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c877c8e6 | 1 | /* Target-dependent code for GDB, the GNU debugger. |
4e052eda | 2 | |
ca557f44 | 3 | Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1995, 1996, |
4be87837 | 4 | 1997, 2000, 2001, 2002, 2003 Free Software Foundation, Inc. |
c877c8e6 KB |
5 | |
6 | This file is part of GDB. | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
20 | Foundation, Inc., 59 Temple Place - Suite 330, | |
21 | Boston, MA 02111-1307, USA. */ | |
22 | ||
23 | #include "defs.h" | |
24 | #include "frame.h" | |
25 | #include "inferior.h" | |
26 | #include "symtab.h" | |
27 | #include "target.h" | |
28 | #include "gdbcore.h" | |
29 | #include "gdbcmd.h" | |
30 | #include "symfile.h" | |
31 | #include "objfiles.h" | |
4e052eda | 32 | #include "regcache.h" |
fd0407d6 | 33 | #include "value.h" |
4be87837 | 34 | #include "osabi.h" |
f9be684a | 35 | #include "regset.h" |
6ded7999 | 36 | #include "solib-svr4.h" |
9aa1e687 | 37 | #include "ppc-tdep.h" |
61a65099 KB |
38 | #include "trad-frame.h" |
39 | #include "frame-unwind.h" | |
9aa1e687 | 40 | |
a2d356b0 DJ |
41 | /* The following instructions are used in the signal trampoline code |
42 | on GNU/Linux PPC. The kernel used to use magic syscalls 0x6666 and | |
43 | 0x7777 but now uses the sigreturn syscalls. We check for both. */ | |
44 | #define INSTR_LI_R0_0x6666 0x38006666 | |
45 | #define INSTR_LI_R0_0x7777 0x38007777 | |
46 | #define INSTR_LI_R0_NR_sigreturn 0x38000077 | |
47 | #define INSTR_LI_R0_NR_rt_sigreturn 0x380000AC | |
48 | ||
49 | #define INSTR_SC 0x44000002 | |
c877c8e6 KB |
50 | |
51 | /* Since the *-tdep.c files are platform independent (i.e, they may be | |
52 | used to build cross platform debuggers), we can't include system | |
53 | headers. Therefore, details concerning the sigcontext structure | |
54 | must be painstakingly rerecorded. What's worse, if these details | |
55 | ever change in the header files, they'll have to be changed here | |
56 | as well. */ | |
57 | ||
58 | /* __SIGNAL_FRAMESIZE from <asm/ptrace.h> */ | |
59 | #define PPC_LINUX_SIGNAL_FRAMESIZE 64 | |
60 | ||
61 | /* From <asm/sigcontext.h>, offsetof(struct sigcontext_struct, regs) == 0x1c */ | |
62 | #define PPC_LINUX_REGS_PTR_OFFSET (PPC_LINUX_SIGNAL_FRAMESIZE + 0x1c) | |
63 | ||
64 | /* From <asm/sigcontext.h>, | |
65 | offsetof(struct sigcontext_struct, handler) == 0x14 */ | |
66 | #define PPC_LINUX_HANDLER_PTR_OFFSET (PPC_LINUX_SIGNAL_FRAMESIZE + 0x14) | |
67 | ||
68 | /* From <asm/ptrace.h>, values for PT_NIP, PT_R1, and PT_LNK */ | |
69 | #define PPC_LINUX_PT_R0 0 | |
70 | #define PPC_LINUX_PT_R1 1 | |
71 | #define PPC_LINUX_PT_R2 2 | |
72 | #define PPC_LINUX_PT_R3 3 | |
73 | #define PPC_LINUX_PT_R4 4 | |
74 | #define PPC_LINUX_PT_R5 5 | |
75 | #define PPC_LINUX_PT_R6 6 | |
76 | #define PPC_LINUX_PT_R7 7 | |
77 | #define PPC_LINUX_PT_R8 8 | |
78 | #define PPC_LINUX_PT_R9 9 | |
79 | #define PPC_LINUX_PT_R10 10 | |
80 | #define PPC_LINUX_PT_R11 11 | |
81 | #define PPC_LINUX_PT_R12 12 | |
82 | #define PPC_LINUX_PT_R13 13 | |
83 | #define PPC_LINUX_PT_R14 14 | |
84 | #define PPC_LINUX_PT_R15 15 | |
85 | #define PPC_LINUX_PT_R16 16 | |
86 | #define PPC_LINUX_PT_R17 17 | |
87 | #define PPC_LINUX_PT_R18 18 | |
88 | #define PPC_LINUX_PT_R19 19 | |
89 | #define PPC_LINUX_PT_R20 20 | |
90 | #define PPC_LINUX_PT_R21 21 | |
91 | #define PPC_LINUX_PT_R22 22 | |
92 | #define PPC_LINUX_PT_R23 23 | |
93 | #define PPC_LINUX_PT_R24 24 | |
94 | #define PPC_LINUX_PT_R25 25 | |
95 | #define PPC_LINUX_PT_R26 26 | |
96 | #define PPC_LINUX_PT_R27 27 | |
97 | #define PPC_LINUX_PT_R28 28 | |
98 | #define PPC_LINUX_PT_R29 29 | |
99 | #define PPC_LINUX_PT_R30 30 | |
100 | #define PPC_LINUX_PT_R31 31 | |
101 | #define PPC_LINUX_PT_NIP 32 | |
102 | #define PPC_LINUX_PT_MSR 33 | |
103 | #define PPC_LINUX_PT_CTR 35 | |
104 | #define PPC_LINUX_PT_LNK 36 | |
105 | #define PPC_LINUX_PT_XER 37 | |
106 | #define PPC_LINUX_PT_CCR 38 | |
107 | #define PPC_LINUX_PT_MQ 39 | |
108 | #define PPC_LINUX_PT_FPR0 48 /* each FP reg occupies 2 slots in this space */ | |
109 | #define PPC_LINUX_PT_FPR31 (PPC_LINUX_PT_FPR0 + 2*31) | |
110 | #define PPC_LINUX_PT_FPSCR (PPC_LINUX_PT_FPR0 + 2*32 + 1) | |
111 | ||
9aa1e687 | 112 | static int ppc_linux_at_sigtramp_return_path (CORE_ADDR pc); |
50c9bd31 | 113 | |
c877c8e6 KB |
114 | /* Determine if pc is in a signal trampoline... |
115 | ||
ca557f44 | 116 | Ha! That's not what this does at all. wait_for_inferior in |
f561f026 AC |
117 | infrun.c calls DEPRECATED_PC_IN_SIGTRAMP in order to detect entry |
118 | into a signal trampoline just after delivery of a signal. But on | |
d7bd68ca AC |
119 | GNU/Linux, signal trampolines are used for the return path only. |
120 | The kernel sets things up so that the signal handler is called | |
121 | directly. | |
c877c8e6 KB |
122 | |
123 | If we use in_sigtramp2() in place of in_sigtramp() (see below) | |
124 | we'll (often) end up with stop_pc in the trampoline and prev_pc in | |
125 | the (now exited) handler. The code there will cause a temporary | |
126 | breakpoint to be set on prev_pc which is not very likely to get hit | |
127 | again. | |
128 | ||
129 | If this is confusing, think of it this way... the code in | |
130 | wait_for_inferior() needs to be able to detect entry into a signal | |
131 | trampoline just after a signal is delivered, not after the handler | |
132 | has been run. | |
133 | ||
134 | So, we define in_sigtramp() below to return 1 if the following is | |
135 | true: | |
136 | ||
137 | 1) The previous frame is a real signal trampoline. | |
138 | ||
139 | - and - | |
140 | ||
141 | 2) pc is at the first or second instruction of the corresponding | |
142 | handler. | |
143 | ||
144 | Why the second instruction? It seems that wait_for_inferior() | |
145 | never sees the first instruction when single stepping. When a | |
146 | signal is delivered while stepping, the next instruction that | |
