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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, |
fb318ff7 | 4 | 1997, 2000, 2001, 2002, 2003, 2004, 2005 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" | |
a8f60bfc | 40 | #include "tramp-frame.h" |
9aa1e687 | 41 | |
a2d356b0 DJ |
42 | /* The following instructions are used in the signal trampoline code |
43 | on GNU/Linux PPC. The kernel used to use magic syscalls 0x6666 and | |
44 | 0x7777 but now uses the sigreturn syscalls. We check for both. */ | |
45 | #define INSTR_LI_R0_0x6666 0x38006666 | |
46 | #define INSTR_LI_R0_0x7777 0x38007777 | |
47 | #define INSTR_LI_R0_NR_sigreturn 0x38000077 | |
48 | #define INSTR_LI_R0_NR_rt_sigreturn 0x380000AC | |
49 | ||
50 | #define INSTR_SC 0x44000002 | |
c877c8e6 KB |
51 | |
52 | /* Since the *-tdep.c files are platform independent (i.e, they may be | |
53 | used to build cross platform debuggers), we can't include system | |
54 | headers. Therefore, details concerning the sigcontext structure | |
55 | must be painstakingly rerecorded. What's worse, if these details | |
56 | ever change in the header files, they'll have to be changed here | |
57 | as well. */ | |
58 | ||
59 | /* __SIGNAL_FRAMESIZE from <asm/ptrace.h> */ | |
60 | #define PPC_LINUX_SIGNAL_FRAMESIZE 64 | |
61 | ||
62 | /* From <asm/sigcontext.h>, offsetof(struct sigcontext_struct, regs) == 0x1c */ | |
63 | #define PPC_LINUX_REGS_PTR_OFFSET (PPC_LINUX_SIGNAL_FRAMESIZE + 0x1c) | |
64 | ||
65 | /* From <asm/sigcontext.h>, | |
66 | offsetof(struct sigcontext_struct, handler) == 0x14 */ | |
67 | #define PPC_LINUX_HANDLER_PTR_OFFSET (PPC_LINUX_SIGNAL_FRAMESIZE + 0x14) | |
68 | ||
69 | /* From <asm/ptrace.h>, values for PT_NIP, PT_R1, and PT_LNK */ | |
70 | #define PPC_LINUX_PT_R0 0 | |
71 | #define PPC_LINUX_PT_R1 1 | |
72 | #define PPC_LINUX_PT_R2 2 | |
73 | #define PPC_LINUX_PT_R3 3 | |
74 | #define PPC_LINUX_PT_R4 4 | |
75 | #define PPC_LINUX_PT_R5 5 | |
76 | #define PPC_LINUX_PT_R6 6 | |
77 | #define PPC_LINUX_PT_R7 7 | |
78 | #define PPC_LINUX_PT_R8 8 | |
79 | #define PPC_LINUX_PT_R9 9 | |
80 | #define PPC_LINUX_PT_R10 10 | |
81 | #define PPC_LINUX_PT_R11 11 | |
82 | #define PPC_LINUX_PT_R12 12 | |
83 | #define PPC_LINUX_PT_R13 13 | |
84 | #define PPC_LINUX_PT_R14 14 | |
85 | #define PPC_LINUX_PT_R15 15 | |
86 | #define PPC_LINUX_PT_R16 16 | |
87 | #define PPC_LINUX_PT_R17 17 | |
88 | #define PPC_LINUX_PT_R18 18 | |
89 | #define PPC_LINUX_PT_R19 19 | |
90 | #define PPC_LINUX_PT_R20 20 | |
91 | #define PPC_LINUX_PT_R21 21 | |
92 | #define PPC_LINUX_PT_R22 22 | |
93 | #define PPC_LINUX_PT_R23 23 | |
94 | #define PPC_LINUX_PT_R24 24 | |
95 | #define PPC_LINUX_PT_R25 25 | |
96 | #define PPC_LINUX_PT_R26 26 | |
97 | #define PPC_LINUX_PT_R27 27 | |
98 | #define PPC_LINUX_PT_R28 28 | |
99 | #define PPC_LINUX_PT_R29 29 | |
100 | #define PPC_LINUX_PT_R30 30 | |
101 | #define PPC_LINUX_PT_R31 31 | |
102 | #define PPC_LINUX_PT_NIP 32 | |
103 | #define PPC_LINUX_PT_MSR 33 | |
104 | #define PPC_LINUX_PT_CTR 35 | |
105 | #define PPC_LINUX_PT_LNK 36 | |
106 | #define PPC_LINUX_PT_XER 37 | |
107 | #define PPC_LINUX_PT_CCR 38 | |
108 | #define PPC_LINUX_PT_MQ 39 | |
109 | #define PPC_LINUX_PT_FPR0 48 /* each FP reg occupies 2 slots in this space */ | |
110 | #define PPC_LINUX_PT_FPR31 (PPC_LINUX_PT_FPR0 + 2*31) | |
111 | #define PPC_LINUX_PT_FPSCR (PPC_LINUX_PT_FPR0 + 2*32 + 1) | |
112 | ||
9aa1e687 | 113 | static int ppc_linux_at_sigtramp_return_path (CORE_ADDR pc); |
50c9bd31 | 114 | |
c877c8e6 KB |
115 | /* Determine if pc is in a signal trampoline... |
116 | ||
ca557f44 | 117 | Ha! That's not what this does at all. wait_for_inferior in |
fcf70625 AC |
118 | infrun.c calls get_frame_type() in order to detect entry into a |
119 | signal trampoline just after delivery of a signal. But on | |
d7bd68ca AC |
120 | GNU/Linux, signal trampolines are used for the return path only. |
121 | The kernel sets things up so that the signal handler is called | |
122 | directly. | |
c877c8e6 KB |
