function\n" |
| ".type __test_function, @function;" |
| "__test_function:\n" |
| "incq (%rdi)\n" |
| "ret\n" |
| ".popsection\n"); |
| #else |
| static void __test_function(volatile long *ptr) |
| { |
| *ptr = 0x1234; |
| } |
| #endif |
| |
| static noinline int test_function(void) |
| { |
| __test_function(&the_var); |
| the_var++; |
| return time(NULL); |
| } |
| |
| static void sig_handler_2(int signum __maybe_unused, |
| siginfo_t *oh __maybe_unused, |
| void *uc __maybe_unused) |
| { |
| overflows_2++; |
| if (overflows_2 > 10) { |
| ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0); |
| ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0); |
| ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0); |
| } |
| } |
| |
| static void sig_handler(int signum __maybe_unused, |
| siginfo_t *oh __maybe_unused, |
| void *uc __maybe_unused) |
| { |
| overflows++; |
| |
| if (overflows > 10) { |
| /* |
| * This should be executed only once during |
| * this test, if we are here for the 10th |
| * time, consider this the recursive issue. |
| * |
| * We can get out of here by disable events, |
| * so no new SIGIO is delivered. |
| */ |
| ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0); |
| ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0); |
| ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0); |
| } |
| } |
| |
| static int __event(bool is_x, void *addr, int sig) |
| { |
| struct perf_event_attr pe; |
| int fd; |
| |
| memset(&pe, 0, sizeof(struct perf_event_attr)); |
| pe.type = PERF_TYPE_BREAKPOINT; |
| pe.size = sizeof(struct perf_event_attr); |
| |
| pe.config = 0; |
| pe.bp_type = is_x ? HW_BREAKPOINT_X : HW_BREAKPOINT_W; |
| pe.bp_addr = (unsigned long) addr; |
| pe.bp_len = sizeof(long); |
| |
| pe.sample_period = 1; |
| pe.sample_type = PERF_SAMPLE_IP; |
| pe.wakeup_events = 1; |
| |
| pe.disabled = 1; |
| pe.exclude_kernel = 1; |
| pe.exclude_hv = 1; |
| |
| fd = sys_perf_event_open(&pe, 0, -1, -1, |
| perf_event_open_cloexec_flag()); |
| if (fd < 0) { |
| pr_debug("failed opening event %llx\n", pe.config); |
| return TEST_FAIL; |
| } |
| |
| fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC); |
| fcntl(fd, F_SETSIG, sig); |
| fcntl(fd, F_SETOWN, getpid()); |
| |
| ioctl(fd, PERF_EVENT_IOC_RESET, 0); |
| |
| return fd; |
| } |
| |
| static int bp_event(void *addr, int sig) |
| { |
| return __event(true, addr, sig); |
| } |
| |
| static int wp_event(void *addr, int sig) |
| { |
| return __event(false, addr, sig); |
| } |
| |
| static long long bp_count(int fd) |
| { |
| long long count; |
| int ret; |
| |
| ret = read(fd, &count, sizeof(long long)); |
| if (ret != sizeof(long long)) { |
| pr_debug("failed to read: %d\n", ret); |
| return TEST_FAIL; |
| } |
| |
| return count; |
| } |
| |
| int test__bp_signal(struct test *test __maybe_unused, int subtest __maybe_unused) |
| { |
| struct sigaction sa; |
| long long count1, count2, count3; |
| |
| /* setup SIGIO signal handler */ |
| memset(&sa, 0, sizeof(struct sigaction)); |
| sa.sa_sigaction = (void *) sig_handler; |
| sa.sa_flags = SA_SIGINFO; |
| |
| if (sigaction(SIGIO, &sa, NULL) < 0) { |
| pr_debug("failed setting up signal handler\n"); |
| return TEST_FAIL; |
| } |
| |
| sa.sa_sigaction = (void *) sig_handler_2; |
| if (sigaction(SIGUSR1, &sa, NULL) < 0) { |
| pr_debug("failed setting up signal handler 2\n"); |
| return TEST_FAIL; |
| } |
| |
| /* |
| * We create following events: |
| * |
| * fd1 - breakpoint event on __test_function with SIGIO |
| * signal configured. We should get signal |
| * notification each time the breakpoint is hit |
| * |
| * fd2 - breakpoint event on sig_handler with SIGUSR1 |
| * configured. We should get SIGUSR1 each time when |
| * breakpoint is hit |
| * |
| * fd3 - watchpoint event on __test_function with SIGIO |
| * configured. |
| * |
