1  /*
       2   * Check decoding of perf_event_open syscall.
       3   *
       4   * Copyright (c) 2016 Eugene Syromyatnikov <evgsyr@gmail.com>
       5   * Copyright (c) 2016-2021 The strace developers.
       6   * All rights reserved.
       7   *
       8   * SPDX-License-Identifier: GPL-2.0-or-later
       9   */
      10  
      11  #include "tests.h"
      12  #include "scno.h"
      13  
      14  #include <limits.h>
      15  #include <stdio.h>
      16  #include <unistd.h>
      17  
      18  #include <linux/perf_event.h>
      19  
      20  #include "xlat.h"
      21  #include "xlat/perf_event_open_flags.h"
      22  
      23  #if ULONG_MAX > UINT_MAX
      24  # define LONG_STR_PREFIX "ffffffff"
      25  #else
      26  # define LONG_STR_PREFIX ""
      27  #endif
      28  
      29  static const char *printaddr(void *ptr)
      30  {
      31  	static char buf[sizeof("0x") + sizeof(void *) * 2];
      32  
      33  	if (ptr == NULL)
      34  		return "NULL";
      35  
      36  	snprintf(buf, sizeof(buf), "%#lx", (unsigned long)ptr);
      37  
      38  	return buf;
      39  }
      40  
      41  int
      42  main(void)
      43  {
      44  	TAIL_ALLOC_OBJECT_CONST_PTR(struct perf_event_attr, attr);
      45  
      46  	attr->type = PERF_TYPE_HARDWARE;
      47  	attr->size = sizeof(*attr);
      48  
      49  	struct {
      50  		struct perf_event_attr *attr;
      51  		pid_t pid;
      52  		int cpu;
      53  		int group_fd;
      54  		unsigned long flags;
      55  		const char *flags_str;
      56  	} args[] = {
      57  		{ NULL,     0xfacef00d, 0xbadabba7, -1,
      58  			(unsigned long) 0xFFFFFFFFFFFFFFFFLLU,
      59  			"PERF_FLAG_FD_NO_GROUP|PERF_FLAG_FD_OUTPUT|"
      60  			"PERF_FLAG_PID_CGROUP|PERF_FLAG_FD_CLOEXEC|"
      61  			"0x" LONG_STR_PREFIX "fffffff0"
      62  			},
      63  		{ attr + 1, 0,          0,          0,
      64  			0, "0" },
      65  		{ attr,     -1,         -1,         1,
      66  			PERF_FLAG_FD_CLOEXEC, "PERF_FLAG_FD_CLOEXEC" },
      67  		{ attr - 1, -100,       100,        0xface1e55,
      68  			PERF_FLAG_FD_NO_GROUP | PERF_FLAG_FD_OUTPUT |
      69  			PERF_FLAG_PID_CGROUP | PERF_FLAG_FD_CLOEXEC,
      70  			"PERF_FLAG_FD_NO_GROUP|PERF_FLAG_FD_OUTPUT|"
      71  			"PERF_FLAG_PID_CGROUP|PERF_FLAG_FD_CLOEXEC" },
      72  	};
      73  	int rc;
      74  
      75  	for (size_t i = 0; i < ARRAY_SIZE(args); ++i) {
      76  		rc = syscall(__NR_perf_event_open, args[i].attr, args[i].pid,
      77  			args[i].cpu, args[i].group_fd, args[i].flags);
      78  		printf("perf_event_open(%s, %d, %d, %d, %s) = %s\n",
      79  			printaddr(args[i].attr), args[i].pid, args[i].cpu,
      80  			args[i].group_fd, args[i].flags_str, sprintrc(rc));
      81  	}
      82  
      83  	puts("+++ exited with 0 +++");
      84  	return 0;
      85  }