xref: /illumos-gate/usr/src/cmd/mdb/common/modules/genunix/kgrep.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * Generic memory walker, used by both the genunix and libumem dmods.
31  */
32 
33 #include <mdb/mdb_modapi.h>
34 #include <sys/sysmacros.h>
35 
36 #include "kgrep.h"
37 
38 #define	KGREP_FULL_MASK		(~(uintmax_t)0)
39 
40 typedef struct kgrep_data {
41 	uintmax_t kg_pattern;
42 	uintmax_t kg_mask;		/* fancy only */
43 	uintmax_t kg_dist;		/* fancy only */
44 	uintptr_t kg_minaddr;		/* fancy only */
45 	uintptr_t kg_maxaddr;		/* fancy only */
46 	void *kg_page;
47 	size_t kg_pagesize;
48 	char kg_cbtype;
49 	char kg_seen;
50 } kgrep_data_t;
51 
52 #define	KG_BASE		0
53 #define	KG_VERBOSE	1
54 #define	KG_PIPE		2
55 
56 static void
57 kgrep_cb(uintptr_t addr, uintmax_t *val, int type)
58 {
59 	switch (type) {
60 	case KG_BASE:
61 	default:
62 		mdb_printf("%p\n", addr);
63 		break;
64 	case KG_VERBOSE:
65 		mdb_printf("%p:\t%llx\n", addr, *val);
66 		break;
67 	case KG_PIPE:
68 		mdb_printf("%#lr\n", addr);
69 		break;
70 	}
71 }
72 
73 static int
74 kgrep_range_basic(uintptr_t base, uintptr_t lim, void *kg_arg)
75 {
76 	kgrep_data_t *kg = kg_arg;
77 	size_t pagesize = kg->kg_pagesize;
78 	uintptr_t pattern = kg->kg_pattern;
79 	uintptr_t *page = kg->kg_page;
80 	uintptr_t *page_end = &page[pagesize / sizeof (uintptr_t)];
81 	uintptr_t *pos;
82 
83 	uintptr_t addr, offset;
84 	int seen = 0;
85 
86 	/*
87 	 * page-align everything, to simplify the loop
88 	 */
89 	base = P2ALIGN(base, pagesize);
90 	lim = P2ROUNDUP(lim, pagesize);
91 
92 	for (addr = base; addr < lim; addr += pagesize) {
93 		if (mdb_vread(page, pagesize, addr) == -1)
94 			continue;
95 		seen = 1;
96 
97 		for (pos = page; pos < page_end; pos++) {
98 			if (*pos != pattern)
99 				continue;
100 
101 			offset = (caddr_t)pos - (caddr_t)page;
102 			kgrep_cb(addr + offset, NULL, kg->kg_cbtype);
103 		}
104 	}
105 	if (seen)
106 		kg->kg_seen = 1;
107 
108 	return (WALK_NEXT);
109 }
110 
111 /*
112  * Full-service template -- instantiated for each supported size.  We support
113  * the following options:
114  *
115  *	addr in [minaddr, maxaddr), and
116  *		value in [pattern, pattern + dist) OR
117  *		mask matching: (value & mask) == (pattern & mask)
118  */
119 #define	KGREP_FANCY_TEMPLATE(kgrep_range_fancybits, uintbits_t)		\
120 static int								\
121 kgrep_range_fancybits(uintptr_t base, uintptr_t lim, void *kg_arg)	\
122 {									\
123 	kgrep_data_t *kg = kg_arg;					\
124 									\
125 	uintbits_t pattern = kg->kg_pattern;				\
126 	uintbits_t dist = kg->kg_dist;					\
127 	uintbits_t mask = kg->kg_mask;					\
128 	uintptr_t minaddr = kg->kg_minaddr;				\
129 	uintptr_t maxaddr = kg->kg_maxaddr;				\
130 	size_t pagesize = kg->kg_pagesize;				\
131 	uintbits_t *page = (uintbits_t *)kg->kg_page;			\
132 	uintbits_t *page_end;						\
133 	uintbits_t *pos;						\
134 	uintbits_t cur;							\
135 	uintmax_t out;							\
136 									\
137 	uintptr_t addr, size, offset;					\
138 	int seen = 0;							\
139 									\
140 	base = P2ROUNDUP(MAX(base, minaddr), sizeof (uintbits_t));	\
141 									\
142 	if (maxaddr != 0 && lim > maxaddr)				\
143 		lim = maxaddr;						\
144 									\
145 	for (addr = base; addr < lim; addr += size) {			\
146 		/* P2END(...) computes the next page boundry */		\
147 		size = MIN(lim, P2END(addr, pagesize)) - addr;		\
148 									\
149 		if (mdb_vread(page, size, addr) == -1)			\
150 			continue;					\
151 									\
152 		seen = 1;						\
153 									\
154 		page_end = &page[size / sizeof (uintbits_t)];		\
155 		for (pos = page; pos < page_end; pos++) {		\
156 			cur = *pos;					\
157 									\
158 			if (((cur ^ pattern) & mask) != 0 &&		\
159 			    (cur - pattern) >= dist)			\
160 				continue;				\
161 									\
162 			out = cur;					\
163 			offset = (caddr_t)pos - (caddr_t)page;		\
164 			kgrep_cb(addr + offset, &out, kg->kg_cbtype);	\
165 		}							\
166 	}								\
167 	if (seen)							\
168 		kg->kg_seen = 1;					\
169 									\
170 	return (WALK_NEXT);						\
171 }
