1 /*- 2 * Copyright (c) 2007-2008 John Birrell <jb@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include "opt_kdb.h" 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/eventhandler.h> 35 #include <sys/kdb.h> 36 #include <sys/kernel.h> 37 #include <sys/malloc.h> 38 #include <sys/proc.h> 39 #include <sys/dtrace_bsd.h> 40 #include <sys/sysctl.h> 41 #include <sys/sysent.h> 42 43 #define KDTRACE_PROC_SIZE 64 44 #define KDTRACE_THREAD_SIZE 256 45 46 FEATURE(kdtrace_hooks, 47 "Kernel DTrace hooks which are required to load DTrace kernel modules"); 48 49 static MALLOC_DEFINE(M_KDTRACE, "kdtrace", "DTrace hooks"); 50 51 /* Hooks used in the machine-dependent trap handlers. */ 52 dtrace_trap_func_t dtrace_trap_func; 53 dtrace_doubletrap_func_t dtrace_doubletrap_func; 54 dtrace_pid_probe_ptr_t dtrace_pid_probe_ptr; 55 dtrace_return_probe_ptr_t dtrace_return_probe_ptr; 56 57 systrace_probe_func_t systrace_probe_func; 58 59 /* Return the DTrace process data size compiled in the kernel hooks. */ 60 size_t 61 kdtrace_proc_size() 62 { 63 64 return (KDTRACE_PROC_SIZE); 65 } 66 67 static void 68 kdtrace_proc_ctor(void *arg __unused, struct proc *p) 69 { 70 71 p->p_dtrace = malloc(KDTRACE_PROC_SIZE, M_KDTRACE, M_WAITOK|M_ZERO); 72 } 73 74 static void 75 kdtrace_proc_dtor(void *arg __unused, struct proc *p) 76 { 77 78 if (p->p_dtrace != NULL) { 79 free(p->p_dtrace, M_KDTRACE); 80 p->p_dtrace = NULL; 81 } 82 } 83 84 /* Return the DTrace thread data size compiled in the kernel hooks. */ 85 size_t 86 kdtrace_thread_size() 87 { 88 89 return (KDTRACE_THREAD_SIZE); 90 } 91 92 static void 93 kdtrace_thread_ctor(void *arg __unused, struct thread *td) 94 { 95 96 td->td_dtrace = malloc(KDTRACE_THREAD_SIZE, M_KDTRACE, M_WAITOK|M_ZERO); 97 } 98 99 static void 100 kdtrace_thread_dtor(void *arg __unused, struct thread *td) 101 { 102 103 if (td->td_dtrace != NULL) { 104 free(td->td_dtrace, M_KDTRACE); 105 td->td_dtrace = NULL; 106 } 107 } 108 109 /* 110 * Initialise the kernel DTrace hooks. 111 */ 112 static void 113 init_dtrace(void *dummy __unused) 114 { 115 116 EVENTHANDLER_REGISTER(process_ctor, kdtrace_proc_ctor, NULL, 117 EVENTHANDLER_PRI_ANY); 118 EVENTHANDLER_REGISTER(process_dtor, kdtrace_proc_dtor, NULL, 119 EVENTHANDLER_PRI_ANY); 120 EVENTHANDLER_REGISTER(thread_ctor, kdtrace_thread_ctor, NULL, 121 EVENTHANDLER_PRI_ANY); 122 EVENTHANDLER_REGISTER(thread_dtor, kdtrace_thread_dtor, NULL, 123 EVENTHANDLER_PRI_ANY); 124 } 125 126 SYSINIT(kdtrace, SI_SUB_KDTRACE, SI_ORDER_FIRST, init_dtrace, NULL); 127