usr/src/cmd/dtrace/test/tst/sparc/ustack/tst.helper.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 #include <stdint.h>
  30 #include <stdlib.h>
  31 #include <strings.h>
  32
  33 int
  34 baz(void)
  35 {
  36         return (8);
  37 }
  38
  39 static int
  40 foo(void)
  41 {
  42         /*
  43          * In order to assure that our helper is properly employed to identify
  44          * the frame, we're going to trampoline through data.
  45          */
  46         uint32_t instr[] = {
  47             0x9de3bfa0,         /* save %sp, -0x60, %sp */
  48             0x40000000,         /* call baz             */
  49             0x01000000,         /* nop                  */
  50             0x81c7e008,         /* ret                  */
  51             0x81e80000          /* restore              */
  52         };
  53         uint32_t *fp = malloc(sizeof (instr));
  54
  55         /*
  56          * Do our little relocation dance.
  57          */
  58         instr[1] |= ((uintptr_t)baz - (uintptr_t)&fp[1]) >> 2;
  59
  60         /*
  61          * Copy the code to the heap (it's a pain to build in ON with an
  62          * executable stack).
  63          */
  64         bcopy(instr, fp, sizeof (instr));
  65
  66         (*(int (*)(void))fp)();
  67
  68         free(fp);
  69
  70         return (0);
  71 }
  72
  73 int
  74 main(int argc, char **argv)
  75 {
  76         for (;;) {
  77                 foo();
  78         }
  79
  80         return (0);
  81 }