| * Following processing should happen: |
| * Exec: Action: Result: |
| * incq (%rdi) - fd1 event breakpoint hit -> count1 == 1 |
| * - SIGIO is delivered |
| * sig_handler - fd2 event breakpoint hit -> count2 == 1 |
| * - SIGUSR1 is delivered |
| * sig_handler_2 -> overflows_2 == 1 (nested signal) |
| * sys_rt_sigreturn - return from sig_handler_2 |
| * overflows++ -> overflows = 1 |
| * sys_rt_sigreturn - return from sig_handler |
| * incq (%rdi) - fd3 event watchpoint hit -> count3 == 1 (wp and bp in one insn) |
| * - SIGIO is delivered |
| * sig_handler - fd2 event breakpoint hit -> count2 == 2 |
| * - SIGUSR1 is delivered |
| * sig_handler_2 -> overflows_2 == 2 (nested signal) |
| * sys_rt_sigreturn - return from sig_handler_2 |
| * overflows++ -> overflows = 2 |
| * sys_rt_sigreturn - return from sig_handler |
| * the_var++ - fd3 event watchpoint hit -> count3 == 2 (standalone watchpoint) |
| * - SIGIO is delivered |
| * sig_handler - fd2 event breakpoint hit -> count2 == 3 |
| * - SIGUSR1 is delivered |
| * sig_handler_2 -> overflows_2 == 3 (nested signal) |
| * sys_rt_sigreturn - return from sig_handler_2 |
| * overflows++ -> overflows == 3 |
| * sys_rt_sigreturn - return from sig_handler |
| * |
| * The test case check following error conditions: |
| * - we get stuck in signal handler because of debug |
| * exception being triggered receursively due to |
| * the wrong RF EFLAG management |
| * |
| * - we never trigger the sig_handler breakpoint due |
| * to the rong RF EFLAG management |
| * |
| */ |
| |
| fd1 = bp_event(__test_function, SIGIO); |
| fd2 = bp_event(sig_handler, SIGUSR1); |
| fd3 = wp_event((void *)&the_var, SIGIO); |
| |
| ioctl(fd1, PERF_EVENT_IOC_ENABLE, 0); |
| ioctl(fd2, PERF_EVENT_IOC_ENABLE, 0); |
| ioctl(fd3, PERF_EVENT_IOC_ENABLE, 0); |
| |
| /* |
| * Kick off the test by trigering 'fd1' |
| * breakpoint. |
| */ |
| test_function(); |
| |
| ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0); |
| ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0); |
| ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0); |
| |
| count1 = bp_count(fd1); |
| count2 = bp_count(fd2); |
| count3 = bp_count(fd3); |
| |
| close(fd1); |
| close(fd2); |
| close(fd3); |
| |
| pr_debug("count1 %lld, count2 %lld, count3 %lld, overflow %d, overflows_2 %d\n", |
| count1, count2, count3, overflows, overflows_2); |
| |
| if (count1 != 1) { |
| if (count1 == 11) |
| pr_debug("failed: RF EFLAG recursion issue detected\n"); |
| else |
| pr_debug("failed: wrong count for bp1%lld\n", count1); |
| } |
| |
| if (overflows != 3) |
| pr_debug("failed: wrong overflow hit\n"); |
| |
| if (overflows_2 != 3) |
| pr_debug("failed: wrong overflow_2 hit\n"); |
| |
| if (count2 != 3) |
| pr_debug("failed: wrong count for bp2\n"); |
| |
| if (count3 != 2) |
| pr_debug("failed: wrong count for bp3\n"); |
| |
| return count1 == 1 && overflows == 3 && count2 == 3 && overflows_2 == 3 && count3 == 2 ? |
| TEST_OK : TEST_FAIL; |
| } |
| |
| bool test__bp_signal_is_supported(void) |
| { |
| /* |
| * PowerPC and S390 do not support creation of instruction |
| * breakpoints using the perf_event interface. |
| * |
| * ARM requires explicit rounding down of the instruction |
| * pointer in Thumb mode, and then requires the single-step |
| * to be handled explicitly in the overflow handler to avoid |
| * stepping into the SIGIO handler and getting stuck on the |
| * breakpointed instruction. |
| * |
| * Since arm64 has the same issue with arm for the single-step |
| * handling, this case also gets suck on the breakpointed |
| * instruction. |
| * |
| * Just disable the test for these architectures until these |
| * issues are resolved. |
| */ |
| #if defined(__powerpc__) || defined(__s390x__) || defined(__arm__) || \ |
| defined(__aarch64__) |
| return false; |
| #else |
| return true; |
| #endif |
| } |