tools/perf/tests/wp.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <unistd.h>
   5 #include <errno.h>
   6 #include <sys/ioctl.h>
   7 #include <linux/compiler.h>
   8 #include <linux/hw_breakpoint.h>
   9 #include <linux/kernel.h>
  10 #include "tests.h"
  11 #include "debug.h"
  12 #include "event.h"
  13 #include "cloexec.h"
  14 #include "../perf-sys.h"
  15
  16 #define WP_TEST_ASSERT_VAL(fd, text, val)       \
  17 do {                                            \
  18         long long count;                        \
  19         wp_read(fd, &count, sizeof(long long)); \
  20         TEST_ASSERT_VAL(text, count == val);    \
  21 } while (0)
  22
  23 #ifdef __i386__
  24 /* Only breakpoint length less-than 8 has hardware support on i386. */
  25 volatile u32 data1;
  26 #else
  27 volatile u64 data1;
  28 #endif
  29 volatile u8 data2[3];
  30
  31 #ifndef __s390x__
  32 static int wp_read(int fd, long long *count, int size)
  33 {
  34         int ret = read(fd, count, size);
  35
  36         if (ret != size) {
  37                 pr_debug("failed to read: %d\n", ret);
  38                 return -1;
  39         }
  40         return 0;
  41 }
  42
  43 static void get__perf_event_attr(struct perf_event_attr *attr, int wp_type,
  44                                  void *wp_addr, unsigned long wp_len)
  45 {
  46         memset(attr, 0, sizeof(struct perf_event_attr));
  47         attr->type           = PERF_TYPE_BREAKPOINT;
  48         attr->size           = sizeof(struct perf_event_attr);
  49         attr->config         = 0;
  50         attr->bp_type        = wp_type;
  51         attr->bp_addr        = (unsigned long)wp_addr;
  52         attr->bp_len         = wp_len;
  53         attr->sample_period  = 1;
  54         attr->sample_type    = PERF_SAMPLE_IP;
  55         attr->exclude_kernel = 1;
  56         attr->exclude_hv     = 1;
  57 }
  58
  59 static int __event(int wp_type, void *wp_addr, unsigned long wp_len)
  60 {
  61         int fd;
  62         struct perf_event_attr attr;
  63
  64         get__perf_event_attr(&attr, wp_type, wp_addr, wp_len);
  65         fd = sys_perf_event_open(&attr, 0, -1, -1,
  66                                  perf_event_open_cloexec_flag());
  67         if (fd < 0) {
  68                 fd = -errno;
  69                 pr_debug("failed opening event %x\n", attr.bp_type);
  70         }
  71
  72         return fd;
  73 }
  74 #endif
  75
  76 static int test__wp_ro(struct test_suite *test __maybe_unused,
  77                        int subtest __maybe_unused)
  78 {
  79 #if defined(__s390x__) || defined(__x86_64__) || defined(__i386__)
  80         return TEST_SKIP;
  81 #else
  82         int fd;
  83         unsigned long tmp, tmp1 = rand();
  84
  85         fd = __event(HW_BREAKPOINT_R, (void *)&data1, sizeof(data1));
  86         if (fd < 0)
  87                 return fd == -ENODEV ? TEST_SKIP : -1;
  88
  89         tmp = data1;
  90         WP_TEST_ASSERT_VAL(fd, "RO watchpoint", 1);
  91
  92         data1 = tmp1 + tmp;
  93         WP_TEST_ASSERT_VAL(fd, "RO watchpoint", 1);
  94
  95         close(fd);
  96         return 0;
  97 #endif
  98 }
  99
 100 static int test__wp_wo(struct test_suite *test __maybe_unused,
 101                        int subtest __maybe_unused)
 102 {
 103 #if defined(__s390x__)
 104         return TEST_SKIP;
 105 #else
 106         int fd;
 107         unsigned long tmp, tmp1 = rand();
 108
 109         fd = __event(HW_BREAKPOINT_W, (void *)&data1, sizeof(data1));
 110         if (fd < 0)
