usr/src/lib/abi/apptrace/common/interceptlib.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  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #pragma ident   "%Z%%M% %I%     %E% SMI"
  27
  28 #include <sys/types.h>
  29 #include <string.h>
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <dlfcn.h>
  33 #include <apptrace.h>
  34 #include <assert.h>
  35 #include "abienv.h"
  36
  37 #define NOTID 0xffffffff
  38
  39 /*
  40  * This file is meant to contain support functions
  41  * for interceptors.  They are built into the auditing
  42  * object making the namespace available to "children"
  43  * objects.
  44  */
  45
  46 static lwp_mutex_t abi_stdio_mutex = DEFAULTMUTEX;
  47 static volatile thread_t locktid = NOTID;
  48 static volatile int count;
  49
  50 /* Return true on empty */
  51 int
  52 is_empty_string(char const *s)
  53 {
  54         if (s != NULL && *s != '\0')
  55                 return (0);
  56
  57         return (1);
  58 }
  59
  60 void
  61 abilock(sigset_t *mask)
  62 {
  63         thread_t tid;
  64
  65         if ((*abi_thr_main)() != -1) {
  66                 tid = (*abi_thr_self)();
  67
  68                 if (tid == locktid) {
  69                         count++;
  70                 } else {
  71                         (void) _lwp_mutex_lock(&abi_stdio_mutex);
  72                         (void) sigprocmask(SIG_BLOCK, &abisigset, mask);
  73                         locktid = tid;
  74                         count = 1;
  75                 }
  76         }
  77 }
  78
  79 void
  80 abiunlock(sigset_t *mask)
  81 {
  82         thread_t tid;
  83
  84         (void) fflush(ABISTREAM);
  85
  86         if ((*abi_thr_main)() != -1) {
  87                 tid = (*abi_thr_self)();
  88                 assert(tid == locktid);
  89                 count--;
  90                 if (count <= 0) {
  91                         count = 0;
  92                         locktid = NOTID;
  93                         (void) sigprocmask(SIG_SETMASK, mask, NULL);
  94                         (void) _lwp_mutex_unlock(&abi_stdio_mutex);
  95                 }
  96         }
  97 }