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8d7f0635 AK |
1 | /* Target dependent code for GNU/Linux ARC. |
2 | ||
3666a048 | 3 | Copyright 2020-2021 Free Software Foundation, Inc. |
8d7f0635 AK |
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 | /* GDB header files. */ | |
21 | #include "defs.h" | |
22 | #include "linux-tdep.h" | |
23 | #include "objfiles.h" | |
24 | #include "opcode/arc.h" | |
25 | #include "osabi.h" | |
26 | #include "solib-svr4.h" | |
27 | ||
28 | /* ARC header files. */ | |
29 | #include "opcodes/arc-dis.h" | |
cc463201 | 30 | #include "arc-linux-tdep.h" |
8d7f0635 | 31 | #include "arc-tdep.h" |
cc463201 AK |
32 | #include "arch/arc.h" |
33 | ||
34 | #define REGOFF(offset) (offset * ARC_REGISTER_SIZE) | |
35 | ||
d4af7272 AK |
36 | /* arc_linux_sc_reg_offsets[i] is the offset of register i in the `struct |
37 | sigcontext'. Array index is an internal GDB register number, as defined in | |
38 | arc-tdep.h:arc_regnum. | |
39 | ||
40 | From <include/uapi/asm/sigcontext.h> and <include/uapi/asm/ptrace.h>. | |
41 | ||
42 | The layout of this struct is tightly bound to "arc_regnum" enum | |
43 | in arc-tdep.h. Any change of order in there, must be reflected | |
44 | here as well. */ | |
45 | static const int arc_linux_sc_reg_offsets[] = { | |
46 | /* R0 - R12. */ | |
47 | REGOFF (22), REGOFF (21), REGOFF (20), REGOFF (19), | |
48 | REGOFF (18), REGOFF (17), REGOFF (16), REGOFF (15), | |
49 | REGOFF (14), REGOFF (13), REGOFF (12), REGOFF (11), | |
50 | REGOFF (10), | |
51 | ||
52 | /* R13 - R25. */ | |
53 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
54 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
55 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
56 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
57 | ARC_OFFSET_NO_REGISTER, | |
58 | ||
59 | REGOFF (9), /* R26 (GP) */ | |
60 | REGOFF (8), /* FP */ | |
61 | REGOFF (23), /* SP */ | |
62 | ARC_OFFSET_NO_REGISTER, /* ILINK */ | |
63 | ARC_OFFSET_NO_REGISTER, /* R30 */ | |
64 | REGOFF (7), /* BLINK */ | |
65 | ||
66 | /* R32 - R59. */ | |
67 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
68 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
69 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
70 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
71 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
72 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
73 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
74 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
75 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
76 | ARC_OFFSET_NO_REGISTER, | |
77 | ||
78 | REGOFF (4), /* LP_COUNT */ | |
79 | ARC_OFFSET_NO_REGISTER, /* RESERVED */ | |
80 | ARC_OFFSET_NO_REGISTER, /* LIMM */ | |
81 | ARC_OFFSET_NO_REGISTER, /* PCL */ | |
82 | ||
83 | REGOFF (6), /* PC */ | |
84 | REGOFF (5), /* STATUS32 */ | |
85 | REGOFF (2), /* LP_START */ | |
86 | REGOFF (3), /* LP_END */ | |
87 | REGOFF (1), /* BTA */ | |
88 | }; | |
89 | ||
cc463201 AK |
90 | /* arc_linux_core_reg_offsets[i] is the offset in the .reg section of GDB |
91 | regnum i. Array index is an internal GDB register number, as defined in | |
92 | arc-tdep.h:arc_regnum. | |
93 | ||
94 | From include/uapi/asm/ptrace.h in the ARC Linux sources. */ | |
95 | ||
