fasttrap_impl.h revision 297077
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/queue.h>
36#include <sys/fasttrap.h>
37#include <sys/fasttrap_isa.h>
38
39#ifdef	__cplusplus
40extern "C" {
41#endif
42
43/*
44 * Fasttrap Providers, Probes and Tracepoints
45 *
46 * Each Solaris process can have multiple providers -- the pid provider as
47 * well as any number of user-level statically defined tracing (USDT)
48 * providers. Those providers are each represented by a fasttrap_provider_t.
49 * All providers for a given process have a pointer to a shared
50 * fasttrap_proc_t. The fasttrap_proc_t has two states: active or defunct.
51 * When the count of active providers goes to zero it becomes defunct; a
52 * provider drops its active count when it is removed individually or as part
53 * of a mass removal when a process exits or performs an exec.
54 *
55 * Each probe is represented by a fasttrap_probe_t which has a pointer to
56 * its associated provider as well as a list of fasttrap_id_tp_t structures
57 * which are tuples combining a fasttrap_id_t and a fasttrap_tracepoint_t.
58 * A fasttrap_tracepoint_t represents the actual point of instrumentation
59 * and it contains two lists of fasttrap_id_t structures (to be fired pre-
60 * and post-instruction emulation) that identify the probes attached to the
61 * tracepoint. Tracepoints also have a pointer to the fasttrap_proc_t for the
62 * process they trace which is used when looking up a tracepoint both when a
63 * probe fires and when enabling and disabling probes.
64 *
65 * It's important to note that probes are preallocated with the necessary
66 * number of tracepoints, but that tracepoints can be shared by probes and
67 * swapped between probes. If a probe's preallocated tracepoint is enabled
68 * (and, therefore, the associated probe is enabled), and that probe is
69 * then disabled, ownership of that tracepoint may be exchanged for an
70 * unused tracepoint belonging to another probe that was attached to the
71 * enabled tracepoint.
72 *
73 * On FreeBSD, fasttrap providers also maintain per-thread scratch space for use
74 * by the ISA-specific fasttrap code. The fasttrap_scrblock_t type stores the
75 * virtual address of a page-sized memory block that is mapped into a process'
76 * address space. Each block is carved up into chunks (fasttrap_scrspace_t) for
77 * use by individual threads, which keep the address of their scratch space
78 * chunk in their struct kdtrace_thread. A thread's scratch space isn't released
79 * until it exits.
80 */
81
82#ifndef illumos
83typedef struct fasttrap_scrblock {
84	vm_offset_t ftsb_addr;			/* address of a scratch block */
85	LIST_ENTRY(fasttrap_scrblock) ftsb_next;/* next block in list */
86} fasttrap_scrblock_t;
87#define	FASTTRAP_SCRBLOCK_SIZE	PAGE_SIZE
88
89typedef struct fasttrap_scrspace {
90	uintptr_t ftss_addr;			/* scratch space address */
91	LIST_ENTRY(fasttrap_scrspace) ftss_next;/* next in list */
92} fasttrap_scrspace_t;
93#define	FASTTRAP_SCRSPACE_SIZE	64
94#endif
95
96typedef struct fasttrap_proc {
97	pid_t ftpc_pid;				/* process ID for this proc */
98	uint64_t ftpc_acount;			/* count of active providers */
99	uint64_t ftpc_rcount;			/* count of extant providers */
100	kmutex_t ftpc_mtx;			/* lock on all but acount */
101	struct fasttrap_proc *ftpc_next;	/* next proc in hash chain */
102#ifndef illumos
103	LIST_HEAD(, fasttrap_scrblock) ftpc_scrblks; /* mapped scratch blocks */
104	LIST_HEAD(, fasttrap_scrspace) ftpc_fscr; /* free scratch space */
105	LIST_HEAD(, fasttrap_scrspace) ftpc_ascr; /* used scratch space */
106#endif
107} fasttrap_proc_t;
108
109typedef struct fasttrap_provider {
110	pid_t ftp_pid;				/* process ID for this prov */
111	char ftp_name[DTRACE_PROVNAMELEN];	/* prov name (w/o the pid) */
112	dtrace_provider_id_t ftp_provid;	/* DTrace provider handle */
113	uint_t ftp_marked;			/* mark for possible removal */
114	uint_t ftp_retired;			/* mark when retired */
115	kmutex_t ftp_mtx;			/* provider lock */
116	kmutex_t ftp_cmtx;			/* lock on creating probes */
117	uint64_t ftp_rcount;			/* enabled probes ref count */
118	uint64_t ftp_ccount;			/* consumers creating probes */
