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c877c8e6 | 1 | /* Target-dependent code for GDB, the GNU debugger. |
4e052eda | 2 | |
6aba47ca | 3 | Copyright (C) 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997, |
9b254dd1 | 4 | 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 |
76a9d10f | 5 | Free Software Foundation, Inc. |
c877c8e6 KB |
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 | |
a9762ec7 | 11 | the Free Software Foundation; either version 3 of the License, or |
c877c8e6 KB |
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 | |
a9762ec7 | 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
c877c8e6 KB |
21 | |
22 | #include "defs.h" | |
23 | #include "frame.h" | |
24 | #include "inferior.h" | |
25 | #include "symtab.h" | |
26 | #include "target.h" | |
27 | #include "gdbcore.h" | |
28 | #include "gdbcmd.h" | |
29 | #include "symfile.h" | |
30 | #include "objfiles.h" | |
4e052eda | 31 | #include "regcache.h" |
fd0407d6 | 32 | #include "value.h" |
4be87837 | 33 | #include "osabi.h" |
f9be684a | 34 | #include "regset.h" |
6ded7999 | 35 | #include "solib-svr4.h" |
9aa1e687 | 36 | #include "ppc-tdep.h" |
7284e1be | 37 | #include "ppc-linux-tdep.h" |
61a65099 KB |
38 | #include "trad-frame.h" |
39 | #include "frame-unwind.h" | |
a8f60bfc | 40 | #include "tramp-frame.h" |
9aa1e687 | 41 | |
7284e1be UW |
42 | #include "features/rs6000/powerpc-32l.c" |
43 | #include "features/rs6000/powerpc-altivec32l.c" | |
44 | #include "features/rs6000/powerpc-64l.c" | |
45 | #include "features/rs6000/powerpc-altivec64l.c" | |
46 | #include "features/rs6000/powerpc-e500l.c" | |
47 | ||
6974274f | 48 | static CORE_ADDR |
52f729a7 | 49 | ppc_linux_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc) |
c877c8e6 | 50 | { |
50fd1280 | 51 | gdb_byte buf[4]; |
c877c8e6 KB |
52 | struct obj_section *sect; |
53 | struct objfile *objfile; | |
54 | unsigned long insn; | |
55 | CORE_ADDR plt_start = 0; | |
56 | CORE_ADDR symtab = 0; | |
57 | CORE_ADDR strtab = 0; | |
58 | int num_slots = -1; | |
59 | int reloc_index = -1; | |
60 | CORE_ADDR plt_table; | |
61 | CORE_ADDR reloc; | |
62 | CORE_ADDR sym; | |
63 | long symidx; | |
64 | char symname[1024]; | |
65 | struct minimal_symbol *msymbol; | |
66 | ||
82233d87 | 67 | /* Find the section pc is in; if not in .plt, try the default method. */ |
c877c8e6 KB |
68 | sect = find_pc_section (pc); |
69 | if (!sect || strcmp (sect->the_bfd_section->name, ".plt") != 0) | |
82233d87 | 70 | return find_solib_trampoline_target (frame, pc); |
c877c8e6 KB |
71 | |
72 | objfile = sect->objfile; | |
73 | ||
74 | /* Pick up the instruction at pc. It had better be of the | |
75 | form | |
76 | li r11, IDX | |
77 | ||
78 | where IDX is an index into the plt_table. */ | |
79 | ||
80 | if (target_read_memory (pc, buf, 4) != 0) | |
81 | return 0; | |
82 | insn = extract_unsigned_integer (buf, 4); | |
83 | ||
84 | if ((insn & 0xffff0000) != 0x39600000 /* li r11, VAL */ ) | |
85 | return 0; | |
86 | ||
87 | reloc_index = (insn << 16) >> 16; | |
88 | ||
89 | /* Find the objfile that pc is in and obtain the information | |
90 | necessary for finding the symbol name. */ | |
91 | for (sect = objfile->sections; sect < objfile->sections_end; ++sect) | |
92 | { | |
93 | const char *secname = sect->the_bfd_section->name; | |
94 | if (strcmp (secname, ".plt") == 0) | |
95 | plt_start = sect->addr; | |
96 | else if (strcmp (secname, ".rela.plt") == 0) | |
97 | num_slots = ((int) sect->endaddr - (int) sect->addr) / 12; | |
98 | else if (strcmp (secname, ".dynsym") == 0) | |
99 | symtab = sect->addr; | |
100 | else if (strcmp (secname, ".dynstr") == 0) | |
101 | strtab = sect->addr; | |
102 | } | |
103 | ||
104 | /* Make sure we have all the information we need. */ | |
105 | if (plt_start == 0 || num_slots == -1 || symtab == 0 || strtab == 0) | |
106 | return 0; | |
107 | ||
108 | /* Compute the value of the plt table */ | |
109 | plt_table = plt_start + 72 + 8 * num_slots; | |
110 | ||
111 | /* Get address of the relocation entry (Elf32_Rela) */ | |
112 | if (target_read_memory (plt_table + reloc_index, buf, 4) != 0) | |
113 | return 0; | |
7c0b4a20 | 114 | reloc = extract_unsigned_integer (buf, 4); |
c877c8e6 KB |
115 | |
116 | sect = find_pc_section (reloc); | |
117 | if (!sect) | |
118 | return 0; | |
119 | ||
120 | if (strcmp (sect->the_bfd_section->name, ".text") == 0) | |
121 | return reloc; | |
122 | ||
123 | /* Now get the r_info field which is the relocation type and symbol | |
124 | index. */ | |
125 | if (target_read_memory (reloc + 4, buf, 4) != 0) | |
126 | return 0; | |
127 | symidx = extract_unsigned_integer (buf, 4); | |
128 | ||
129 | /* Shift out the relocation type leaving just the symbol index */ | |
130 | /* symidx = ELF32_R_SYM(symidx); */ | |
131 | symidx = symidx >> 8; | |
132 | ||
133 | /* compute the address of the symbol */ | |
134 | sym = symtab + symidx * 4; | |
135 | ||
136 | /* Fetch the string table index */ | |
137 | if (target_read_memory (sym, buf, 4) != 0) | |
138 | return 0; | |
139 | symidx = extract_unsigned_integer (buf, 4); | |
140 | ||
141 | /* Fetch the string; we don't know how long it is. Is it possible | |
142 | that the following will fail because we're trying to fetch too | |
143 | much? */ | |
50fd1280 AC |
144 | if (target_read_memory (strtab + symidx, (gdb_byte *) symname, |
145 | sizeof (symname)) != 0) | |
c877c8e6 KB |
146 | return 0; |
147 | ||
148 | /* This might not work right if we have multiple symbols with the | |
149 | same name; the only way to really get it right is to perform | |
150 | the same sort of lookup as the dynamic linker. */ | |
5520a790 | 151 | msymbol = lookup_minimal_symbol_text (symname, NULL); |
c877c8e6 KB |
152 | if (!msymbol) |
153 | return 0; | |
154 | ||
155 | return SYMBOL_VALUE_ADDRESS (msymbol); | |
156 | } | |
157 | ||
122a33de KB |
