xref: /xnu-11215/bsd/sys/fasttrap_impl.h (revision 5c2921b0)
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/user.h>
34 #include <sys/fasttrap.h>
35 #include <sys/fasttrap_isa.h>
36 
37 /* Solaris proc_t is the struct. Darwin's proc_t is a pointer to it. */
38 #define proc_t struct proc /* Steer clear of the Darwin typedef for proc_t */
39 
40 #ifdef	__cplusplus
41 extern "C" {
42 #endif
43 
44 /*
45  * Fasttrap Providers, Probes and Tracepoints
46  *
47  * Each Solaris process can have multiple providers -- the pid provider as
48  * well as any number of user-level statically defined tracing (USDT)
49  * providers. Those providers are each represented by a fasttrap_provider_t.
50  * All providers for a given process have a pointer to a shared
51  * fasttrap_proc_t. The fasttrap_proc_t has two states: active or defunct.
52  * When the count of active providers goes to zero it becomes defunct; a
53  * provider drops its active count when it is removed individually or as part
54  * of a mass removal when a process exits or performs an exec.
55  *
56  * Each probe is represented by a fasttrap_probe_t which has a pointer to
57  * its associated provider as well as a list of fasttrap_id_tp_t structures
58  * which are tuples combining a fasttrap_id_t and a fasttrap_tracepoint_t.
59  * A fasttrap_tracepoint_t represents the actual point of instrumentation
60  * and it contains two lists of fasttrap_id_t structures (to be fired pre-
61  * and post-instruction emulation) that identify the probes attached to the
62  * tracepoint. Tracepoints also have a pointer to the fasttrap_proc_t for the
63  * process they trace which is used when looking up a tracepoint both when a
64  * probe fires and when enabling and disabling probes.
65  *
66  * It's important to note that probes are preallocated with the necessary
67  * number of tracepoints, but that tracepoints can be shared by probes and
68  * swapped between probes. If a probe's preallocated tracepoint is enabled
69  * (and, therefore, the associated probe is enabled), and that probe is
70  * then disabled, ownership of that tracepoint may be exchanged for an
71  * unused tracepoint belonging to another probe that was attached to the
72  * enabled tracepoint.
73  */
74 
75 /*
76  * APPLE NOTE: All kmutex_t's have been converted to lck_mtx_t
77  */
78 
79 typedef struct fasttrap_proc {
80 	pid_t ftpc_pid;				/* process ID for this proc */
81 	uint64_t ftpc_acount;			/* count of active providers */
82 	uint64_t ftpc_rcount;			/* count of extant providers */
83 	lck_mtx_t ftpc_mtx;			/* lock on all but acount */
84 	struct fasttrap_proc *ftpc_next;	/* next proc in hash chain */
85 } fasttrap_proc_t;
86 
87 typedef struct fasttrap_provider {
88 	pid_t ftp_pid;				/* process ID for this prov */
89 	fasttrap_provider_type_t ftp_provider_type;	/* type of this provider (usdt, pid, objc, oneshot) */
90 	char ftp_name[DTRACE_PROVNAMELEN];	/* prov name (w/o the pid) */
91 	dtrace_provider_id_t ftp_provid;	/* DTrace provider handle */
92 	uint_t ftp_marked;			/* mark for possible removal */
93 	uint_t ftp_retired;			/* mark when retired */
94 	lck_mtx_t ftp_mtx;			/* provider lock */
95 	lck_mtx_t ftp_cmtx;			/* lock on creating probes */
96 	uint64_t ftp_pcount;			/* probes in provider count */
97 	uint64_t ftp_rcount;			/* enabled probes ref count */
98 	uint64_t ftp_ccount;			/* consumers creating probes */
99 	uint64_t ftp_mcount;			/* meta provider count */
100 	fasttrap_proc_t *ftp_proc;		/* shared proc for all provs */
101 	struct fasttrap_provider *ftp_next;	/* next prov in hash chain */
102 } fasttrap_provider_t;
103 
104 typedef struct fasttrap_id fasttrap_id_t;
105 typedef struct fasttrap_probe fasttrap_probe_t;
106 typedef struct fasttrap_tracepoint fasttrap_tracepoint_t;
107 
108 struct fasttrap_id {
109 	fasttrap_probe_t *fti_probe;		/* referrring probe */
110 	fasttrap_id_t *fti_next;		/* enabled probe list on tp */
111 	fasttrap_probe_type_t fti_ptype;	/* probe type */
112 };
113 
