diff options
Diffstat (limited to 'tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c')
| -rw-r--r-- | tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c b/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c new file mode 100644 index 000000000000..60df0b5e628a --- /dev/null +++ b/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c @@ -0,0 +1,195 @@ +/* + * perf events self profiling example test case for hw breakpoints. + * + * This tests perf PERF_TYPE_BREAKPOINT parameters + * 1) tests all variants of the break on read/write flags + * 2) tests exclude_user == 0 and 1 + * 3) test array matches (if DAWR is supported)) + * 4) test different numbers of breakpoints matches + * + * Configure this breakpoint, then read and write the data a number of + * times. Then check the output count from perf is as expected. + * + * Based on: + * http://ozlabs.org/~anton/junkcode/perf_events_example1.c + * + * Copyright (C) 2018 Michael Neuling, IBM Corporation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <unistd.h> +#include <assert.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/ioctl.h> +#include <elf.h> +#include <pthread.h> +#include <sys/syscall.h> +#include <linux/perf_event.h> +#include <linux/hw_breakpoint.h> +#include "utils.h" + +#define MAX_LOOPS 10000 + +#define DAWR_LENGTH_MAX ((0x3f + 1) * 8) + +static inline int sys_perf_event_open(struct perf_event_attr *attr, pid_t pid, + int cpu, int group_fd, + unsigned long flags) +{ + attr->size = sizeof(*attr); + return syscall(__NR_perf_event_open, attr, pid, cpu, group_fd, flags); +} + +static inline bool breakpoint_test(int len) +{ + struct perf_event_attr attr; + int fd; + + /* setup counters */ + memset(&attr, 0, sizeof(attr)); + attr.disabled = 1; + attr.type = PERF_TYPE_BREAKPOINT; + attr.bp_type = HW_BREAKPOINT_R; + /* bp_addr can point anywhere but needs to be aligned */ + attr.bp_addr = (__u64)(&attr) & 0xfffffffffffff800; + attr.bp_len = len; + fd = sys_perf_event_open(&attr, 0, -1, -1, 0); + if (fd < 0) + return false; + close(fd); + return true; +} + +static inline bool perf_breakpoint_supported(void) +{ + return breakpoint_test(4); +} + +static inline bool dawr_supported(void) +{ + return breakpoint_test(DAWR_LENGTH_MAX); +} + +static int runtestsingle(int readwriteflag, int exclude_user, int arraytest) +{ + int i,j; + struct perf_event_attr attr; + size_t res; + unsigned long long breaks, needed; + int readint; + int readintarraybig[2*DAWR_LENGTH_MAX/sizeof(int)]; + int *readintalign; + volatile int *ptr; + int break_fd; + int loop_num = MAX_LOOPS - (rand() % 100); /* provide some variability */ + volatile int *k; + + /* align to 0x400 boundary as required by DAWR */ + readintalign = (int *)(((unsigned long)readintarraybig + 0x7ff) & + 0xfffffffffffff800); + + ptr = &readint; + if (arraytest) + ptr = &readintalign[0]; + + /* setup counters */ + memset(&attr, 0, sizeof(attr)); + attr.disabled = 1; + attr.type = PERF_TYPE_BREAKPOINT; + attr.bp_type = readwriteflag; + attr.bp_addr = (__u64)ptr; + attr.bp_len = sizeof(int); + if (arraytest) + attr.bp_len = DAWR_LENGTH_MAX; + attr.exclude_user = exclude_user; + break_fd = sys_perf_event_open(&attr, 0, -1, -1, 0); + if (break_fd < 0) { + perror("sys_perf_event_open"); + exit(1); + } + + /* start counters */ + ioctl(break_fd, PERF_EVENT_IOC_ENABLE); + + /* Test a bunch of reads and writes */ + k = &readint; + for (i = 0; i < loop_num; i++) { + if (arraytest) + k = &(readintalign[i % (DAWR_LENGTH_MAX/sizeof(int))]); + + j = *k; + *k = j; + } + + /* stop counters */ + ioctl(break_fd, PERF_EVENT_IOC_DISABLE); + + /* read and check counters */ + res = read(break_fd, &breaks, sizeof(unsigned long long)); + assert(res == sizeof(unsigned long long)); + /* we read and write each loop, so subtract the ones we are counting */ + needed = 0; + if (readwriteflag & HW_BREAKPOINT_R) + needed += loop_num; + if (readwriteflag & HW_BREAKPOINT_W) + needed += loop_num; + needed = needed * (1 - exclude_user); + printf("TESTED: addr:0x%lx brks:% 8lld loops:% 8i rw:%i !user:%i array:%i\n", + (unsigned long int)ptr, breaks, loop_num, readwriteflag, exclude_user, arraytest); + if (breaks != needed) { + printf("FAILED: 0x%lx brks:%lld needed:%lli %i %i %i\n\n", + (unsigned long int)ptr, breaks, needed, loop_num, readwriteflag, exclude_user); + return 1; + } + close(break_fd); + + return 0; +} + +static int runtest(void) +{ + int rwflag; + int exclude_user; + int ret; + + /* + * perf defines rwflag as two bits read and write and at least + * one must be set. So range 1-3. + */ + for (rwflag = 1 ; rwflag < 4; rwflag++) { + for (exclude_user = 0 ; exclude_user < 2; exclude_user++) { + ret = runtestsingle(rwflag, exclude_user, 0); + if (ret) + return ret; + + /* if we have the dawr, we can do an array test */ + if (!dawr_supported()) + continue; + ret = runtestsingle(rwflag, exclude_user, 1); + if (ret) + return ret; + } + } + return 0; +} + + +static int perf_hwbreak(void) +{ + srand ( time(NULL) ); + + SKIP_IF(!perf_breakpoint_supported()); + + return runtest(); +} + +int main(int argc, char *argv[], char **envp) +{ + return test_harness(perf_hwbreak, "perf_hwbreak"); +} |