123 | |
124 | If we use in_sigtramp2() in place of in_sigtramp() (see below) | |
125 | we'll (often) end up with stop_pc in the trampoline and prev_pc in | |
126 | the (now exited) handler. The code there will cause a temporary | |
127 | breakpoint to be set on prev_pc which is not very likely to get hit | |
128 | again. | |
129 | ||
130 | If this is confusing, think of it this way... the code in | |
131 | wait_for_inferior() needs to be able to detect entry into a signal | |
132 | trampoline just after a signal is delivered, not after the handler | |
133 | has been run. | |
134 | ||
135 | So, we define in_sigtramp() below to return 1 if the following is | |
136 | true: | |
137 | ||
138 | 1) The previous frame is a real signal trampoline. | |
139 | ||
140 | - and - | |
141 | ||
142 | 2) pc is at the first or second instruction of the corresponding | |
143 | handler. | |
144 | ||
145 | Why the second instruction? It seems that wait_for_inferior() | |
146 | never sees the first instruction when single stepping. When a | |
147 | signal is delivered while stepping, the next instruction that | |
148 | would've been stepped over isn't, instead a signal is delivered and | |
149 | the first instruction of the handler is stepped over instead. That | |
fcf70625 AC |
150 | puts us on the second instruction. (I added the test for the first |
151 | instruction long after the fact, just in case the observed behavior | |
152 | is ever fixed.) */ | |
c877c8e6 KB |
153 | |
154 | int | |
155 | ppc_linux_in_sigtramp (CORE_ADDR pc, char *func_name) | |
156 | { | |
157 | CORE_ADDR lr; | |
158 | CORE_ADDR sp; | |
159 | CORE_ADDR tramp_sp; | |
50fd1280 | 160 | gdb_byte buf[4]; |
c877c8e6 KB |
161 | CORE_ADDR handler; |
162 | ||
2188cbdd | 163 | lr = read_register (gdbarch_tdep (current_gdbarch)->ppc_lr_regnum); |
c877c8e6 KB |
164 | if (!ppc_linux_at_sigtramp_return_path (lr)) |
165 | return 0; | |
166 | ||
167 | sp = read_register (SP_REGNUM); | |
168 | ||
169 | if (target_read_memory (sp, buf, sizeof (buf)) != 0) | |
170 | return 0; | |
171 | ||
172 | tramp_sp = extract_unsigned_integer (buf, 4); | |
173 | ||
174 | if (target_read_memory (tramp_sp + PPC_LINUX_HANDLER_PTR_OFFSET, buf, | |
175 | sizeof (buf)) != 0) | |
176 | return 0; | |
177 | ||
178 | handler = extract_unsigned_integer (buf, 4); | |
179 | ||
180 | return (pc == handler || pc == handler + 4); | |
181 | } | |
182 | ||
39efb398 | 183 | static int |
a2d356b0 DJ |
184 | insn_is_sigreturn (unsigned long pcinsn) |
185 | { | |
186 | switch(pcinsn) | |
187 | { | |
188 | case INSTR_LI_R0_0x6666: | |
189 | case INSTR_LI_R0_0x7777: | |
190 | case INSTR_LI_R0_NR_sigreturn: | |
191 | case INSTR_LI_R0_NR_rt_sigreturn: | |
192 | return 1; | |
193 | default: | |
194 | return 0; | |
195 | } | |
196 | } | |
197 | ||
c877c8e6 KB |
198 | /* |
199 | * The signal handler trampoline is on the stack and consists of exactly | |
200 | * two instructions. The easiest and most accurate way of determining | |
201 | * whether the pc is in one of these trampolines is by inspecting the | |
202 | * instructions. It'd be faster though if we could find a way to do this | |
203 | * via some simple address comparisons. | |
204 | */ | |
9aa1e687 | 205 | static int |
c877c8e6 KB |
206 | ppc_linux_at_sigtramp_return_path (CORE_ADDR pc) |
207 | { | |
50fd1280 | 208 | gdb_byte buf[12]; |
c877c8e6 KB |
209 | unsigned long pcinsn; |
210 | if (target_read_memory (pc - 4, buf, sizeof (buf)) != 0) | |
211 | return 0; | |
212 | ||
213 | /* extract the instruction at the pc */ | |
214 | pcinsn = extract_unsigned_integer (buf + 4, 4); | |
215 | ||
216 | return ( | |
a2d356b0 | 217 | (insn_is_sigreturn (pcinsn) |
c877c8e6 KB |
218 | && extract_unsigned_integer (buf + 8, 4) == INSTR_SC) |
219 | || | |
220 | (pcinsn == INSTR_SC | |
a2d356b0 | 221 | && insn_is_sigreturn (extract_unsigned_integer (buf, 4)))); |
c877c8e6 KB |
222 | } |
223 | ||
6974274f | 224 | static CORE_ADDR |
c877c8e6 KB |
225 | ppc_linux_skip_trampoline_code (CORE_ADDR pc) |
