81338031c4
The reasons: 1. Get rid of the stubs/quirks with process dethreading, process reparent when the process group leader exits and close to this problems on wait(), waitpid(), etc. 2. Reuse our kernel code instead of writing excessive thread managment routines in Linuxulator. Implementation details: 1. The thread is created via kern_thr_new() in the clone() call with the CLONE_THREAD parameter. Thus, everything else is a process. 2. The test that the process has a threads is done via P_HADTHREADS bit p_flag of struct proc. 3. Per thread emulator state data structure is now located in the struct thread and freed in the thread_dtor() hook. Mandatory holdig of the p_mtx required when referencing emuldata from the other threads. 4. PID mangling has changed. Now Linux pid is the native tid and Linux tgid is the native pid, with the exception of the first thread in the process where tid and pid are one and the same. Ugliness: In case when the Linux thread is the initial thread in the thread group thread id is equal to the process id. Glibc depends on this magic (assert in pthread_getattr_np.c). So for system calls that take thread id as a parameter we should use the special method to reference struct thread. Differential Revision: https://reviews.freebsd.org/D1039
98 lines
2.8 KiB
D
98 lines
2.8 KiB
D
#!/usr/sbin/dtrace -qs
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/*-
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* Copyright (c) 2008-2012 Alexander Leidinger <netchild@FreeBSD.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer
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* in this position and unchanged.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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/**
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* Check if the internal locks are correctly acquired/released:
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* - no recursive locking (mtx locks, write locks)
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* - no unlocking of already unlocked one
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*
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* Print stacktrace if a lock is longer locked than about 10sec or more.
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*/
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#pragma D option dynvarsize=32m
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#pragma D option specsize=32m
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BEGIN
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{
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check["futex_mtx"] = 0;
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}
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linuxulator*:locks:futex_mtx:locked
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/check[probefunc] > 0/
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{
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printf("ERROR: recursive lock of %s (%p),", probefunc, arg0);
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printf(" or missing SDT probe in kernel. Stack trace follows:");
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stack();
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}
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linuxulator*:locks:futex_mtx:locked
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{
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++check[probefunc];
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@stats[probefunc] = count();
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ts[probefunc] = timestamp;
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spec[probefunc] = speculation();
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}
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linuxulator*:locks:futex_mtx:unlock
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/check[probefunc] == 0/
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{
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printf("ERROR: unlock attemt of unlocked %s (%p),", probefunc, arg0);
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printf(" missing SDT probe in kernel, or dtrace program started");
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printf(" while the %s was already held (race condition).", probefunc);
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printf(" Stack trace follows:");
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stack();
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}
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linuxulator*:locks:futex_mtx:unlock
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{
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discard(spec[probefunc]);
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spec[probefunc] = 0;
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--check[probefunc];
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}
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/* Timeout handling */
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tick-10s
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/spec["futex_mtx"] != 0 && timestamp - ts["futex_mtx"] >= 9999999000/
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{
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commit(spec["futex_mtx"]);
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spec["futex_mtx"] = 0;
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}
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/* Statistics */
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END
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{
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printf("Number of locks per type:");
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printa(@stats);
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}
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