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 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 #pragma ident "%Z%%M% %I% %E% SMI"
27
28 /*
29 * Workarounds for stabs generation bugs in the compiler and general needed
30 * fixups.
31 */
32
33 #if HAVE_NBTOOL_CONFIG_H
34 # include "nbtool_config.h"
35 #endif
36
37 #include <stdio.h>
38 #include <strings.h>
39
40 #include "ctf_headers.h"
41 #include "ctftools.h"
42 #include "hash.h"
43 #include "memory.h"
44 #include "traverse.h"
45
46 /*
47 * Due to 4432619, the 6.1 compiler will sometimes incorrectly generate pointer
48 * stabs. Given a struct foo, and a corresponding typedef struct foo foo_t.
49 * In some cases, when faced with a pointer to a foo_t, the compiler will
50 * sometimes generate a stab that describes a pointer to a struct foo.
51 * Regardless of correctness, this breaks merges, as it occurs inconsistently
52 * by file. The following two routines know how to recognize and repair foo_t *
53 * and foo_t ** bugs in a specific set of cases. There is no general way to
54 * solve this problem without a fix to the compiler. In general, cases should
55 * only be added to these routines to fix merging problems in genunix.
56 */
57 static void
fix_ptrptr_to_struct(tdata_t * td)58 fix_ptrptr_to_struct(tdata_t *td)
59 {
60 const char *strs[2] = { "as", "fdbuffer" };
61 const char *mems[2] = { "a_objectdir", "fd_shadow" };
62 const char *acts[2] = { "vnode", "page" };
63 const char *tgts[2] = { "vnode_t", "page_t" };
64 tdesc_t *str;
65 tdesc_t *act, *tgt;
66 tdesc_t *p1, *p2;
67 mlist_t *ml;
68 int i;
69
70 for (i = 0; i < (int) (sizeof (strs) / sizeof (strs[0])); i++) {
71 if (!(str = lookupname(strs[i])) || str->t_type != STRUCT)
72 continue;
73
74 for (ml = str->t_members; ml; ml = ml->ml_next) {
75 if (streq(ml->ml_name, mems[i]))
76 break;
77 }
78 if (!ml)
79 continue;
80
81 if (ml->ml_type->t_type != POINTER || ml->ml_type->t_name ||
82 ml->ml_type->t_tdesc->t_type != POINTER ||
83 ml->ml_type->t_tdesc->t_name)
84 continue;
85
86 act = ml->ml_type->t_tdesc->t_tdesc;
87 if (act->t_type != STRUCT || !streq(act->t_name, acts[i]))
88 continue;
89
90 if (!(tgt = lookupname(tgts[i])) || tgt->t_type != TYPEDEF)
91 continue;
92
93 /* We have an instance of the bug */
94 p2 = xcalloc(sizeof (*p2));
95 p2->t_type = POINTER;
96 p2->t_id = td->td_nextid++;
97 p2->t_tdesc = tgt;
98
99 p1 = xcalloc(sizeof (*p1));
100 p1->t_type = POINTER;
101 p1->t_id = td->td_nextid++;
102 p1->t_tdesc = p2;
103
104 ml->ml_type = p1;
105
106 debug(3, "Fixed %s->%s => ptrptr struct %s bug\n",
107 strs[i], mems[i], acts[i]);
108 }
109 }
110
111 static void
fix_ptr_to_struct(tdata_t * td)112 fix_ptr_to_struct(tdata_t *td)
113 {
114 const char *strs[2] = { "vmem", "id_space" };
115 const char *mems[2] = { NULL, "is_vmem" };
116 tdesc_t *ptr = NULL;
117 tdesc_t *str, *vmt;
118 mlist_t *ml;
119 int i;
120
121 if ((vmt = lookupname("vmem_t")) == NULL || vmt->t_type != TYPEDEF)
122 return;
123
124 for (i = 0; i < (int) (sizeof (strs) / sizeof (strs[0])); i++) {
125 if (!(str = lookupname(strs[i])) || str->t_type != STRUCT)
126 continue;
127
128 for (ml = str->t_members; ml; ml = ml->ml_next) {
129 if (mems[i] && !streq(ml->ml_name, mems[i]))
130 continue;
131
132 if (ml->ml_type->t_type != POINTER ||
133 ml->ml_type->t_name ||
134 (ml->ml_type->t_tdesc->t_type != STRUCT &&
135 ml->ml_type->t_tdesc->t_type != FORWARD) ||
136 !streq(ml->ml_type->t_tdesc->t_name, "vmem"))
