1 /* Register support routines for the remote server for GDB.
2    Copyright (C) 2001, 2002, 2004, 2005, 2011
3    Free Software Foundation, Inc.
4 
5    This file is part of GDB.
6    It has been modified to integrate it in valgrind
7 
8    This program is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 2 of the License, or
11    (at your option) any later version.
12 
13    This program is distributed in the hope that it will be useful,
14    but WITHOUT ANY WARRANTY; without even the implied warranty of
15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16    GNU General Public License for more details.
17 
18    You should have received a copy of the GNU General Public License
19    along with this program; if not, write to the Free Software
20    Foundation, Inc., 51 Franklin Street, Fifth Floor,
21    Boston, MA 02110-1301, USA.  */
22 
23 #include "server.h"
24 #include "regdef.h"
25 
26 /* The private data for the register cache.  Note that we have one
27    per inferior; this is primarily for simplicity, as the performance
28    benefit is minimal.  */
29 
30 struct inferior_regcache_data
31 {
32    int registers_valid;
33    unsigned char *registers;
34    Bool *register_supplied; /* set to True once it has been supplied */
35 };
36 
37 static int register_bytes;
38 
39 static struct reg *reg_defs;
40 static int num_registers;
41 
42 const char **gdbserver_expedite_regs;
43 
44 static
get_regcache(struct thread_info * inf,int fetch)45 struct inferior_regcache_data * get_regcache (struct thread_info *inf,
46                                               int fetch)
47 {
48    struct inferior_regcache_data *regcache;
49 
50    regcache = (struct inferior_regcache_data *) inferior_regcache_data (inf);
51 
52    if (regcache == NULL)
53       fatal ("no register cache\n");
54 
55    /* FIXME - fetch registers for INF */
56    if (fetch && regcache->registers_valid == 0) {
57       valgrind_fetch_registers (0);
58       regcache->registers_valid = 1;
59    }
60 
61    return regcache;
62 }
63 
regcache_invalidate_one(struct inferior_list_entry * entry)64 void regcache_invalidate_one (struct inferior_list_entry *entry)
65 {
66    struct thread_info *thread = (struct thread_info *) entry;
67    struct inferior_regcache_data *regcache;
68 
69    regcache = (struct inferior_regcache_data *) inferior_regcache_data (thread);
70 
71    if (regcache->registers_valid) {
72       struct thread_info *saved_inferior = current_inferior;
73 
74       current_inferior = thread;
75       valgrind_store_registers (-1);
76       current_inferior = saved_inferior;
77    }
78 
79    regcache->registers_valid = 0;
80 }
81 
regcache_invalidate()82 void regcache_invalidate ()
83 {
84    for_each_inferior (&all_threads, regcache_invalidate_one);
85 }
86 
registers_length(void)87 int registers_length (void)
88 {
89    return 2 * register_bytes;
90 }
91 
new_register_cache(void)92 void *new_register_cache (void)
93 {
94    struct inferior_regcache_data *regcache;
95 
96    regcache = malloc (sizeof (*regcache));
97 
98    /* Make sure to zero-initialize the register cache when it is created,
99       in case there are registers the target never fetches.  This way they'll
100       read as zero instead of garbage.  */
101    regcache->registers = calloc (1, register_bytes);
102    if (regcache->registers == NULL)
103       fatal ("Could not allocate register cache.\n");
104 
105    regcache->register_supplied = calloc (1, num_registers);
106    if (regcache->register_supplied == NULL)
107       fatal ("Could not allocate register_supplied cache.\n");
108 
109    regcache->registers_valid = 0;
110 
111    return regcache;
112 }
113 
free_register_cache(void * regcache_p)114 void free_register_cache (void *regcache_p)
115 {
116    struct inferior_regcache_data *regcache
117       = (struct inferior_regcache_data *) regcache_p;
118 
119    free (regcache->registers);
120    free (regcache->register_supplied);
121    free (regcache);
122 }
123 
124 /* if a regcache exists for entry, reallocate it.
