1 #!/usr/sbin/dtrace -qs 2 3 /*- 4 * Copyright (c) 2008-2012 Alexander Leidinger <netchild@FreeBSD.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer 12 * in this position and unchanged. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 /** 32 * Check if the internal locks are correctly acquired/released: 33 * - no recursive locking (mtx locks, write locks) 34 * - no unlocking of already unlocked one 35 * 36 * Print stacktrace if a lock is longer locked than about 10sec or more. 37 */ 38 39 #pragma D option dynvarsize=32m 40 #pragma D option specsize=32m 41 42 BEGIN 43 { 44 check["emul_lock"] = 0; 45 check["emul_shared_rlock"] = 0; 46 check["emul_shared_wlock"] = 0; 47 check["futex_mtx"] = 0; 48 } 49 50 linuxulator*:locks:emul_lock:locked, 51 linuxulator*:locks:emul_shared_wlock:locked, 52 linuxulator*:locks:futex_mtx:locked 53 /check[probefunc] > 0/ 54 { 55 printf("ERROR: recursive lock of %s (%p),", probefunc, arg0); 56 printf(" or missing SDT probe in kernel. Stack trace follows:"); 57 stack(); 58 } 59 60 linuxulator*:locks:emul_lock:locked, 61 linuxulator*:locks:emul_shared_rlock:locked, 62 linuxulator*:locks:emul_shared_wlock:locked, 63 linuxulator*:locks:futex_mtx:locked 64 { 65 ++check[probefunc]; 66 @stats[probefunc] = count(); 67 68 ts[probefunc] = timestamp; 69 spec[probefunc] = speculation(); 70 } 71 72 linuxulator*:locks:emul_lock:unlock, 73 linuxulator*:locks:emul_shared_rlock:unlock, 74 linuxulator*:locks:emul_shared_wlock:unlock, 75 linuxulator*:locks:futex_mtx:unlock 76 /check[probefunc] == 0/ 77 { 78 printf("ERROR: unlock attemt of unlocked %s (%p),", probefunc, arg0); 79 printf(" missing SDT probe in kernel, or dtrace program started"); 80 printf(" while the %s was already held (race condition).", probefunc); 81 printf(" Stack trace follows:"); 82 stack(); 83 } 84 85 linuxulator*:locks:emul_lock:unlock, 86 linuxulator*:locks:emul_shared_rlock:unlock, 87 linuxulator*:locks:emul_shared_wlock:unlock, 88 linuxulator*:locks:futex_mtx:unlock 89 { 90 discard(spec[probefunc]); 91 spec[probefunc] = 0; 92 --check[probefunc]; 93 } 94 95 /* Timeout handling */ 96 97 tick-10s 98 /spec["emul_lock"] != 0 && timestamp - ts["emul_lock"] >= 9999999000/ 99 { 100 commit(spec["emul_lock"]); 101 spec["emul_lock"] = 0; 102 } 103 104 tick-10s 105 /spec["emul_shared_wlock"] != 0 && timestamp - ts["emul_shared_wlock"] >= 9999999000/ 106 { 107 commit(spec["emul_shared_wlock"]); 108 spec["emul_shared_wlock"] = 0; 109 } 110 111 tick-10s 112 /spec["emul_shared_rlock"] != 0 && timestamp - ts["emul_shared_rlock"] >= 9999999000/ 113 { 114 commit(spec["emul_shared_rlock"]); 115 spec["emul_shared_rlock"] = 0; 116 } 117 118 tick-10s 119 /spec["futex_mtx"] != 0 && timestamp - ts["futex_mtx"] >= 9999999000/ 120 { 121 commit(spec["futex_mtx"]); 122 spec["futex_mtx"] = 0; 123 } 124 125 126 /* Statistics */ 127 128 END 129 { 130 printf("Number of locks per type:"); 131 printa(@stats); 132 } 133