147 | would've been stepped over isn't, instead a signal is delivered and | |
148 | the first instruction of the handler is stepped over instead. That | |
149 | puts us on the second instruction. (I added the test for the | |
150 | first instruction long after the fact, just in case the observed | |
151 | behavior is ever fixed.) | |
152 | ||
f561f026 AC |
153 | DEPRECATED_PC_IN_SIGTRAMP is called from blockframe.c as well in |
154 | order to set the frame's type (if a SIGTRAMP_FRAME). Because of | |
155 | our strange definition of in_sigtramp below, we can't rely on the | |
156 | frame's type getting set correctly from within blockframe.c. This | |
157 | is why we take pains to set it in init_extra_frame_info(). | |
5a203e44 AC |
158 | |
159 | NOTE: cagney/2002-11-10: I suspect the real problem here is that | |
160 | the get_prev_frame() only initializes the frame's type after the | |
161 | call to INIT_FRAME_INFO. get_prev_frame() should be fixed, this | |
162 | code shouldn't be working its way around a bug :-(. */ | |
c877c8e6 KB |
163 | |
164 | int | |
165 | ppc_linux_in_sigtramp (CORE_ADDR pc, char *func_name) | |
166 | { | |
167 | CORE_ADDR lr; | |
168 | CORE_ADDR sp; | |
169 | CORE_ADDR tramp_sp; | |
170 | char buf[4]; | |
171 | CORE_ADDR handler; | |
172 | ||
2188cbdd | 173 | lr = read_register (gdbarch_tdep (current_gdbarch)->ppc_lr_regnum); |
c877c8e6 KB |
174 | if (!ppc_linux_at_sigtramp_return_path (lr)) |
175 | return 0; | |
176 | ||
177 | sp = read_register (SP_REGNUM); | |
178 | ||
179 | if (target_read_memory (sp, buf, sizeof (buf)) != 0) | |
180 | return 0; | |
181 | ||
182 | tramp_sp = extract_unsigned_integer (buf, 4); | |
183 | ||
184 | if (target_read_memory (tramp_sp + PPC_LINUX_HANDLER_PTR_OFFSET, buf, | |
185 | sizeof (buf)) != 0) | |
186 | return 0; | |
187 | ||
188 | handler = extract_unsigned_integer (buf, 4); | |
189 | ||
190 | return (pc == handler || pc == handler + 4); | |
191 | } | |
192 | ||
39efb398 | 193 | static int |
a2d356b0 DJ |
194 | insn_is_sigreturn (unsigned long pcinsn) |
195 | { | |
196 | switch(pcinsn) | |
197 | { | |
198 | case INSTR_LI_R0_0x6666: | |
199 | case INSTR_LI_R0_0x7777: | |
200 | case INSTR_LI_R0_NR_sigreturn: | |
201 | case INSTR_LI_R0_NR_rt_sigreturn: | |
202 | return 1; | |
203 | default: | |
204 | return 0; | |
205 | } | |
206 | } | |
207 | ||
c877c8e6 KB |
208 | /* |
209 | * The signal handler trampoline is on the stack and consists of exactly | |
210 | * two instructions. The easiest and most accurate way of determining | |
211 | * whether the pc is in one of these trampolines is by inspecting the | |
212 | * instructions. It'd be faster though if we could find a way to do this | |
213 | * via some simple address comparisons. | |
214 | */ | |
9aa1e687 | 215 | static int |
c877c8e6 KB |
216 | ppc_linux_at_sigtramp_return_path (CORE_ADDR pc) |
217 | { | |
218 | char buf[12]; | |
219 | unsigned long pcinsn; | |
220 | if (target_read_memory (pc - 4, buf, sizeof (buf)) != 0) | |
221 | return 0; | |
222 | ||
223 | /* extract the instruction at the pc */ | |
224 | pcinsn = extract_unsigned_integer (buf + 4, 4); | |
225 | ||
226 | return ( | |
a2d356b0 | 227 | (insn_is_sigreturn (pcinsn) |
c877c8e6 KB |
228 | && extract_unsigned_integer (buf + 8, 4) == INSTR_SC) |
229 | || | |
230 | (pcinsn == INSTR_SC | |
a2d356b0 | 231 | && insn_is_sigreturn (extract_unsigned_integer (buf, 4)))); |
c877c8e6 KB |
232 | } |
233 | ||
6974274f | 234 | static CORE_ADDR |
c877c8e6 KB |
235 | ppc_linux_skip_trampoline_code (CORE_ADDR pc) |
236 | { | |
237 | char buf[4]; | |
238 | struct obj_section *sect; | |
239 | struct objfile *objfile; | |
240 | unsigned long insn; | |
241 | CORE_ADDR plt_start = 0; | |
242 | CORE_ADDR symtab = 0; | |
243 | CORE_ADDR strtab = 0; | |
244 | int num_slots = -1; | |
245 | int reloc_index = -1; | |
246 | CORE_ADDR plt_table; | |
247 | CORE_ADDR reloc; | |
248 | CORE_ADDR sym; | |
249 | long symidx; | |
250 | char symname[1024]; | |
251 | struct minimal_symbol *msymbol; | |
252 | ||
253 | /* Find the section pc is in; return if not in .plt */ | |
254 | sect = find_pc_section (pc); | |
255 | if (!sect || strcmp (sect->the_bfd_section->name, ".plt") != 0) | |
256 | return 0; | |
257 | ||
258 | objfile = sect->objfile; | |
259 | ||
260 | /* Pick up the instruction at pc. It had better be of the | |
261 | form | |
262 | li r11, IDX | |
263 | ||
264 | where IDX is an index into the plt_table. */ | |
265 | ||
266 | if (target_read_memory (pc, buf, 4) != 0) | |
267 | return 0; | |
268 | insn = extract_unsigned_integer (buf, 4); | |
269 | ||
270 | if ((insn & 0xffff0000) != 0x39600000 /* li r11, VAL */ ) | |
271 | return 0; | |
272 | ||
273 | reloc_index = (insn << 16) >> 16; | |
274 | ||
275 | /* Find the objfile that pc is in and obtain the information | |
276 | necessary for finding the symbol name. */ | |
277 | for (sect = objfile->sections; sect < objfile->sections_end; ++sect) | |
278 | { | |
279 | const char *secname = sect->the_bfd_section->name; | |
280 | if (strcmp (secname, ".plt") == 0) | |
281 | plt_start = sect->addr; | |
282 | else if (strcmp (secname, ".rela.plt") == 0) | |
283 | num_slots = ((int) sect->endaddr - (int) sect->addr) / 12; | |
284 | else if (strcmp (secname, ".dynsym") == 0) | |
285 | symtab = sect->addr; | |
286 | else if (strcmp (secname, ".dynstr") == 0) | |
287 | strtab = sect->addr; | |
288 | } | |
289 | ||
290 | /* Make sure we have all the information we need. */ | |
291 | if (plt_start == 0 || num_slots == -1 || symtab == 0 || strtab == 0) | |
292 | return 0; | |
293 | ||
294 | /* Compute the value of the plt table */ | |
295 | plt_table = plt_start + 72 + 8 * num_slots; | |
296 | ||
297 | /* Get address of the relocation entry (Elf32_Rela) */ | |
298 | if (target_read_memory (plt_table + reloc_index, buf, 4) != 0) | |
299 | return 0; | |
7c0b4a20 | 300 | reloc = extract_unsigned_integer (buf, 4); |
c877c8e6 KB |
301 | |
302 | sect = find_pc_section (reloc); | |
303 | if (!sect) | |
304 | return 0; | |
