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3c77f97e | 1 | /* Native-dependent code for GNU/Linux RISC-V. |
b811d2c2 | 2 | Copyright (C) 2018-2020 Free Software Foundation, Inc. |
3c77f97e JW |
3 | |
4 | This file is part of GDB. | |
5 | ||
6 | This program is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 3 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | This program is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
18 | ||
19 | #include "defs.h" | |
20 | #include "regcache.h" | |
21 | #include "gregset.h" | |
22 | #include "linux-nat.h" | |
3c77f97e | 23 | #include "riscv-tdep.h" |
92528b67 | 24 | #include "inferior.h" |
3c77f97e | 25 | |
4d3928d7 JW |
26 | #include "elf/common.h" |
27 | ||
f6480e70 MR |
28 | #include "nat/riscv-linux-tdesc.h" |
29 | ||
3c77f97e JW |
30 | #include <sys/ptrace.h> |
31 | ||
ee98c0da MR |
32 | /* Work around glibc header breakage causing ELF_NFPREG not to be usable. */ |
33 | #ifndef NFPREG | |
34 | # define NFPREG 33 | |
35 | #endif | |
36 | ||
3c77f97e JW |
37 | /* RISC-V Linux native additions to the default linux support. */ |
38 | ||
39 | class riscv_linux_nat_target final : public linux_nat_target | |
40 | { | |
41 | public: | |
42 | /* Add our register access methods. */ | |
43 | void fetch_registers (struct regcache *regcache, int regnum) override; | |
44 | void store_registers (struct regcache *regcache, int regnum) override; | |
92528b67 AB |
45 | |
46 | /* Read suitable target description. */ | |
47 | const struct target_desc *read_description () override; | |
3c77f97e JW |
48 | }; |
49 | ||
50 | static riscv_linux_nat_target the_riscv_linux_nat_target; | |
51 | ||
52 | /* Copy general purpose register REGNUM (or all gp regs if REGNUM == -1) | |
53 | from regset GREGS into REGCACHE. */ | |
54 | ||
55 | static void | |
56 | supply_gregset_regnum (struct regcache *regcache, const prgregset_t *gregs, | |
57 | int regnum) | |
58 | { | |
59 | int i; | |
60 | const elf_greg_t *regp = *gregs; | |
61 | ||
62 | if (regnum == -1) | |
63 | { | |
64 | /* We only support the integer registers and PC here. */ | |
65 | for (i = RISCV_ZERO_REGNUM + 1; i < RISCV_PC_REGNUM; i++) | |
66 | regcache->raw_supply (i, regp + i); | |
67 | ||
68 | /* GDB stores PC in reg 32. Linux kernel stores it in reg 0. */ | |
69 | regcache->raw_supply (32, regp + 0); | |
70 | ||
71 | /* Fill the inaccessible zero register with zero. */ | |
72 | regcache->raw_supply_zeroed (0); | |
73 | } | |
74 | else if (regnum == RISCV_ZERO_REGNUM) | |
75 | regcache->raw_supply_zeroed (0); | |
76 | else if (regnum > RISCV_ZERO_REGNUM && regnum < RISCV_PC_REGNUM) | |
77 | regcache->raw_supply (regnum, regp + regnum); | |
78 | else if (regnum == RISCV_PC_REGNUM) | |
79 | regcache->raw_supply (32, regp + 0); | |
80 | } | |
81 | ||
82 | /* Copy all general purpose registers from regset GREGS into REGCACHE. */ | |
83 | ||
84 | void | |
85 | supply_gregset (struct regcache *regcache, const prgregset_t *gregs) | |
86 | { | |