96 | /* The layout of this struct is tightly bound to "arc_regnum" enum | |
97 | in arc-tdep.h. Any change of order in there, must be reflected | |
98 | here as well. */ | |
99 | static const int arc_linux_core_reg_offsets[] = { | |
100 | /* R0 - R12. */ | |
101 | REGOFF (22), REGOFF (21), REGOFF (20), REGOFF (19), | |
102 | REGOFF (18), REGOFF (17), REGOFF (16), REGOFF (15), | |
103 | REGOFF (14), REGOFF (13), REGOFF (12), REGOFF (11), | |
104 | REGOFF (10), | |
105 | ||
106 | /* R13 - R25. */ | |
107 | REGOFF (37), REGOFF (36), REGOFF (35), REGOFF (34), | |
108 | REGOFF (33), REGOFF (32), REGOFF (31), REGOFF (30), | |
109 | REGOFF (29), REGOFF (28), REGOFF (27), REGOFF (26), | |
110 | REGOFF (25), | |
111 | ||
112 | REGOFF (9), /* R26 (GP) */ | |
113 | REGOFF (8), /* FP */ | |
114 | REGOFF (23), /* SP */ | |
115 | ARC_OFFSET_NO_REGISTER, /* ILINK */ | |
116 | ARC_OFFSET_NO_REGISTER, /* R30 */ | |
117 | REGOFF (7), /* BLINK */ | |
118 | ||
119 | /* R32 - R59. */ | |
120 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
121 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
122 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
123 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
124 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
125 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
126 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
127 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
128 | ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, | |
129 | ARC_OFFSET_NO_REGISTER, | |
130 | ||
131 | REGOFF (4), /* LP_COUNT */ | |
132 | ARC_OFFSET_NO_REGISTER, /* RESERVED */ | |
133 | ARC_OFFSET_NO_REGISTER, /* LIMM */ | |
134 | ARC_OFFSET_NO_REGISTER, /* PCL */ | |
135 | ||
136 | REGOFF (39), /* PC */ | |
137 | REGOFF (5), /* STATUS32 */ | |
138 | REGOFF (2), /* LP_START */ | |
139 | REGOFF (3), /* LP_END */ | |
140 | REGOFF (1), /* BTA */ | |
141 | REGOFF (6) /* ERET */ | |
142 | }; | |
8d7f0635 | 143 | |
d4af7272 AK |
144 | /* Is THIS_FRAME a sigtramp function - the function that returns from |
145 | signal handler into normal execution flow? This is the case if the PC is | |
146 | either at the start of, or in the middle of the two instructions: | |
147 | ||
148 | mov r8, __NR_rt_sigreturn ; __NR_rt_sigreturn == 139 | |
149 | trap_s 0 ; `swi' for ARC700 | |
150 | ||
151 | On ARC uClibc Linux this function is called __default_rt_sa_restorer. | |
152 | ||
153 | Returns TRUE if this is a sigtramp frame. */ | |
154 | ||
155 | static bool | |
156 | arc_linux_is_sigtramp (struct frame_info *this_frame) | |
157 | { | |
158 | struct gdbarch *gdbarch = get_frame_arch (this_frame); | |
159 | CORE_ADDR pc = get_frame_pc (this_frame); | |
160 | ||
161 | if (arc_debug) | |
162 | { | |
163 | debug_printf ("arc-linux: arc_linux_is_sigtramp, pc=%s\n", | |
164 | paddress(gdbarch, pc)); | |
165 | } | |
166 | ||
167 | static const gdb_byte insns_be_hs[] = { | |
168 | 0x20, 0x8a, 0x12, 0xc2, /* mov r8,nr_rt_sigreturn */ | |
169 | 0x78, 0x1e /* trap_s 0 */ | |
170 | }; | |
171 | static const gdb_byte insns_be_700[] = { | |
172 | 0x20, 0x8a, 0x12, 0xc2, /* mov r8,nr_rt_sigreturn */ | |
173 | 0x22, 0x6f, 0x00, 0x3f /* swi */ | |
174 | }; | |
175 | ||
176 | gdb_byte arc_sigtramp_insns[sizeof (insns_be_700)]; | |
177 | size_t insns_sz; | |