158 | /* ppc_linux_memory_remove_breakpoints attempts to remove a breakpoint |
159 | in much the same fashion as memory_remove_breakpoint in mem-break.c, | |
160 | but is careful not to write back the previous contents if the code | |
161 | in question has changed in between inserting the breakpoint and | |
162 | removing it. | |
163 | ||
164 | Here is the problem that we're trying to solve... | |
165 | ||
166 | Once upon a time, before introducing this function to remove | |
167 | breakpoints from the inferior, setting a breakpoint on a shared | |
168 | library function prior to running the program would not work | |
169 | properly. In order to understand the problem, it is first | |
170 | necessary to understand a little bit about dynamic linking on | |
171 | this platform. | |
172 | ||
173 | A call to a shared library function is accomplished via a bl | |
174 | (branch-and-link) instruction whose branch target is an entry | |
175 | in the procedure linkage table (PLT). The PLT in the object | |
176 | file is uninitialized. To gdb, prior to running the program, the | |
177 | entries in the PLT are all zeros. | |
178 | ||
179 | Once the program starts running, the shared libraries are loaded | |
180 | and the procedure linkage table is initialized, but the entries in | |
181 | the table are not (necessarily) resolved. Once a function is | |
182 | actually called, the code in the PLT is hit and the function is | |
183 | resolved. In order to better illustrate this, an example is in | |
184 | order; the following example is from the gdb testsuite. | |
185 | ||
186 | We start the program shmain. | |
187 | ||
188 | [kev@arroyo testsuite]$ ../gdb gdb.base/shmain | |
189 | [...] | |
190 | ||
191 | We place two breakpoints, one on shr1 and the other on main. | |
192 | ||
193 | (gdb) b shr1 | |
194 | Breakpoint 1 at 0x100409d4 | |
195 | (gdb) b main | |
196 | Breakpoint 2 at 0x100006a0: file gdb.base/shmain.c, line 44. | |
197 | ||
198 | Examine the instruction (and the immediatly following instruction) | |
199 | upon which the breakpoint was placed. Note that the PLT entry | |
200 | for shr1 contains zeros. | |
201 | ||
202 | (gdb) x/2i 0x100409d4 | |
203 | 0x100409d4 <shr1>: .long 0x0 | |
204 | 0x100409d8 <shr1+4>: .long 0x0 | |
205 | ||
206 | Now run 'til main. | |
207 | ||
208 | (gdb) r | |
209 | Starting program: gdb.base/shmain | |
210 | Breakpoint 1 at 0xffaf790: file gdb.base/shr1.c, line 19. | |
211 | ||
212 | Breakpoint 2, main () | |
213 | at gdb.base/shmain.c:44 | |
214 | 44 g = 1; | |
215 | ||
216 | Examine the PLT again. Note that the loading of the shared | |
217 | library has initialized the PLT to code which loads a constant | |
218 | (which I think is an index into the GOT) into r11 and then | |
219 | branchs a short distance to the code which actually does the | |
220 | resolving. | |
221 | ||
222 | (gdb) x/2i 0x100409d4 | |
223 | 0x100409d4 <shr1>: li r11,4 | |
224 | 0x100409d8 <shr1+4>: b 0x10040984 <sg+4> | |
225 | (gdb) c | |
226 | Continuing. | |
227 | ||
228 | Breakpoint 1, shr1 (x=1) | |
229 | at gdb.base/shr1.c:19 | |
230 | 19 l = 1; | |
231 | ||
232 | Now we've hit the breakpoint at shr1. (The breakpoint was | |
233 | reset from the PLT entry to the actual shr1 function after the | |
234 | shared library was loaded.) Note that the PLT entry has been | |
235 | resolved to contain a branch that takes us directly to shr1. | |
236 | (The real one, not the PLT entry.) | |
237 | ||
238 | (gdb) x/2i 0x100409d4 | |
239 | 0x100409d4 <shr1>: b 0xffaf76c <shr1> | |
240 | 0x100409d8 <shr1+4>: b 0x10040984 <sg+4> | |
241 | ||
242 | The thing to note here is that the PLT entry for shr1 has been | |
243 | changed twice. | |
244 | ||
245 | Now the problem should be obvious. GDB places a breakpoint (a | |
246 | trap instruction) on the zero value of the PLT entry for shr1. | |
247 | Later on, after the shared library had been loaded and the PLT | |
248 | initialized, GDB gets a signal indicating this fact and attempts | |
249 | (as it always does when it stops) to remove all the breakpoints. | |
250 | ||
251 | The breakpoint removal was causing the former contents (a zero | |
252 | word) to be written back to the now initialized PLT entry thus | |
253 | destroying a portion of the initialization that had occurred only a | |
254 | short time ago. When execution continued, the zero word would be | |
255 | executed as an instruction an an illegal instruction trap was | |
256 | generated instead. (0 is not a legal instruction.) | |
257 | ||
258 | The fix for this problem was fairly straightforward. The function | |
259 | memory_remove_breakpoint from mem-break.c was copied to this file, | |
260 | modified slightly, and renamed to ppc_linux_memory_remove_breakpoint. | |
261 | In tm-linux.h, MEMORY_REMOVE_BREAKPOINT is defined to call this new | |
262 | function. | |
263 | ||
264 | The differences between ppc_linux_memory_remove_breakpoint () and | |
265 | memory_remove_breakpoint () are minor. All that the former does | |
266 | that the latter does not is check to make sure that the breakpoint | |
267 | location actually contains a breakpoint (trap instruction) prior | |
268 | to attempting to write back the old contents. If it does contain | |
269 | a trap instruction, we allow the old contents to be written back. | |
270 | Otherwise, we silently do nothing. | |
271 | ||
272 | The big question is whether memory_remove_breakpoint () should be | |
273 | changed to have the same functionality. The downside is that more | |
274 | traffic is generated for remote targets since we'll have an extra | |
275 | fetch of a memory word each time a breakpoint is removed. | |
276 | ||
277 | For the time being, we'll leave this self-modifying-code-friendly | |
278 | version in ppc-linux-tdep.c, but it ought to be migrated somewhere | |
279 | else in the event that some other platform has similar needs with | |