 111                 return fd == -ENODEV ? TEST_SKIP : -1;
 112
 113         tmp = data1;
 114         WP_TEST_ASSERT_VAL(fd, "WO watchpoint", 0);
 115
 116         data1 = tmp1 + tmp;
 117         WP_TEST_ASSERT_VAL(fd, "WO watchpoint", 1);
 118
 119         close(fd);
 120         return 0;
 121 #endif
 122 }
 123
 124 static int test__wp_rw(struct test_suite *test __maybe_unused,
 125                        int subtest __maybe_unused)
 126 {
 127 #if defined(__s390x__)
 128         return TEST_SKIP;
 129 #else
 130         int fd;
 131         unsigned long tmp, tmp1 = rand();
 132
 133         fd = __event(HW_BREAKPOINT_R | HW_BREAKPOINT_W, (void *)&data1,
 134                      sizeof(data1));
 135         if (fd < 0)
 136                 return fd == -ENODEV ? TEST_SKIP : -1;
 137
 138         tmp = data1;
 139         WP_TEST_ASSERT_VAL(fd, "RW watchpoint", 1);
 140
 141         data1 = tmp1 + tmp;
 142         WP_TEST_ASSERT_VAL(fd, "RW watchpoint", 2);
 143
 144         close(fd);
 145         return 0;
 146 #endif
 147 }
 148
 149 static int test__wp_modify(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
 150 {
 151 #if defined(__s390x__)
 152         return TEST_SKIP;
 153 #else
 154         int fd, ret;
 155         unsigned long tmp = rand();
 156         struct perf_event_attr new_attr;
 157
 158         fd = __event(HW_BREAKPOINT_W, (void *)&data1, sizeof(data1));
 159         if (fd < 0)
 160                 return fd == -ENODEV ? TEST_SKIP : -1;
 161
 162         data1 = tmp;
 163         WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 1);
 164
 165         /* Modify watchpoint with disabled = 1 */
 166         get__perf_event_attr(&new_attr, HW_BREAKPOINT_W, (void *)&data2[0],
 167                              sizeof(u8) * 2);
 168         new_attr.disabled = 1;
 169         ret = ioctl(fd, PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &new_attr);
 170         if (ret < 0) {
 171                 if (errno == ENOTTY) {
 172                         test->test_cases[subtest].skip_reason = "missing kernel support";
 173                         ret = TEST_SKIP;
 174                 }
 175
 176                 pr_debug("ioctl(PERF_EVENT_IOC_MODIFY_ATTRIBUTES) failed\n");
 177                 close(fd);
 178                 return ret;
 179         }
 180
 181         data2[1] = tmp; /* Not Counted */
 182         WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 1);
 183
 184         /* Enable the event */
 185         ioctl(fd, PERF_EVENT_IOC_ENABLE, 0);
 186         if (ret < 0) {
 187                 pr_debug("Failed to enable event\n");
 188                 close(fd);
 189                 return ret;
 190         }
 191
 192         data2[1] = tmp; /* Counted */
 193         WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 2);
 194
 195         data2[2] = tmp; /* Not Counted */
 196         WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 2);
 197
 198         close(fd);
 199         return 0;
 200 #endif
 201 }
 202
 203 static struct test_case wp_tests[] = {
 204         TEST_CASE_REASON("Read Only Watchpoint", wp_ro, "missing hardware support"),
 205         TEST_CASE_REASON("Write Only Watchpoint", wp_wo, "missing hardware support"),
 206         TEST_CASE_REASON("Read / Write Watchpoint", wp_rw, "missing hardware support"),
 207         TEST_CASE_REASON("Modify Watchpoint", wp_modify, "missing hardware support"),
 208         { .name = NULL, }
 209 };
 210
 211 struct test_suite suite__wp = {
 212         .desc = "Watchpoint",
 213         .test_cases = wp_tests,
 214 };