1 /* Generic GNU/Linux target using traditional ptrace register access.
3 Copyright (C) 1988-2018 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "linux-nat-trad.h"
23 #include "nat/gdb_ptrace.h"
24 #include "inf-ptrace.h"
26 /* Pointer to a function that returns the offset within the user area
27 where a particular register is stored. */
28 static CORE_ADDR (*inf_ptrace_register_u_offset)(struct gdbarch *, int, int);
30 /* Fetch register REGNUM from the inferior. */
33 inf_ptrace_fetch_register (struct regcache *regcache, int regnum)
35 struct gdbarch *gdbarch = regcache->arch ();
42 /* This isn't really an address, but ptrace thinks of it as one. */
43 addr = inf_ptrace_register_u_offset (gdbarch, regnum, 0);
44 if (addr == (CORE_ADDR)-1
45 || gdbarch_cannot_fetch_register (gdbarch, regnum))
47 regcache_raw_supply (regcache, regnum, NULL);
51 pid = get_ptrace_pid (regcache_get_ptid (regcache));
53 size = register_size (gdbarch, regnum);
54 gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0);
55 buf = (PTRACE_TYPE_RET *) alloca (size);
57 /* Read the register contents from the inferior a chunk at a time. */
58 for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++)
61 buf[i] = ptrace (PT_READ_U, pid, (PTRACE_TYPE_ARG3)(uintptr_t)addr, 0);
63 error (_("Couldn't read register %s (#%d): %s."),
64 gdbarch_register_name (gdbarch, regnum),
65 regnum, safe_strerror (errno));
67 addr += sizeof (PTRACE_TYPE_RET);
69 regcache_raw_supply (regcache, regnum, buf);
72 /* Fetch register REGNUM from the inferior. If REGNUM is -1, do this
76 inf_ptrace_fetch_registers (struct target_ops *ops,
77 struct regcache *regcache, int regnum)
81 regnum < gdbarch_num_regs (regcache->arch ());
83 inf_ptrace_fetch_register (regcache, regnum);
85 inf_ptrace_fetch_register (regcache, regnum);
88 /* Store register REGNUM into the inferior. */
91 inf_ptrace_store_register (const struct regcache *regcache, int regnum)
93 struct gdbarch *gdbarch = regcache->arch ();
100 /* This isn't really an address, but ptrace thinks of it as one. */
101 addr = inf_ptrace_register_u_offset (gdbarch, regnum, 1);
102 if (addr == (CORE_ADDR)-1
103 || gdbarch_cannot_store_register (gdbarch, regnum))
106 pid = get_ptrace_pid (regcache_get_ptid (regcache));
108 size = register_size (gdbarch, regnum);
109 gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0);
110 buf = (PTRACE_TYPE_RET *) alloca (size);
112 /* Write the register contents into the inferior a chunk at a time. */
113 regcache_raw_collect (regcache, regnum, buf);
114 for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++)
117 ptrace (PT_WRITE_U, pid, (PTRACE_TYPE_ARG3)(uintptr_t)addr, buf[i]);
119 error (_("Couldn't write register %s (#%d): %s."),
120 gdbarch_register_name (gdbarch, regnum),
121 regnum, safe_strerror (errno));
123 addr += sizeof (PTRACE_TYPE_RET);
127 /* Store register REGNUM back into the inferior. If REGNUM is -1, do
128 this for all registers. */
131 inf_ptrace_store_registers (struct target_ops *ops,
132 struct regcache *regcache, int regnum)
136 regnum < gdbarch_num_regs (regcache->arch ());
138 inf_ptrace_store_register (regcache, regnum);
140 inf_ptrace_store_register (regcache, regnum);
143 /* Create a "traditional" Linux/ptrace target. REGISTER_U_OFFSET
144 should be a function returning the offset within the user area
145 where a particular register is stored. */
148 linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
150 struct target_ops *t = inf_ptrace_target();
152 gdb_assert (register_u_offset);
153 inf_ptrace_register_u_offset = register_u_offset;
154 t->to_fetch_registers = inf_ptrace_fetch_registers;
155 t->to_store_registers = inf_ptrace_store_registers;
157 linux_target_install_ops (t);