226 | { | |
50fd1280 | 227 | gdb_byte buf[4]; |
c877c8e6 KB |
228 | struct obj_section *sect; |
229 | struct objfile *objfile; | |
230 | unsigned long insn; | |
231 | CORE_ADDR plt_start = 0; | |
232 | CORE_ADDR symtab = 0; | |
233 | CORE_ADDR strtab = 0; | |
234 | int num_slots = -1; | |
235 | int reloc_index = -1; | |
236 | CORE_ADDR plt_table; | |
237 | CORE_ADDR reloc; | |
238 | CORE_ADDR sym; | |
239 | long symidx; | |
240 | char symname[1024]; | |
241 | struct minimal_symbol *msymbol; | |
242 | ||
243 | /* Find the section pc is in; return if not in .plt */ | |
244 | sect = find_pc_section (pc); | |
245 | if (!sect || strcmp (sect->the_bfd_section->name, ".plt") != 0) | |
246 | return 0; | |
247 | ||
248 | objfile = sect->objfile; | |
249 | ||
250 | /* Pick up the instruction at pc. It had better be of the | |
251 | form | |
252 | li r11, IDX | |
253 | ||
254 | where IDX is an index into the plt_table. */ | |
255 | ||
256 | if (target_read_memory (pc, buf, 4) != 0) | |
257 | return 0; | |
258 | insn = extract_unsigned_integer (buf, 4); | |
259 | ||
260 | if ((insn & 0xffff0000) != 0x39600000 /* li r11, VAL */ ) | |
261 | return 0; | |
262 | ||
263 | reloc_index = (insn << 16) >> 16; | |
264 | ||
265 | /* Find the objfile that pc is in and obtain the information | |
266 | necessary for finding the symbol name. */ | |
267 | for (sect = objfile->sections; sect < objfile->sections_end; ++sect) | |
268 | { | |
269 | const char *secname = sect->the_bfd_section->name; | |
270 | if (strcmp (secname, ".plt") == 0) | |
271 | plt_start = sect->addr; | |
272 | else if (strcmp (secname, ".rela.plt") == 0) | |
273 | num_slots = ((int) sect->endaddr - (int) sect->addr) / 12; | |
274 | else if (strcmp (secname, ".dynsym") == 0) | |
275 | symtab = sect->addr; | |
276 | else if (strcmp (secname, ".dynstr") == 0) | |
277 | strtab = sect->addr; | |
278 | } | |
279 | ||
280 | /* Make sure we have all the information we need. */ | |
281 | if (plt_start == 0 || num_slots == -1 || symtab == 0 || strtab == 0) | |
282 | return 0; | |
283 | ||
284 | /* Compute the value of the plt table */ | |
285 | plt_table = plt_start + 72 + 8 * num_slots; | |
286 | ||
287 | /* Get address of the relocation entry (Elf32_Rela) */ | |
288 | if (target_read_memory (plt_table + reloc_index, buf, 4) != 0) | |
289 | return 0; | |
7c0b4a20 | 290 | reloc = extract_unsigned_integer (buf, 4); |
c877c8e6 KB |
291 | |
292 | sect = find_pc_section (reloc); | |
293 | if (!sect) | |
294 | return 0; | |
295 | ||
296 | if (strcmp (sect->the_bfd_section->name, ".text") == 0) | |
297 | return reloc; | |
298 | ||
299 | /* Now get the r_info field which is the relocation type and symbol | |
300 | index. */ | |
301 | if (target_read_memory (reloc + 4, buf, 4) != 0) | |
302 | return 0; | |
303 | symidx = extract_unsigned_integer (buf, 4); | |
304 | ||
305 | /* Shift out the relocation type leaving just the symbol index */ | |
306 | /* symidx = ELF32_R_SYM(symidx); */ | |
307 | symidx = symidx >> 8; | |
308 | ||
309 | /* compute the address of the symbol */ | |
310 | sym = symtab + symidx * 4; | |
311 | ||
312 | /* Fetch the string table index */ | |
313 | if (target_read_memory (sym, buf, 4) != 0) | |
314 | return 0; | |
315 | symidx = extract_unsigned_integer (buf, 4); | |
316 | ||
317 | /* Fetch the string; we don't know how long it is. Is it possible | |
318 | that the following will fail because we're trying to fetch too | |
319 | much? */ | |
50fd1280 AC |
320 | if (target_read_memory (strtab + symidx, (gdb_byte *) symname, |
321 | sizeof (symname)) != 0) | |
c877c8e6 KB |
322 | return 0; |
323 | ||
324 | /* This might not work right if we have multiple symbols with the | |
325 | same name; the only way to really get it right is to perform | |
326 | the same sort of lookup as the dynamic linker. */ | |
5520a790 | 327 | msymbol = lookup_minimal_symbol_text (symname, NULL); |
c877c8e6 KB |
328 | if (!msymbol) |
329 | return 0; | |
330 | ||
331 | return SYMBOL_VALUE_ADDRESS (msymbol); | |
