1 /* Low level DECstation interface to ptrace, for GDB when running native.
2 Copyright 1988, 1989, 1991, 1992, 1993, 1995, 1996, 1999, 2000, 2001
3 Free Software Foundation, Inc.
4 Contributed by Alessandro Forin(af@cs.cmu.edu) at CMU
5 and by Per Bothner(bothner@cs.wisc.edu) at U.Wisconsin.
6
7 This file is part of GDB.
8
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
23
24 #include "defs.h"
25 #include "inferior.h"
26 #include "gdbcore.h"
27 #include "regcache.h"
28 #include <sys/ptrace.h>
29 #include <sys/types.h>
30 #include <sys/param.h>
31 #include <sys/user.h>
32 #undef JB_S0
33 #undef JB_S1
34 #undef JB_S2
35 #undef JB_S3
36 #undef JB_S4
37 #undef JB_S5
38 #undef JB_S6
39 #undef JB_S7
40 #undef JB_SP
41 #undef JB_S8
42 #undef JB_PC
43 #undef JB_SR
44 #undef NJBREGS
45 #include <setjmp.h> /* For JB_XXX. */
46
47 /* Size of elements in jmpbuf */
48
49 #define JB_ELEMENT_SIZE 4
50
51 /* Map gdb internal register number to ptrace ``address''.
52 These ``addresses'' are defined in DECstation <sys/ptrace.h> */
53
54 static int
register_ptrace_addr(int regno)55 register_ptrace_addr (int regno)
56 {
57 return (regno < 32 ? GPR_BASE + regno
58 : regno == mips_regnum (current_gdbarch)->pc ? PC
59 : regno == mips_regnum (current_gdbarch)->cause ? CAUSE
60 : regno == mips_regnum (current_gdbarch)->hi ? MMHI
61 : regno == mips_regnum (current_gdbarch)->lo ? MMLO
62 : regno == mips_regnum (current_gdbarch)->fp_control_status ? FPC_CSR
63 : regno == mips_regnum (current_gdbarch)->fp_implementation_revision ? FPC_EIR
64 : regno >= FP0_REGNUM ? FPR_BASE + (regno - FP0_REGNUM)
65 : 0);
66 }
67
68 static void fetch_core_registers (char *, unsigned, int, CORE_ADDR);
69
70 /* Get all registers from the inferior */
71
72 void
fetch_inferior_registers(int regno)73 fetch_inferior_registers (int regno)
74 {
75 unsigned int regaddr;
76 char buf[MAX_REGISTER_SIZE];
77 int i;
78 char zerobuf[MAX_REGISTER_SIZE];
79 memset (zerobuf, 0, MAX_REGISTER_SIZE);
80
81 deprecated_registers_fetched ();
82
83 for (regno = 1; regno < NUM_REGS; regno++)
84 {
85 regaddr = register_ptrace_addr (regno);
86 for (i = 0; i < DEPRECATED_REGISTER_RAW_SIZE (regno); i += sizeof (int))
87 {
88 *(int *) &buf[i] = ptrace (PT_READ_U, PIDGET (inferior_ptid),
89 (PTRACE_ARG3_TYPE) regaddr, 0);
90 regaddr += sizeof (int);
91 }
92 supply_register (regno, buf);
93 }
94
95 supply_register (ZERO_REGNUM, zerobuf);
96 /* Frame ptr reg must appear to be 0; it is faked by stack handling code. */
97 supply_register (DEPRECATED_FP_REGNUM, zerobuf);
98 }
99
100 /* Store our register values back into the inferior.
101 If REGNO is -1, do this for all registers.
102 Otherwise, REGNO specifies which register (so we can save time). */
103
104 void
store_inferior_registers(int regno)105 store_inferior_registers (int regno)
106 {
107 unsigned int regaddr;
108 char buf[80];
109
110 if (regno > 0)
111 {
112 if (regno == ZERO_REGNUM || regno == PS_REGNUM
113 || regno == mips_regnum (current_gdbarch)->badvaddr
114 || regno == mips_regnum (current_gdbarch)->cause
115 || regno == mips_regnum (current_gdbarch)->fp_implementation_revision
116 || regno == DEPRECATED_FP_REGNUM
117 || (regno >= FIRST_EMBED_REGNUM && regno <= LAST_EMBED_REGNUM))
118 return;
119 regaddr = register_ptrace_addr (regno);
120 errno = 0;
121 ptrace (PT_WRITE_U, PIDGET (inferior_ptid), (PTRACE_ARG3_TYPE) regaddr,
122 read_register (regno));
123 if (errno != 0)
124 {
125 sprintf (buf, "writing register number %d", regno);
126 perror_with_name (buf);
127 }
128 }
129 else
130 {
131 for (regno = 0; regno < NUM_REGS; regno++)
132 store_inferior_registers (regno);
133 }
134 }
135
136
137 /* Figure out where the longjmp will land.