305 | ||
306 | if (strcmp (sect->the_bfd_section->name, ".text") == 0) | |
307 | return reloc; | |
308 | ||
309 | /* Now get the r_info field which is the relocation type and symbol | |
310 | index. */ | |
311 | if (target_read_memory (reloc + 4, buf, 4) != 0) | |
312 | return 0; | |
313 | symidx = extract_unsigned_integer (buf, 4); | |
314 | ||
315 | /* Shift out the relocation type leaving just the symbol index */ | |
316 | /* symidx = ELF32_R_SYM(symidx); */ | |
317 | symidx = symidx >> 8; | |
318 | ||
319 | /* compute the address of the symbol */ | |
320 | sym = symtab + symidx * 4; | |
321 | ||
322 | /* Fetch the string table index */ | |
323 | if (target_read_memory (sym, buf, 4) != 0) | |
324 | return 0; | |
325 | symidx = extract_unsigned_integer (buf, 4); | |
326 | ||
327 | /* Fetch the string; we don't know how long it is. Is it possible | |
328 | that the following will fail because we're trying to fetch too | |
329 | much? */ | |
330 | if (target_read_memory (strtab + symidx, symname, sizeof (symname)) != 0) | |
331 | return 0; | |
332 | ||
333 | /* This might not work right if we have multiple symbols with the | |
334 | same name; the only way to really get it right is to perform | |
335 | the same sort of lookup as the dynamic linker. */ | |
5520a790 | 336 | msymbol = lookup_minimal_symbol_text (symname, NULL); |
c877c8e6 KB |
337 | if (!msymbol) |
338 | return 0; | |
339 | ||
340 | return SYMBOL_VALUE_ADDRESS (msymbol); | |
341 | } | |
342 | ||
122a33de KB |
343 | /* ppc_linux_memory_remove_breakpoints attempts to remove a breakpoint |
344 | in much the same fashion as memory_remove_breakpoint in mem-break.c, | |
345 | but is careful not to write back the previous contents if the code | |
346 | in question has changed in between inserting the breakpoint and | |
347 | removing it. | |
348 | ||
349 | Here is the problem that we're trying to solve... | |
350 | ||
351 | Once upon a time, before introducing this function to remove | |
352 | breakpoints from the inferior, setting a breakpoint on a shared | |
353 | library function prior to running the program would not work | |
354 | properly. In order to understand the problem, it is first | |
355 | necessary to understand a little bit about dynamic linking on | |
356 | this platform. | |
357 | ||
358 | A call to a shared library function is accomplished via a bl | |
359 | (branch-and-link) instruction whose branch target is an entry | |
360 | in the procedure linkage table (PLT). The PLT in the object | |
361 | file is uninitialized. To gdb, prior to running the program, the | |
362 | entries in the PLT are all zeros. | |
363 | ||
364 | Once the program starts running, the shared libraries are loaded | |
365 | and the procedure linkage table is initialized, but the entries in | |
366 | the table are not (necessarily) resolved. Once a function is | |
367 | actually called, the code in the PLT is hit and the function is | |
368 | resolved. In order to better illustrate this, an example is in | |
369 | order; the following example is from the gdb testsuite. | |
370 | ||
371 | We start the program shmain. | |
372 | ||
373 | [kev@arroyo testsuite]$ ../gdb gdb.base/shmain | |
374 | [...] | |
375 | ||
376 | We place two breakpoints, one on shr1 and the other on main. | |
377 | ||
378 | (gdb) b shr1 | |
379 | Breakpoint 1 at 0x100409d4 | |
380 | (gdb) b main | |
381 | Breakpoint 2 at 0x100006a0: file gdb.base/shmain.c, line 44. | |
382 | ||
383 | Examine the instruction (and the immediatly following instruction) | |
384 | upon which the breakpoint was placed. Note that the PLT entry | |
385 | for shr1 contains zeros. | |
386 | ||
387 | (gdb) x/2i 0x100409d4 | |
388 | 0x100409d4 <shr1>: .long 0x0 | |
389 | 0x100409d8 <shr1+4>: .long 0x0 | |
390 | ||
391 | Now run 'til main. | |
392 | ||
393 | (gdb) r | |
394 | Starting program: gdb.base/shmain | |
395 | Breakpoint 1 at 0xffaf790: file gdb.base/shr1.c, line 19. | |
396 | ||
397 | Breakpoint 2, main () | |
398 | at gdb.base/shmain.c:44 | |
399 | 44 g = 1; | |
400 | ||
401 | Examine the PLT again. Note that the loading of the shared | |
402 | library has initialized the PLT to code which loads a constant | |
403 | (which I think is an index into the GOT) into r11 and then | |
404 | branchs a short distance to the code which actually does the | |
405 | resolving. | |
406 | ||
407 | (gdb) x/2i 0x100409d4 | |
408 | 0x100409d4 <shr1>: li r11,4 | |
409 | 0x100409d8 <shr1+4>: b 0x10040984 <sg+4> | |
410 | (gdb) c | |
411 | Continuing. | |
412 | ||
413 | Breakpoint 1, shr1 (x=1) | |
414 | at gdb.base/shr1.c:19 | |
415 | 19 l = 1; | |
416 | ||
417 | Now we've hit the breakpoint at shr1. (The breakpoint was | |
418 | reset from the PLT entry to the actual shr1 function after the | |
419 | shared library was loaded.) Note that the PLT entry has been | |
420 | resolved to contain a branch that takes us directly to shr1. | |
421 | (The real one, not the PLT entry.) | |
422 | ||
423 | (gdb) x/2i 0x100409d4 | |
424 | 0x100409d4 <shr1>: b 0xffaf76c <shr1> | |
425 | 0x100409d8 <shr1+4>: b 0x10040984 <sg+4> | |
426 | ||
427 | The thing to note here is that the PLT entry for shr1 has been | |
428 | changed twice. | |
429 | ||
430 | Now the problem should be obvious. GDB places a breakpoint (a | |
431 | trap instruction) on the zero value of the PLT entry for shr1. | |
432 | Later on, after the shared library had been loaded and the PLT | |
433 | initialized, GDB gets a signal indicating this fact and attempts | |
434 | (as it always does when it stops) to remove all the breakpoints. | |
435 | ||
436 | The breakpoint removal was causing the former contents (a zero | |
437 | word) to be written back to the now initialized PLT entry thus | |
438 | destroying a portion of the initialization that had occurred only a | |
439 | short time ago. When execution continued, the zero word would be | |
440 | executed as an instruction an an illegal instruction trap was | |
