1#!/bin/sh 2 3# https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=227041 4 5# panic: [pmc,2749] (ri21, rc1) waiting too long for pmc to be free 6# cpuid = 23 7# time = 1624293771 8# KDB: stack backtrace: 9# db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe01ab083850 10# vpanic() at vpanic+0x181/frame 0xfffffe01ab0838a0 11# panic() at panic+0x43/frame 0xfffffe01ab083900 12# pmc_wait_for_pmc_idle() at pmc_wait_for_pmc_idle+0xa2/frame 0xfffffe01ab083930 13# pmc_release_pmc_descriptor() at pmc_release_pmc_descriptor+0x20b/frame 0xfffffe01ab083980 14# pmc_syscall_handler() at pmc_syscall_handler+0x4bd/frame 0xfffffe01ab083ac0 15# amd64_syscall() at amd64_syscall+0x762/frame 0xfffffe01ab083bf0 16# fast_syscall_common() at fast_syscall_common+0xf8/frame 0xfffffe01ab083bf0 17# --- syscall (0, FreeBSD ELF64, nosys), rip = 0x8009c154a, rsp = 0x7fffffffe4d8, rbp = 0x7fffffffe500 --- 18# KDB: enter: panic 19# [ thread pid 3123 tid 100454 ] 20# Stopped at kdb_enter+0x37: movq $0,0x1285d1e(%rip) 21# db> x/s version 22# version: FreeBSD 14.0-CURRENT #1 ufs-n247476-f77f86ecfea: Mon Jun 21 08:40:40 CEST 2021 23# pho@t2.osted.lan:/var/tmp/deviant3/sys/amd64/compile/PHO 24# db> 25 26. ../default.cfg 27cat > /tmp/pmc-crash.c <<EOF 28/* 29 Copyright (c) 2018 Dominic Dwyer <dom@itsallbroken.com> 30 All rights reserved. 31 32 Redistribution and use in source and binary forms, with or without 33 modification, are permitted provided that the following conditions are met: 34 35 1. Redistributions of source code must retain the above copyright notice, 36 this list of conditions and the following disclaimer. 37 38 2. Redistributions in binary form must reproduce the above copyright notice, 39 this list of conditions and the following disclaimer in the documentation 40 and/or other materials provided with the distribution. 41 42 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 43 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 44 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 45 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 46 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 47 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 48 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 49 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 50 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 51 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 52 POSSIBILITY OF SUCH DAMAGE. 53 54 clang -lpmc pmc-crash.c -o pmc-crash 55*/ 56 57#include <sys/types.h> 58#include <errno.h> 59#include <pmc.h> 60#include <stdio.h> 61#include <stdlib.h> 62#include <string.h> 63#include <unistd.h> 64 65int main(void) 66{ 67 if (pmc_init() != 0) 68 { 69 printf("pmc_init %s", strerror(errno)); 70 exit(-1); 71 } 72 73 pmc_id_t pmc_id = 0; 74 if (pmc_allocate("inst_retired.any", PMC_MODE_TC, 0, PMC_CPU_ANY, 75 &pmc_id, 1024) != 0) 76 { 77 printf("pmc_allocate %s", strerror(errno)); 78 exit(-1); 79 } 80 81 printf("attaching to self\n"); 82 if (pmc_attach(pmc_id, 0) != 0) 83 { 84 printf("pmc_attach %s", strerror(errno)); 85 exit(-1); 86 } 87 88 if (pmc_start(pmc_id) != 0) 89 { 90 printf("pmc_start %s", strerror(errno)); 91 exit(-1); 92 } 93 94 pmc_value_t v = 0; 95 for (int i = 0; i < 100; i++) 96 { 97 pmc_read(pmc_id, &v); 98 } 99 pmc_stop(pmc_id); 100 101 printf("success, detaching...\n"); 102 pmc_detach(pmc_id, 0); 103 pmc_release(pmc_id); 104 105 printf("ok?"); 106} 107EOF 108mycc -o /tmp/pmc-crash -Wall -Wextra -O0 /tmp/pmc-crash.c -lpmc || exit 109kldstat -v | grep -q hwpmc || { kldload hwpmc; loaded=1; } 110here=`pwd` 111cd /tmp 112./pmc-crash; s=$? 113cd $here 114rm -f /tmp/pmc-crash /tmp/pmc-crash.core /tmp/pmc-crash.c 115[ $loaded ] && kldunload hwpmc 116exit $s 117