xref: /titanic_41/usr/src/uts/common/sys/fasttrap_impl.h (revision 6009dbc6db3fe0e2890761d3d562bb4c4b9bf0be)
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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #include <sys/types.h>
33 #include <sys/dtrace.h>
34 #include <sys/proc.h>
35 #include <sys/fasttrap.h>
36 #include <sys/fasttrap_isa.h>
37 
38 #ifdef	__cplusplus
39 extern "C" {
40 #endif
41 
42 /*
43  * Fasttrap Providers, Probes and Tracepoints
44  *
45  * Each Solaris process can have multiple providers -- the pid provider as
46  * well as any number of user-level statically defined tracing (USDT)
47  * providers. Those providers are each represented by a fasttrap_provider_t.
48  * All providers for a given process have a pointer to a shared
49  * fasttrap_proc_t. The fasttrap_proc_t has two states: active or defunct.
50  * When the count of active providers goes to zero it becomes defunct; a
51  * provider drops its active count when it is removed individually or as part
52  * of a mass removal when a process exits or performs an exec.
53  *
54  * Each probe is represented by a fasttrap_probe_t which has a pointer to
55  * its associated provider as well as a list of fasttrap_id_tp_t structures
56  * which are tuples combining a fasttrap_id_t and a fasttrap_tracepoint_t.
57  * A fasttrap_tracepoint_t represents the actual point of instrumentation
58  * and it contains two lists of fasttrap_id_t structures (to be fired pre-
59  * and post-instruction emulation) that identify the probes attached to the
60  * tracepoint. Tracepoints also have a pointer to the fasttrap_proc_t for the
61  * process they trace which is used when looking up a tracepoint both when a
62  * probe fires and when enabling and disabling probes.
63  *
64  * It's important to note that probes are preallocated with the necessary
65  * number of tracepoints, but that tracepoints can be shared by probes and
66  * swapped between probes. If a probe's preallocated tracepoint is enabled
67  * (and, therefore, the associated probe is enabled), and that probe is
68  * then disabled, ownership of that tracepoint may be exchanged for an
69  * unused tracepoint belonging to another probe that was attached to the
70  * enabled tracepoint.
71  */
72 
73 typedef struct fasttrap_proc {
74 	pid_t ftpc_pid;				/* process ID for this proc */
75 	uint64_t ftpc_acount;			/* count of active providers */
76 	uint64_t ftpc_rcount;			/* count of extant providers */
77 	kmutex_t ftpc_mtx;			/* lock on all but acount */
78 	struct fasttrap_proc *ftpc_next;	/* next proc in hash chain */
79 } fasttrap_proc_t;
80 
81 typedef struct fasttrap_provider {
82 	pid_t ftp_pid;				/* process ID for this prov */
83 	char ftp_name[DTRACE_PROVNAMELEN];	/* prov name (w/o the pid) */
84 	dtrace_provider_id_t ftp_provid;	/* DTrace provider handle */
85 	uint_t ftp_marked;			/* mark for possible removal */
86 	uint_t ftp_retired;			/* mark when retired */
87 	kmutex_t ftp_mtx;			/* provider lock */
88 	kmutex_t ftp_cmtx;			/* lock on creating probes */
89 	uint64_t ftp_rcount;			/* enabled probes ref count */
90 	uint64_t ftp_ccount;			/* consumers creating probes */
91 	uint64_t ftp_mcount;			/* meta provider count */
92 	fasttrap_proc_t *ftp_proc;		/* shared proc for all provs */
93 	struct fasttrap_provider *ftp_next;	/* next prov in hash chain */
94 } fasttrap_provider_t;
95 
96 typedef struct fasttrap_id fasttrap_id_t;
97 typedef struct fasttrap_probe fasttrap_probe_t;
98 typedef struct fasttrap_tracepoint fasttrap_tracepoint_t;
99 
100 struct fasttrap_id {