441 | generated instead. (0 is not a legal instruction.) | |
442 | ||
443 | The fix for this problem was fairly straightforward. The function | |
444 | memory_remove_breakpoint from mem-break.c was copied to this file, | |
445 | modified slightly, and renamed to ppc_linux_memory_remove_breakpoint. | |
446 | In tm-linux.h, MEMORY_REMOVE_BREAKPOINT is defined to call this new | |
447 | function. | |
448 | ||
449 | The differences between ppc_linux_memory_remove_breakpoint () and | |
450 | memory_remove_breakpoint () are minor. All that the former does | |
451 | that the latter does not is check to make sure that the breakpoint | |
452 | location actually contains a breakpoint (trap instruction) prior | |
453 | to attempting to write back the old contents. If it does contain | |
454 | a trap instruction, we allow the old contents to be written back. | |
455 | Otherwise, we silently do nothing. | |
456 | ||
457 | The big question is whether memory_remove_breakpoint () should be | |
458 | changed to have the same functionality. The downside is that more | |
459 | traffic is generated for remote targets since we'll have an extra | |
460 | fetch of a memory word each time a breakpoint is removed. | |
461 | ||
462 | For the time being, we'll leave this self-modifying-code-friendly | |
463 | version in ppc-linux-tdep.c, but it ought to be migrated somewhere | |
464 | else in the event that some other platform has similar needs with | |
465 | regard to removing breakpoints in some potentially self modifying | |
466 | code. */ | |
482ca3f5 KB |
467 | int |
468 | ppc_linux_memory_remove_breakpoint (CORE_ADDR addr, char *contents_cache) | |
469 | { | |
f4f9705a | 470 | const unsigned char *bp; |
482ca3f5 KB |
471 | int val; |
472 | int bplen; | |
473 | char old_contents[BREAKPOINT_MAX]; | |
474 | ||
475 | /* Determine appropriate breakpoint contents and size for this address. */ | |
476 | bp = BREAKPOINT_FROM_PC (&addr, &bplen); | |
477 | if (bp == NULL) | |
478 | error ("Software breakpoints not implemented for this target."); | |
479 | ||
480 | val = target_read_memory (addr, old_contents, bplen); | |
481 | ||
482 | /* If our breakpoint is no longer at the address, this means that the | |
483 | program modified the code on us, so it is wrong to put back the | |
484 | old value */ | |
485 | if (val == 0 && memcmp (bp, old_contents, bplen) == 0) | |
486 | val = target_write_memory (addr, contents_cache, bplen); | |
487 | ||
488 | return val; | |
489 | } | |
6ded7999 | 490 | |
b9ff3018 AC |
491 | /* For historic reasons, PPC 32 GNU/Linux follows PowerOpen rather |
492 | than the 32 bit SYSV R4 ABI structure return convention - all | |
493 | structures, no matter their size, are put in memory. Vectors, | |
494 | which were added later, do get returned in a register though. */ | |
495 | ||
05580c65 AC |
496 | static enum return_value_convention |
497 | ppc_linux_return_value (struct gdbarch *gdbarch, struct type *valtype, | |
475b6ddd AC |
498 | struct regcache *regcache, void *readbuf, |
499 | const void *writebuf) | |
b9ff3018 | 500 | { |
05580c65 AC |
501 | if ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT |
502 | || TYPE_CODE (valtype) == TYPE_CODE_UNION) | |
503 | && !((TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 8) | |
504 | && TYPE_VECTOR (valtype))) | |
505 | return RETURN_VALUE_STRUCT_CONVENTION; | |
506 | else | |
475b6ddd AC |
507 | return ppc_sysv_abi_return_value (gdbarch, valtype, regcache, readbuf, |
508 | writebuf); | |
b9ff3018 AC |
509 | } |
510 | ||
6ded7999 | 511 | /* Fetch (and possibly build) an appropriate link_map_offsets |
ca557f44 | 512 | structure for GNU/Linux PPC targets using the struct offsets |
6ded7999 KB |
513 | defined in link.h (but without actual reference to that file). |
514 | ||
ca557f44 AC |
515 | This makes it possible to access GNU/Linux PPC shared libraries |
516 | from a GDB that was not built on an GNU/Linux PPC host (for cross | |
517 | debugging). */ | |
6ded7999 KB |
518 | |
519 | struct link_map_offsets * | |
520 | ppc_linux_svr4_fetch_link_map_offsets (void) | |
521 | { | |
522 | static struct link_map_offsets lmo; | |
523 | static struct link_map_offsets *lmp = NULL; | |
524 | ||
525 | if (lmp == NULL) | |
526 | { | |
527 | lmp = &lmo; | |
528 | ||
529 | lmo.r_debug_size = 8; /* The actual size is 20 bytes, but | |
530 | this is all we need. */ | |
531 | lmo.r_map_offset = 4; | |
532 | lmo.r_map_size = 4; | |
533 | ||
534 | lmo.link_map_size = 20; /* The actual size is 560 bytes, but | |
535 | this is all we need. */ | |
536 | lmo.l_addr_offset = 0; | |
537 | lmo.l_addr_size = 4; | |
538 | ||
539 | lmo.l_name_offset = 4; | |
540 | lmo.l_name_size = 4; | |
541 | ||
542 | lmo.l_next_offset = 12; | |
543 | lmo.l_next_size = 4; | |
544 | ||
545 | lmo.l_prev_offset = 16; | |
546 | lmo.l_prev_size = 4; | |
547 | } | |
548 | ||
549 | return lmp; | |
550 | } | |
7b112f9c | 551 | |
f470a70a JB |
552 | |
553 | /* Macros for matching instructions. Note that, since all the | |
554 | operands are masked off before they're or-ed into the instruction, | |
555 | you can use -1 to make masks. */ | |
556 | ||
557 | #define insn_d(opcd, rts, ra, d) \ | |
558 | ((((opcd) & 0x3f) << 26) \ | |
559 | | (((rts) & 0x1f) << 21) \ | |
560 | | (((ra) & 0x1f) << 16) \ | |
561 | | ((d) & 0xffff)) | |
562 | ||
563 | #define insn_ds(opcd, rts, ra, d, xo) \ | |
564 | ((((opcd) & 0x3f) << 26) \ | |
565 | | (((rts) & 0x1f) << 21) \ | |
566 | | (((ra) & 0x1f) << 16) \ | |
567 | | ((d) & 0xfffc) \ | |
568 | | ((xo) & 0x3)) | |
569 | ||
570 | #define insn_xfx(opcd, rts, spr, xo) \ | |
571 | ((((opcd) & 0x3f) << 26) \ | |
572 | | (((rts) & 0x1f) << 21) \ | |
573 | | (((spr) & 0x1f) << 16) \ | |
574 | | (((spr) & 0x3e0) << 6) \ | |
575 | | (((xo) & 0x3ff) << 1)) | |
576 | ||
577 | /* Read a PPC instruction from memory. PPC instructions are always | |
578 | big-endian, no matter what endianness the program is running in, so | |
579 | we can't use read_memory_integer or one of its friends here. */ | |