280 | regard to removing breakpoints in some potentially self modifying | |
281 | code. */ | |
482ca3f5 | 282 | int |
ae4b2284 MD |
283 | ppc_linux_memory_remove_breakpoint (struct gdbarch *gdbarch, |
284 | struct bp_target_info *bp_tgt) | |
482ca3f5 | 285 | { |
8181d85f | 286 | CORE_ADDR addr = bp_tgt->placed_address; |
f4f9705a | 287 | const unsigned char *bp; |
482ca3f5 KB |
288 | int val; |
289 | int bplen; | |
50fd1280 | 290 | gdb_byte old_contents[BREAKPOINT_MAX]; |
8defab1a | 291 | struct cleanup *cleanup; |
482ca3f5 KB |
292 | |
293 | /* Determine appropriate breakpoint contents and size for this address. */ | |
ae4b2284 | 294 | bp = gdbarch_breakpoint_from_pc (gdbarch, &addr, &bplen); |
482ca3f5 | 295 | if (bp == NULL) |
8a3fe4f8 | 296 | error (_("Software breakpoints not implemented for this target.")); |
482ca3f5 | 297 | |
8defab1a DJ |
298 | /* Make sure we see the memory breakpoints. */ |
299 | cleanup = make_show_memory_breakpoints_cleanup (1); | |
482ca3f5 KB |
300 | val = target_read_memory (addr, old_contents, bplen); |
301 | ||
302 | /* If our breakpoint is no longer at the address, this means that the | |
303 | program modified the code on us, so it is wrong to put back the | |
304 | old value */ | |
305 | if (val == 0 && memcmp (bp, old_contents, bplen) == 0) | |
8181d85f | 306 | val = target_write_memory (addr, bp_tgt->shadow_contents, bplen); |
482ca3f5 | 307 | |
8defab1a | 308 | do_cleanups (cleanup); |
482ca3f5 KB |
309 | return val; |
310 | } | |
6ded7999 | 311 | |
b9ff3018 AC |
312 | /* For historic reasons, PPC 32 GNU/Linux follows PowerOpen rather |
313 | than the 32 bit SYSV R4 ABI structure return convention - all | |
314 | structures, no matter their size, are put in memory. Vectors, | |
315 | which were added later, do get returned in a register though. */ | |
316 | ||
05580c65 | 317 | static enum return_value_convention |
c055b101 CV |
318 | ppc_linux_return_value (struct gdbarch *gdbarch, struct type *func_type, |
319 | struct type *valtype, struct regcache *regcache, | |
320 | gdb_byte *readbuf, const gdb_byte *writebuf) | |
b9ff3018 | 321 | { |
05580c65 AC |
322 | if ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT |
323 | || TYPE_CODE (valtype) == TYPE_CODE_UNION) | |
324 | && !((TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 8) | |
325 | && TYPE_VECTOR (valtype))) | |
326 | return RETURN_VALUE_STRUCT_CONVENTION; | |
327 | else | |
c055b101 CV |
328 | return ppc_sysv_abi_return_value (gdbarch, func_type, valtype, regcache, |
329 | readbuf, writebuf); | |
b9ff3018 AC |
330 | } |
331 | ||
f470a70a JB |
332 | /* Macros for matching instructions. Note that, since all the |
333 | operands are masked off before they're or-ed into the instruction, | |
334 | you can use -1 to make masks. */ | |
335 | ||
336 | #define insn_d(opcd, rts, ra, d) \ | |
337 | ((((opcd) & 0x3f) << 26) \ | |
338 | | (((rts) & 0x1f) << 21) \ | |
339 | | (((ra) & 0x1f) << 16) \ | |
340 | | ((d) & 0xffff)) | |
341 | ||
342 | #define insn_ds(opcd, rts, ra, d, xo) \ | |
343 | ((((opcd) & 0x3f) << 26) \ | |
344 | | (((rts) & 0x1f) << 21) \ | |
345 | | (((ra) & 0x1f) << 16) \ | |
346 | | ((d) & 0xfffc) \ | |
347 | | ((xo) & 0x3)) | |
348 | ||
349 | #define insn_xfx(opcd, rts, spr, xo) \ | |
350 | ((((opcd) & 0x3f) << 26) \ | |
351 | | (((rts) & 0x1f) << 21) \ | |
352 | | (((spr) & 0x1f) << 16) \ | |
353 | | (((spr) & 0x3e0) << 6) \ | |
354 | | (((xo) & 0x3ff) << 1)) | |
355 | ||
356 | /* Read a PPC instruction from memory. PPC instructions are always | |
357 | big-endian, no matter what endianness the program is running in, so | |
358 | we can't use read_memory_integer or one of its friends here. */ | |
359 | static unsigned int | |
360 | read_insn (CORE_ADDR pc) | |
361 | { | |
362 | unsigned char buf[4]; | |
363 | ||
364 | read_memory (pc, buf, 4); | |
365 | return (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3]; | |
366 | } | |
367 | ||
368 | ||
369 | /* An instruction to match. */ | |
370 | struct insn_pattern | |
371 | { | |
372 | unsigned int mask; /* mask the insn with this... */ | |
373 | unsigned int data; /* ...and see if it matches this. */ | |
374 | int optional; /* If non-zero, this insn may be absent. */ | |
375 | }; | |
376 | ||
377 | /* Return non-zero if the instructions at PC match the series | |
378 | described in PATTERN, or zero otherwise. PATTERN is an array of | |
379 | 'struct insn_pattern' objects, terminated by an entry whose mask is | |
380 | zero. | |
381 | ||
382 | When the match is successful, fill INSN[i] with what PATTERN[i] | |
383 | matched. If PATTERN[i] is optional, and the instruction wasn't | |
384 | present, set INSN[i] to 0 (which is not a valid PPC instruction). | |
385 | INSN should have as many elements as PATTERN. Note that, if | |
386 | PATTERN contains optional instructions which aren't present in | |
387 | memory, then INSN will have holes, so INSN[i] isn't necessarily the | |
388 | i'th instruction in memory. */ | |
389 | static int | |
390 | insns_match_pattern (CORE_ADDR pc, | |
391 | struct insn_pattern *pattern, | |
392 | unsigned int *insn) | |
393 | { | |
394 | int i; | |
395 | ||
396 | for (i = 0; pattern[i].mask; i++) | |
397 | { | |
398 | insn[i] = read_insn (pc); | |
399 | if ((insn[i] & pattern[i].mask) == pattern[i].data) | |
400 | pc += 4; | |
401 | else if (pattern[i].optional) | |
402 | insn[i] = 0; | |
403 | else | |
404 | return 0; | |
405 | } | |
406 | ||
407 | return 1; | |
408 | } | |
409 | ||
410 | ||
411 | /* Return the 'd' field of the d-form instruction INSN, properly | |
412 | sign-extended. */ | |
413 | static CORE_ADDR | |
414 | insn_d_field (unsigned int insn) | |
415 | { | |
416 | return ((((CORE_ADDR) insn & 0xffff) ^ 0x8000) - 0x8000); | |
417 | } | |
418 | ||
419 | ||
420 | /* Return the 'ds' field of the ds-form instruction INSN, with the two | |