138 We expect the first arg to be a pointer to the jmp_buf structure from which
139 we extract the pc (JB_PC) that we will land at. The pc is copied into PC.
140 This routine returns true on success. */
141
142 int
get_longjmp_target(CORE_ADDR * pc)143 get_longjmp_target (CORE_ADDR *pc)
144 {
145 CORE_ADDR jb_addr;
146 char *buf;
147
148 buf = alloca (TARGET_PTR_BIT / TARGET_CHAR_BIT);
149 jb_addr = read_register (A0_REGNUM);
150
151 if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf,
152 TARGET_PTR_BIT / TARGET_CHAR_BIT))
153 return 0;
154
155 *pc = extract_unsigned_integer (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
156
157 return 1;
158 }
159
160 /* Extract the register values out of the core file and store
161 them where `read_register' will find them.
162
163 CORE_REG_SECT points to the register values themselves, read into memory.
164 CORE_REG_SIZE is the size of that area.
165 WHICH says which set of registers we are handling (0 = int, 2 = float
166 on machines where they are discontiguous).
167 REG_ADDR is the offset from u.u_ar0 to the register values relative to
168 core_reg_sect. This is used with old-fashioned core files to
169 locate the registers in a large upage-plus-stack ".reg" section.
170 Original upage address X is at location core_reg_sect+x+reg_addr.
171 */
172
173 static void
fetch_core_registers(char * core_reg_sect,unsigned core_reg_size,int which,CORE_ADDR reg_addr)174 fetch_core_registers (char *core_reg_sect, unsigned core_reg_size, int which,
175 CORE_ADDR reg_addr)
176 {
177 int regno;
178 unsigned int addr;
179 int bad_reg = -1;
180 reg_ptr = -reg_addr; /* Original u.u_ar0 is -reg_addr. */
181
182 char zerobuf[MAX_REGISTER_SIZE];
183 memset (zerobuf, 0, MAX_REGISTER_SIZE);
184
185
186 /* If u.u_ar0 was an absolute address in the core file, relativize it now,
187 so we can use it as an offset into core_reg_sect. When we're done,
188 "register 0" will be at core_reg_sect+reg_ptr, and we can use
189 register_addr to offset to the other registers. If this is a modern
190 core file without a upage, reg_ptr will be zero and this is all a big
191 NOP. */
192 if (reg_ptr > core_reg_size)
193 #ifdef KERNEL_U_ADDR
194 reg_ptr -= KERNEL_U_ADDR;
195 #else
196 error ("Old mips core file can't be processed on this machine.");
197 #endif
198
199 for (regno = 0; regno < NUM_REGS; regno++)
200 {
201 addr = register_addr (regno, reg_ptr);
202 if (addr >= core_reg_size)
203 {
204 if (bad_reg < 0)
205 bad_reg = regno;
206 }
207 else
208 {
209 supply_register (regno, core_reg_sect + addr);
210 }
211 }
212 if (bad_reg >= 0)
213 {
214 error ("Register %s not found in core file.", REGISTER_NAME (bad_reg));
215 }
216 supply_register (ZERO_REGNUM, zerobuf);
217 /* Frame ptr reg must appear to be 0; it is faked by stack handling code. */
218 supply_register (DEPRECATED_FP_REGNUM, zerobuf);
219 }
220
221 /* Return the address in the core dump or inferior of register REGNO.
222 BLOCKEND is the address of the end of the user structure. */
223
224 CORE_ADDR
register_addr(int regno,CORE_ADDR blockend)225 register_addr (int regno, CORE_ADDR blockend)
226 {
227 CORE_ADDR addr;
228
229 if (regno < 0 || regno >= NUM_REGS)
230 error ("Invalid register number %d.", regno);
231
232 REGISTER_U_ADDR (addr, blockend, regno);
233
234 return addr;
235 }
236
237
238 /* Register that we are able to handle mips core file formats.
239 FIXME: is this really bfd_target_unknown_flavour? */
240
241 static struct core_fns mips_core_fns =
242 {
243 bfd_target_unknown_flavour, /* core_flavour */
244 default_check_format, /* check_format */
245 default_core_sniffer, /* core_sniffer */
246 fetch_core_registers, /* core_read_registers */
247 NULL /* next */
248 };
249
250 void
_initialize_core_mips(void)251 _initialize_core_mips (void)
252 {
253 deprecated_add_core_fns (&mips_core_fns);
254 }
255