137 continue;
138
139 debug(3, "Fixed %s->%s => ptr struct vmem bug\n",
140 strs[i], ml->ml_name);
141
142 if (!ptr) {
143 ptr = xcalloc(sizeof (*ptr));
144 ptr->t_type = POINTER;
145 ptr->t_id = td->td_nextid++;
146 ptr->t_tdesc = vmt;
147 }
148
149 ml->ml_type = ptr;
150 }
151 }
152 }
153
154 /*
155 * Fix stabs generation bugs. These routines must be run before the
156 * post-conversion merge
157 */
158 void
cvt_fixstabs(tdata_t * td)159 cvt_fixstabs(tdata_t *td)
160 {
161 fix_ptrptr_to_struct(td);
162 fix_ptr_to_struct(td);
163 }
164
165 struct match {
166 tdesc_t *m_ret;
167 const char *m_name;
168 };
169
170 static int
matching_iidesc(void * arg1,void * arg2)171 matching_iidesc(void *arg1, void *arg2)
172 {
173 iidesc_t *iidesc = arg1;
174 struct match *match = arg2;
175 if (!streq(iidesc->ii_name, match->m_name))
176 return (0);
177
178 if (iidesc->ii_type != II_TYPE && iidesc->ii_type != II_SOU)
179 return (0);
180
181 match->m_ret = iidesc->ii_dtype;
182 return (-1);
183 }
184
185 static tdesc_t *
lookup_tdesc(tdata_t * td,char const * name)186 lookup_tdesc(tdata_t *td, char const *name)
187 {
188 struct match match = { NULL, name };
189 iter_iidescs_by_name(td, name, matching_iidesc, &match);
190 return (match.m_ret);
191 }
192
193 /*
194 * The cpu structure grows, with the addition of a machcpu member, if
195 * _MACHDEP is defined. This means that, for example, the cpu structure
196 * in unix is different from the cpu structure in genunix. As one might
197 * expect, this causes merges to fail. Since everyone indirectly contains
198 * a pointer to a CPU structure, the failed merges can cause massive amounts
199 * of duplication. In the case of unix uniquifying against genunix, upwards
200 * of 50% of the structures were unmerged due to this problem. We fix this
201 * by adding a cpu_m member. If machcpu hasn't been defined in our module,
202 * we make a forward node for it.
203 */
204 static void
fix_small_cpu_struct(tdata_t * td,size_t ptrsize)205 fix_small_cpu_struct(tdata_t *td, size_t ptrsize)
206 {
207 tdesc_t *cput, *cpu;
208 tdesc_t *machcpu;
209 mlist_t *ml, *lml;
210 mlist_t *cpum;
211 int foundcpucyc = 0;
212
213 /*
214 * We're going to take the circuitous route finding the cpu structure,
215 * because we want to make sure that we find the right one. It would
216 * be nice if we could verify the header name too. DWARF might not
217 * have the cpu_t, so we let this pass.
218 */
219 if ((cput = lookup_tdesc(td, "cpu_t")) != NULL) {
220 if (cput->t_type != TYPEDEF)
221 return;
222 cpu = cput->t_tdesc;
223 } else {
224 cpu = lookup_tdesc(td, "cpu");
225 }
226
227 if (cpu == NULL)
228 return;
229
230 if (!streq(cpu->t_name, "cpu") || cpu->t_type != STRUCT)
231 return;
232
233 for (ml = cpu->t_members, lml = NULL; ml;
234 lml = ml, ml = ml->ml_next) {
235 if (strcmp(ml->ml_name, "cpu_cyclic") == 0)
236 foundcpucyc = 1;
237 }
238
239 if (foundcpucyc == 0 || lml == NULL ||
240 strcmp(lml->ml_name, "cpu_m") == 0)
241 return;
242
243 /*
244 * We need to derive the right offset for the fake cpu_m member. To do
245 * that, we require a special unused member to be the last member
246 * before the 'cpu_m', that we encode knowledge of here. ABI alignment
247 * on all platforms is such that we only need to add a pointer-size
248 * number of bits to get the right offset for cpu_m. This would most
249 * likely break if gcc's -malign-double were ever used, but that option
250 * breaks the ABI anyway.