580 | static unsigned int | |
581 | read_insn (CORE_ADDR pc) | |
582 | { | |
583 | unsigned char buf[4]; | |
584 | ||
585 | read_memory (pc, buf, 4); | |
586 | return (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3]; | |
587 | } | |
588 | ||
589 | ||
590 | /* An instruction to match. */ | |
591 | struct insn_pattern | |
592 | { | |
593 | unsigned int mask; /* mask the insn with this... */ | |
594 | unsigned int data; /* ...and see if it matches this. */ | |
595 | int optional; /* If non-zero, this insn may be absent. */ | |
596 | }; | |
597 | ||
598 | /* Return non-zero if the instructions at PC match the series | |
599 | described in PATTERN, or zero otherwise. PATTERN is an array of | |
600 | 'struct insn_pattern' objects, terminated by an entry whose mask is | |
601 | zero. | |
602 | ||
603 | When the match is successful, fill INSN[i] with what PATTERN[i] | |
604 | matched. If PATTERN[i] is optional, and the instruction wasn't | |
605 | present, set INSN[i] to 0 (which is not a valid PPC instruction). | |
606 | INSN should have as many elements as PATTERN. Note that, if | |
607 | PATTERN contains optional instructions which aren't present in | |
608 | memory, then INSN will have holes, so INSN[i] isn't necessarily the | |
609 | i'th instruction in memory. */ | |
610 | static int | |
611 | insns_match_pattern (CORE_ADDR pc, | |
612 | struct insn_pattern *pattern, | |
613 | unsigned int *insn) | |
614 | { | |
615 | int i; | |
616 | ||
617 | for (i = 0; pattern[i].mask; i++) | |
618 | { | |
619 | insn[i] = read_insn (pc); | |
620 | if ((insn[i] & pattern[i].mask) == pattern[i].data) | |
621 | pc += 4; | |
622 | else if (pattern[i].optional) | |
623 | insn[i] = 0; | |
624 | else | |
625 | return 0; | |
626 | } | |
627 | ||
628 | return 1; | |
629 | } | |
630 | ||
631 | ||
632 | /* Return the 'd' field of the d-form instruction INSN, properly | |
633 | sign-extended. */ | |
634 | static CORE_ADDR | |
635 | insn_d_field (unsigned int insn) | |
636 | { | |
637 | return ((((CORE_ADDR) insn & 0xffff) ^ 0x8000) - 0x8000); | |
638 | } | |
639 | ||
640 | ||
641 | /* Return the 'ds' field of the ds-form instruction INSN, with the two | |
642 | zero bits concatenated at the right, and properly | |
643 | sign-extended. */ | |
644 | static CORE_ADDR | |
645 | insn_ds_field (unsigned int insn) | |
646 | { | |
647 | return ((((CORE_ADDR) insn & 0xfffc) ^ 0x8000) - 0x8000); | |
648 | } | |
649 | ||
650 | ||
e538d2d7 | 651 | /* If DESC is the address of a 64-bit PowerPC GNU/Linux function |
d64558a5 JB |
652 | descriptor, return the descriptor's entry point. */ |
653 | static CORE_ADDR | |
654 | ppc64_desc_entry_point (CORE_ADDR desc) | |
655 | { | |
656 | /* The first word of the descriptor is the entry point. */ | |
657 | return (CORE_ADDR) read_memory_unsigned_integer (desc, 8); | |
658 | } | |
659 | ||
660 | ||
f470a70a JB |
661 | /* Pattern for the standard linkage function. These are built by |
662 | build_plt_stub in elf64-ppc.c, whose GLINK argument is always | |
663 | zero. */ | |
664 | static struct insn_pattern ppc64_standard_linkage[] = | |
665 | { | |
666 | /* addis r12, r2, <any> */ | |
667 | { insn_d (-1, -1, -1, 0), insn_d (15, 12, 2, 0), 0 }, | |
668 | ||
669 | /* std r2, 40(r1) */ | |
670 | { -1, insn_ds (62, 2, 1, 40, 0), 0 }, | |
671 | ||
672 | /* ld r11, <any>(r12) */ | |
673 | { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 0 }, | |
674 | ||
675 | /* addis r12, r12, 1 <optional> */ | |
676 | { insn_d (-1, -1, -1, -1), insn_d (15, 12, 2, 1), 1 }, | |
677 | ||
678 | /* ld r2, <any>(r12) */ | |
679 | { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 12, 0, 0), 0 }, | |
680 | ||
681 | /* addis r12, r12, 1 <optional> */ | |
682 | { insn_d (-1, -1, -1, -1), insn_d (15, 12, 2, 1), 1 }, | |
683 | ||
684 | /* mtctr r11 */ | |
685 | { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467), | |
686 | 0 }, | |
687 | ||
688 | /* ld r11, <any>(r12) */ | |
689 | { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 0 }, | |
690 | ||
691 | /* bctr */ | |
692 | { -1, 0x4e800420, 0 }, | |
693 | ||
694 | { 0, 0, 0 } | |
695 | }; | |
696 | #define PPC64_STANDARD_LINKAGE_LEN \ | |
697 | (sizeof (ppc64_standard_linkage) / sizeof (ppc64_standard_linkage[0])) | |
698 | ||
699 | ||
1a38736e | 700 | /* Recognize a 64-bit PowerPC GNU/Linux linkage function --- what GDB |
f470a70a JB |
701 | calls a "solib trampoline". */ |
702 | static int | |
703 | ppc64_in_solib_call_trampoline (CORE_ADDR pc, char *name) | |
704 | { | |
1a38736e | 705 | /* Detecting solib call trampolines on PPC64 GNU/Linux is a pain. |
f470a70a JB |
706 | |
707 | It's not specifically solib call trampolines that are the issue. | |
708 | Any call from one function to another function that uses a | |
709 | different TOC requires a trampoline, to save the caller's TOC | |
710 | pointer and then load the callee's TOC. An executable or shared | |
711 | library may have more than one TOC, so even intra-object calls | |
712 | may require a trampoline. Since executable and shared libraries | |
713 | will all have their own distinct TOCs, every inter-object call is | |
714 | also an inter-TOC call, and requires a trampoline --- so "solib | |
715 | call trampolines" are just a special case. | |
716 | ||
1a38736e | 717 | The 64-bit PowerPC GNU/Linux ABI calls these call trampolines |
f470a70a JB |
718 | "linkage functions". Since they need to be near the functions |
719 | that call them, they all appear in .text, not in any special | |
720 | section. The .plt section just contains an array of function | |
721 | descriptors, from which the linkage functions load the callee's | |
722 | entry point, TOC value, and environment pointer. So | |
723 | in_plt_section is useless. The linkage functions don't have any | |
724 | special linker symbols to name them, either. | |
725 | ||
726 | The only way I can see to recognize them is to actually look at | |
727 | their code. They're generated by ppc_build_one_stub and some | |
