trgt_i386.c revision 167143 
1/*
2 * Copyright (c) 2004 Marcel Moolenaar
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/gnu/usr.bin/gdb/kgdb/trgt_i386.c 167143 2007-03-01 13:56:08Z kib $");
29
30#include <sys/types.h>
31#include <machine/pcb.h>
32#include <machine/frame.h>
33#include <err.h>
34#include <kvm.h>
35#include <string.h>
36
37#include <defs.h>
38#include <target.h>
39#include <gdbthread.h>
40#include <inferior.h>
41#include <regcache.h>
42#include <frame-unwind.h>
43#include <i386-tdep.h>
44
45#include "kgdb.h"
46
47void
48kgdb_trgt_fetch_registers(int regno __unused)
49{
50	struct kthr *kt;
51	struct pcb pcb;
52
53	kt = kgdb_thr_lookup_tid(ptid_get_tid(inferior_ptid));
54	if (kt == NULL)
55		return;
56	if (kvm_read(kvm, kt->pcb, &pcb, sizeof(pcb)) != sizeof(pcb)) {
57		warnx("kvm_read: %s", kvm_geterr(kvm));
58		memset(&pcb, 0, sizeof(pcb));
59	}
60	supply_register(I386_EBX_REGNUM, (char *)&pcb.pcb_ebx);
61	supply_register(I386_ESP_REGNUM, (char *)&pcb.pcb_esp);
62	supply_register(I386_EBP_REGNUM, (char *)&pcb.pcb_ebp);
63	supply_register(I386_ESI_REGNUM, (char *)&pcb.pcb_esi);
64	supply_register(I386_EDI_REGNUM, (char *)&pcb.pcb_edi);
65	supply_register(I386_EIP_REGNUM, (char *)&pcb.pcb_eip);
66}
67
68void
69kgdb_trgt_store_registers(int regno __unused)
70{
71	fprintf_unfiltered(gdb_stderr, "XXX: %s\n", __func__);
72}
73
74struct kgdb_frame_cache {
75	int		intrframe;
76	CORE_ADDR	pc;
77	CORE_ADDR	sp;
78};
79
80static int kgdb_trgt_frame_offset[15] = {
81	offsetof(struct trapframe, tf_eax),
82	offsetof(struct trapframe, tf_ecx),
83	offsetof(struct trapframe, tf_edx),
84	offsetof(struct trapframe, tf_ebx),
85	offsetof(struct trapframe, tf_esp),
86	offsetof(struct trapframe, tf_ebp),
87	offsetof(struct trapframe, tf_esi),
88	offsetof(struct trapframe, tf_edi),
89	offsetof(struct trapframe, tf_eip),
90	offsetof(struct trapframe, tf_eflags),
91	offsetof(struct trapframe, tf_cs),
92	offsetof(struct trapframe, tf_ss),
93	offsetof(struct trapframe, tf_ds),
94	offsetof(struct trapframe, tf_es),
95	offsetof(struct trapframe, tf_fs)
96};
97
98static struct kgdb_frame_cache *
99kgdb_trgt_frame_cache(struct frame_info *next_frame, void **this_cache)
100{
101	char buf[MAX_REGISTER_SIZE];
102	struct kgdb_frame_cache *cache;
103	char *pname;
104
105	cache = *this_cache;
106	if (cache == NULL) {
107		cache = FRAME_OBSTACK_ZALLOC(struct kgdb_frame_cache);
108		*this_cache = cache;
109		cache->pc = frame_func_unwind(next_frame);
110		find_pc_partial_function(cache->pc, &pname, NULL, NULL);
111		cache->intrframe = (pname[0] == 'X') ? 1 : 0;
112		frame_unwind_register(next_frame, SP_REGNUM, buf);
113		cache->sp = extract_unsigned_integer(buf,
114		    register_size(current_gdbarch, SP_REGNUM));
115	}
116	return (cache);
117}
118
119static void
120kgdb_trgt_trapframe_this_id(struct frame_info *next_frame, void **this_cache,
121    struct frame_id *this_id)
122{
123	struct kgdb_frame_cache *cache;
124
125	cache = kgdb_trgt_frame_cache(next_frame, this_cache);
126	*this_id = frame_id_build(cache->sp, cache->pc);
127}
128
129static void
130kgdb_trgt_trapframe_prev_register(struct frame_info *next_frame,
131    void **this_cache, int regnum, int *optimizedp, enum lval_type *lvalp,
132    CORE_ADDR *addrp, int *realnump, void *valuep)
133{
134	char dummy_valuep[MAX_REGISTER_SIZE];
135	struct kgdb_frame_cache *cache;
136	int ofs, regsz;
137	static int ofs_fix = 0;
138	static int ofs_fixed = 0;
139
140	regsz = register_size(current_gdbarch, regnum);
141
142	if (valuep == NULL)
143		valuep = dummy_valuep;
144	memset(valuep, 0, regsz);
145	*optimizedp = 0;
146	*addrp = 0;
147	*lvalp = not_lval;
148	*realnump = -1;
149
150	if (!ofs_fixed) {
151		uintptr_t calltrap_addr;
152		char calltrap[1];
153
154		calltrap_addr = kgdb_lookup("calltrap");
155		if (calltrap_addr != 0) {
156			if (kvm_read(kvm, calltrap_addr, calltrap,
157				     sizeof(calltrap)) != sizeof(calltrap)) {
158				warnx("kvm_read: %s", kvm_geterr(kvm));
159			} else if (calltrap[0] == 0x54) /* push %esp */ {
160				/*
161				 * To accomodate for rev. 1.117 of
162				 * i386/i386/exception.s
163				 */
164				ofs_fix = 4;
165			}
166		}
167		ofs_fixed = 1;
168	}
169	ofs = (regnum >= I386_EAX_REGNUM && regnum <= I386_FS_REGNUM)
170	    ? kgdb_trgt_frame_offset[regnum] + ofs_fix : -1;
171	if (ofs == -1)
172		return;
173
174	cache = kgdb_trgt_frame_cache(next_frame, this_cache);
175	*addrp = cache->sp + ofs + (cache->intrframe ? 4 : 0);
176	*lvalp = lval_memory;
177	target_read_memory(*addrp, valuep, regsz);
178}
179
180static const struct frame_unwind kgdb_trgt_trapframe_unwind = {
181        UNKNOWN_FRAME,
182        &kgdb_trgt_trapframe_this_id,
183        &kgdb_trgt_trapframe_prev_register
184};
185
186const struct frame_unwind *
187kgdb_trgt_trapframe_sniffer(struct frame_info *next_frame)
188{
189	char *pname;
190	CORE_ADDR pc;
191
192	pc = frame_pc_unwind(next_frame);
193	pname = NULL;
194	find_pc_partial_function(pc, &pname, NULL, NULL);
195	if (pname == NULL)
196		return (NULL);
197	if (strcmp(pname, "calltrap") == 0 ||
198	    (pname[0] == 'X' && pname[1] != '_'))
199		return (&kgdb_trgt_trapframe_unwind);
200	/* printf("%s: %llx =%s\n", __func__, pc, pname); */
201	return (NULL);
202}
203