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["futex_mtx"] = 0; 45 } 46 47 linuxulator*:locks:futex_mtx:locked 48 /check[probefunc] > 0/ 49 { 50 printf("ERROR: recursive lock of %s (%p),", probefunc, arg0); 51 printf(" or missing SDT probe in kernel. Stack trace follows:"); 52 stack(); 53 } 54 55 linuxulator*:locks:futex_mtx:locked 56 { 57 ++check[probefunc]; 58 @stats[probefunc] = count(); 59 60 ts[probefunc] = timestamp; 61 spec[probefunc] = speculation(); 62 } 63 64 linuxulator*:locks:futex_mtx:unlock 65 /check[probefunc] == 0/ 66 { 67 printf("ERROR: unlock attemt of unlocked %s (%p),", probefunc, arg0); 68 printf(" missing SDT probe in kernel, or dtrace program started"); 69 printf(" while the %s was already held (race condition).", probefunc); 70 printf(" Stack trace follows:"); 71 stack(); 72 } 73 74 linuxulator*:locks:futex_mtx:unlock 75 { 76 discard(spec[probefunc]); 77 spec[probefunc] = 0; 78 --check[probefunc]; 79 } 80 81 /* Timeout handling */ 82 83 tick-10s 84 /spec["futex_mtx"] != 0 && timestamp - ts["futex_mtx"] >= 9999999000/ 85 { 86 commit(spec["futex_mtx"]); 87 spec["futex_mtx"] = 0; 88 } 89 90 91 /* Statistics */ 92 93 END 94 { 95 printf("Number of locks per type:"); 96 printa(@stats); 97 } 98