101 	fasttrap_probe_t *fti_probe;		/* referrring probe */
102 	fasttrap_id_t *fti_next;		/* enabled probe list on tp */
103 	fasttrap_probe_type_t fti_ptype;	/* probe type */
104 };
105 
106 typedef struct fasttrap_id_tp {
107 	fasttrap_id_t fit_id;
108 	fasttrap_tracepoint_t *fit_tp;
109 } fasttrap_id_tp_t;
110 
111 struct fasttrap_probe {
112 	dtrace_id_t ftp_id;			/* DTrace probe identifier */
113 	pid_t ftp_pid;				/* pid for this probe */
114 	fasttrap_provider_t *ftp_prov;		/* this probe's provider */
115 	uintptr_t ftp_faddr;			/* associated function's addr */
116 	size_t ftp_fsize;			/* associated function's size */
117 	uint64_t ftp_gen;			/* modification generation */
118 	uint64_t ftp_ntps;			/* number of tracepoints */
119 	uint8_t *ftp_argmap;			/* native to translated args */
120 	uint8_t ftp_nargs;			/* translated argument count */
121 	uint8_t ftp_enabled;			/* is this probe enabled */
122 	char *ftp_xtypes;			/* translated types index */
123 	char *ftp_ntypes;			/* native types index */
124 	fasttrap_id_tp_t ftp_tps[1];		/* flexible array */
125 };
126 
127 #define	FASTTRAP_ID_INDEX(id)	\
128 ((fasttrap_id_tp_t *)(((char *)(id) - offsetof(fasttrap_id_tp_t, fit_id))) - \
129 &(id)->fti_probe->ftp_tps[0])
130 
131 struct fasttrap_tracepoint {
132 	fasttrap_proc_t *ftt_proc;		/* associated process struct */
133 	uintptr_t ftt_pc;			/* address of tracepoint */
134 	pid_t ftt_pid;				/* pid of tracepoint */
135 	fasttrap_machtp_t ftt_mtp;		/* ISA-specific portion */
136 	fasttrap_id_t *ftt_ids;			/* NULL-terminated list */
137 	fasttrap_id_t *ftt_retids;		/* NULL-terminated list */
138 	fasttrap_tracepoint_t *ftt_next;	/* link in global hash */
139 };
140 
141 typedef struct fasttrap_bucket {
142 	kmutex_t ftb_mtx;			/* bucket lock */
143 	void *ftb_data;				/* data payload */
144 
145 	uint8_t ftb_pad[64 - sizeof (kmutex_t) - sizeof (void *)];
146 } fasttrap_bucket_t;
147 
148 typedef struct fasttrap_hash {
149 	ulong_t fth_nent;			/* power-of-2 num. of entries */
150 	ulong_t fth_mask;			/* fth_nent - 1 */
151 	fasttrap_bucket_t *fth_table;		/* array of buckets */
152 } fasttrap_hash_t;
153 
154 /*
155  * If at some future point these assembly functions become observable by
156  * DTrace, then these defines should become separate functions so that the
157  * fasttrap provider doesn't trigger probes during internal operations.
158  */
159 #define	fasttrap_copyout	copyout
160 #define	fasttrap_fuword32	fuword32
161 #define	fasttrap_suword32	suword32
162 
163 #define	fasttrap_fulword	fulword
164 #define	fasttrap_sulword	sulword
165 
166 extern void fasttrap_sigtrap(proc_t *, kthread_t *, uintptr_t);
167 
168 extern dtrace_id_t 		fasttrap_probe_id;
169 extern fasttrap_hash_t		fasttrap_tpoints;
170 
171 #define	FASTTRAP_TPOINTS_INDEX(pid, pc) \
172 	(((pc) / sizeof (fasttrap_instr_t) + (pid)) & fasttrap_tpoints.fth_mask)
173 
174 /*
175  * Must be implemented by fasttrap_isa.c
176  */
177 extern int fasttrap_tracepoint_init(proc_t *, fasttrap_tracepoint_t *,
178     uintptr_t, fasttrap_probe_type_t);
179 extern int fasttrap_tracepoint_install(proc_t *, fasttrap_tracepoint_t *);
180 extern int fasttrap_tracepoint_remove(proc_t *, fasttrap_tracepoint_t *);
181 
182 extern int fasttrap_pid_probe(struct regs *);
183 extern int fasttrap_return_probe(struct regs *);
184 
185 extern uint64_t fasttrap_pid_getarg(void *, dtrace_id_t, void *, int, int);
186 extern uint64_t fasttrap_usdt_getarg(void *, dtrace_id_t, void *, int, int);
187 
188 #ifdef	__cplusplus
189 }
190 #endif
191 
192 #endif	/* _FASTTRAP_IMPL_H */
193