178 | if (arc_mach_is_arcv2 (gdbarch)) | |
179 | { | |
180 | insns_sz = sizeof (insns_be_hs); | |
181 | memcpy (arc_sigtramp_insns, insns_be_hs, insns_sz); | |
182 | } | |
183 | else | |
184 | { | |
185 | insns_sz = sizeof (insns_be_700); | |
186 | memcpy (arc_sigtramp_insns, insns_be_700, insns_sz); | |
187 | } | |
188 | if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_LITTLE) | |
189 | { | |
190 | /* On little endian targets, ARC code section is in what is called | |
191 | "middle endian", where half-words are in the big-endian order, | |
192 | only bytes inside the halfwords are in the little endian order. | |
193 | As a result it is very easy to convert big endian instruction to | |
194 | little endian, since it is needed to swap bytes in the halfwords, | |
195 | so there is no need to have information on whether that is a | |
196 | 4-byte instruction or 2-byte. */ | |
197 | gdb_assert ((insns_sz % 2) == 0); | |
198 | for (int i = 0; i < insns_sz; i += 2) | |
199 | std::swap (arc_sigtramp_insns[i], arc_sigtramp_insns[i+1]); | |
200 | } | |
201 | ||
202 | gdb_byte buf[insns_sz]; | |
203 | ||
204 | /* Read the memory at the PC. Since we are stopped, any breakpoint must | |
205 | have been removed. */ | |
206 | if (!safe_frame_unwind_memory (this_frame, pc, buf, insns_sz)) | |
207 | { | |
208 | /* Failed to unwind frame. */ | |
209 | return FALSE; | |
210 | } | |
211 | ||
212 | /* Is that code the sigtramp instruction sequence? */ | |
213 | if (memcmp (buf, arc_sigtramp_insns, insns_sz) == 0) | |
214 | return TRUE; | |
215 | ||
216 | /* No - look one instruction earlier in the code... */ | |
217 | if (!safe_frame_unwind_memory (this_frame, pc - 4, buf, insns_sz)) | |
218 | { | |
219 | /* Failed to unwind frame. */ | |
220 | return FALSE; | |
221 | } | |
222 | ||
223 | return (memcmp (buf, arc_sigtramp_insns, insns_sz) == 0); | |
224 | } | |
225 | ||
226 | /* Get sigcontext structure of sigtramp frame - it contains saved | |
227 | registers of interrupted frame. | |
228 | ||
229 | Stack pointer points to the rt_sigframe structure, and sigcontext can | |
230 | be found as in: | |
231 | ||
232 | struct rt_sigframe { | |
233 | struct siginfo info; | |
234 | struct ucontext uc; | |
235 | ... | |
236 | }; | |
237 | ||
238 | struct ucontext { | |
239 | unsigned long uc_flags; | |
240 | struct ucontext *uc_link; | |
241 | stack_t uc_stack; | |
242 | struct sigcontext uc_mcontext; | |
243 | sigset_t uc_sigmask; | |
244 | }; | |
245 | ||
246 | sizeof (struct siginfo) == 0x80 | |
247 | offsetof (struct ucontext, uc_mcontext) == 0x14 | |
248 | ||
249 | GDB cannot include linux headers and use offsetof () because those are | |
250 | target headers and GDB might be built for a different run host. There | |
251 | doesn't seem to be an established mechanism to figure out those offsets | |
252 | via gdbserver, so the only way is to hardcode values in the GDB, | |
253 | meaning that GDB will be broken if values will change. That seems to | |
254 | be a very unlikely scenario and other arches (aarch64, alpha, amd64, | |
255 | etc) in GDB hardcode values. */ | |
256 | ||
257 | static CORE_ADDR | |
258 | arc_linux_sigcontext_addr (struct frame_info *this_frame) | |
259 | { | |
260 | const int ucontext_offset = 0x80; | |
261 | const int sigcontext_offset = 0x14; | |