87 | supply_gregset_regnum (regcache, gregs, -1); | |
88 | } | |
89 | ||
90 | /* Copy floating point register REGNUM (or all fp regs if REGNUM == -1) | |
91 | from regset FPREGS into REGCACHE. */ | |
92 | ||
93 | static void | |
94 | supply_fpregset_regnum (struct regcache *regcache, const prfpregset_t *fpregs, | |
95 | int regnum) | |
96 | { | |
ee98c0da MR |
97 | int flen = register_size (regcache->arch (), RISCV_FIRST_FP_REGNUM); |
98 | union | |
99 | { | |
100 | const prfpregset_t *fpregs; | |
101 | const gdb_byte *buf; | |
102 | } | |
103 | fpbuf = { .fpregs = fpregs }; | |
3c77f97e JW |
104 | int i; |
105 | ||
106 | if (regnum == -1) | |
107 | { | |
108 | /* We only support the FP registers and FCSR here. */ | |
ee98c0da MR |
109 | for (i = RISCV_FIRST_FP_REGNUM; |
110 | i <= RISCV_LAST_FP_REGNUM; | |
111 | i++, fpbuf.buf += flen) | |
112 | regcache->raw_supply (i, fpbuf.buf); | |
3c77f97e | 113 | |
ee98c0da | 114 | regcache->raw_supply (RISCV_CSR_FCSR_REGNUM, fpbuf.buf); |
3c77f97e JW |
115 | } |
116 | else if (regnum >= RISCV_FIRST_FP_REGNUM && regnum <= RISCV_LAST_FP_REGNUM) | |
ee98c0da MR |
117 | { |
118 | fpbuf.buf += flen * (regnum - RISCV_FIRST_FP_REGNUM); | |
119 | regcache->raw_supply (regnum, fpbuf.buf); | |
120 | } | |
3c77f97e | 121 | else if (regnum == RISCV_CSR_FCSR_REGNUM) |
ee98c0da MR |
122 | { |
123 | fpbuf.buf += flen * (RISCV_LAST_FP_REGNUM - RISCV_FIRST_FP_REGNUM + 1); | |
124 | regcache->raw_supply (RISCV_CSR_FCSR_REGNUM, fpbuf.buf); | |
125 | } | |
3c77f97e JW |
126 | } |
127 | ||
128 | /* Copy all floating point registers from regset FPREGS into REGCACHE. */ | |
129 | ||
130 | void | |
131 | supply_fpregset (struct regcache *regcache, const prfpregset_t *fpregs) | |
132 | { | |
133 | supply_fpregset_regnum (regcache, fpregs, -1); | |
134 | } | |
135 | ||
136 | /* Copy general purpose register REGNUM (or all gp regs if REGNUM == -1) | |
137 | from REGCACHE into regset GREGS. */ | |
138 | ||
139 | void | |
140 | fill_gregset (const struct regcache *regcache, prgregset_t *gregs, int regnum) | |
141 | { | |
142 | elf_greg_t *regp = *gregs; | |
143 | ||
144 | if (regnum == -1) | |
145 | { | |
146 | /* We only support the integer registers and PC here. */ | |
147 | for (int i = RISCV_ZERO_REGNUM + 1; i < RISCV_PC_REGNUM; i++) | |
148 | regcache->raw_collect (i, regp + i); | |
149 | ||
150 | regcache->raw_collect (32, regp + 0); | |
151 | } | |
152 | else if (regnum == RISCV_ZERO_REGNUM) | |
153 | /* Nothing to do here. */ | |
154 | ; | |
155 | else if (regnum > RISCV_ZERO_REGNUM && regnum < RISCV_PC_REGNUM) | |
156 | regcache->raw_collect (regnum, regp + regnum); | |
157 | else if (regnum == RISCV_PC_REGNUM) | |
158 | regcache->raw_collect (32, regp + 0); | |
159 | } | |
160 | ||
161 | /* Copy floating point register REGNUM (or all fp regs if REGNUM == -1) | |
162 | from REGCACHE into regset FPREGS. */ | |
163 | ||
164 | void | |
165 | fill_fpregset (const struct regcache *regcache, prfpregset_t *fpregs, | |
166 | int regnum) | |
167 | { | |
ee98c0da MR |