421 | zero bits concatenated at the right, and properly | |
422 | sign-extended. */ | |
423 | static CORE_ADDR | |
424 | insn_ds_field (unsigned int insn) | |
425 | { | |
426 | return ((((CORE_ADDR) insn & 0xfffc) ^ 0x8000) - 0x8000); | |
427 | } | |
428 | ||
429 | ||
e538d2d7 | 430 | /* If DESC is the address of a 64-bit PowerPC GNU/Linux function |
d64558a5 JB |
431 | descriptor, return the descriptor's entry point. */ |
432 | static CORE_ADDR | |
433 | ppc64_desc_entry_point (CORE_ADDR desc) | |
434 | { | |
435 | /* The first word of the descriptor is the entry point. */ | |
436 | return (CORE_ADDR) read_memory_unsigned_integer (desc, 8); | |
437 | } | |
438 | ||
439 | ||
f470a70a JB |
440 | /* Pattern for the standard linkage function. These are built by |
441 | build_plt_stub in elf64-ppc.c, whose GLINK argument is always | |
442 | zero. */ | |
443 | static struct insn_pattern ppc64_standard_linkage[] = | |
444 | { | |
445 | /* addis r12, r2, <any> */ | |
446 | { insn_d (-1, -1, -1, 0), insn_d (15, 12, 2, 0), 0 }, | |
447 | ||
448 | /* std r2, 40(r1) */ | |
449 | { -1, insn_ds (62, 2, 1, 40, 0), 0 }, | |
450 | ||
451 | /* ld r11, <any>(r12) */ | |
452 | { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 0 }, | |
453 | ||
454 | /* addis r12, r12, 1 <optional> */ | |
455 | { insn_d (-1, -1, -1, -1), insn_d (15, 12, 2, 1), 1 }, | |
456 | ||
457 | /* ld r2, <any>(r12) */ | |
458 | { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 12, 0, 0), 0 }, | |
459 | ||
460 | /* addis r12, r12, 1 <optional> */ | |
461 | { insn_d (-1, -1, -1, -1), insn_d (15, 12, 2, 1), 1 }, | |
462 | ||
463 | /* mtctr r11 */ | |
464 | { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467), | |
465 | 0 }, | |
466 | ||
467 | /* ld r11, <any>(r12) */ | |
468 | { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 0 }, | |
469 | ||
470 | /* bctr */ | |
471 | { -1, 0x4e800420, 0 }, | |
472 | ||
473 | { 0, 0, 0 } | |
474 | }; | |
475 | #define PPC64_STANDARD_LINKAGE_LEN \ | |
476 | (sizeof (ppc64_standard_linkage) / sizeof (ppc64_standard_linkage[0])) | |
477 | ||
f470a70a JB |
478 | /* When the dynamic linker is doing lazy symbol resolution, the first |
479 | call to a function in another object will go like this: | |
480 | ||
481 | - The user's function calls the linkage function: | |
482 | ||
483 | 100007c4: 4b ff fc d5 bl 10000498 | |
484 | 100007c8: e8 41 00 28 ld r2,40(r1) | |
485 | ||
486 | - The linkage function loads the entry point (and other stuff) from | |
487 | the function descriptor in the PLT, and jumps to it: | |
488 | ||
489 | 10000498: 3d 82 00 00 addis r12,r2,0 | |
490 | 1000049c: f8 41 00 28 std r2,40(r1) | |
491 | 100004a0: e9 6c 80 98 ld r11,-32616(r12) | |
492 | 100004a4: e8 4c 80 a0 ld r2,-32608(r12) | |
493 | 100004a8: 7d 69 03 a6 mtctr r11 | |
494 | 100004ac: e9 6c 80 a8 ld r11,-32600(r12) | |
495 | 100004b0: 4e 80 04 20 bctr | |
496 | ||
497 | - But since this is the first time that PLT entry has been used, it | |
498 | sends control to its glink entry. That loads the number of the | |
499 | PLT entry and jumps to the common glink0 code: | |
500 | ||
501 | 10000c98: 38 00 00 00 li r0,0 | |
502 | 10000c9c: 4b ff ff dc b 10000c78 | |
503 | ||
504 | - The common glink0 code then transfers control to the dynamic | |
505 | linker's fixup code: | |
506 | ||
507 | 10000c78: e8 41 00 28 ld r2,40(r1) | |
508 | 10000c7c: 3d 82 00 00 addis r12,r2,0 | |
509 | 10000c80: e9 6c 80 80 ld r11,-32640(r12) | |
510 | 10000c84: e8 4c 80 88 ld r2,-32632(r12) | |
511 | 10000c88: 7d 69 03 a6 mtctr r11 | |
512 | 10000c8c: e9 6c 80 90 ld r11,-32624(r12) | |
513 | 10000c90: 4e 80 04 20 bctr | |
514 | ||
515 | Eventually, this code will figure out how to skip all of this, | |
516 | including the dynamic linker. At the moment, we just get through | |
517 | the linkage function. */ | |
518 | ||
519 | /* If the current thread is about to execute a series of instructions | |
520 | at PC matching the ppc64_standard_linkage pattern, and INSN is the result | |
521 | from that pattern match, return the code address to which the | |
522 | standard linkage function will send them. (This doesn't deal with | |
523 | dynamic linker lazy symbol resolution stubs.) */ | |
524 | static CORE_ADDR | |
52f729a7 UW |
525 | ppc64_standard_linkage_target (struct frame_info *frame, |
526 | CORE_ADDR pc, unsigned int *insn) | |
f470a70a | 527 | { |
52f729a7 | 528 | struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (frame)); |
f470a70a JB |
529 | |
530 | /* The address of the function descriptor this linkage function | |
531 | references. */ | |
532 | CORE_ADDR desc | |
52f729a7 UW |
533 | = ((CORE_ADDR) get_frame_register_unsigned (frame, |
534 | tdep->ppc_gp0_regnum + 2) | |
f470a70a JB |
535 | + (insn_d_field (insn[0]) << 16) |
536 | + insn_ds_field (insn[2])); | |
537 | ||
538 | /* The first word of the descriptor is the entry point. Return that. */ | |
d64558a5 | 539 | return ppc64_desc_entry_point (desc); |
f470a70a JB |
540 | } |
541 | ||
542 | ||
543 | /* Given that we've begun executing a call trampoline at PC, return | |
544 | the entry point of the function the trampoline will go to. */ | |
545 | static CORE_ADDR | |
52f729a7 | 546 | ppc64_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc) |
f470a70a JB |
547 | { |
548 | unsigned int ppc64_standard_linkage_insn[PPC64_STANDARD_LINKAGE_LEN]; | |
549 | ||
550 | if (insns_match_pattern (pc, ppc64_standard_linkage, | |
551 | ppc64_standard_linkage_insn)) | |
52f729a7 UW |
552 | return ppc64_standard_linkage_target (frame, pc, |
553 | ppc64_standard_linkage_insn); | |
f470a70a JB |
554 | else |
555 | return 0; | |
556 | } | |
557 | ||
558 | ||
2bbe3cc1 | 559 | /* Support for convert_from_func_ptr_addr (ARCH, ADDR, TARG) on PPC |
e2d0e7eb | 560 | GNU/Linux. |
02631ec0 JB |
561 | |
562 | Usually a function pointer's representation is simply the address | |
2bbe3cc1 DJ |