262 | return get_frame_sp (this_frame) + ucontext_offset + sigcontext_offset; | |
263 | } | |
264 | ||
8d7f0635 AK |
265 | /* Implement the "cannot_fetch_register" gdbarch method. */ |
266 | ||
267 | static int | |
268 | arc_linux_cannot_fetch_register (struct gdbarch *gdbarch, int regnum) | |
269 | { | |
270 | /* Assume that register is readable if it is unknown. */ | |
271 | switch (regnum) | |
272 | { | |
273 | case ARC_ILINK_REGNUM: | |
274 | case ARC_RESERVED_REGNUM: | |
275 | case ARC_LIMM_REGNUM: | |
276 | return true; | |
277 | case ARC_R30_REGNUM: | |
278 | case ARC_R58_REGNUM: | |
279 | case ARC_R59_REGNUM: | |
280 | return !arc_mach_is_arcv2 (gdbarch); | |
281 | } | |
282 | return (regnum > ARC_BLINK_REGNUM) && (regnum < ARC_LP_COUNT_REGNUM); | |
283 | } | |
284 | ||
285 | /* Implement the "cannot_store_register" gdbarch method. */ | |
286 | ||
287 | static int | |
288 | arc_linux_cannot_store_register (struct gdbarch *gdbarch, int regnum) | |
289 | { | |
290 | /* Assume that register is writable if it is unknown. */ | |
291 | switch (regnum) | |
292 | { | |
293 | case ARC_ILINK_REGNUM: | |
294 | case ARC_RESERVED_REGNUM: | |
295 | case ARC_LIMM_REGNUM: | |
296 | case ARC_PCL_REGNUM: | |
297 | return true; | |
298 | case ARC_R30_REGNUM: | |
299 | case ARC_R58_REGNUM: | |
300 | case ARC_R59_REGNUM: | |
301 | return !arc_mach_is_arcv2 (gdbarch); | |
302 | } | |
303 | return (regnum > ARC_BLINK_REGNUM) && (regnum < ARC_LP_COUNT_REGNUM); | |
304 | } | |
305 | ||
306 | /* For ARC Linux, breakpoints use the 16-bit TRAP_S 1 instruction, which | |
307 | is 0x3e78 (little endian) or 0x783e (big endian). */ | |
308 | ||
309 | static const gdb_byte arc_linux_trap_s_be[] = { 0x78, 0x3e }; | |
310 | static const gdb_byte arc_linux_trap_s_le[] = { 0x3e, 0x78 }; | |
311 | static const int trap_size = 2; /* Number of bytes to insert "trap". */ | |
312 | ||
313 | /* Implement the "breakpoint_kind_from_pc" gdbarch method. */ | |
314 | ||
315 | static int | |
316 | arc_linux_breakpoint_kind_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr) | |
317 | { | |
318 | return trap_size; | |
319 | } | |
320 | ||
321 | /* Implement the "sw_breakpoint_from_kind" gdbarch method. */ | |
322 | ||
323 | static const gdb_byte * | |
324 | arc_linux_sw_breakpoint_from_kind (struct gdbarch *gdbarch, | |
325 | int kind, int *size) | |
326 | { | |
6f2643db | 327 | gdb_assert (kind == trap_size); |
8d7f0635 AK |
328 | *size = kind; |
329 | return ((gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG) | |
330 | ? arc_linux_trap_s_be | |
331 | : arc_linux_trap_s_le); | |
332 | } | |
333 | ||
334 | /* Implement the "software_single_step" gdbarch method. */ | |
335 | ||
336 | static std::vector<CORE_ADDR> | |
337 | arc_linux_software_single_step (struct regcache *regcache) | |
338 | { | |
339 | struct gdbarch *gdbarch = regcache->arch (); | |
340 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
341 | struct disassemble_info di = arc_disassemble_info (gdbarch); | |
342 | ||
343 | /* Read current instruction. */ | |
344 | struct arc_instruction curr_insn; | |
345 | arc_insn_decode (regcache_read_pc (regcache), &di, arc_delayed_print_insn, | |
346 | &curr_insn); | |
347 | CORE_ADDR next_pc = arc_insn_get_linear_next_pc (curr_insn); | |
348 | ||
349 | std::vector<CORE_ADDR> next_pcs; | |
