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 2006 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*
  28  * #pragma ident        "@(#)dtrace_subr.c      1.7     06/04/24 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 #define proc_t struct proc
  41 #endif
  42
  43 /* Copied from an arch specific dtrace_subr.c. */
  44 int (*dtrace_fasttrap_probe_ptr)(struct regs *);
  45
  46 /*
  47  * Following DTrace hooks are taken from Solaris' dtrace_subr.c
  48  * They're assigned in dtrace.c but Darwin never calls them.
  49  */
  50 void (*dtrace_cpu_init)(processorid_t);
  51 void (*dtrace_modload)(struct modctl *);
  52 void (*dtrace_modunload)(struct modctl *);
  53 #if defined(__APPLE__)
  54 void (*dtrace_helpers_cleanup)(proc_t *);
  55 #endif
  56 void (*dtrace_helpers_fork)(proc_t *, proc_t *);
  57 void (*dtrace_cpustart_init)(void);
  58 void (*dtrace_cpustart_fini)(void);
  59
  60 void (*dtrace_kreloc_init)(void);
  61 void (*dtrace_kreloc_fini)(void);
  62
  63 void (*dtrace_debugger_init)(void);
  64 void (*dtrace_debugger_fini)(void);
  65
  66 dtrace_vtime_state_t dtrace_vtime_active = 0;
  67 dtrace_cacheid_t dtrace_predcache_id = DTRACE_CACHEIDNONE + 1;
  68
  69 void (*dtrace_fasttrap_fork_ptr)(proc_t *, proc_t *);
  70 void (*dtrace_fasttrap_exec_ptr)(proc_t *);
  71 void (*dtrace_fasttrap_exit_ptr)(proc_t *);
  72
  73 /*
  74  * This function is called by cfork() in the event that it appears that
  75  * there may be dtrace tracepoints active in the parent process's address
  76  * space. This first confirms the existence of dtrace tracepoints in the
  77  * parent process and calls into the fasttrap module to remove the
  78  * corresponding tracepoints from the child. By knowing that there are
  79  * existing tracepoints, and ensuring they can't be removed, we can rely
  80  * on the fasttrap module remaining loaded.
  81  */
  82 void
  83 dtrace_fasttrap_fork(proc_t *p, proc_t *cp)
  84 {
  85 #if !defined(__APPLE__)
  86         ASSERT(p->p_proc_flag & P_PR_LOCK);
  87         ASSERT(p->p_dtrace_count > 0);
  88 #endif /* __APPLE__ */
  89
  90         if (dtrace_fasttrap_fork_ptr) {
  91                 (*dtrace_fasttrap_fork_ptr)(p, cp);
  92         }
  93 }
  94
  95 typedef struct dtrace_invop_hdlr {
  96         int (*dtih_func)(uintptr_t, uintptr_t *, uintptr_t);
  97         struct dtrace_invop_hdlr *dtih_next;
  98 } dtrace_invop_hdlr_t;
  99
 100 dtrace_invop_hdlr_t *dtrace_invop_hdlr;
 101
 102 int
 103 dtrace_invop(uintptr_t, uintptr_t *, uintptr_t);
 104
 105 int
 106 dtrace_invop(uintptr_t addr, uintptr_t *stack, uintptr_t eax)
 107 {
 108         dtrace_invop_hdlr_t *hdlr;
 109         int rval;
 110
 111         for (hdlr = dtrace_invop_hdlr; hdlr != NULL; hdlr = hdlr->dtih_next) {
 112                 if ((rval = hdlr->dtih_func(addr, stack, eax)) != 0)
 113                         return (rval);
 114         }
 115
 116         return (0);
 117 }
 118
 119 void
 120 dtrace_invop_add(int (*func)(uintptr_t, uintptr_t *, uintptr_t))
 121 {
 122         dtrace_invop_hdlr_t *hdlr;
 123
 124         hdlr = kmem_alloc(sizeof (dtrace_invop_hdlr_t), KM_SLEEP);
 125         hdlr->dtih_func = func;
 126         hdlr->dtih_next = dtrace_invop_hdlr;
 127         dtrace_invop_hdlr = hdlr;
 128 }
 129
 130 void
 131 dtrace_invop_remove(int (*func)(uintptr_t, uintptr_t *, uintptr_t))
 132 {
 133         dtrace_invop_hdlr_t *hdlr = dtrace_invop_hdlr, *prev = NULL;
 134
 135         for (;;) {
 136                 if (hdlr == NULL)
 137                         panic("attempt to remove non-existent invop handler");
 138
 139                 if (hdlr->dtih_func == func)
 140                         break;
 141
 142                 prev = hdlr;
 143                 hdlr = hdlr->dtih_next;
 144         }
 145
 146         if (prev == NULL) {
 147                 ASSERT(dtrace_invop_hdlr == hdlr);
 148                 dtrace_invop_hdlr = hdlr->dtih_next;
 149         } else {
 150                 ASSERT(dtrace_invop_hdlr != hdlr);
 151                 prev->dtih_next = hdlr->dtih_next;
 152         }
 153
 154         kmem_free(hdlr, sizeof (dtrace_invop_hdlr_t));
 155 }
 156