332 | } | |
333 | ||
122a33de KB |
334 | /* ppc_linux_memory_remove_breakpoints attempts to remove a breakpoint |
335 | in much the same fashion as memory_remove_breakpoint in mem-break.c, | |
336 | but is careful not to write back the previous contents if the code | |
337 | in question has changed in between inserting the breakpoint and | |
338 | removing it. | |
339 | ||
340 | Here is the problem that we're trying to solve... | |
341 | ||
342 | Once upon a time, before introducing this function to remove | |
343 | breakpoints from the inferior, setting a breakpoint on a shared | |
344 | library function prior to running the program would not work | |
345 | properly. In order to understand the problem, it is first | |
346 | necessary to understand a little bit about dynamic linking on | |
347 | this platform. | |
348 | ||
349 | A call to a shared library function is accomplished via a bl | |
350 | (branch-and-link) instruction whose branch target is an entry | |
351 | in the procedure linkage table (PLT). The PLT in the object | |
352 | file is uninitialized. To gdb, prior to running the program, the | |
353 | entries in the PLT are all zeros. | |
354 | ||
355 | Once the program starts running, the shared libraries are loaded | |
356 | and the procedure linkage table is initialized, but the entries in | |
357 | the table are not (necessarily) resolved. Once a function is | |
358 | actually called, the code in the PLT is hit and the function is | |
359 | resolved. In order to better illustrate this, an example is in | |
360 | order; the following example is from the gdb testsuite. | |
361 | ||
362 | We start the program shmain. | |
363 | ||
364 | [kev@arroyo testsuite]$ ../gdb gdb.base/shmain | |
365 | [...] | |
366 | ||
367 | We place two breakpoints, one on shr1 and the other on main. | |
368 | ||
369 | (gdb) b shr1 | |
370 | Breakpoint 1 at 0x100409d4 | |
371 | (gdb) b main | |
372 | Breakpoint 2 at 0x100006a0: file gdb.base/shmain.c, line 44. | |
373 | ||
374 | Examine the instruction (and the immediatly following instruction) | |
375 | upon which the breakpoint was placed. Note that the PLT entry | |
376 | for shr1 contains zeros. | |
377 | ||
378 | (gdb) x/2i 0x100409d4 | |
379 | 0x100409d4 <shr1>: .long 0x0 | |
380 | 0x100409d8 <shr1+4>: .long 0x0 | |
381 | ||
382 | Now run 'til main. | |
383 | ||
384 | (gdb) r | |
385 | Starting program: gdb.base/shmain | |
386 | Breakpoint 1 at 0xffaf790: file gdb.base/shr1.c, line 19. | |
387 | ||
388 | Breakpoint 2, main () | |
389 | at gdb.base/shmain.c:44 | |
390 | 44 g = 1; | |
391 | ||
392 | Examine the PLT again. Note that the loading of the shared | |
393 | library has initialized the PLT to code which loads a constant | |
394 | (which I think is an index into the GOT) into r11 and then | |
395 | branchs a short distance to the code which actually does the | |
396 | resolving. | |
397 | ||
398 | (gdb) x/2i 0x100409d4 | |
399 | 0x100409d4 <shr1>: li r11,4 | |
400 | 0x100409d8 <shr1+4>: b 0x10040984 <sg+4> | |
401 | (gdb) c | |
402 | Continuing. | |
403 | ||
404 | Breakpoint 1, shr1 (x=1) | |
405 | at gdb.base/shr1.c:19 | |
406 | 19 l = 1; | |
407 | ||
408 | Now we've hit the breakpoint at shr1. (The breakpoint was | |
409 | reset from the PLT entry to the actual shr1 function after the | |
410 | shared library was loaded.) Note that the PLT entry has been | |
411 | resolved to contain a branch that takes us directly to shr1. | |
412 | (The real one, not the PLT entry.) | |
413 | ||
414 | (gdb) x/2i 0x100409d4 | |
415 | 0x100409d4 <shr1>: b 0xffaf76c <shr1> | |
416 | 0x100409d8 <shr1+4>: b 0x10040984 <sg+4> | |
417 | ||
418 | The thing to note here is that the PLT entry for shr1 has been | |
419 | changed twice. | |
420 | ||
421 | Now the problem should be obvious. GDB places a breakpoint (a | |
422 | trap instruction) on the zero value of the PLT entry for shr1. | |
423 | Later on, after the shared library had been loaded and the PLT | |