563 | of the function. On GNU/Linux on the PowerPC however, a function |
564 | pointer may be a pointer to a function descriptor. | |
565 | ||
566 | For PPC64, a function descriptor is a TOC entry, in a data section, | |
567 | which contains three words: the first word is the address of the | |
568 | function, the second word is the TOC pointer (r2), and the third word | |
569 | is the static chain value. | |
570 | ||
571 | For PPC32, there are two kinds of function pointers: non-secure and | |
572 | secure. Non-secure function pointers point directly to the | |
573 | function in a code section and thus need no translation. Secure | |
574 | ones (from GCC's -msecure-plt option) are in a data section and | |
575 | contain one word: the address of the function. | |
576 | ||
577 | Throughout GDB it is currently assumed that a function pointer contains | |
578 | the address of the function, which is not easy to fix. In addition, the | |
e538d2d7 JB |
579 | conversion of a function address to a function pointer would |
580 | require allocation of a TOC entry in the inferior's memory space, | |
581 | with all its drawbacks. To be able to call C++ virtual methods in | |
582 | the inferior (which are called via function pointers), | |
583 | find_function_addr uses this function to get the function address | |
2bbe3cc1 | 584 | from a function pointer. |
02631ec0 | 585 | |
2bbe3cc1 DJ |
586 | If ADDR points at what is clearly a function descriptor, transform |
587 | it into the address of the corresponding function, if needed. Be | |
588 | conservative, otherwise GDB will do the transformation on any | |
589 | random addresses such as occur when there is no symbol table. */ | |
02631ec0 JB |
590 | |
591 | static CORE_ADDR | |
2bbe3cc1 DJ |
592 | ppc_linux_convert_from_func_ptr_addr (struct gdbarch *gdbarch, |
593 | CORE_ADDR addr, | |
594 | struct target_ops *targ) | |
02631ec0 | 595 | { |
2bbe3cc1 | 596 | struct gdbarch_tdep *tdep; |
b6591e8b | 597 | struct section_table *s = target_section_by_addr (targ, addr); |
2bbe3cc1 DJ |
598 | char *sect_name = NULL; |
599 | ||
600 | if (!s) | |
601 | return addr; | |
602 | ||
603 | tdep = gdbarch_tdep (gdbarch); | |
604 | ||
605 | switch (tdep->wordsize) | |
606 | { | |
607 | case 4: | |
608 | sect_name = ".plt"; | |
609 | break; | |
610 | case 8: | |
611 | sect_name = ".opd"; | |
612 | break; | |
613 | default: | |
614 | internal_error (__FILE__, __LINE__, | |
615 | _("failed internal consistency check")); | |
616 | } | |
02631ec0 | 617 | |
9b540880 | 618 | /* Check if ADDR points to a function descriptor. */ |
2bbe3cc1 DJ |
619 | |
620 | /* NOTE: this depends on the coincidence that the address of a functions | |
621 | entry point is contained in the first word of its function descriptor | |
622 | for both PPC-64 and for PPC-32 with secure PLTs. */ | |
623 | if ((strcmp (s->the_bfd_section->name, sect_name) == 0) | |
624 | && s->the_bfd_section->flags & SEC_DATA) | |
625 | return get_target_memory_unsigned (targ, addr, tdep->wordsize); | |
9b540880 AC |
626 | |
627 | return addr; | |
02631ec0 JB |
628 | } |
629 | ||
7284e1be UW |
630 | /* Wrappers to handle Linux-only registers. */ |
631 | ||
632 | static void | |
633 | ppc_linux_supply_gregset (const struct regset *regset, | |
634 | struct regcache *regcache, | |
635 | int regnum, const void *gregs, size_t len) | |
636 | { | |
637 | const struct ppc_reg_offsets *offsets = regset->descr; | |
638 | ||
639 | ppc_supply_gregset (regset, regcache, regnum, gregs, len); | |
640 | ||
641 | if (ppc_linux_trap_reg_p (get_regcache_arch (regcache))) | |
642 | { | |
643 | /* "orig_r3" is stored 2 slots after "pc". */ | |
644 | if (regnum == -1 || regnum == PPC_ORIG_R3_REGNUM) | |
645 | ppc_supply_reg (regcache, PPC_ORIG_R3_REGNUM, gregs, | |
646 | offsets->pc_offset + 2 * offsets->gpr_size, | |
647 | offsets->gpr_size); | |
648 | ||
649 | /* "trap" is stored 8 slots after "pc". */ | |
650 | if (regnum == -1 || regnum == PPC_TRAP_REGNUM) | |
651 | ppc_supply_reg (regcache, PPC_TRAP_REGNUM, gregs, | |
652 | offsets->pc_offset + 8 * offsets->gpr_size, | |
653 | offsets->gpr_size); | |
654 | } | |
655 | } | |
f2db237a | 656 | |
f9be684a | 657 | static void |
f2db237a AM |
658 | ppc_linux_collect_gregset (const struct regset *regset, |
659 | const struct regcache *regcache, | |
660 | int regnum, void *gregs, size_t len) | |
f9be684a | 661 | { |
7284e1be UW |
662 | const struct ppc_reg_offsets *offsets = regset->descr; |
663 | ||
664 | /* Clear areas in the linux gregset not written elsewhere. */ | |
f2db237a AM |
665 | if (regnum == -1) |
666 | memset (gregs, 0, len); | |
7284e1be | 667 | |
f2db237a | 668 | ppc_collect_gregset (regset, regcache, regnum, gregs, len); |
7284e1be UW |
669 | |
670 | if (ppc_linux_trap_reg_p (get_regcache_arch (regcache))) | |
671 | { | |
672 | /* "orig_r3" is stored 2 slots after "pc". */ | |
673 | if (regnum == -1 || regnum == PPC_ORIG_R3_REGNUM) | |
674 | ppc_collect_reg (regcache, PPC_ORIG_R3_REGNUM, gregs, | |
675 | offsets->pc_offset + 2 * offsets->gpr_size, | |
676 | offsets->gpr_size); | |
677 | ||
678 | /* "trap" is stored 8 slots after "pc". */ | |
679 | if (regnum == -1 || regnum == PPC_TRAP_REGNUM) | |
680 | ppc_collect_reg (regcache, PPC_TRAP_REGNUM, gregs, | |
681 | offsets->pc_offset + 8 * offsets->gpr_size, | |
682 | offsets->gpr_size); | |
683 | } | |
f9be684a AC |
684 | } |
685 | ||
f2db237a AM |
686 | /* Regset descriptions. */ |
687 | static const struct ppc_reg_offsets ppc32_linux_reg_offsets = | |
688 | { | |
689 | /* General-purpose registers. */ | |
690 | /* .r0_offset = */ 0, | |
691 | /* .gpr_size = */ 4, | |
692 | /* .xr_size = */ 4, | |
693 | /* .pc_offset = */ 128, | |
694 | /* .ps_offset = */ 132, | |
695 | /* .cr_offset = */ 152, | |
696 | /* .lr_offset = */ 144, | |
697 | /* .ctr_offset = */ 140, | |
698 | /* .xer_offset = */ 148, | |