114 typedef struct fasttrap_id_tp {
115 	fasttrap_id_t fit_id;
116 	fasttrap_tracepoint_t *fit_tp;
117 } fasttrap_id_tp_t;
118 
119 struct fasttrap_probe {
120 	dtrace_id_t ftp_id;			/* DTrace probe identifier */
121 	pid_t ftp_pid;				/* pid for this probe */
122 	fasttrap_provider_t *ftp_prov;		/* this probe's provider */
123 	user_addr_t ftp_faddr;			/* associated function's addr */
124 	size_t ftp_fsize;			/* associated function's size */
125 	uint64_t ftp_gen;			/* modification generation */
126 	uint64_t ftp_ntps;			/* number of tracepoints */
127 	uint8_t *ftp_argmap;			/* native to translated args */
128 	uint8_t ftp_nargs;			/* translated argument count */
129 	uint8_t ftp_enabled;			/* is this probe enabled */
130 	uint8_t ftp_triggered;
131 	char *ftp_xtypes;			/* translated types index */
132 	char *ftp_ntypes;			/* native types index */
133 	fasttrap_id_tp_t ftp_tps[1];		/* flexible array */
134 };
135 
136 #define	FASTTRAP_ID_INDEX(id)	\
137 ((fasttrap_id_tp_t *)(((char *)(id) - offsetof(fasttrap_id_tp_t, fit_id))) - \
138 &(id)->fti_probe->ftp_tps[0])
139 
140 struct fasttrap_tracepoint {
141 	fasttrap_proc_t *ftt_proc;		/* associated process struct */
142 	user_addr_t ftt_pc;			/* address of tracepoint */
143 	pid_t ftt_pid;				/* pid of tracepoint */
144 	fasttrap_machtp_t ftt_mtp;		/* ISA-specific portion */
145 	fasttrap_id_t *ftt_ids;			/* NULL-terminated list */
146 	fasttrap_id_t *ftt_retids;		/* NULL-terminated list */
147 	fasttrap_tracepoint_t *ftt_next;	/* link in global hash */
148 };
149 
150 typedef struct fasttrap_bucket {
151 	lck_mtx_t ftb_mtx;			/* bucket lock */
152 	void *ftb_data;				/* data payload */
153 
154 	uint8_t ftb_pad[64 - sizeof (lck_mtx_t) - sizeof (void *)];
155 } fasttrap_bucket_t;
156 
157 typedef struct fasttrap_hash {
158 	ulong_t fth_nent;			/* power-of-2 num. of entries */
159 	ulong_t fth_mask;			/* fth_nent - 1 */
160 	fasttrap_bucket_t *fth_table;		/* array of buckets */
161 } fasttrap_hash_t;
162 
163 /*
164  * If at some future point these assembly functions become observable by
165  * DTrace, then these defines should become separate functions so that the
166  * fasttrap provider doesn't trigger probes during internal operations.
167  */
168 #define	fasttrap_copyout	copyout
169 #define	fasttrap_fuword32	fuword32
170 #define	fasttrap_suword32	suword32
171 
172 /*
173  * APPLE NOTE: xnu supports both 32bit and 64bit user processes.
174  * We need to make size explicit.
175  */
176 #define	fasttrap_fuword64	fuword64
177 #define	fasttrap_suword64	suword64
178 #define fasttrap_fuword64_noerr	fuword64_noerr
179 #define fasttrap_fuword32_noerr	fuword32_noerr
180 
181 extern void fasttrap_sigtrap(proc_t *, uthread_t, user_addr_t);
182 
183 extern dtrace_id_t 		fasttrap_probe_id;
184 extern fasttrap_hash_t		fasttrap_tpoints;
185 
186 #define	FASTTRAP_TPOINTS_INDEX(pid, pc) \
187 	(((pc) / sizeof (fasttrap_instr_t) + (pid)) & fasttrap_tpoints.fth_mask)
188 
189 extern void fasttrap_tracepoint_retire(proc_t *p, fasttrap_tracepoint_t *tp);
190 
191 /*
192  * Must be implemented by fasttrap_isa.c
193  */
194 extern int fasttrap_tracepoint_init(proc_t *, fasttrap_tracepoint_t *,
195     user_addr_t, fasttrap_probe_type_t);
196 extern int fasttrap_tracepoint_install(proc_t *, fasttrap_tracepoint_t *);
197 extern int fasttrap_tracepoint_remove(proc_t *, fasttrap_tracepoint_t *);
198 
199 #if defined(__x86_64__)
200 extern int fasttrap_pid_probe(x86_saved_state_t *regs);
201 extern int fasttrap_return_probe(x86_saved_state_t* regs);
202 #elif defined(__arm64__)
203 extern int fasttrap_pid_probe(arm_saved_state_t *rp);
204 extern int fasttrap_return_probe(arm_saved_state_t *regs);
205 #else
206 #error architecture not supported
207 #endif
208 
209 extern uint64_t fasttrap_pid_getarg(void *, dtrace_id_t, void *, int, int);
210 extern uint64_t fasttrap_usdt_getarg(void *, dtrace_id_t, void *, int, int);
211 
212 
213 #ifdef	__cplusplus
214 }
215 #endif
216 
217 #undef proc_t
218 
219 #endif	/* _FASTTRAP_IMPL_H */
220