424 | initialized, GDB gets a signal indicating this fact and attempts | |
425 | (as it always does when it stops) to remove all the breakpoints. | |
426 | ||
427 | The breakpoint removal was causing the former contents (a zero | |
428 | word) to be written back to the now initialized PLT entry thus | |
429 | destroying a portion of the initialization that had occurred only a | |
430 | short time ago. When execution continued, the zero word would be | |
431 | executed as an instruction an an illegal instruction trap was | |
432 | generated instead. (0 is not a legal instruction.) | |
433 | ||
434 | The fix for this problem was fairly straightforward. The function | |
435 | memory_remove_breakpoint from mem-break.c was copied to this file, | |
436 | modified slightly, and renamed to ppc_linux_memory_remove_breakpoint. | |
437 | In tm-linux.h, MEMORY_REMOVE_BREAKPOINT is defined to call this new | |
438 | function. | |
439 | ||
440 | The differences between ppc_linux_memory_remove_breakpoint () and | |
441 | memory_remove_breakpoint () are minor. All that the former does | |
442 | that the latter does not is check to make sure that the breakpoint | |
443 | location actually contains a breakpoint (trap instruction) prior | |
444 | to attempting to write back the old contents. If it does contain | |
445 | a trap instruction, we allow the old contents to be written back. | |
446 | Otherwise, we silently do nothing. | |
447 | ||
448 | The big question is whether memory_remove_breakpoint () should be | |
449 | changed to have the same functionality. The downside is that more | |
450 | traffic is generated for remote targets since we'll have an extra | |
451 | fetch of a memory word each time a breakpoint is removed. | |
452 | ||
453 | For the time being, we'll leave this self-modifying-code-friendly | |
454 | version in ppc-linux-tdep.c, but it ought to be migrated somewhere | |
455 | else in the event that some other platform has similar needs with | |
456 | regard to removing breakpoints in some potentially self modifying | |
457 | code. */ | |
482ca3f5 | 458 | int |
50fd1280 AC |
459 | ppc_linux_memory_remove_breakpoint (CORE_ADDR addr, |
460 | gdb_byte *contents_cache) | |
482ca3f5 | 461 | { |
f4f9705a | 462 | const unsigned char *bp; |
482ca3f5 KB |
463 | int val; |
464 | int bplen; | |
50fd1280 | 465 | gdb_byte old_contents[BREAKPOINT_MAX]; |
482ca3f5 KB |
466 | |
467 | /* Determine appropriate breakpoint contents and size for this address. */ | |
468 | bp = BREAKPOINT_FROM_PC (&addr, &bplen); | |
469 | if (bp == NULL) | |
8a3fe4f8 | 470 | error (_("Software breakpoints not implemented for this target.")); |
482ca3f5 KB |
471 | |
472 | val = target_read_memory (addr, old_contents, bplen); | |
473 | ||
474 | /* If our breakpoint is no longer at the address, this means that the | |
475 | program modified the code on us, so it is wrong to put back the | |
476 | old value */ | |
477 | if (val == 0 && memcmp (bp, old_contents, bplen) == 0) | |
478 | val = target_write_memory (addr, contents_cache, bplen); | |
479 | ||
480 | return val; | |
481 | } | |
6ded7999 | 482 | |
b9ff3018 AC |
483 | /* For historic reasons, PPC 32 GNU/Linux follows PowerOpen rather |
484 | than the 32 bit SYSV R4 ABI structure return convention - all | |
485 | structures, no matter their size, are put in memory. Vectors, | |
486 | which were added later, do get returned in a register though. */ | |
487 | ||
05580c65 AC |
488 | static enum return_value_convention |
489 | ppc_linux_return_value (struct gdbarch *gdbarch, struct type *valtype, | |
50fd1280 AC |
490 | struct regcache *regcache, gdb_byte *readbuf, |
491 | const gdb_byte *writebuf) | |
b9ff3018 | 492 | { |
05580c65 AC |
493 | if ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT |
494 | || TYPE_CODE (valtype) == TYPE_CODE_UNION) | |
495 | && !((TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 8) | |
496 | && TYPE_VECTOR (valtype))) | |
497 | return RETURN_VALUE_STRUCT_CONVENTION; | |
498 | else | |
475b6ddd AC |