699 | /* .mq_offset = */ 156, | |
700 | ||
701 | /* Floating-point registers. */ | |
702 | /* .f0_offset = */ 0, | |
703 | /* .fpscr_offset = */ 256, | |
704 | /* .fpscr_size = */ 8, | |
705 | ||
706 | /* AltiVec registers. */ | |
707 | /* .vr0_offset = */ 0, | |
06caf7d2 CES |
708 | /* .vscr_offset = */ 512 + 12, |
709 | /* .vrsave_offset = */ 528 | |
f2db237a | 710 | }; |
f9be684a | 711 | |
f2db237a AM |
712 | static const struct ppc_reg_offsets ppc64_linux_reg_offsets = |
713 | { | |
714 | /* General-purpose registers. */ | |
715 | /* .r0_offset = */ 0, | |
716 | /* .gpr_size = */ 8, | |
717 | /* .xr_size = */ 8, | |
718 | /* .pc_offset = */ 256, | |
719 | /* .ps_offset = */ 264, | |
720 | /* .cr_offset = */ 304, | |
721 | /* .lr_offset = */ 288, | |
722 | /* .ctr_offset = */ 280, | |
723 | /* .xer_offset = */ 296, | |
724 | /* .mq_offset = */ 312, | |
725 | ||
726 | /* Floating-point registers. */ | |
727 | /* .f0_offset = */ 0, | |
728 | /* .fpscr_offset = */ 256, | |
729 | /* .fpscr_size = */ 8, | |
730 | ||
731 | /* AltiVec registers. */ | |
732 | /* .vr0_offset = */ 0, | |
06caf7d2 CES |
733 | /* .vscr_offset = */ 512 + 12, |
734 | /* .vrsave_offset = */ 528 | |
f2db237a | 735 | }; |
2fda4977 | 736 | |
f2db237a AM |
737 | static const struct regset ppc32_linux_gregset = { |
738 | &ppc32_linux_reg_offsets, | |
7284e1be | 739 | ppc_linux_supply_gregset, |
f2db237a AM |
740 | ppc_linux_collect_gregset, |
741 | NULL | |
f9be684a AC |
742 | }; |
743 | ||
f2db237a AM |
744 | static const struct regset ppc64_linux_gregset = { |
745 | &ppc64_linux_reg_offsets, | |
7284e1be | 746 | ppc_linux_supply_gregset, |
f2db237a AM |
747 | ppc_linux_collect_gregset, |
748 | NULL | |
749 | }; | |
f9be684a | 750 | |
f2db237a AM |
751 | static const struct regset ppc32_linux_fpregset = { |
752 | &ppc32_linux_reg_offsets, | |
753 | ppc_supply_fpregset, | |
754 | ppc_collect_fpregset, | |
755 | NULL | |
f9be684a AC |
756 | }; |
757 | ||
06caf7d2 CES |
758 | static const struct regset ppc32_linux_vrregset = { |
759 | &ppc32_linux_reg_offsets, | |
760 | ppc_supply_vrregset, | |
761 | ppc_collect_vrregset, | |
762 | NULL | |
763 | }; | |
764 | ||
f2db237a AM |
765 | const struct regset * |
766 | ppc_linux_gregset (int wordsize) | |
2fda4977 | 767 | { |
f2db237a | 768 | return wordsize == 8 ? &ppc64_linux_gregset : &ppc32_linux_gregset; |
2fda4977 DJ |
769 | } |
770 | ||
f2db237a AM |
771 | const struct regset * |
772 | ppc_linux_fpregset (void) | |
773 | { | |
774 | return &ppc32_linux_fpregset; | |
775 | } | |
2fda4977 | 776 | |
f9be684a AC |
777 | static const struct regset * |
778 | ppc_linux_regset_from_core_section (struct gdbarch *core_arch, | |
779 | const char *sect_name, size_t sect_size) | |
2fda4977 | 780 | { |
f9be684a AC |
781 | struct gdbarch_tdep *tdep = gdbarch_tdep (core_arch); |
782 | if (strcmp (sect_name, ".reg") == 0) | |
2fda4977 | 783 | { |
f9be684a AC |
784 | if (tdep->wordsize == 4) |
785 | return &ppc32_linux_gregset; | |
2fda4977 | 786 | else |
f9be684a | 787 | return &ppc64_linux_gregset; |
2fda4977 | 788 | } |
f9be684a | 789 | if (strcmp (sect_name, ".reg2") == 0) |
f2db237a | 790 | return &ppc32_linux_fpregset; |
06caf7d2 CES |
791 | if (strcmp (sect_name, ".reg-ppc-vmx") == 0) |
792 | return &ppc32_linux_vrregset; | |
f9be684a | 793 | return NULL; |
2fda4977 DJ |
794 | } |
795 | ||
a8f60bfc | 796 | static void |
5366653e | 797 | ppc_linux_sigtramp_cache (struct frame_info *this_frame, |
a8f60bfc AC |
798 | struct trad_frame_cache *this_cache, |
799 | CORE_ADDR func, LONGEST offset, | |
800 | int bias) | |
801 | { | |
802 | CORE_ADDR base; | |
803 | CORE_ADDR regs; | |
804 | CORE_ADDR gpregs; | |
805 | CORE_ADDR fpregs; | |
806 | int i; | |
5366653e | 807 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
a8f60bfc AC |
808 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
809 | ||
5366653e DJ |
810 | base = get_frame_register_unsigned (this_frame, |
811 | gdbarch_sp_regnum (gdbarch)); | |
812 | if (bias > 0 && get_frame_pc (this_frame) != func) | |
a8f60bfc AC |
813 | /* See below, some signal trampolines increment the stack as their |
814 | first instruction, need to compensate for that. */ | |
815 | base -= bias; | |
816 | ||
817 | /* Find the address of the register buffer pointer. */ | |
818 | regs = base + offset; | |
819 | /* Use that to find the address of the corresponding register | |
820 | buffers. */ | |
821 | gpregs = read_memory_unsigned_integer (regs, tdep->wordsize); | |
822 | fpregs = gpregs + 48 * tdep->wordsize; | |
823 | ||
824 | /* General purpose. */ | |
825 | for (i = 0; i < 32; i++) | |
826 | { | |
827 | int regnum = i + tdep->ppc_gp0_regnum; | |
828 | trad_frame_set_reg_addr (this_cache, regnum, gpregs + i * tdep->wordsize); | |
829 | } | |
3e8c568d | 830 | trad_frame_set_reg_addr (this_cache, |
40a6adc1 | 831 | gdbarch_pc_regnum (gdbarch), |
3e8c568d | 832 | gpregs + 32 * tdep->wordsize); |
a8f60bfc AC |
833 | trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, |
834 | gpregs + 35 * tdep->wordsize); | |
835 | trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, | |
836 | gpregs + 36 * tdep->wordsize); | |
837 | trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, | |
838 | gpregs + 37 * tdep->wordsize); | |
839 | trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, | |
840 | gpregs + 38 * tdep->wordsize); | |
841 | ||
7284e1be UW |
842 | if (ppc_linux_trap_reg_p (gdbarch)) |
843 | { | |
844 | trad_frame_set_reg_addr (this_cache, PPC_ORIG_R3_REGNUM, | |
845 | gpregs + 34 * tdep->wordsize); | |
846 | trad_frame_set_reg_addr (this_cache, PPC_TRAP_REGNUM, | |
847 | gpregs + 40 * tdep->wordsize); | |
848 | } | |
849 | ||
60f140f9 PG |
850 | if (ppc_floating_point_unit_p (gdbarch)) |
851 | { | |
852 | /* Floating point registers. */ | |
853 | for (i = 0; i < 32; i++) | |
854 | { | |
40a6adc1 | 855 | int regnum = i + gdbarch_fp0_regnum (gdbarch); |