125    This is needed if the shadow registers are added.
126    In such a case, a 2nd call to set_register_cache is done
127    which will cause the reallocation of already created caches. */
128 static
regcache_realloc_one(struct inferior_list_entry * entry)129 void regcache_realloc_one (struct inferior_list_entry *entry)
130 {
131    struct thread_info *thread = (struct thread_info *) entry;
132    struct inferior_regcache_data *regcache;
133 
134    regcache = (struct inferior_regcache_data *) inferior_regcache_data (thread);
135 
136    if (regcache) {
137       free_register_cache (regcache);
138       set_inferior_regcache_data (thread, new_register_cache ());
139    }
140 }
141 
set_register_cache(struct reg * regs,int n)142 void set_register_cache (struct reg *regs, int n)
143 {
144    int offset, i;
145 
146    reg_defs = regs;
147    num_registers = n;
148 
149    offset = 0;
150    for (i = 0; i < n; i++) {
151       regs[i].offset = offset;
152       offset += regs[i].size;
153    }
154 
155    register_bytes = offset / 8;
156 
157    for_each_inferior (&all_threads, regcache_realloc_one);
158 }
159 
registers_to_string(char * buf)160 void registers_to_string (char *buf)
161 {
162    unsigned char *registers = get_regcache (current_inferior, 1)->registers;
163 
164    convert_int_to_ascii (registers, buf, register_bytes);
165 }
166 
registers_from_string(const char * buf)167 void registers_from_string (const char *buf)
168 {
169    int len = strlen (buf);
170    unsigned char *registers = get_regcache (current_inferior, 1)->registers;
171 
172    if (len != register_bytes * 2) {
173       warning ("Wrong sized register packet (expected %d bytes, got %d)\n",
174                2*register_bytes, len);
175       if (len > register_bytes * 2)
176          len = register_bytes * 2;
177    }
178    convert_ascii_to_int (buf, registers, len / 2);
179 }
180 
find_regno(const char * name)181 int find_regno (const char *name)
182 {
183    int i;
184 
185    for (i = 0; i < num_registers; i++)
186       if (!strcmp (name, reg_defs[i].name))
187          return i;
188    fatal ("Unknown register %s requested\n", name);
189    return -1;
190 }
191 
find_register_by_number(int n)192 struct reg *find_register_by_number (int n)
193 {
194    return &reg_defs[n];
195 }
196 
register_size(int n)197 int register_size (int n)
198 {
199    return reg_defs[n].size / 8;
200 }
201 
202 static
register_data(int n,int fetch)203 unsigned char *register_data (int n, int fetch)
204 {
205    unsigned char *registers
206       = get_regcache (current_inferior, fetch)->registers;
207 
208    return registers + (reg_defs[n].offset / 8);
209 }
210 static
register_data_for_supply(int n,int fetch,Bool * mod)211 unsigned char *register_data_for_supply (int n, int fetch, Bool *mod)
212 {
213    struct inferior_regcache_data * cache
214       = get_regcache (current_inferior, fetch);
215    unsigned char *registers = cache->registers;
216 
217    if (cache->register_supplied[n])
218       *mod = False;
219    else
220       *mod = True;
221    cache->register_supplied[n] = True;
222    return registers + (reg_defs[n].offset / 8);
223 }
224 
supply_register(int n,const void * buf,Bool * mod)225 void supply_register (int n, const void *buf, Bool *mod)
226 {
227    Bool new;
228    VG_(dmemcpy) (register_data_for_supply (n, 0, &new),
229                  buf, register_size (n), mod);
230    if (new)
231       *mod = True;
232 }
233 
supply_register_from_string(int n,const char * buf,Bool * mod)234 void supply_register_from_string (int n, const char *buf, Bool *mod)
235 {
236    Bool new;
237    unsigned char bytes_register[register_size (n)];
238    convert_ascii_to_int (buf, bytes_register, register_size (n));
239    VG_(dmemcpy) (register_data_for_supply (n, 0, &new),
240                  bytes_register, register_size (n), mod);
241    if (new)
242       *mod = True;
243 }
244 
supply_register_by_name(const char * name,const void * buf,Bool * mod)245 void supply_register_by_name (const char *name, const void *buf, Bool *mod)
246 {
247    supply_register (find_regno (name), buf, mod);
248 }
249 
collect_register(int n,void * buf)250 void collect_register (int n, void *buf)
251 {
252    VG_(memcpy) (buf, register_data (n, 1), register_size (n));
253 }
254 
collect_register_as_string(int n,char * buf)255 void collect_register_as_string (int n, char *buf)
256 {
257    convert_int_to_ascii (register_data (n, 1), buf, register_size (n));
258 }
259 
collect_register_by_name(const char * name,void * buf)260 void collect_register_by_name (const char *name, void *buf)
261 {
262    collect_register (find_regno (name), buf);
263 }
264