499 | return ppc_sysv_abi_return_value (gdbarch, valtype, regcache, readbuf, |
500 | writebuf); | |
b9ff3018 AC |
501 | } |
502 | ||
6ded7999 | 503 | /* Fetch (and possibly build) an appropriate link_map_offsets |
ca557f44 | 504 | structure for GNU/Linux PPC targets using the struct offsets |
6ded7999 KB |
505 | defined in link.h (but without actual reference to that file). |
506 | ||
ca557f44 AC |
507 | This makes it possible to access GNU/Linux PPC shared libraries |
508 | from a GDB that was not built on an GNU/Linux PPC host (for cross | |
509 | debugging). */ | |
6ded7999 KB |
510 | |
511 | struct link_map_offsets * | |
512 | ppc_linux_svr4_fetch_link_map_offsets (void) | |
513 | { | |
514 | static struct link_map_offsets lmo; | |
515 | static struct link_map_offsets *lmp = NULL; | |
516 | ||
517 | if (lmp == NULL) | |
518 | { | |
519 | lmp = &lmo; | |
520 | ||
521 | lmo.r_debug_size = 8; /* The actual size is 20 bytes, but | |
522 | this is all we need. */ | |
523 | lmo.r_map_offset = 4; | |
524 | lmo.r_map_size = 4; | |
525 | ||
526 | lmo.link_map_size = 20; /* The actual size is 560 bytes, but | |
527 | this is all we need. */ | |
528 | lmo.l_addr_offset = 0; | |
529 | lmo.l_addr_size = 4; | |
530 | ||
531 | lmo.l_name_offset = 4; | |
532 | lmo.l_name_size = 4; | |
533 | ||
534 | lmo.l_next_offset = 12; | |
535 | lmo.l_next_size = 4; | |
536 | ||
537 | lmo.l_prev_offset = 16; | |
538 | lmo.l_prev_size = 4; | |
539 | } | |
540 | ||
541 | return lmp; | |
542 | } | |
7b112f9c | 543 | |
f470a70a JB |
544 | |
545 | /* Macros for matching instructions. Note that, since all the | |
546 | operands are masked off before they're or-ed into the instruction, | |
547 | you can use -1 to make masks. */ | |
548 | ||
549 | #define insn_d(opcd, rts, ra, d) \ | |
550 | ((((opcd) & 0x3f) << 26) \ | |
551 | | (((rts) & 0x1f) << 21) \ | |
552 | | (((ra) & 0x1f) << 16) \ | |
553 | | ((d) & 0xffff)) | |
554 | ||
555 | #define insn_ds(opcd, rts, ra, d, xo) \ | |
556 | ((((opcd) & 0x3f) << 26) \ | |
557 | | (((rts) & 0x1f) << 21) \ | |
558 | | (((ra) & 0x1f) << 16) \ | |
559 | | ((d) & 0xfffc) \ | |
560 | | ((xo) & 0x3)) | |
561 | ||
562 | #define insn_xfx(opcd, rts, spr, xo) \ | |
563 | ((((opcd) & 0x3f) << 26) \ | |
564 | | (((rts) & 0x1f) << 21) \ | |
565 | | (((spr) & 0x1f) << 16) \ | |
566 | | (((spr) & 0x3e0) << 6) \ | |
567 | | (((xo) & 0x3ff) << 1)) | |
568 | ||
569 | /* Read a PPC instruction from memory. PPC instructions are always | |
570 | big-endian, no matter what endianness the program is running in, so | |
571 | we can't use read_memory_integer or one of its friends here. */ | |
572 | static unsigned int | |
573 | read_insn (CORE_ADDR pc) | |
574 | { | |
575 | unsigned char buf[4]; | |
576 | ||
577 | read_memory (pc, buf, 4); | |
578 | return (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3]; | |
579 | } | |
580 | ||
581 | ||
582 | /* An instruction to match. */ | |
583 | struct insn_pattern | |
584 | { | |
585 | unsigned int mask; /* mask the insn with this... */ | |
586 | unsigned int data; /* ...and see if it matches this. */ | |
587 | int optional; /* If non-zero, this insn may be absent. */ | |
588 | }; | |
589 | ||
590 | /* Return non-zero if the instructions at PC match the series | |
591 | described in PATTERN, or zero otherwise. PATTERN is an array of | |
592 | 'struct insn_pattern' objects, terminated by an entry whose mask is | |
593 | zero. | |
594 | ||
595 | When the match is successful, fill INSN[i] with what PATTERN[i] | |
596 | matched. If PATTERN[i] is optional, and the instruction wasn't | |
597 | present, set INSN[i] to 0 (which is not a valid PPC instruction). | |
598 | INSN should have as many elements as PATTERN. Note that, if | |
599 | PATTERN contains optional instructions which aren't present in | |
600 | memory, then INSN will have holes, so INSN[i] isn't necessarily the | |
601 | i'th instruction in memory. */ | |
602 | static int | |
603 | insns_match_pattern (CORE_ADDR pc, | |
604 | struct insn_pattern *pattern, | |