728 | other functions in bfd/elf64-ppc.c, so that should show us all | |
729 | the instruction sequences we need to recognize. */ | |
730 | unsigned int insn[PPC64_STANDARD_LINKAGE_LEN]; | |
731 | ||
732 | return insns_match_pattern (pc, ppc64_standard_linkage, insn); | |
733 | } | |
734 | ||
735 | ||
736 | /* When the dynamic linker is doing lazy symbol resolution, the first | |
737 | call to a function in another object will go like this: | |
738 | ||
739 | - The user's function calls the linkage function: | |
740 | ||
741 | 100007c4: 4b ff fc d5 bl 10000498 | |
742 | 100007c8: e8 41 00 28 ld r2,40(r1) | |
743 | ||
744 | - The linkage function loads the entry point (and other stuff) from | |
745 | the function descriptor in the PLT, and jumps to it: | |
746 | ||
747 | 10000498: 3d 82 00 00 addis r12,r2,0 | |
748 | 1000049c: f8 41 00 28 std r2,40(r1) | |
749 | 100004a0: e9 6c 80 98 ld r11,-32616(r12) | |
750 | 100004a4: e8 4c 80 a0 ld r2,-32608(r12) | |
751 | 100004a8: 7d 69 03 a6 mtctr r11 | |
752 | 100004ac: e9 6c 80 a8 ld r11,-32600(r12) | |
753 | 100004b0: 4e 80 04 20 bctr | |
754 | ||
755 | - But since this is the first time that PLT entry has been used, it | |
756 | sends control to its glink entry. That loads the number of the | |
757 | PLT entry and jumps to the common glink0 code: | |
758 | ||
759 | 10000c98: 38 00 00 00 li r0,0 | |
760 | 10000c9c: 4b ff ff dc b 10000c78 | |
761 | ||
762 | - The common glink0 code then transfers control to the dynamic | |
763 | linker's fixup code: | |
764 | ||
765 | 10000c78: e8 41 00 28 ld r2,40(r1) | |
766 | 10000c7c: 3d 82 00 00 addis r12,r2,0 | |
767 | 10000c80: e9 6c 80 80 ld r11,-32640(r12) | |
768 | 10000c84: e8 4c 80 88 ld r2,-32632(r12) | |
769 | 10000c88: 7d 69 03 a6 mtctr r11 | |
770 | 10000c8c: e9 6c 80 90 ld r11,-32624(r12) | |
771 | 10000c90: 4e 80 04 20 bctr | |
772 | ||
773 | Eventually, this code will figure out how to skip all of this, | |
774 | including the dynamic linker. At the moment, we just get through | |
775 | the linkage function. */ | |
776 | ||
777 | /* If the current thread is about to execute a series of instructions | |
778 | at PC matching the ppc64_standard_linkage pattern, and INSN is the result | |
779 | from that pattern match, return the code address to which the | |
780 | standard linkage function will send them. (This doesn't deal with | |
781 | dynamic linker lazy symbol resolution stubs.) */ | |
782 | static CORE_ADDR | |
783 | ppc64_standard_linkage_target (CORE_ADDR pc, unsigned int *insn) | |
784 | { | |
785 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); | |
786 | ||
787 | /* The address of the function descriptor this linkage function | |
788 | references. */ | |
789 | CORE_ADDR desc | |
790 | = ((CORE_ADDR) read_register (tdep->ppc_gp0_regnum + 2) | |
791 | + (insn_d_field (insn[0]) << 16) | |
792 | + insn_ds_field (insn[2])); | |
793 | ||
794 | /* The first word of the descriptor is the entry point. Return that. */ | |
d64558a5 | 795 | return ppc64_desc_entry_point (desc); |
f470a70a JB |
796 | } |
797 | ||
798 | ||
799 | /* Given that we've begun executing a call trampoline at PC, return | |
800 | the entry point of the function the trampoline will go to. */ | |
801 | static CORE_ADDR | |
802 | ppc64_skip_trampoline_code (CORE_ADDR pc) | |
803 | { | |
804 | unsigned int ppc64_standard_linkage_insn[PPC64_STANDARD_LINKAGE_LEN]; | |
805 | ||
806 | if (insns_match_pattern (pc, ppc64_standard_linkage, | |
807 | ppc64_standard_linkage_insn)) | |
808 | return ppc64_standard_linkage_target (pc, ppc64_standard_linkage_insn); | |
809 | else | |
810 | return 0; | |
811 | } | |
812 | ||
813 | ||
e2d0e7eb AC |
814 | /* Support for CONVERT_FROM_FUNC_PTR_ADDR (ARCH, ADDR, TARG) on PPC64 |
815 | GNU/Linux. | |
02631ec0 JB |
816 | |
817 | Usually a function pointer's representation is simply the address | |
e538d2d7 JB |
818 | of the function. On GNU/Linux on the 64-bit PowerPC however, a |
819 | function pointer is represented by a pointer to a TOC entry. This | |
820 | TOC entry contains three words, the first word is the address of | |
821 | the function, the second word is the TOC pointer (r2), and the | |
822 | third word is the static chain value. Throughout GDB it is | |
823 | currently assumed that a function pointer contains the address of | |
824 | the function, which is not easy to fix. In addition, the | |
825 | conversion of a function address to a function pointer would | |
826 | require allocation of a TOC entry in the inferior's memory space, | |
827 | with all its drawbacks. To be able to call C++ virtual methods in | |
828 | the inferior (which are called via function pointers), | |
829 | find_function_addr uses this function to get the function address | |
830 | from a function pointer. */ | |
02631ec0 | 831 | |
9b540880 AC |
832 | /* If ADDR points at what is clearly a function descriptor, transform |
833 | it into the address of the corresponding function. Be | |
834 | conservative, otherwize GDB will do the transformation on any | |
835 | random addresses such as occures when there is no symbol table. */ | |
02631ec0 JB |
836 | |
837 | static CORE_ADDR | |
e2d0e7eb AC |
838 | ppc64_linux_convert_from_func_ptr_addr (struct gdbarch *gdbarch, |
839 | CORE_ADDR addr, | |
840 | struct target_ops *targ) | |
02631ec0 | 841 | { |
b6591e8b | 842 | struct section_table *s = target_section_by_addr (targ, addr); |
02631ec0 | 843 | |
9b540880 AC |
844 | /* Check if ADDR points to a function descriptor. */ |
845 | if (s && strcmp (s->the_bfd_section->name, ".opd") == 0) | |
b6591e8b | 846 | return get_target_memory_unsigned (targ, addr, 8); |
9b540880 AC |
847 | |
848 | return addr; | |
02631ec0 JB |
849 | } |
850 | ||
f9be684a AC |
851 | static void |
852 | right_supply_register (struct regcache *regcache, int wordsize, int regnum, | |
853 | const bfd_byte *buf) | |
854 | { | |
855 | regcache_raw_supply (regcache, regnum, | |
856 | (buf + wordsize | |
