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 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #ifndef	_FASTTRAP_IMPL_H
28 #define	_FASTTRAP_IMPL_H
29 
30 #include <sys/types.h>
31 #include <sys/dtrace.h>
32 #include <sys/proc.h>
33 #include <sys/fasttrap.h>
34 #include <sys/fasttrap_isa.h>
35 
36 #ifdef	__cplusplus
37 extern "C" {
38 #endif
39 
40 /*
41  * Fasttrap Providers, Probes and Tracepoints
42  *
43  * Each Solaris process can have multiple providers -- the pid provider as
44  * well as any number of user-level statically defined tracing (USDT)
45  * providers. Those providers are each represented by a fasttrap_provider_t.
46  * All providers for a given process have a pointer to a shared
47  * fasttrap_proc_t. The fasttrap_proc_t has two states: active or defunct.
48  * When the count of active providers goes to zero it becomes defunct; a
49  * provider drops its active count when it is removed individually or as part
50  * of a mass removal when a process exits or performs an exec.
51  *
52  * Each probe is represented by a fasttrap_probe_t which has a pointer to
53  * its associated provider as well as a list of fasttrap_id_tp_t structures
54  * which are tuples combining a fasttrap_id_t and a fasttrap_tracepoint_t.
55  * A fasttrap_tracepoint_t represents the actual point of instrumentation
56  * and it contains two lists of fasttrap_id_t structures (to be fired pre-
57  * and post-instruction emulation) that identify the probes attached to the
58  * tracepoint. Tracepoints also have a pointer to the fasttrap_proc_t for the
59  * process they trace which is used when looking up a tracepoint both when a
60  * probe fires and when enabling and disabling probes.
61  *
62  * It's important to note that probes are preallocated with the necessary
63  * number of tracepoints, but that tracepoints can be shared by probes and
64  * swapped between probes. If a probe's preallocated tracepoint is enabled
65  * (and, therefore, the associated probe is enabled), and that probe is
66  * then disabled, ownership of that tracepoint may be exchanged for an
67  * unused tracepoint belonging to another probe that was attached to the
68  * enabled tracepoint.
69  */
70 
71 typedef struct fasttrap_proc {
72 	pid_t ftpc_pid;				/* process ID for this proc */
73 	uint64_t ftpc_acount;			/* count of active providers */
74 	uint64_t ftpc_rcount;			/* count of extant providers */
75 	kmutex_t ftpc_mtx;			/* lock on all but acount */
76 	struct fasttrap_proc *ftpc_next;	/* next proc in hash chain */
77 } fasttrap_proc_t;
78 
79 typedef struct fasttrap_provider {
80 	pid_t ftp_pid;				/* process ID for this prov */
81 	char ftp_name[DTRACE_PROVNAMELEN];	/* prov name (w/o the pid) */
82 	dtrace_provider_id_t ftp_provid;	/* DTrace provider handle */
83 	uint_t ftp_marked;			/* mark for possible removal */
84 	uint_t ftp_retired;			/* mark when retired */
85 	kmutex_t ftp_mtx;			/* provider lock */
86 	kmutex_t ftp_cmtx;			/* lock on creating probes */
87 	uint64_t ftp_rcount;			/* enabled probes ref count */
88 	uint64_t ftp_ccount;			/* consumers creating probes */
89 	uint64_t ftp_mcount;			/* meta provider count */
90 	fasttrap_proc_t *ftp_proc;		/* shared proc for all provs */
91 	struct fasttrap_provider *ftp_next;	/* next prov in hash chain */
92 } fasttrap_provider_t;
93 
94 typedef struct fasttrap_id fasttrap_id_t;
95 typedef struct fasttrap_probe fasttrap_probe_t;
96 typedef struct fasttrap_tracepoint fasttrap_tracepoint_t;
97 
98 struct fasttrap_id {
99 	fasttrap_probe_t *fti_probe;		/* referrring probe */