605 | unsigned int *insn) | |
606 | { | |
607 | int i; | |
608 | ||
609 | for (i = 0; pattern[i].mask; i++) | |
610 | { | |
611 | insn[i] = read_insn (pc); | |
612 | if ((insn[i] & pattern[i].mask) == pattern[i].data) | |
613 | pc += 4; | |
614 | else if (pattern[i].optional) | |
615 | insn[i] = 0; | |
616 | else | |
617 | return 0; | |
618 | } | |
619 | ||
620 | return 1; | |
621 | } | |
622 | ||
623 | ||
624 | /* Return the 'd' field of the d-form instruction INSN, properly | |
625 | sign-extended. */ | |
626 | static CORE_ADDR | |
627 | insn_d_field (unsigned int insn) | |
628 | { | |
629 | return ((((CORE_ADDR) insn & 0xffff) ^ 0x8000) - 0x8000); | |
630 | } | |
631 | ||
632 | ||
633 | /* Return the 'ds' field of the ds-form instruction INSN, with the two | |
634 | zero bits concatenated at the right, and properly | |
635 | sign-extended. */ | |
636 | static CORE_ADDR | |
637 | insn_ds_field (unsigned int insn) | |
638 | { | |
639 | return ((((CORE_ADDR) insn & 0xfffc) ^ 0x8000) - 0x8000); | |
640 | } | |
641 | ||
642 | ||
e538d2d7 | 643 | /* If DESC is the address of a 64-bit PowerPC GNU/Linux function |
d64558a5 JB |
644 | descriptor, return the descriptor's entry point. */ |
645 | static CORE_ADDR | |
646 | ppc64_desc_entry_point (CORE_ADDR desc) | |
647 | { | |
648 | /* The first word of the descriptor is the entry point. */ | |
649 | return (CORE_ADDR) read_memory_unsigned_integer (desc, 8); | |
650 | } | |
651 | ||
652 | ||
f470a70a JB |
653 | /* Pattern for the standard linkage function. These are built by |
654 | build_plt_stub in elf64-ppc.c, whose GLINK argument is always | |
655 | zero. */ | |
656 | static struct insn_pattern ppc64_standard_linkage[] = | |
657 | { | |
658 | /* addis r12, r2, <any> */ | |
659 | { insn_d (-1, -1, -1, 0), insn_d (15, 12, 2, 0), 0 }, | |
660 | ||
661 | /* std r2, 40(r1) */ | |
662 | { -1, insn_ds (62, 2, 1, 40, 0), 0 }, | |
663 | ||
664 | /* ld r11, <any>(r12) */ | |
665 | { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 0 }, | |
666 | ||
667 | /* addis r12, r12, 1 <optional> */ | |
668 | { insn_d (-1, -1, -1, -1), insn_d (15, 12, 2, 1), 1 }, | |
669 | ||
670 | /* ld r2, <any>(r12) */ | |
671 | { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 12, 0, 0), 0 }, | |
672 | ||
673 | /* addis r12, r12, 1 <optional> */ | |
674 | { insn_d (-1, -1, -1, -1), insn_d (15, 12, 2, 1), 1 }, | |
675 | ||
676 | /* mtctr r11 */ | |
677 | { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467), | |
678 | 0 }, | |
679 | ||
680 | /* ld r11, <any>(r12) */ | |
681 | { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 0 }, | |
682 | ||
683 | /* bctr */ | |
684 | { -1, 0x4e800420, 0 }, | |
685 | ||
686 | { 0, 0, 0 } | |
687 | }; | |
688 | #define PPC64_STANDARD_LINKAGE_LEN \ | |
689 | (sizeof (ppc64_standard_linkage) / sizeof (ppc64_standard_linkage[0])) | |
690 | ||
f470a70a JB |
691 | /* When the dynamic linker is doing lazy symbol resolution, the first |
692 | call to a function in another object will go like this: | |
693 | ||
694 | - The user's function calls the linkage function: | |
695 | ||
696 | 100007c4: 4b ff fc d5 bl 10000498 | |
697 | 100007c8: e8 41 00 28 ld r2,40(r1) | |
698 | ||
699 | - The linkage function loads the entry point (and other stuff) from | |
700 | the function descriptor in the PLT, and jumps to it: | |
701 | ||
702 | 10000498: 3d 82 00 00 addis r12,r2,0 | |
703 | 1000049c: f8 41 00 28 std r2,40(r1) | |
704 | 100004a0: e9 6c 80 98 ld r11,-32616(r12) | |
705 | 100004a4: e8 4c 80 a0 ld r2,-32608(r12) | |
706 | 100004a8: 7d 69 03 a6 mtctr r11 | |
707 | 100004ac: e9 6c 80 a8 ld r11,-32600(r12) | |
708 | 100004b0: 4e 80 04 20 bctr | |
709 | ||
710 | - But since this is the first time that PLT entry has been used, it | |
711 | sends control to its glink entry. That loads the number of the | |
712 | PLT entry and jumps to the common glink0 code: | |
713 | ||
714 | 10000c98: 38 00 00 00 li r0,0 | |
715 | 10000c9c: 4b ff ff dc b 10000c78 | |
716 | ||
