bsd/dev/dtrace/dtrace_subr.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*
  28  * #pragma ident        "@(#)dtrace_subr.c      1.8     07/06/05 SMI"
  29  */
  30
  31 #include <stdarg.h>
  32 #include <string.h>
  33 #include <sys/malloc.h>
  34 #include <sys/time.h>
  35 #include <sys/dtrace.h>
  36 #include <sys/dtrace_impl.h>
  37 #include <kern/debug.h>
  38
  39 #if defined(__APPLE__)
  40 /* Solaris proc_t is the struct. Darwin's proc_t is a pointer to it. */
  41 #define proc_t struct proc /* Steer clear of the Darwin typedef for proc_t */
  42 #endif
  43
  44 /* Copied from an arch specific dtrace_subr.c. */
  45 int (*dtrace_fasttrap_probe_ptr)(struct regs *);
  46
  47 /*
  48  * Following DTrace hooks are taken from Solaris' dtrace_subr.c
  49  * They're assigned in dtrace.c but Darwin never calls them.
  50  */
  51 void (*dtrace_cpu_init)(processorid_t);
  52 void (*dtrace_modload)(struct modctl *);
  53 void (*dtrace_modunload)(struct modctl *);
  54 #if defined(__APPLE__)
  55 void (*dtrace_helpers_cleanup)(proc_t *);
  56 #endif
  57 void (*dtrace_helpers_fork)(proc_t *, proc_t *);
  58 void (*dtrace_cpustart_init)(void);
  59 void (*dtrace_cpustart_fini)(void);
  60
  61 void (*dtrace_debugger_init)(void);
  62 void (*dtrace_debugger_fini)(void);
  63
  64 dtrace_vtime_state_t dtrace_vtime_active = 0;
  65 dtrace_cacheid_t dtrace_predcache_id = DTRACE_CACHEIDNONE + 1;
  66
  67 void (*dtrace_fasttrap_fork_ptr)(proc_t *, proc_t *);
  68 void (*dtrace_fasttrap_exec_ptr)(proc_t *);
  69 void (*dtrace_fasttrap_exit_ptr)(proc_t *);
  70
  71 /*
  72  * This function is called by cfork() in the event that it appears that
  73  * there may be dtrace tracepoints active in the parent process's address
  74  * space. This first confirms the existence of dtrace tracepoints in the
  75  * parent process and calls into the fasttrap module to remove the
  76  * corresponding tracepoints from the child. By knowing that there are
  77  * existing tracepoints, and ensuring they can't be removed, we can rely
  78  * on the fasttrap module remaining loaded.
  79  */
  80 void
  81 dtrace_fasttrap_fork(proc_t *p, proc_t *cp)
  82 {
  83 #if !defined(__APPLE__)
  84         ASSERT(p->p_proc_flag & P_PR_LOCK);
  85         ASSERT(p->p_dtrace_count > 0);
  86 #endif /* __APPLE__ */
  87
  88         if (dtrace_fasttrap_fork_ptr) {
  89                 (*dtrace_fasttrap_fork_ptr)(p, cp);
  90         }
  91 }
  92
  93 typedef struct dtrace_invop_hdlr {
  94         int (*dtih_func)(uintptr_t, uintptr_t *, uintptr_t);
  95         struct dtrace_invop_hdlr *dtih_next;
  96 } dtrace_invop_hdlr_t;
  97
  98 dtrace_invop_hdlr_t *dtrace_invop_hdlr;
  99
 100 int
 101 dtrace_invop(uintptr_t, uintptr_t *, uintptr_t);
 102
 103 int
 104 dtrace_invop(uintptr_t addr, uintptr_t *stack, uintptr_t eax)
 105 {
 106         dtrace_invop_hdlr_t *hdlr;
 107         int rval;
 108
 109         for (hdlr = dtrace_invop_hdlr; hdlr != NULL; hdlr = hdlr->dtih_next) {
 110                 if ((rval = hdlr->dtih_func(addr, stack, eax)) != 0)
 111                         return (rval);
 112         }
 113
 114         return (0);
 115 }
 116
 117 void
 118 dtrace_invop_add(int (*func)(uintptr_t, uintptr_t *, uintptr_t))
 119 {
 120         dtrace_invop_hdlr_t *hdlr;
 121
 122         hdlr = kmem_alloc(sizeof (dtrace_invop_hdlr_t), KM_SLEEP);
 123         hdlr->dtih_func = func;
 124         hdlr->dtih_next = dtrace_invop_hdlr;
 125         dtrace_invop_hdlr = hdlr;
 126 }
 127
 128 void
 129 dtrace_invop_remove(int (*func)(uintptr_t, uintptr_t *, uintptr_t))
 130 {
 131         dtrace_invop_hdlr_t *hdlr = dtrace_invop_hdlr, *prev = NULL;
 132
 133         for (;;) {
 134                 if (hdlr == NULL)
 135                         panic("attempt to remove non-existent invop handler");
 136
 137                 if (hdlr->dtih_func == func)
 138                         break;
 139
 140                 prev = hdlr;
 141                 hdlr = hdlr->dtih_next;
 142         }
 143
 144         if (prev == NULL) {
 145                 ASSERT(dtrace_invop_hdlr == hdlr);
 146                 dtrace_invop_hdlr = hdlr->dtih_next;
 147         } else {
 148                 ASSERT(dtrace_invop_hdlr != hdlr);
 149                 prev->dtih_next = hdlr->dtih_next;
 150         }
 151
 152         kmem_free(hdlr, sizeof (dtrace_invop_hdlr_t));
 153 }
 154