350 | ||
351 | /* For instructions with delay slots, the fall thru is not the | |
352 | instruction immediately after the current instruction, but the one | |
353 | after that. */ | |
354 | if (curr_insn.has_delay_slot) | |
355 | { | |
356 | struct arc_instruction next_insn; | |
357 | arc_insn_decode (next_pc, &di, arc_delayed_print_insn, &next_insn); | |
358 | next_pcs.push_back (arc_insn_get_linear_next_pc (next_insn)); | |
359 | } | |
360 | else | |
361 | next_pcs.push_back (next_pc); | |
362 | ||
363 | ULONGEST status32; | |
364 | regcache_cooked_read_unsigned (regcache, gdbarch_ps_regnum (gdbarch), | |
365 | &status32); | |
366 | ||
367 | if (curr_insn.is_control_flow) | |
368 | { | |
369 | CORE_ADDR branch_pc = arc_insn_get_branch_target (curr_insn); | |
370 | if (branch_pc != next_pc) | |
371 | next_pcs.push_back (branch_pc); | |
372 | } | |
373 | /* Is current instruction the last in a loop body? */ | |
374 | else if (tdep->has_hw_loops) | |
375 | { | |
376 | /* If STATUS32.L is 1, then ZD-loops are disabled. */ | |
377 | if ((status32 & ARC_STATUS32_L_MASK) == 0) | |
378 | { | |
379 | ULONGEST lp_end, lp_start, lp_count; | |
380 | regcache_cooked_read_unsigned (regcache, ARC_LP_START_REGNUM, | |
381 | &lp_start); | |
382 | regcache_cooked_read_unsigned (regcache, ARC_LP_END_REGNUM, &lp_end); | |
383 | regcache_cooked_read_unsigned (regcache, ARC_LP_COUNT_REGNUM, | |
384 | &lp_count); | |
385 | ||
386 | if (arc_debug) | |
387 | { | |
388 | debug_printf ("arc-linux: lp_start = %s, lp_end = %s, " | |
389 | "lp_count = %s, next_pc = %s\n", | |
390 | paddress (gdbarch, lp_start), | |
391 | paddress (gdbarch, lp_end), | |
392 | pulongest (lp_count), | |
393 | paddress (gdbarch, next_pc)); | |
394 | } | |
395 | ||
396 | if (next_pc == lp_end && lp_count > 1) | |
397 | { | |
398 | /* The instruction is in effect a jump back to the start of | |
399 | the loop. */ | |
400 | next_pcs.push_back (lp_start); | |
401 | } | |
402 | } | |
403 | } | |
404 | ||
405 | /* Is this a delay slot? Then next PC is in BTA register. */ | |
406 | if ((status32 & ARC_STATUS32_DE_MASK) != 0) | |
407 | { | |
408 | ULONGEST bta; | |
409 | regcache_cooked_read_unsigned (regcache, ARC_BTA_REGNUM, &bta); | |
410 | next_pcs.push_back (bta); | |
411 | } | |
412 | ||
413 | return next_pcs; | |
414 | } | |
415 | ||
416 | /* Implement the "skip_solib_resolver" gdbarch method. | |
417 | ||
418 | See glibc_skip_solib_resolver for details. */ | |
419 | ||
420 | static CORE_ADDR | |
421 | arc_linux_skip_solib_resolver (struct gdbarch *gdbarch, CORE_ADDR pc) | |
422 | { | |
423 | /* For uClibc 0.9.26+. | |
424 | ||
425 | An unresolved PLT entry points to "__dl_linux_resolve", which calls | |
426 | "_dl_linux_resolver" to do the resolving and then eventually jumps to | |
427 | the function. | |
428 | ||
429 | So we look for the symbol `_dl_linux_resolver', and if we are there, | |
430 | gdb sets a breakpoint at the return address, and continues. */ | |
431 | struct bound_minimal_symbol resolver | |
432 | = lookup_minimal_symbol ("_dl_linux_resolver", NULL, NULL); | |
433 | ||
434 | if (arc_debug) | |
435 | { | |
436 | if (resolver.minsym != nullptr) | |
437 | { | |
438 | CORE_ADDR res_addr = BMSYMBOL_VALUE_ADDRESS (resolver); | |
439 | debug_printf ("arc-linux: skip_solib_resolver (): " | |
