text: /*
   * 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 <sys/ioctl.h>
  
  #include "tests.h"
  #include "debug.h"
  #include "perf.h"
  #include "cloexec.h"
  
  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);
  }
  