172 
173 KGREP_FANCY_TEMPLATE(kgrep_range_fancy8, uint8_t)
174 KGREP_FANCY_TEMPLATE(kgrep_range_fancy16, uint16_t)
175 KGREP_FANCY_TEMPLATE(kgrep_range_fancy32, uint32_t)
176 KGREP_FANCY_TEMPLATE(kgrep_range_fancy64, uint64_t)
177 
178 #undef KGREP_FANCY_TEMPLATE
179 
180 /*ARGSUSED*/
181 int
182 kgrep(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
183 {
184 	uintmax_t pattern = mdb_get_dot();
185 	uintmax_t mask = KGREP_FULL_MASK;
186 	uintmax_t invmask = 0;
187 	uintmax_t dist = 0;
188 	uintptr_t size = sizeof (uintptr_t);
189 	uintptr_t minaddr = 0;
190 	uintptr_t maxaddr = 0;
191 	size_t pagesize = kgrep_subr_pagesize();
192 	int verbose = 0;
193 	int ret;
194 	int args = 0;
195 
196 	kgrep_cb_func *func;
197 	kgrep_data_t kg;
198 
199 	uintmax_t size_mask;
200 
201 	if (mdb_getopts(argc, argv,
202 	    'a', MDB_OPT_UINTPTR, &minaddr,
203 	    'A', MDB_OPT_UINTPTR, &maxaddr,
204 	    'd', MDB_OPT_UINT64, &dist,
205 	    'm', MDB_OPT_UINT64, &mask,
206 	    'M', MDB_OPT_UINT64, &invmask,
207 	    's', MDB_OPT_UINTPTR, &size,
208 	    'v', MDB_OPT_SETBITS, B_TRUE, &verbose, NULL) != argc)
209 		return (DCMD_USAGE);
210 
211 	if (invmask != 0)
212 		args++;
213 	if (mask != KGREP_FULL_MASK)
214 		args++;
215 	if (dist != 0)
216 		args++;
217 
218 	if (args > 1) {
219 		mdb_warn("only one of -d, -m and -M may be specified\n");
220 		return (DCMD_USAGE);
221 	}
222 
223 	if (!(flags & DCMD_ADDRSPEC))
224 		return (DCMD_USAGE);
225 
226 	if (invmask != 0)
227 		mask = ~invmask;
228 
229 	if (pattern & ~mask)
230 		mdb_warn("warning: pattern does not match mask\n");
231 
232 	if (size > sizeof (uintmax_t)) {
233 		mdb_warn("sizes greater than %d not supported\n",
234 		    sizeof (uintmax_t));
235 		return (DCMD_ERR);
236 	}
237 
238 	if (size == 0 || (size & (size - 1)) != 0) {
239 		mdb_warn("size must be a power of 2\n");
240 		return (DCMD_ERR);
241 	}
242 
243 	if (size == sizeof (uintmax_t))
244 		size_mask = KGREP_FULL_MASK;
245 	else
246 		size_mask = (1ULL << (size * NBBY)) - 1ULL;
247 
248 	if (pattern & ~size_mask)
249 		mdb_warn("warning: pattern %llx overflows requested size "
250 		    "%d (max: %llx)\n",
251 		    pattern, size, size_mask);
252 
253 	if (dist > 0 &&
254 	    ((dist & ~size_mask) || size_mask + 1 - dist < pattern)) {
255 		mdb_warn("pattern %llx + distance %llx overflows size\n"
256 		    "%d (max: %llx)\n", pattern, dist, size, size_mask);
257 		return (DCMD_ERR);
258 	}
259 
260 	/*
261 	 * All arguments have now been validated.
262 	 */
263 
264 	(void) memset(&kg, '\0', sizeof (kg));
265 	kg.kg_page = mdb_alloc(pagesize, UM_SLEEP | UM_GC);
266 	kg.kg_pagesize = pagesize;
267 	kg.kg_pattern = pattern;
268 	kg.kg_mask = mask;
269 	kg.kg_dist = dist;
270 	kg.kg_minaddr = minaddr;
271 	kg.kg_maxaddr = maxaddr;
272 
273 	if (flags & DCMD_PIPE_OUT) {
274 		verbose = 0;
275 		kg.kg_cbtype = KG_PIPE;
276 	} else if (verbose) {
277 		kg.kg_cbtype = KG_VERBOSE;
278 	} else {
279 		kg.kg_cbtype = KG_BASE;
280 	}
281 
282 	/*
283 	 * kgrep_range_basic handles the common case (no arguments)
284 	 * with dispatch.
285 	 */
286 	if (size == sizeof (uintptr_t) && !verbose && mask == KGREP_FULL_MASK &&
287 	    dist == 0 && minaddr == 0 && maxaddr == 0)
288 		func = kgrep_range_basic;
289 	else {
290 		switch (size) {
291 		case 1:
292 			func = kgrep_range_fancy8;
293 			break;
294 		case 2:
295 			func = kgrep_range_fancy16;
296 			break;
297 		case 4:
298 			func = kgrep_range_fancy32;
299 			break;
300 		case 8:
301 			func = kgrep_range_fancy64;
302 			break;
303 		default:
304 			mdb_warn("can't happen: non-recognized kgrep size\n");
305 			return (DCMD_ERR);
306 		}
307 	}
308 
309 	/*
310 	 * Invoke the target, which should invoke func(start, end, &kg) for
311 	 * every range [start, end) of vaddrs which might have backing.
312 	 * Both start and end must be multiples of kgrep_subr_pagesize().
313 	 */
314 	ret = kgrep_subr(func, &kg);
315 
316 	if (ret == DCMD_OK && !kg.kg_seen)
317 		mdb_warn("warning: nothing searched\n");
318 
319 	return (ret);
320 }
321