60f140f9 PG |
856 | trad_frame_set_reg_addr (this_cache, regnum, |
857 | fpregs + i * tdep->wordsize); | |
858 | } | |
859 | trad_frame_set_reg_addr (this_cache, tdep->ppc_fpscr_regnum, | |
4019046a | 860 | fpregs + 32 * tdep->wordsize); |
60f140f9 | 861 | } |
a8f60bfc AC |
862 | trad_frame_set_id (this_cache, frame_id_build (base, func)); |
863 | } | |
864 | ||
865 | static void | |
866 | ppc32_linux_sigaction_cache_init (const struct tramp_frame *self, | |
5366653e | 867 | struct frame_info *this_frame, |
a8f60bfc AC |
868 | struct trad_frame_cache *this_cache, |
869 | CORE_ADDR func) | |
870 | { | |
5366653e | 871 | ppc_linux_sigtramp_cache (this_frame, this_cache, func, |
a8f60bfc AC |
872 | 0xd0 /* Offset to ucontext_t. */ |
873 | + 0x30 /* Offset to .reg. */, | |
874 | 0); | |
875 | } | |
876 | ||
877 | static void | |
878 | ppc64_linux_sigaction_cache_init (const struct tramp_frame *self, | |
5366653e | 879 | struct frame_info *this_frame, |
a8f60bfc AC |
880 | struct trad_frame_cache *this_cache, |
881 | CORE_ADDR func) | |
882 | { | |
5366653e | 883 | ppc_linux_sigtramp_cache (this_frame, this_cache, func, |
a8f60bfc AC |
884 | 0x80 /* Offset to ucontext_t. */ |
885 | + 0xe0 /* Offset to .reg. */, | |
886 | 128); | |
887 | } | |
888 | ||
889 | static void | |
890 | ppc32_linux_sighandler_cache_init (const struct tramp_frame *self, | |
5366653e | 891 | struct frame_info *this_frame, |
a8f60bfc AC |
892 | struct trad_frame_cache *this_cache, |
893 | CORE_ADDR func) | |
894 | { | |
5366653e | 895 | ppc_linux_sigtramp_cache (this_frame, this_cache, func, |
a8f60bfc AC |
896 | 0x40 /* Offset to ucontext_t. */ |
897 | + 0x1c /* Offset to .reg. */, | |
898 | 0); | |
899 | } | |
900 | ||
901 | static void | |
902 | ppc64_linux_sighandler_cache_init (const struct tramp_frame *self, | |
5366653e | 903 | struct frame_info *this_frame, |
a8f60bfc AC |
904 | struct trad_frame_cache *this_cache, |
905 | CORE_ADDR func) | |
906 | { | |
5366653e | 907 | ppc_linux_sigtramp_cache (this_frame, this_cache, func, |
a8f60bfc AC |
908 | 0x80 /* Offset to struct sigcontext. */ |
909 | + 0x38 /* Offset to .reg. */, | |
910 | 128); | |
911 | } | |
912 | ||
913 | static struct tramp_frame ppc32_linux_sigaction_tramp_frame = { | |
914 | SIGTRAMP_FRAME, | |
915 | 4, | |
916 | { | |
917 | { 0x380000ac, -1 }, /* li r0, 172 */ | |
918 | { 0x44000002, -1 }, /* sc */ | |
919 | { TRAMP_SENTINEL_INSN }, | |
920 | }, | |
921 | ppc32_linux_sigaction_cache_init | |
922 | }; | |
923 | static struct tramp_frame ppc64_linux_sigaction_tramp_frame = { | |
924 | SIGTRAMP_FRAME, | |
925 | 4, | |
926 | { | |
927 | { 0x38210080, -1 }, /* addi r1,r1,128 */ | |
928 | { 0x380000ac, -1 }, /* li r0, 172 */ | |
929 | { 0x44000002, -1 }, /* sc */ | |
930 | { TRAMP_SENTINEL_INSN }, | |
931 | }, | |
932 | ppc64_linux_sigaction_cache_init | |
933 | }; | |
934 | static struct tramp_frame ppc32_linux_sighandler_tramp_frame = { | |
935 | SIGTRAMP_FRAME, | |
936 | 4, | |
937 | { | |
938 | { 0x38000077, -1 }, /* li r0,119 */ | |
939 | { 0x44000002, -1 }, /* sc */ | |
940 | { TRAMP_SENTINEL_INSN }, | |
941 | }, | |
942 | ppc32_linux_sighandler_cache_init | |
943 | }; | |
944 | static struct tramp_frame ppc64_linux_sighandler_tramp_frame = { | |
945 | SIGTRAMP_FRAME, | |
946 | 4, | |
947 | { | |
948 | { 0x38210080, -1 }, /* addi r1,r1,128 */ | |
949 | { 0x38000077, -1 }, /* li r0,119 */ | |
950 | { 0x44000002, -1 }, /* sc */ | |
951 | { TRAMP_SENTINEL_INSN }, | |
952 | }, | |
953 | ppc64_linux_sighandler_cache_init | |
954 | }; | |
955 | ||
7284e1be UW |
956 | |
957 | /* Return 1 if PPC_ORIG_R3_REGNUM and PPC_TRAP_REGNUM are usable. */ | |
958 | int | |
959 | ppc_linux_trap_reg_p (struct gdbarch *gdbarch) | |
960 | { | |
961 | /* If we do not have a target description with registers, then | |
962 | the special registers will not be included in the register set. */ | |
963 | if (!tdesc_has_registers (gdbarch_target_desc (gdbarch))) | |
964 | return 0; | |
965 | ||
966 | /* If we do, then it is safe to check the size. */ | |
967 | return register_size (gdbarch, PPC_ORIG_R3_REGNUM) > 0 | |
968 | && register_size (gdbarch, PPC_TRAP_REGNUM) > 0; | |
969 | } | |
970 | ||
971 | static void | |
972 | ppc_linux_write_pc (struct regcache *regcache, CORE_ADDR pc) | |
973 | { | |
974 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
975 | ||
976 | regcache_cooked_write_unsigned (regcache, gdbarch_pc_regnum (gdbarch), pc); | |
977 | ||
978 | /* Set special TRAP register to -1 to prevent the kernel from | |
979 | messing with the PC we just installed, if we happen to be | |
980 | within an interrupted system call that the kernel wants to | |
981 | restart. | |
982 | ||
983 | Note that after we return from the dummy call, the TRAP and | |
984 | ORIG_R3 registers will be automatically restored, and the | |
985 | kernel continues to restart the system call at this point. */ | |
986 | if (ppc_linux_trap_reg_p (gdbarch)) | |
987 | regcache_cooked_write_unsigned (regcache, PPC_TRAP_REGNUM, -1); | |
988 | } | |
989 | ||
990 | static const struct target_desc * | |
991 | ppc_linux_core_read_description (struct gdbarch *gdbarch, | |
992 | struct target_ops *target, | |
993 | bfd *abfd) | |
994 | { | |
995 | asection *altivec = bfd_get_section_by_name (abfd, ".reg-ppc-vmx"); | |
996 | asection *section = bfd_get_section_by_name (abfd, ".reg"); | |
997 | if (! section) | |
998 | return NULL; | |
999 | ||
1000 | switch (bfd_section_size (abfd, section)) | |
1001 | { | |
1002 | case 48 * 4: | |
1003 | return altivec? tdesc_powerpc_altivec32l : tdesc_powerpc_32l; | |
1004 | ||
1005 | case 48 * 8: | |
1006 | return altivec? tdesc_powerpc_altivec64l : tdesc_powerpc_64l; | |
1007 | ||
1008 | default: | |
1009 | return NULL; | |
1010 | } | |
1011 | } | |
1012 | ||
7b112f9c JT |
1013 | static void |
