1 2 /* 3 * db_sysctl.c 4 * 5 * Copyright (c) 2000 Whistle Communications, Inc. 6 * All rights reserved. 7 * 8 * Subject to the following obligations and disclaimer of warranty, use and 9 * redistribution of this software, in source or object code forms, with or 10 * without modifications are expressly permitted by Whistle Communications; 11 * provided, however, that: 12 * 1. Any and all reproductions of the source or object code must include the 13 * copyright notice above and the following disclaimer of warranties; and 14 * 2. No rights are granted, in any manner or form, to use Whistle 15 * Communications, Inc. trademarks, including the mark "WHISTLE 16 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as 17 * such appears in the above copyright notice or in the software. 18 * 19 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND 20 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO 21 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, 22 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF 23 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. 24 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY 25 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS 26 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. 27 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES 28 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING 29 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 30 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR 31 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY 32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 34 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY 35 * OF SUCH DAMAGE. 36 * 37 * Author: Archie Cobbs <archie@whistle.com> 38 * 39 * $FreeBSD: src/sys/ddb/db_sysctl.c,v 1.1.4.1 2000/08/03 00:09:27 ps Exp $ 40 * $DragonFly: src/sys/ddb/db_sysctl.c,v 1.2 2003/06/17 04:28:20 dillon Exp $ 41 */ 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/kernel.h> 46 #include <sys/sysctl.h> 47 #include <sys/reboot.h> 48 49 #define DESCRIPTION "Set to `ddb' or `gdb' to enter the kernel debugger" 50 #define READ_MODE "" 51 #define MODE_DDB "ddb" 52 #define MODE_GDB "gdb" 53 54 /* 55 * This sysctl forces the kernel to enter the debugger. 56 */ 57 static int 58 sysctl_debug_enter_debugger(SYSCTL_HANDLER_ARGS) 59 { 60 char dmode[64]; 61 int error; 62 63 strncpy(dmode, READ_MODE, sizeof(dmode) - 1); 64 dmode[sizeof(dmode) - 1] = '\0'; 65 error = sysctl_handle_string(oidp, &dmode[0], sizeof(dmode), req); 66 67 if (error == 0 && req->newptr != NULL) { 68 if (strcmp(dmode, MODE_DDB) == 0) 69 boothowto &= ~RB_GDB; 70 else if (strcmp(dmode, MODE_GDB) == 0) 71 boothowto |= RB_GDB; 72 else 73 return EINVAL; 74 Debugger("debug.enter_debugger"); 75 } 76 return error; 77 } 78 SYSCTL_PROC(_debug, OID_AUTO, enter_debugger, CTLTYPE_STRING | CTLFLAG_RW, 79 0, 0, sysctl_debug_enter_debugger, "A", DESCRIPTION); 80 81 /* 82 * This sysctl forces a kernel panic. 83 */ 84 static int 85 sysctl_debug_panic(SYSCTL_HANDLER_ARGS) 86 { 87 int err; 88 int val = 0; 89 90 err = sysctl_handle_int(oidp, &val, sizeof(val), req); 91 if (val == 1) 92 panic("sysctl_debug_panic"); 93 return err; 94 } 95 SYSCTL_PROC(_debug, OID_AUTO, panic, CTLTYPE_INT | CTLFLAG_RW, 0, 0, 96 sysctl_debug_panic, "I", "Set to panic the system"); 97 98 /* 99 * This sysctl forces a kernel stack guard panic. If you don't get 100 * a nice clean page-fault guard panic message then the guard isn't 101 * working. 102 */ 103 static void 104 stack_guard_panic2(void) 105 { 106 volatile char dummy[128]; 107 108 stack_guard_panic2(); 109 /* NOT REACHED */ 110 kprintf("%p", dummy); /* dummy to force dummy[] to be allocated */ 111 } 112 113 static int 114 sysctl_debug_panic2(SYSCTL_HANDLER_ARGS) 115 { 116 int err; 117 int val = 0; 118 119 err = sysctl_handle_int(oidp, &val, sizeof(val), req); 120 if (val == 1) 121 stack_guard_panic2(); 122 return err; 123 } 124 SYSCTL_PROC(_debug, OID_AUTO, panic2, CTLTYPE_INT | CTLFLAG_RW, 0, 0, 125 sysctl_debug_panic2, "I", "Set to panic the system w/stack guard"); 126