100 	fasttrap_id_t *fti_next;		/* enabled probe list on tp */
101 	fasttrap_probe_type_t fti_ptype;	/* probe type */
102 };
103 
104 typedef struct fasttrap_id_tp {
105 	fasttrap_id_t fit_id;
106 	fasttrap_tracepoint_t *fit_tp;
107 } fasttrap_id_tp_t;
108 
109 struct fasttrap_probe {
110 	dtrace_id_t ftp_id;			/* DTrace probe identifier */
111 	pid_t ftp_pid;				/* pid for this probe */
112 	fasttrap_provider_t *ftp_prov;		/* this probe's provider */
113 	uintptr_t ftp_faddr;			/* associated function's addr */
114 	size_t ftp_fsize;			/* associated function's size */
115 	uint64_t ftp_gen;			/* modification generation */
116 	uint64_t ftp_ntps;			/* number of tracepoints */
117 	uint8_t *ftp_argmap;			/* native to translated args */
118 	uint8_t ftp_nargs;			/* translated argument count */
119 	uint8_t ftp_enabled;			/* is this probe enabled */
120 	char *ftp_xtypes;			/* translated types index */
121 	char *ftp_ntypes;			/* native types index */
122 	fasttrap_id_tp_t ftp_tps[1];		/* flexible array */
123 };
124 
125 #define	FASTTRAP_ID_INDEX(id)	\
126 ((fasttrap_id_tp_t *)(((char *)(id) - offsetof(fasttrap_id_tp_t, fit_id))) - \
127 &(id)->fti_probe->ftp_tps[0])
128 
129 struct fasttrap_tracepoint {
130 	fasttrap_proc_t *ftt_proc;		/* associated process struct */
131 	uintptr_t ftt_pc;			/* address of tracepoint */
132 	pid_t ftt_pid;				/* pid of tracepoint */
133 	fasttrap_machtp_t ftt_mtp;		/* ISA-specific portion */
134 	fasttrap_id_t *ftt_ids;			/* NULL-terminated list */
135 	fasttrap_id_t *ftt_retids;		/* NULL-terminated list */
136 	fasttrap_tracepoint_t *ftt_next;	/* link in global hash */
137 };
138 
139 typedef struct fasttrap_bucket {
140 	kmutex_t ftb_mtx;			/* bucket lock */
141 	void *ftb_data;				/* data payload */
142 
143 	uint8_t ftb_pad[64 - sizeof (kmutex_t) - sizeof (void *)];
144 } fasttrap_bucket_t;
145 
146 typedef struct fasttrap_hash {
147 	ulong_t fth_nent;			/* power-of-2 num. of entries */
148 	ulong_t fth_mask;			/* fth_nent - 1 */
149 	fasttrap_bucket_t *fth_table;		/* array of buckets */
150 } fasttrap_hash_t;
151 
152 /*
153  * If at some future point these assembly functions become observable by
154  * DTrace, then these defines should become separate functions so that the
155  * fasttrap provider doesn't trigger probes during internal operations.
156  */
157 #define	fasttrap_copyout	copyout
158 #define	fasttrap_fuword32	fuword32
159 #define	fasttrap_suword32	suword32
160 
161 #define	fasttrap_fulword	fulword
162 #define	fasttrap_sulword	sulword
163 
164 extern void fasttrap_sigtrap(proc_t *, kthread_t *, uintptr_t);
165 
166 extern dtrace_id_t 		fasttrap_probe_id;
167 extern fasttrap_hash_t		fasttrap_tpoints;
168 
169 #define	FASTTRAP_TPOINTS_INDEX(pid, pc) \
170 	(((pc) / sizeof (fasttrap_instr_t) + (pid)) & fasttrap_tpoints.fth_mask)
171 
172 /*
173  * Must be implemented by fasttrap_isa.c
174  */
175 extern int fasttrap_tracepoint_init(proc_t *, fasttrap_tracepoint_t *,
176     uintptr_t, fasttrap_probe_type_t);
177 extern int fasttrap_tracepoint_install(proc_t *, fasttrap_tracepoint_t *);
178 extern int fasttrap_tracepoint_remove(proc_t *, fasttrap_tracepoint_t *);
179 
180 extern int fasttrap_pid_probe(struct regs *);
181 extern int fasttrap_return_probe(struct regs *);
182 
183 extern uint64_t fasttrap_pid_getarg(void *, dtrace_id_t, void *, int, int);
184 extern uint64_t fasttrap_usdt_getarg(void *, dtrace_id_t, void *, int, int);
185 
186 #ifdef	__cplusplus
187 }
188 #endif
189 
190 #endif	/* _FASTTRAP_IMPL_H */
191