857 | - register_size (current_gdbarch, regnum))); | |
858 | } | |
859 | ||
860 | /* Extract the register values found in the WORDSIZED ABI GREGSET, | |
861 | storing their values in REGCACHE. Note that some are left-aligned, | |
862 | while others are right aligned. */ | |
863 | ||
2fda4977 | 864 | void |
f9be684a AC |
865 | ppc_linux_supply_gregset (struct regcache *regcache, |
866 | int regnum, const void *gregs, size_t size, | |
867 | int wordsize) | |
2fda4977 DJ |
868 | { |
869 | int regi; | |
f9be684a AC |
870 | struct gdbarch *regcache_arch = get_regcache_arch (regcache); |
871 | struct gdbarch_tdep *regcache_tdep = gdbarch_tdep (regcache_arch); | |
872 | const bfd_byte *buf = gregs; | |
2fda4977 DJ |
873 | |
874 | for (regi = 0; regi < 32; regi++) | |
f9be684a AC |
875 | right_supply_register (regcache, wordsize, regi, buf + wordsize * regi); |
876 | ||
877 | right_supply_register (regcache, wordsize, gdbarch_pc_regnum (regcache_arch), | |
878 | buf + wordsize * PPC_LINUX_PT_NIP); | |
879 | right_supply_register (regcache, wordsize, regcache_tdep->ppc_lr_regnum, | |
880 | buf + wordsize * PPC_LINUX_PT_LNK); | |
881 | regcache_raw_supply (regcache, regcache_tdep->ppc_cr_regnum, | |
882 | buf + wordsize * PPC_LINUX_PT_CCR); | |
883 | regcache_raw_supply (regcache, regcache_tdep->ppc_xer_regnum, | |
884 | buf + wordsize * PPC_LINUX_PT_XER); | |
885 | regcache_raw_supply (regcache, regcache_tdep->ppc_ctr_regnum, | |
886 | buf + wordsize * PPC_LINUX_PT_CTR); | |
887 | if (regcache_tdep->ppc_mq_regnum != -1) | |
888 | right_supply_register (regcache, wordsize, regcache_tdep->ppc_mq_regnum, | |
889 | buf + wordsize * PPC_LINUX_PT_MQ); | |
890 | right_supply_register (regcache, wordsize, regcache_tdep->ppc_ps_regnum, | |
891 | buf + wordsize * PPC_LINUX_PT_MSR); | |
892 | } | |
893 | ||
894 | static void | |
895 | ppc32_linux_supply_gregset (const struct regset *regset, | |
896 | struct regcache *regcache, | |
897 | int regnum, const void *gregs, size_t size) | |
898 | { | |
899 | ppc_linux_supply_gregset (regcache, regnum, gregs, size, 4); | |
2fda4977 DJ |
900 | } |
901 | ||
f9be684a AC |
902 | static struct regset ppc32_linux_gregset = { |
903 | NULL, ppc32_linux_supply_gregset | |
904 | }; | |
905 | ||
61a65099 KB |
906 | struct ppc_linux_sigtramp_cache |
907 | { | |
908 | CORE_ADDR base; | |
909 | struct trad_frame_saved_reg *saved_regs; | |
910 | }; | |
911 | ||
912 | static struct ppc_linux_sigtramp_cache * | |
913 | ppc_linux_sigtramp_cache (struct frame_info *next_frame, void **this_cache) | |
914 | { | |
915 | CORE_ADDR regs; | |
916 | CORE_ADDR gpregs; | |
917 | CORE_ADDR fpregs; | |
918 | int i; | |
919 | struct ppc_linux_sigtramp_cache *cache; | |
920 | struct gdbarch *gdbarch = get_frame_arch (next_frame); | |
921 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
922 | ||
923 | if ((*this_cache) != NULL) | |
924 | return (*this_cache); | |
925 | cache = FRAME_OBSTACK_ZALLOC (struct ppc_linux_sigtramp_cache); | |
926 | (*this_cache) = cache; | |
927 | cache->saved_regs = trad_frame_alloc_saved_regs (next_frame); | |
928 | ||
929 | cache->base = frame_unwind_register_unsigned (next_frame, SP_REGNUM); | |
930 | ||
931 | /* Find the register pointer, which gives the address of the | |
932 | register buffers. */ | |
933 | if (tdep->wordsize == 4) | |
934 | regs = (cache->base | |
935 | + 0xd0 /* Offset to ucontext_t. */ | |
936 | + 0x30 /* Offset to .reg. */); | |
937 | else | |
938 | regs = (cache->base | |
939 | + 0x80 /* Offset to ucontext_t. */ | |
940 | + 0xe0 /* Offset to .reg. */); | |
941 | /* And the corresponding register buffers. */ | |
942 | gpregs = read_memory_unsigned_integer (regs, tdep->wordsize); | |
943 | fpregs = gpregs + 48 * tdep->wordsize; | |
944 | ||
945 | /* General purpose. */ | |
946 | for (i = 0; i < 32; i++) | |
947 | { | |
948 | int regnum = i + tdep->ppc_gp0_regnum; | |
949 | cache->saved_regs[regnum].addr = gpregs + i * tdep->wordsize; | |
950 | } | |
951 | cache->saved_regs[PC_REGNUM].addr = gpregs + 32 * tdep->wordsize; | |
952 | cache->saved_regs[tdep->ppc_ctr_regnum].addr = gpregs + 35 * tdep->wordsize; | |
953 | cache->saved_regs[tdep->ppc_lr_regnum].addr = gpregs + 36 * tdep->wordsize; | |
954 | cache->saved_regs[tdep->ppc_xer_regnum].addr = gpregs + 37 * tdep->wordsize; | |
955 | cache->saved_regs[tdep->ppc_cr_regnum].addr = gpregs + 38 * tdep->wordsize; | |
956 | ||
957 | /* Floating point registers. */ | |
958 | for (i = 0; i < 32; i++) | |
959 | { | |
960 | int regnum = i + FP0_REGNUM; | |
961 | cache->saved_regs[regnum].addr = fpregs + i * tdep->wordsize; | |
962 | } | |
963 | cache->saved_regs[tdep->ppc_fpscr_regnum].addr = fpregs + 32 * tdep->wordsize; | |
964 | ||
965 | return cache; | |
966 | } | |
967 | ||
968 | static void | |
969 | ppc_linux_sigtramp_this_id (struct frame_info *next_frame, void **this_cache, | |
970 | struct frame_id *this_id) | |
971 | { | |
972 | struct ppc_linux_sigtramp_cache *info | |
973 | = ppc_linux_sigtramp_cache (next_frame, this_cache); | |
974 | (*this_id) = frame_id_build (info->base, frame_pc_unwind (next_frame)); | |
975 | } | |
976 | ||
977 | static void | |
978 | ppc_linux_sigtramp_prev_register (struct frame_info *next_frame, | |
979 | void **this_cache, | |
980 | int regnum, int *optimizedp, | |
981 | enum lval_type *lvalp, CORE_ADDR *addrp, | |
982 | int *realnump, void *valuep) | |
983 | { | |
984 | struct ppc_linux_sigtramp_cache *info | |
985 | = ppc_linux_sigtramp_cache (next_frame, this_cache); | |
986 | trad_frame_prev_register (next_frame, info->saved_regs, regnum, | |
987 | optimizedp, lvalp, addrp, realnump, valuep); | |
988 | } | |
989 | ||
990 | static const struct frame_unwind ppc_linux_sigtramp_unwind = | |
991 | { | |
992 | SIGTRAMP_FRAME, | |
993 | ppc_linux_sigtramp_this_id, | |
994 | ppc_linux_sigtramp_prev_register | |
995 | }; | |
996 | ||
997 | static const struct frame_unwind * | |
998 | ppc_linux_sigtramp_sniffer (struct frame_info *next_frame) | |