168 | int flen = register_size (regcache->arch (), RISCV_FIRST_FP_REGNUM); |
169 | union | |
170 | { | |
171 | prfpregset_t *fpregs; | |
172 | gdb_byte *buf; | |
173 | } | |
174 | fpbuf = { .fpregs = fpregs }; | |
175 | int i; | |
176 | ||
3c77f97e JW |
177 | if (regnum == -1) |
178 | { | |
179 | /* We only support the FP registers and FCSR here. */ | |
ee98c0da MR |
180 | for (i = RISCV_FIRST_FP_REGNUM; |
181 | i <= RISCV_LAST_FP_REGNUM; | |
182 | i++, fpbuf.buf += flen) | |
183 | regcache->raw_collect (i, fpbuf.buf); | |
3c77f97e | 184 | |
ee98c0da | 185 | regcache->raw_collect (RISCV_CSR_FCSR_REGNUM, fpbuf.buf); |
3c77f97e JW |
186 | } |
187 | else if (regnum >= RISCV_FIRST_FP_REGNUM && regnum <= RISCV_LAST_FP_REGNUM) | |
ee98c0da MR |
188 | { |
189 | fpbuf.buf += flen * (regnum - RISCV_FIRST_FP_REGNUM); | |
190 | regcache->raw_collect (regnum, fpbuf.buf); | |
191 | } | |
3c77f97e | 192 | else if (regnum == RISCV_CSR_FCSR_REGNUM) |
ee98c0da MR |
193 | { |
194 | fpbuf.buf += flen * (RISCV_LAST_FP_REGNUM - RISCV_FIRST_FP_REGNUM + 1); | |
195 | regcache->raw_collect (RISCV_CSR_FCSR_REGNUM, fpbuf.buf); | |
196 | } | |
3c77f97e JW |
197 | } |
198 | ||
92528b67 AB |
199 | /* Return a target description for the current target. */ |
200 | ||
201 | const struct target_desc * | |
202 | riscv_linux_nat_target::read_description () | |
203 | { | |
d1c9b20f AB |
204 | const struct riscv_gdbarch_features features |
205 | = riscv_linux_read_features (inferior_ptid.lwp ()); | |
206 | return riscv_lookup_target_description (features); | |
92528b67 AB |
207 | } |
208 | ||
3c77f97e JW |
209 | /* Fetch REGNUM (or all registers if REGNUM == -1) from the target |
210 | into REGCACHE using PTRACE_GETREGSET. */ | |
211 | ||
212 | void | |
213 | riscv_linux_nat_target::fetch_registers (struct regcache *regcache, int regnum) | |
214 | { | |
215 | int tid; | |
216 | ||
217 | tid = get_ptrace_pid (regcache->ptid()); | |
218 | ||
219 | if ((regnum >= RISCV_ZERO_REGNUM && regnum <= RISCV_PC_REGNUM) | |
220 | || (regnum == -1)) | |
221 | { | |
222 | struct iovec iov; | |
223 | elf_gregset_t regs; | |
224 | ||
225 | iov.iov_base = ®s; | |
226 | iov.iov_len = sizeof (regs); | |
227 | ||
228 | if (ptrace (PTRACE_GETREGSET, tid, NT_PRSTATUS, | |
229 | (PTRACE_TYPE_ARG3) &iov) == -1) | |
230 | perror_with_name (_("Couldn't get registers")); | |
231 | else | |
232 | supply_gregset_regnum (regcache, ®s, regnum); | |
233 | } | |
234 | ||
235 | if ((regnum >= RISCV_FIRST_FP_REGNUM | |
236 | && regnum <= RISCV_LAST_FP_REGNUM) | |
237 | || (regnum == RISCV_CSR_FCSR_REGNUM) | |
238 | || (regnum == -1)) | |
239 | { | |
240 | struct iovec iov; | |
241 | elf_fpregset_t regs; | |
242 | ||
243 | iov.iov_base = ®s; | |
ee98c0da MR |
244 | iov.iov_len = ELF_NFPREG * register_size (regcache->arch (), |
245 | RISCV_FIRST_FP_REGNUM); | |
246 | gdb_assert (iov.iov_len <= sizeof (regs)); | |
3c77f97e | 247 | |
4d3928d7 | 248 | if (ptrace (PTRACE_GETREGSET, tid, NT_FPREGSET, |
3c77f97e JW |
249 | (PTRACE_TYPE_ARG3) &iov) == -1) |
