1 /* Native-dependent code for NetBSD/aarch64.
2
3 Copyright (C) 2017-2018 Free Software Foundation, Inc.
4
5 This file is part of GDB.
6
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.
11
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.
16
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/>. */
19
20 #include "defs.h"
21 #include "target.h"
22
23 #include <sys/types.h>
24 #include <sys/ptrace.h>
25
26 #include <machine/frame.h>
27 #include <machine/pcb.h>
28
29 #include "netbsd-nat.h"
30 #include "aarch64-tdep.h"
31 #include "aarch64-netbsd-tdep.h"
32 #include "regcache.h"
33 #include "gdbcore.h"
34 #include "bsd-kvm.h"
35 #include "inf-ptrace.h"
36
37 struct aarch64_nbsd_nat_target final : public nbsd_nat_target
38 {
39 void fetch_registers (struct regcache *, int) override;
40 void store_registers (struct regcache *, int) override;
41 };
42
43 static aarch64_nbsd_nat_target the_aarch64_nbsd_nat_target;
44
45 /* Determine if PT_GETREGS fetches REGNUM. */
46
47 static bool
getregs_supplies(struct gdbarch * gdbarch,int regnum)48 getregs_supplies (struct gdbarch *gdbarch, int regnum)
49 {
50 return (regnum >= AARCH64_X0_REGNUM && regnum <= AARCH64_CPSR_REGNUM);
51 }
52
53 /* Determine if PT_GETFPREGS fetches REGNUM. */
54
55 static bool
getfpregs_supplies(struct gdbarch * gdbarch,int regnum)56 getfpregs_supplies (struct gdbarch *gdbarch, int regnum)
57 {
58 return (regnum >= AARCH64_V0_REGNUM && regnum <= AARCH64_FPCR_REGNUM);
59 }
60
61 void
fetch_registers(struct regcache * regcache,int regnum)62 aarch64_nbsd_nat_target::fetch_registers (struct regcache *regcache, int regnum)
63 {
64 ptid_t ptid = regcache->ptid ();
65 pid_t pid = ptid.pid ();
66 int lwp = ptid.lwp ();
67
68 struct gdbarch *gdbarch = regcache->arch ();
69 if (regnum == -1 || getregs_supplies (gdbarch, regnum))
70 {
71 struct reg regs;
72
73 if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) ®s, lwp) == -1)
74 perror_with_name (_("Couldn't get registers"));
75
76 regcache_supply_regset (&aarch64_nbsd_gregset, regcache, regnum, ®s,
77 sizeof (regs));
78 }
79
80 if (regnum == -1 || getfpregs_supplies (gdbarch, regnum))
81 {
82 struct fpreg fpregs;
83
84 if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, lwp) == -1)
85 perror_with_name (_("Couldn't get floating point status"));
86
87 regcache_supply_regset (&aarch64_nbsd_fpregset, regcache, regnum, &fpregs,
88 sizeof (fpregs));
89 }
90 }
91
92 /* Store register REGNUM back into the inferior. If REGNUM is -1, do
93 this for all registers. */
94
95 void
store_registers(struct regcache * regcache,int regnum)96 aarch64_nbsd_nat_target::store_registers (struct regcache *regcache, int regnum)
97 {
98 ptid_t ptid = regcache->ptid ();
99 pid_t pid = ptid.pid ();
100 int lwp = ptid.lwp ();
101
102 struct gdbarch *gdbarch = regcache->arch ();
103 if (regnum == -1 || getregs_supplies (gdbarch, regnum))
104 {
105 struct reg regs;
106
107 if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) ®s, lwp) == -1)
108 perror_with_name (_("Couldn't get registers"));
109
110 regcache_collect_regset (&aarch64_nbsd_gregset, regcache,regnum, ®s,
111 sizeof (regs));
112
113 if (ptrace (PT_SETREGS, pid, (PTRACE_TYPE_ARG3) ®s, lwp) == -1)
114 perror_with_name (_("Couldn't write registers"));
115 }
116
117 if (regnum == -1 || getfpregs_supplies (gdbarch, regnum))
118 {
119 struct fpreg fpregs;
120
121 if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, lwp) == -1)
122 perror_with_name (_("Couldn't get floating point status"));
123
124 regcache_collect_regset (&aarch64_nbsd_fpregset, regcache,regnum, &fpregs,
125 sizeof (fpregs));
126
127 if (ptrace (PT_SETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, lwp) == -1)
128 perror_with_name (_("Couldn't write floating point status"));
129 }
130 }
131
132 static int
aarch64_nbsd_supply_pcb(struct regcache * regcache,struct pcb * pcb)133 aarch64_nbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
134 {
135 struct trapframe tf;
136 int i;
137
138 /* The following is true for NetBSD/arm64:
139
140 The pcb contains the frame pointer at the point of the context
141 switch in cpu_switchto(). At that point we have a stack frame as
142 described by `struct trapframe', which has the following layout:
143
144 x0..x30
145 sp
146 pc
147 spsr
148 tpidr
149
150 This accounts for all callee-saved registers specified by the psABI.
151 From this information we reconstruct the register state as it would
152 look when we just returned from cpu_switchto().
153
154 For kernel core dumps, dumpsys() builds a fake trapframe for us. */
155
156 /* The trapframe pointer shouldn't be zero. */
157 if (pcb->pcb_tf == 0)
158 return 0;
159
160 /* Read the stack frame, and check its validity. */
161 read_memory ((uintptr_t)pcb->pcb_tf, (gdb_byte *) &tf, sizeof tf);
162
163 for (i = 0; i <= 30; i++)
164 {
165 regcache->raw_supply (AARCH64_X0_REGNUM + i, &tf.tf_reg[i]);
166 }
167 regcache->raw_supply (AARCH64_SP_REGNUM, &tf.tf_sp);
168 regcache->raw_supply (AARCH64_PC_REGNUM, &tf.tf_pc);
169
170 regcache->raw_supply (AARCH64_FPCR_REGNUM, &pcb->pcb_fpregs.fpcr);
171 regcache->raw_supply (AARCH64_FPSR_REGNUM, &pcb->pcb_fpregs.fpsr);
172
173 return 1;
174 }
175
176 void
_initialize_aarch64_nbsd_nat()177 _initialize_aarch64_nbsd_nat ()
178 {
179 add_inf_child_target (&the_aarch64_nbsd_nat_target);
180
181 /* Support debugging kernel virtual memory images. */
182 bsd_kvm_add_target (aarch64_nbsd_supply_pcb);
183 }
184