440 | "pc = %s, resolver at %s\n", | |
441 | print_core_address (gdbarch, pc), | |
442 | print_core_address (gdbarch, res_addr)); | |
443 | } | |
444 | else | |
445 | { | |
446 | debug_printf ("arc-linux: skip_solib_resolver (): " | |
447 | "pc = %s, no resolver found\n", | |
448 | print_core_address (gdbarch, pc)); | |
449 | } | |
450 | } | |
451 | ||
452 | if (resolver.minsym != nullptr && BMSYMBOL_VALUE_ADDRESS (resolver) == pc) | |
453 | { | |
454 | /* Find the return address. */ | |
455 | return frame_unwind_caller_pc (get_current_frame ()); | |
456 | } | |
457 | else | |
458 | { | |
459 | /* No breakpoint required. */ | |
460 | return 0; | |
461 | } | |
462 | } | |
463 | ||
46023bbe SV |
464 | /* Populate REGCACHE with register REGNUM from BUF. */ |
465 | ||
466 | static void | |
467 | supply_register (struct regcache *regcache, int regnum, const gdb_byte *buf) | |
468 | { | |
469 | /* Skip non-existing registers. */ | |
470 | if ((arc_linux_core_reg_offsets[regnum] == ARC_OFFSET_NO_REGISTER)) | |
471 | return; | |
472 | ||
473 | regcache->raw_supply (regnum, buf + arc_linux_core_reg_offsets[regnum]); | |
474 | } | |
475 | ||
cc463201 AK |
476 | void |
477 | arc_linux_supply_gregset (const struct regset *regset, | |
478 | struct regcache *regcache, | |
479 | int regnum, const void *gregs, size_t size) | |
480 | { | |
481 | gdb_static_assert (ARC_LAST_REGNUM | |
482 | < ARRAY_SIZE (arc_linux_core_reg_offsets)); | |
483 | ||
484 | const bfd_byte *buf = (const bfd_byte *) gregs; | |
485 | ||
acf10cac | 486 | /* REGNUM == -1 means writing all the registers. */ |
46023bbe SV |
487 | if (regnum == -1) |
488 | for (int reg = 0; reg <= ARC_LAST_REGNUM; reg++) | |
489 | supply_register (regcache, reg, buf); | |
490 | else if (regnum <= ARC_LAST_REGNUM) | |
491 | supply_register (regcache, regnum, buf); | |
492 | else | |
493 | gdb_assert_not_reached ("Invalid regnum in arc_linux_supply_gregset."); | |
cc463201 AK |
494 | } |
495 | ||
496 | void | |
497 | arc_linux_supply_v2_regset (const struct regset *regset, | |
498 | struct regcache *regcache, int regnum, | |
499 | const void *v2_regs, size_t size) | |
500 | { | |
501 | const bfd_byte *buf = (const bfd_byte *) v2_regs; | |
502 | ||
503 | /* user_regs_arcv2 is defined in linux arch/arc/include/uapi/asm/ptrace.h. */ | |
46023bbe SV |
504 | if (regnum == -1 || regnum == ARC_R30_REGNUM) |
505 | regcache->raw_supply (ARC_R30_REGNUM, buf); | |
506 | if (regnum == -1 || regnum == ARC_R58_REGNUM) | |
507 | regcache->raw_supply (ARC_R58_REGNUM, buf + REGOFF (1)); | |
508 | if (regnum == -1 || regnum == ARC_R59_REGNUM) | |
509 | regcache->raw_supply (ARC_R59_REGNUM, buf + REGOFF (2)); | |
cc463201 AK |
510 | } |
511 | ||
512 | /* Populate BUF with register REGNUM from the REGCACHE. */ | |
513 | ||
514 | static void | |
515 | collect_register (const struct regcache *regcache, struct gdbarch *gdbarch, | |
516 | int regnum, gdb_byte *buf) | |
517 | { | |
10c19fad SV |
518 | int offset; |
519 | ||
cc463201 | 520 | /* Skip non-existing registers. */ |
10c19fad | 521 | if (arc_linux_core_reg_offsets[regnum] == ARC_OFFSET_NO_REGISTER) |
cc463201 AK |
522 | return; |
523 | ||
524 | /* The address where the execution has stopped is in pseudo-register | |
525 | STOP_PC. However, when kernel code is returning from the exception, | |