1014 | ppc_linux_init_abi (struct gdbarch_info info, | |
1015 | struct gdbarch *gdbarch) | |
1016 | { | |
1017 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
7284e1be | 1018 | struct tdesc_arch_data *tdesc_data = (void *) info.tdep_info; |
7b112f9c | 1019 | |
b14d30e1 JM |
1020 | /* PPC GNU/Linux uses either 64-bit or 128-bit long doubles; where |
1021 | 128-bit, they are IBM long double, not IEEE quad long double as | |
1022 | in the System V ABI PowerPC Processor Supplement. We can safely | |
1023 | let them default to 128-bit, since the debug info will give the | |
1024 | size of type actually used in each case. */ | |
1025 | set_gdbarch_long_double_bit (gdbarch, 16 * TARGET_CHAR_BIT); | |
1026 | set_gdbarch_long_double_format (gdbarch, floatformats_ibm_long_double); | |
0598a43c | 1027 | |
2bbe3cc1 DJ |
1028 | /* Handle PPC GNU/Linux 64-bit function pointers (which are really |
1029 | function descriptors) and 32-bit secure PLT entries. */ | |
1030 | set_gdbarch_convert_from_func_ptr_addr | |
1031 | (gdbarch, ppc_linux_convert_from_func_ptr_addr); | |
1032 | ||
7284e1be UW |
1033 | /* Handle inferior calls during interrupted system calls. */ |
1034 | set_gdbarch_write_pc (gdbarch, ppc_linux_write_pc); | |
1035 | ||
7b112f9c JT |
1036 | if (tdep->wordsize == 4) |
1037 | { | |
b9ff3018 AC |
1038 | /* Until November 2001, gcc did not comply with the 32 bit SysV |
1039 | R4 ABI requirement that structures less than or equal to 8 | |
1040 | bytes should be returned in registers. Instead GCC was using | |
1041 | the the AIX/PowerOpen ABI - everything returned in memory | |
1042 | (well ignoring vectors that is). When this was corrected, it | |
1043 | wasn't fixed for GNU/Linux native platform. Use the | |
1044 | PowerOpen struct convention. */ | |
05580c65 | 1045 | set_gdbarch_return_value (gdbarch, ppc_linux_return_value); |
b9ff3018 | 1046 | |
7b112f9c JT |
1047 | set_gdbarch_memory_remove_breakpoint (gdbarch, |
1048 | ppc_linux_memory_remove_breakpoint); | |
61a65099 | 1049 | |
f470a70a | 1050 | /* Shared library handling. */ |
f470a70a JB |
1051 | set_gdbarch_skip_trampoline_code (gdbarch, |
1052 | ppc_linux_skip_trampoline_code); | |
7b112f9c | 1053 | set_solib_svr4_fetch_link_map_offsets |
76a9d10f | 1054 | (gdbarch, svr4_ilp32_fetch_link_map_offsets); |
a8f60bfc AC |
1055 | |
1056 | /* Trampolines. */ | |
1057 | tramp_frame_prepend_unwinder (gdbarch, &ppc32_linux_sigaction_tramp_frame); | |
1058 | tramp_frame_prepend_unwinder (gdbarch, &ppc32_linux_sighandler_tramp_frame); | |
7b112f9c | 1059 | } |
f470a70a JB |
1060 | |
1061 | if (tdep->wordsize == 8) | |
1062 | { | |
4a7622d1 UW |
1063 | /* Handle the 64-bit SVR4 minimal-symbol convention of using "FN" |
1064 | for the descriptor and ".FN" for the entry-point -- a user | |
1065 | specifying "break FN" will unexpectedly end up with a breakpoint | |
1066 | on the descriptor and not the function. This architecture method | |
1067 | transforms any breakpoints on descriptors into breakpoints on the | |
1068 | corresponding entry point. */ | |
1069 | set_gdbarch_adjust_breakpoint_address | |
1070 | (gdbarch, ppc64_sysv_abi_adjust_breakpoint_address); | |
1071 | ||
fb318ff7 | 1072 | /* Shared library handling. */ |
2bbe3cc1 | 1073 | set_gdbarch_skip_trampoline_code (gdbarch, ppc64_skip_trampoline_code); |
fb318ff7 DJ |
1074 | set_solib_svr4_fetch_link_map_offsets |
1075 | (gdbarch, svr4_lp64_fetch_link_map_offsets); | |
1076 | ||
a8f60bfc AC |
1077 | /* Trampolines. */ |
1078 | tramp_frame_prepend_unwinder (gdbarch, &ppc64_linux_sigaction_tramp_frame); | |
1079 | tramp_frame_prepend_unwinder (gdbarch, &ppc64_linux_sighandler_tramp_frame); | |
f470a70a | 1080 | } |
f9be684a | 1081 | set_gdbarch_regset_from_core_section (gdbarch, ppc_linux_regset_from_core_section); |
7284e1be | 1082 | set_gdbarch_core_read_description (gdbarch, ppc_linux_core_read_description); |
b2756930 KB |
1083 | |
1084 | /* Enable TLS support. */ | |
1085 | set_gdbarch_fetch_tls_load_module_address (gdbarch, | |
1086 | svr4_fetch_objfile_link_map); | |
7284e1be UW |
1087 | |
1088 | if (tdesc_data) | |
1089 | { | |
1090 | const struct tdesc_feature *feature; | |
1091 | ||
1092 | /* If we have target-described registers, then we can safely | |
1093 | reserve a number for PPC_ORIG_R3_REGNUM and PPC_TRAP_REGNUM | |
1094 | (whether they are described or not). */ | |
1095 | gdb_assert (gdbarch_num_regs (gdbarch) <= PPC_ORIG_R3_REGNUM); | |
1096 | set_gdbarch_num_regs (gdbarch, PPC_TRAP_REGNUM + 1); | |
1097 | ||
1098 | /* If they are present, then assign them to the reserved number. */ | |
1099 | feature = tdesc_find_feature (info.target_desc, | |
1100 | "org.gnu.gdb.power.linux"); | |
1101 | if (feature != NULL) | |
1102 | { | |
1103 | tdesc_numbered_register (feature, tdesc_data, | |
1104 | PPC_ORIG_R3_REGNUM, "orig_r3"); | |
1105 | tdesc_numbered_register (feature, tdesc_data, | |
1106 | PPC_TRAP_REGNUM, "trap"); | |
1107 | } | |
1108 | } | |
7b112f9c JT |
1109 | } |
1110 | ||
1111 | void | |
1112 | _initialize_ppc_linux_tdep (void) | |
1113 | { | |
0a0a4ac3 AC |
1114 | /* Register for all sub-familes of the POWER/PowerPC: 32-bit and |
1115 | 64-bit PowerPC, and the older rs6k. */ | |
1116 | gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc, GDB_OSABI_LINUX, | |
1117 | ppc_linux_init_abi); | |
1118 | gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc64, GDB_OSABI_LINUX, | |
1119 | ppc_linux_init_abi); | |
1120 | gdbarch_register_osabi (bfd_arch_rs6000, bfd_mach_rs6k, GDB_OSABI_LINUX, | |
1121 | ppc_linux_init_abi); | |
7284e1be UW |
1122 | |
1123 | /* Initialize the Linux target descriptions. */ | |
1124 | initialize_tdesc_powerpc_32l (); | |
1125 | initialize_tdesc_powerpc_altivec32l (); | |
1126 | initialize_tdesc_powerpc_64l (); | |
1127 | initialize_tdesc_powerpc_altivec64l (); | |
1128 | initialize_tdesc_powerpc_e500l (); | |
7b112f9c | 1129 | } |