119	uint64_t ftp_mcount;			/* meta provider count */
120	fasttrap_proc_t *ftp_proc;		/* shared proc for all provs */
121	struct fasttrap_provider *ftp_next;	/* next prov in hash chain */
122} fasttrap_provider_t;
123
124typedef struct fasttrap_id fasttrap_id_t;
125typedef struct fasttrap_probe fasttrap_probe_t;
126typedef struct fasttrap_tracepoint fasttrap_tracepoint_t;
127
128struct fasttrap_id {
129	fasttrap_probe_t *fti_probe;		/* referrring probe */
130	fasttrap_id_t *fti_next;		/* enabled probe list on tp */
131	fasttrap_probe_type_t fti_ptype;	/* probe type */
132};
133
134typedef struct fasttrap_id_tp {
135	fasttrap_id_t fit_id;
136	fasttrap_tracepoint_t *fit_tp;
137} fasttrap_id_tp_t;
138
139struct fasttrap_probe {
140	dtrace_id_t ftp_id;			/* DTrace probe identifier */
141	pid_t ftp_pid;				/* pid for this probe */
142	fasttrap_provider_t *ftp_prov;		/* this probe's provider */
143	uintptr_t ftp_faddr;			/* associated function's addr */
144	size_t ftp_fsize;			/* associated function's size */
145	uint64_t ftp_gen;			/* modification generation */
146	uint64_t ftp_ntps;			/* number of tracepoints */
147	uint8_t *ftp_argmap;			/* native to translated args */
148	uint8_t ftp_nargs;			/* translated argument count */
149	uint8_t ftp_enabled;			/* is this probe enabled */
150	char *ftp_xtypes;			/* translated types index */
151	char *ftp_ntypes;			/* native types index */
152	fasttrap_id_tp_t ftp_tps[1];		/* flexible array */
153};
154
155#define	FASTTRAP_ID_INDEX(id)	\
156((fasttrap_id_tp_t *)(((char *)(id) - offsetof(fasttrap_id_tp_t, fit_id))) - \
157&(id)->fti_probe->ftp_tps[0])
158
159struct fasttrap_tracepoint {
160	fasttrap_proc_t *ftt_proc;		/* associated process struct */
161	uintptr_t ftt_pc;			/* address of tracepoint */
162	pid_t ftt_pid;				/* pid of tracepoint */
163	fasttrap_machtp_t ftt_mtp;		/* ISA-specific portion */
164	fasttrap_id_t *ftt_ids;			/* NULL-terminated list */
165	fasttrap_id_t *ftt_retids;		/* NULL-terminated list */
166	fasttrap_tracepoint_t *ftt_next;	/* link in global hash */
167};
168
169typedef struct fasttrap_bucket {
170	kmutex_t ftb_mtx;			/* bucket lock */
171	void *ftb_data;				/* data payload */
172
173	uint8_t ftb_pad[64 - sizeof (kmutex_t) - sizeof (void *)];
174} fasttrap_bucket_t;
175
176typedef struct fasttrap_hash {
177	ulong_t fth_nent;			/* power-of-2 num. of entries */
178	ulong_t fth_mask;			/* fth_nent - 1 */
179	fasttrap_bucket_t *fth_table;		/* array of buckets */
180} fasttrap_hash_t;
181
182/*
183 * If at some future point these assembly functions become observable by
184 * DTrace, then these defines should become separate functions so that the
185 * fasttrap provider doesn't trigger probes during internal operations.
186 */
187#define	fasttrap_copyout	copyout
188#define	fasttrap_fuword32	fuword32
189#define	fasttrap_suword32	suword32
190#define	fasttrap_suword64	suword64
191
192#ifdef __amd64__
193#define	fasttrap_fulword	fuword64
194#define	fasttrap_sulword	suword64
195#else
196#define	fasttrap_fulword	fuword32
197#define	fasttrap_sulword	suword32
198#endif
199
200extern void fasttrap_sigtrap(proc_t *, kthread_t *, uintptr_t);
201#ifndef illumos
202extern fasttrap_scrspace_t *fasttrap_scraddr(struct thread *,
203    fasttrap_proc_t *);
204#endif
205
206extern dtrace_id_t 		fasttrap_probe_id;
207extern fasttrap_hash_t		fasttrap_tpoints;
208
209#define	FASTTRAP_TPOINTS_INDEX(pid, pc) \
210	(((pc) / sizeof (fasttrap_instr_t) + (pid)) & fasttrap_tpoints.fth_mask)
211
212/*
213 * Must be implemented by fasttrap_isa.c
214 */
215extern int fasttrap_tracepoint_init(proc_t *, fasttrap_tracepoint_t *,
216    uintptr_t, fasttrap_probe_type_t);
217extern int fasttrap_tracepoint_install(proc_t *, fasttrap_tracepoint_t *);
218extern int fasttrap_tracepoint_remove(proc_t *, fasttrap_tracepoint_t *);
219
220struct reg;
221extern int fasttrap_pid_probe(struct reg *);
222extern int fasttrap_return_probe(struct reg *);
223
224extern uint64_t fasttrap_pid_getarg(void *, dtrace_id_t, void *, int, int);
225extern uint64_t fasttrap_usdt_getarg(void *, dtrace_id_t, void *, int, int);
226
227#ifdef	__cplusplus
228}
229#endif
230
231#endif	/* _FASTTRAP_IMPL_H */
232