526 | it uses the value from ERET register. Since, TRAP_S (the breakpoint | |
527 | instruction) commits, the ERET points to the next instruction. In | |
528 | other words: ERET != STOP_PC. To jump back from the kernel code to | |
529 | the correct address, ERET must be overwritten by GDB's STOP_PC. Else, | |
530 | the program will continue at the address after the current instruction. | |
531 | */ | |
532 | if (regnum == gdbarch_pc_regnum (gdbarch)) | |
10c19fad SV |
533 | offset = arc_linux_core_reg_offsets[ARC_ERET_REGNUM]; |
534 | else | |
535 | offset = arc_linux_core_reg_offsets[regnum]; | |
536 | regcache->raw_collect (regnum, buf + offset); | |
cc463201 AK |
537 | } |
538 | ||
539 | void | |
540 | arc_linux_collect_gregset (const struct regset *regset, | |
541 | const struct regcache *regcache, | |
542 | int regnum, void *gregs, size_t size) | |
543 | { | |
544 | gdb_static_assert (ARC_LAST_REGNUM | |
545 | < ARRAY_SIZE (arc_linux_core_reg_offsets)); | |
546 | ||
547 | gdb_byte *buf = (gdb_byte *) gregs; | |
548 | struct gdbarch *gdbarch = regcache->arch (); | |
549 | ||
acf10cac | 550 | /* REGNUM == -1 means writing all the registers. */ |
cc463201 AK |
551 | if (regnum == -1) |
552 | for (int reg = 0; reg <= ARC_LAST_REGNUM; reg++) | |
553 | collect_register (regcache, gdbarch, reg, buf); | |
554 | else if (regnum <= ARC_LAST_REGNUM) | |
555 | collect_register (regcache, gdbarch, regnum, buf); | |
556 | else | |
557 | gdb_assert_not_reached ("Invalid regnum in arc_linux_collect_gregset."); | |
558 | } | |
559 | ||
560 | void | |
561 | arc_linux_collect_v2_regset (const struct regset *regset, | |
562 | const struct regcache *regcache, int regnum, | |
563 | void *v2_regs, size_t size) | |
564 | { | |
565 | bfd_byte *buf = (bfd_byte *) v2_regs; | |
566 | ||
46023bbe SV |
567 | if (regnum == -1 || regnum == ARC_R30_REGNUM) |
568 | regcache->raw_collect (ARC_R30_REGNUM, buf); | |
569 | if (regnum == -1 || regnum == ARC_R58_REGNUM) | |
570 | regcache->raw_collect (ARC_R58_REGNUM, buf + REGOFF (1)); | |
571 | if (regnum == -1 || regnum == ARC_R59_REGNUM) | |
572 | regcache->raw_collect (ARC_R59_REGNUM, buf + REGOFF (2)); | |
cc463201 AK |
573 | } |
574 | ||
575 | /* Linux regset definitions. */ | |
576 | ||
577 | static const struct regset arc_linux_gregset = { | |
578 | arc_linux_core_reg_offsets, | |
579 | arc_linux_supply_gregset, | |
580 | arc_linux_collect_gregset, | |
581 | }; | |
582 | ||
583 | static const struct regset arc_linux_v2_regset = { | |
584 | NULL, | |
585 | arc_linux_supply_v2_regset, | |
586 | arc_linux_collect_v2_regset, | |
587 | }; | |
588 | ||
589 | /* Implement the `iterate_over_regset_sections` gdbarch method. */ | |
590 | ||
591 | static void | |
592 | arc_linux_iterate_over_regset_sections (struct gdbarch *gdbarch, | |
593 | iterate_over_regset_sections_cb *cb, | |
594 | void *cb_data, | |
595 | const struct regcache *regcache) | |
596 | { | |
597 | /* There are 40 registers in Linux user_regs_struct, although some of | |
598 | them are now just a mere paddings, kept to maintain binary | |
599 | compatibility with older tools. */ | |
600 | const int sizeof_gregset = 40 * ARC_REGISTER_SIZE; | |
601 | ||
602 | cb (".reg", sizeof_gregset, sizeof_gregset, &arc_linux_gregset, NULL, | |
