1 /* $NetBSD: subr_spldebug.c,v 1.3 2010/04/25 11:49:22 ad Exp $ */ 2 3 /*- 4 * Copyright (c) 2009, 2010 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by David Young. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * Interrupt priority level debugging code. 34 */ 35 36 #include <sys/cdefs.h> 37 __KERNEL_RCSID(0, "$NetBSD: subr_spldebug.c,v 1.3 2010/04/25 11:49:22 ad Exp $"); 38 39 #include <sys/param.h> 40 #include <sys/spldebug.h> 41 #include <sys/systm.h> 42 #include <sys/kernel.h> 43 #include <sys/cpu.h> 44 #include <machine/return.h> 45 46 #define SPLRAISE_STACKLEN 32 47 48 void *splraise_retaddrs[MAXCPUS][SPLRAISE_STACKLEN][4]; 49 int splraise_depth[MAXCPUS] = {0}; 50 int spllowered_to[MAXCPUS] = {0}; 51 void *spllowered_from[MAXCPUS][2] = {{0}}; 52 bool spldebug = false; 53 54 void spldebug_start(void); 55 void spldebug_stop(void); 56 57 void 58 spldebug_start(void) 59 { 60 spldebug = true; 61 } 62 63 void 64 spldebug_stop(void) 65 { 66 spldebug = false; 67 } 68 69 void 70 spldebug_lower(int ipl) 71 { 72 u_int cidx; 73 74 if (!spldebug) 75 return; 76 77 if (ipl == IPL_HIGH) 78 return; 79 80 cidx = cpu_index(curcpu()); 81 82 KASSERT(cidx < maxcpus); 83 84 splraise_depth[cidx] = 0; 85 spllowered_to[cidx] = ipl; 86 #if 0 87 spllowered_from[cidx][0] = return_address(0); 88 spllowered_from[cidx][1] = return_address(1); 89 #endif 90 } 91 92 void 93 spldebug_raise(int ipl) 94 { 95 int i; 96 u_int cidx; 97 void **retaddrs; 98 99 if (!spldebug) 100 return; 101 102 if (ipl != IPL_HIGH) 103 return; 104 105 cidx = cpu_index(curcpu()); 106 107 KASSERT(cidx < maxcpus); 108 109 if (splraise_depth[cidx] >= SPLRAISE_STACKLEN) 110 return; 111 112 retaddrs = &splraise_retaddrs[cidx][splraise_depth[cidx]++][0]; 113 114 retaddrs[0] = retaddrs[1] = retaddrs[2] = retaddrs[3] = NULL; 115 116 for (i = 0; i < 4; i++) { 117 retaddrs[i] = return_address(i); 118 119 if (retaddrs[i] == NULL) 120 break; 121 } 122 } 123