251 */
252 if (!streq(lml->ml_name, "cpu_m_pad") &&
253 getenv("CTFCONVERT_PERMISSIVE") == NULL) {
254 terminate("last cpu_t member before cpu_m is %s; "
255 "it must be cpu_m_pad.\n", lml->ml_name);
256 }
257
258 if ((machcpu = lookup_tdesc(td, "machcpu")) == NULL) {
259 machcpu = xcalloc(sizeof (*machcpu));
260 machcpu->t_name = xstrdup("machcpu");
261 machcpu->t_id = td->td_nextid++;
262 machcpu->t_type = FORWARD;
263 } else if (machcpu->t_type != STRUCT) {
264 return;
265 }
266
267 debug(3, "Adding cpu_m machcpu %s to cpu struct\n",
268 (machcpu->t_type == FORWARD ? "forward" : "struct"));
269
270 cpum = xmalloc(sizeof (*cpum));
271 cpum->ml_offset = lml->ml_offset + (ptrsize * NBBY);
272 cpum->ml_size = 0;
273 cpum->ml_name = xstrdup("cpu_m");
274 cpum->ml_type = machcpu;
275 cpum->ml_next = NULL;
276
277 lml->ml_next = cpum;
278 }
279
280 #ifdef __NetBSD__
281
282 /*
283 * XXX: A crude hack to bring down the number of types for a
284 * GENERIC kernel below 2**15-1 (from ~34000 to ~29800).
285 *
286 * Remove the type attributes "volatile", "const" and "restrict",
287 * for DTRACE these attributes are of little value.
288 */
289
290 static int
fix_kill_attr_cb(tdesc_t * tdp,tdesc_t ** tdpp,void * private __unused)291 fix_kill_attr_cb(tdesc_t *tdp, tdesc_t **tdpp, void *private __unused)
292 {
293
294 while (tdp->t_type == VOLATILE ||
295 tdp->t_type == RESTRICT ||
296 tdp->t_type == CONST)
297 tdp = tdp->t_tdesc;
298
299 *tdpp = tdp;
300
301 return 1;
302 }
303
304 static tdtrav_cb_f fix_kill_attr_tab[] = {
305 NULL,
306 NULL, /* intrinsic */
307 NULL, /* pointer */
308 NULL, /* reference */
309 NULL, /* array */
310 NULL, /* function */
311 NULL, /* struct */
312 NULL, /* union */
313 NULL, /* class */
314 NULL, /* enum */
315 NULL , /* forward */
316 NULL, /* typedef */
317 NULL, /* typedef unres */
318 fix_kill_attr_cb, /* volatile */
319 fix_kill_attr_cb, /* const */
320 fix_kill_attr_cb, /* restrict */
321 };
322
323 static void
fix_kill_attr(tdata_t * td,size_t ptrsize)324 fix_kill_attr(tdata_t *td, size_t ptrsize)
325 {
326
327 (void) iitraverse_hash(td->td_iihash, &td->td_curvgen,
328 fix_kill_attr_tab, NULL, NULL, NULL);
329 }
330
331 #endif /* __NetBSD__ */
332
333 void
cvt_fixups(tdata_t * td,size_t ptrsize)334 cvt_fixups(tdata_t *td, size_t ptrsize)
335 {
336 fix_small_cpu_struct(td, ptrsize);
337 #ifdef __NetBSD__
338 fix_kill_attr(td, ptrsize);
339 #endif
340 }
341