250 | perror_with_name (_("Couldn't get registers")); | |
251 | else | |
252 | supply_fpregset_regnum (regcache, ®s, regnum); | |
253 | } | |
254 | ||
255 | if ((regnum == RISCV_CSR_MISA_REGNUM) | |
256 | || (regnum == -1)) | |
a3d72268 AB |
257 | { |
258 | /* TODO: Need to add a ptrace call for this. */ | |
259 | regcache->raw_supply_zeroed (RISCV_CSR_MISA_REGNUM); | |
260 | } | |
3c77f97e JW |
261 | |
262 | /* Access to other CSRs has potential security issues, don't support them for | |
263 | now. */ | |
264 | } | |
265 | ||
266 | /* Store REGNUM (or all registers if REGNUM == -1) to the target | |
267 | from REGCACHE using PTRACE_SETREGSET. */ | |
268 | ||
269 | void | |
270 | riscv_linux_nat_target::store_registers (struct regcache *regcache, int regnum) | |
271 | { | |
272 | int tid; | |
273 | ||
274 | tid = get_ptrace_pid (regcache->ptid ()); | |
275 | ||
276 | if ((regnum >= RISCV_ZERO_REGNUM && regnum <= RISCV_PC_REGNUM) | |
277 | || (regnum == -1)) | |
278 | { | |
279 | struct iovec iov; | |
280 | elf_gregset_t regs; | |
281 | ||
282 | iov.iov_base = ®s; | |
283 | iov.iov_len = sizeof (regs); | |
284 | ||
285 | if (ptrace (PTRACE_GETREGSET, tid, NT_PRSTATUS, | |
286 | (PTRACE_TYPE_ARG3) &iov) == -1) | |
287 | perror_with_name (_("Couldn't get registers")); | |
288 | else | |
289 | { | |
290 | fill_gregset (regcache, ®s, regnum); | |
291 | ||
292 | if (ptrace (PTRACE_SETREGSET, tid, NT_PRSTATUS, | |
293 | (PTRACE_TYPE_ARG3) &iov) == -1) | |
294 | perror_with_name (_("Couldn't set registers")); | |
295 | } | |
296 | } | |
297 | ||
298 | if ((regnum >= RISCV_FIRST_FP_REGNUM | |
299 | && regnum <= RISCV_LAST_FP_REGNUM) | |
300 | || (regnum == RISCV_CSR_FCSR_REGNUM) | |
301 | || (regnum == -1)) | |
302 | { | |
303 | struct iovec iov; | |
304 | elf_fpregset_t regs; | |
305 | ||
306 | iov.iov_base = ®s; | |
ee98c0da MR |
307 | iov.iov_len = ELF_NFPREG * register_size (regcache->arch (), |
308 | RISCV_FIRST_FP_REGNUM); | |
309 | gdb_assert (iov.iov_len <= sizeof (regs)); | |
3c77f97e | 310 | |
4d3928d7 | 311 | if (ptrace (PTRACE_GETREGSET, tid, NT_FPREGSET, |
3c77f97e JW |
312 | (PTRACE_TYPE_ARG3) &iov) == -1) |
313 | perror_with_name (_("Couldn't get registers")); | |
314 | else | |
315 | { | |
316 | fill_fpregset (regcache, ®s, regnum); | |
317 | ||
4d3928d7 | 318 | if (ptrace (PTRACE_SETREGSET, tid, NT_FPREGSET, |
3c77f97e JW |
319 | (PTRACE_TYPE_ARG3) &iov) == -1) |
320 | perror_with_name (_("Couldn't set registers")); | |
321 | } | |
322 | } | |
323 | ||
324 | /* Access to CSRs has potential security issues, don't support them for | |
325 | now. */ | |
326 | } | |
327 | ||
328 | /* Initialize RISC-V Linux native support. */ | |
329 | ||
6c265988 | 330 | void _initialize_riscv_linux_nat (); |
3c77f97e | 331 | void |
6c265988 | 332 | _initialize_riscv_linux_nat () |
3c77f97e JW |
333 | { |
334 | /* Register the target. */ | |
335 | linux_target = &the_riscv_linux_nat_target; | |
336 | add_inf_child_target (&the_riscv_linux_nat_target); | |
337 | } |