603 | cb_data); | |
604 | cb (".reg-arc-v2", ARC_LINUX_SIZEOF_V2_REGSET, ARC_LINUX_SIZEOF_V2_REGSET, | |
605 | &arc_linux_v2_regset, NULL, cb_data); | |
606 | } | |
607 | ||
608 | /* Implement the `core_read_description` gdbarch method. */ | |
609 | ||
610 | static const struct target_desc * | |
611 | arc_linux_core_read_description (struct gdbarch *gdbarch, | |
612 | struct target_ops *target, | |
613 | bfd *abfd) | |
614 | { | |
615 | arc_arch_features features | |
616 | = arc_arch_features_create (abfd, | |
617 | gdbarch_bfd_arch_info (gdbarch)->mach); | |
618 | return arc_lookup_target_description (features); | |
619 | } | |
620 | ||
8d7f0635 AK |
621 | /* Initialization specific to Linux environment. */ |
622 | ||
623 | static void | |
624 | arc_linux_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
625 | { | |
626 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
627 | ||
628 | if (arc_debug) | |
629 | debug_printf ("arc-linux: GNU/Linux OS/ABI initialization.\n"); | |
630 | ||
d4af7272 AK |
631 | /* Fill in target-dependent info in ARC-private structure. */ |
632 | tdep->is_sigtramp = arc_linux_is_sigtramp; | |
633 | tdep->sigcontext_addr = arc_linux_sigcontext_addr; | |
634 | tdep->sc_reg_offset = arc_linux_sc_reg_offsets; | |
635 | tdep->sc_num_regs = ARRAY_SIZE (arc_linux_sc_reg_offsets); | |
636 | ||
8d7f0635 AK |
637 | /* If we are using Linux, we have in uClibc |
638 | (libc/sysdeps/linux/arc/bits/setjmp.h): | |
639 | ||
640 | typedef int __jmp_buf[13+1+1+1]; //r13-r25, fp, sp, blink | |
641 | ||
642 | Where "blink" is a stored PC of a caller function. | |
643 | */ | |
644 | tdep->jb_pc = 15; | |
645 | ||
480af54c | 646 | linux_init_abi (info, gdbarch, 0); |
8d7f0635 AK |
647 | |
648 | /* Set up target dependent GDB architecture entries. */ | |
649 | set_gdbarch_cannot_fetch_register (gdbarch, arc_linux_cannot_fetch_register); | |
650 | set_gdbarch_cannot_store_register (gdbarch, arc_linux_cannot_store_register); | |
651 | set_gdbarch_breakpoint_kind_from_pc (gdbarch, | |
652 | arc_linux_breakpoint_kind_from_pc); | |
653 | set_gdbarch_sw_breakpoint_from_kind (gdbarch, | |
654 | arc_linux_sw_breakpoint_from_kind); | |
655 | set_gdbarch_fetch_tls_load_module_address (gdbarch, | |
656 | svr4_fetch_objfile_link_map); | |
657 | set_gdbarch_software_single_step (gdbarch, arc_linux_software_single_step); | |
658 | set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); | |
659 | set_gdbarch_skip_solib_resolver (gdbarch, arc_linux_skip_solib_resolver); | |
cc463201 AK |
660 | set_gdbarch_iterate_over_regset_sections |
661 | (gdbarch, arc_linux_iterate_over_regset_sections); | |
662 | set_gdbarch_core_read_description (gdbarch, arc_linux_core_read_description); | |
8d7f0635 AK |
663 | |
664 | /* GNU/Linux uses SVR4-style shared libraries, with 32-bit ints, longs | |
665 | and pointers (ILP32). */ | |
666 | set_solib_svr4_fetch_link_map_offsets (gdbarch, | |
667 | svr4_ilp32_fetch_link_map_offsets); | |
668 | } | |
669 | ||
670 | /* Suppress warning from -Wmissing-prototypes. */ | |
671 | extern initialize_file_ftype _initialize_arc_linux_tdep; | |
672 | ||
673 | void | |
674 | _initialize_arc_linux_tdep () | |
675 | { | |
676 | gdbarch_register_osabi (bfd_arch_arc, 0, GDB_OSABI_LINUX, | |
677 | arc_linux_init_osabi); | |
678 | } |