999 | { | |
1000 | struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (next_frame)); | |
1001 | if (frame_pc_unwind (next_frame) | |
1002 | > frame_unwind_register_unsigned (next_frame, SP_REGNUM)) | |
1003 | /* Assume anything that is vaguely on the stack is a signal | |
1004 | trampoline. */ | |
1005 | return &ppc_linux_sigtramp_unwind; | |
1006 | else | |
1007 | return NULL; | |
1008 | } | |
1009 | ||
f9be684a AC |
1010 | static void |
1011 | ppc64_linux_supply_gregset (const struct regset *regset, | |
1012 | struct regcache * regcache, | |
1013 | int regnum, const void *gregs, size_t size) | |
1014 | { | |
1015 | ppc_linux_supply_gregset (regcache, regnum, gregs, size, 8); | |
1016 | } | |
1017 | ||
1018 | static struct regset ppc64_linux_gregset = { | |
1019 | NULL, ppc64_linux_supply_gregset | |
1020 | }; | |
1021 | ||
2fda4977 | 1022 | void |
f9be684a AC |
1023 | ppc_linux_supply_fpregset (const struct regset *regset, |
1024 | struct regcache * regcache, | |
1025 | int regnum, const void *fpset, size_t size) | |
2fda4977 DJ |
1026 | { |
1027 | int regi; | |
f9be684a AC |
1028 | struct gdbarch *regcache_arch = get_regcache_arch (regcache); |
1029 | struct gdbarch_tdep *regcache_tdep = gdbarch_tdep (regcache_arch); | |
1030 | const bfd_byte *buf = fpset; | |
2fda4977 DJ |
1031 | |
1032 | for (regi = 0; regi < 32; regi++) | |
f9be684a | 1033 | regcache_raw_supply (regcache, FP0_REGNUM + regi, buf + 8 * regi); |
2fda4977 DJ |
1034 | |
1035 | /* The FPSCR is stored in the low order word of the last doubleword in the | |
1036 | fpregset. */ | |
f9be684a AC |
1037 | regcache_raw_supply (regcache, regcache_tdep->ppc_fpscr_regnum, |
1038 | buf + 8 * 32 + 4); | |
2fda4977 DJ |
1039 | } |
1040 | ||
f9be684a | 1041 | static struct regset ppc_linux_fpregset = { NULL, ppc_linux_supply_fpregset }; |
2fda4977 | 1042 | |
f9be684a AC |
1043 | static const struct regset * |
1044 | ppc_linux_regset_from_core_section (struct gdbarch *core_arch, | |
1045 | const char *sect_name, size_t sect_size) | |
2fda4977 | 1046 | { |
f9be684a AC |
1047 | struct gdbarch_tdep *tdep = gdbarch_tdep (core_arch); |
1048 | if (strcmp (sect_name, ".reg") == 0) | |
2fda4977 | 1049 | { |
f9be684a AC |
1050 | if (tdep->wordsize == 4) |
1051 | return &ppc32_linux_gregset; | |
2fda4977 | 1052 | else |
f9be684a | 1053 | return &ppc64_linux_gregset; |
2fda4977 | 1054 | } |
f9be684a AC |
1055 | if (strcmp (sect_name, ".reg2") == 0) |
1056 | return &ppc_linux_fpregset; | |
1057 | return NULL; | |
2fda4977 DJ |
1058 | } |
1059 | ||
7b112f9c JT |
1060 | static void |
1061 | ppc_linux_init_abi (struct gdbarch_info info, | |
1062 | struct gdbarch *gdbarch) | |
1063 | { | |
1064 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
1065 | ||
7b112f9c JT |
1066 | if (tdep->wordsize == 4) |
1067 | { | |
81a07a45 JB |
1068 | /* NOTE: jimb/2004-03-26: The System V ABI PowerPC Processor |
1069 | Supplement says that long doubles are sixteen bytes long. | |
1070 | However, as one of the known warts of its ABI, PPC GNU/Linux | |
1071 | uses eight-byte long doubles. GCC only recently got 128-bit | |
1072 | long double support on PPC, so it may be changing soon. The | |
1073 | Linux Standards Base says that programs that use 'long | |
1074 | double' on PPC GNU/Linux are non-conformant. */ | |
1075 | set_gdbarch_long_double_bit (gdbarch, 8 * TARGET_CHAR_BIT); | |
1076 | ||
b9ff3018 AC |
1077 | /* Until November 2001, gcc did not comply with the 32 bit SysV |
1078 | R4 ABI requirement that structures less than or equal to 8 | |
1079 | bytes should be returned in registers. Instead GCC was using | |
1080 | the the AIX/PowerOpen ABI - everything returned in memory | |
1081 | (well ignoring vectors that is). When this was corrected, it | |
1082 | wasn't fixed for GNU/Linux native platform. Use the | |
1083 | PowerOpen struct convention. */ | |
05580c65 | 1084 | set_gdbarch_return_value (gdbarch, ppc_linux_return_value); |
b9ff3018 | 1085 | |
7b112f9c JT |
1086 | set_gdbarch_memory_remove_breakpoint (gdbarch, |
1087 | ppc_linux_memory_remove_breakpoint); | |
61a65099 | 1088 | |
f470a70a JB |
1089 | /* Shared library handling. */ |
1090 | set_gdbarch_in_solib_call_trampoline (gdbarch, in_plt_section); | |
1091 | set_gdbarch_skip_trampoline_code (gdbarch, | |
1092 | ppc_linux_skip_trampoline_code); | |
7b112f9c JT |
1093 | set_solib_svr4_fetch_link_map_offsets |
1094 | (gdbarch, ppc_linux_svr4_fetch_link_map_offsets); | |
1095 | } | |
f470a70a JB |
1096 | |
1097 | if (tdep->wordsize == 8) | |
1098 | { | |
e538d2d7 | 1099 | /* Handle PPC64 GNU/Linux function pointers (which are really |
02631ec0 JB |
1100 | function descriptors). */ |
1101 | set_gdbarch_convert_from_func_ptr_addr | |
1102 | (gdbarch, ppc64_linux_convert_from_func_ptr_addr); | |
1103 | ||
f470a70a JB |
1104 | set_gdbarch_in_solib_call_trampoline |
1105 | (gdbarch, ppc64_in_solib_call_trampoline); | |
1106 | set_gdbarch_skip_trampoline_code (gdbarch, ppc64_skip_trampoline_code); | |
9ea97f2a AC |
1107 | |
1108 | /* PPC64 malloc's entry-point is called ".malloc". */ | |
1109 | set_gdbarch_name_of_malloc (gdbarch, ".malloc"); | |
f470a70a | 1110 | } |
f9be684a | 1111 | set_gdbarch_regset_from_core_section (gdbarch, ppc_linux_regset_from_core_section); |
61a65099 | 1112 | frame_unwind_append_sniffer (gdbarch, ppc_linux_sigtramp_sniffer); |
7b112f9c JT |
1113 | } |
1114 | ||
1115 | void | |
1116 | _initialize_ppc_linux_tdep (void) | |
1117 | { | |
0a0a4ac3 AC |
1118 | /* Register for all sub-familes of the POWER/PowerPC: 32-bit and |
1119 | 64-bit PowerPC, and the older rs6k. */ | |
1120 | gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc, GDB_OSABI_LINUX, | |
1121 | ppc_linux_init_abi); | |
1122 | gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc64, GDB_OSABI_LINUX, | |
1123 | ppc_linux_init_abi); | |
1124 | gdbarch_register_osabi (bfd_arch_rs6000, bfd_mach_rs6k, GDB_OSABI_LINUX, | |
1125 | ppc_linux_init_abi); | |
7b112f9c | 1126 | } |