717 | - The common glink0 code then transfers control to the dynamic | |
718 | linker's fixup code: | |
719 | ||
720 | 10000c78: e8 41 00 28 ld r2,40(r1) | |
721 | 10000c7c: 3d 82 00 00 addis r12,r2,0 | |
722 | 10000c80: e9 6c 80 80 ld r11,-32640(r12) | |
723 | 10000c84: e8 4c 80 88 ld r2,-32632(r12) | |
724 | 10000c88: 7d 69 03 a6 mtctr r11 | |
725 | 10000c8c: e9 6c 80 90 ld r11,-32624(r12) | |
726 | 10000c90: 4e 80 04 20 bctr | |
727 | ||
728 | Eventually, this code will figure out how to skip all of this, | |
729 | including the dynamic linker. At the moment, we just get through | |
730 | the linkage function. */ | |
731 | ||
732 | /* If the current thread is about to execute a series of instructions | |
733 | at PC matching the ppc64_standard_linkage pattern, and INSN is the result | |
734 | from that pattern match, return the code address to which the | |
735 | standard linkage function will send them. (This doesn't deal with | |
736 | dynamic linker lazy symbol resolution stubs.) */ | |
737 | static CORE_ADDR | |
738 | ppc64_standard_linkage_target (CORE_ADDR pc, unsigned int *insn) | |
739 | { | |
740 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); | |
741 | ||
742 | /* The address of the function descriptor this linkage function | |
743 | references. */ | |
744 | CORE_ADDR desc | |
745 | = ((CORE_ADDR) read_register (tdep->ppc_gp0_regnum + 2) | |
746 | + (insn_d_field (insn[0]) << 16) | |
747 | + insn_ds_field (insn[2])); | |
748 | ||
749 | /* The first word of the descriptor is the entry point. Return that. */ | |
d64558a5 | 750 | return ppc64_desc_entry_point (desc); |
f470a70a JB |
751 | } |
752 | ||
753 | ||
754 | /* Given that we've begun executing a call trampoline at PC, return | |
755 | the entry point of the function the trampoline will go to. */ | |
756 | static CORE_ADDR | |
757 | ppc64_skip_trampoline_code (CORE_ADDR pc) | |
758 | { | |
759 | unsigned int ppc64_standard_linkage_insn[PPC64_STANDARD_LINKAGE_LEN]; | |
760 | ||
761 | if (insns_match_pattern (pc, ppc64_standard_linkage, | |
762 | ppc64_standard_linkage_insn)) | |
763 | return ppc64_standard_linkage_target (pc, ppc64_standard_linkage_insn); | |
764 | else | |
765 | return 0; | |
766 | } | |
767 | ||
768 | ||
e2d0e7eb AC |
769 | /* Support for CONVERT_FROM_FUNC_PTR_ADDR (ARCH, ADDR, TARG) on PPC64 |
770 | GNU/Linux. | |
02631ec0 JB |
771 | |
772 | Usually a function pointer's representation is simply the address | |
e538d2d7 JB |
773 | of the function. On GNU/Linux on the 64-bit PowerPC however, a |
774 | function pointer is represented by a pointer to a TOC entry. This | |
775 | TOC entry contains three words, the first word is the address of | |
776 | the function, the second word is the TOC pointer (r2), and the | |
777 | third word is the static chain value. Throughout GDB it is | |
778 | currently assumed that a function pointer contains the address of | |
779 | the function, which is not easy to fix. In addition, the | |
780 | conversion of a function address to a function pointer would | |
781 | require allocation of a TOC entry in the inferior's memory space, | |
782 | with all its drawbacks. To be able to call C++ virtual methods in | |
783 | the inferior (which are called via function pointers), | |
784 | find_function_addr uses this function to get the function address | |
785 | from a function pointer. */ | |
02631ec0 | 786 | |
9b540880 AC |
787 | /* If ADDR points at what is clearly a function descriptor, transform |
788 | it into the address of the corresponding function. Be | |
789 | conservative, otherwize GDB will do the transformation on any | |
790 | random addresses such as occures when there is no symbol table. */ | |
02631ec0 JB |
791 | |
792 | static CORE_ADDR | |
e2d0e7eb AC |
793 | ppc64_linux_convert_from_func_ptr_addr (struct gdbarch *gdbarch, |
794 | CORE_ADDR addr, | |
795 | struct target_ops *targ) | |
02631ec0 | 796 | { |
b6591e8b | 797 | struct section_table *s = target_section_by_addr (targ, addr); |
02631ec0 | 798 | |
9b540880 AC |
799 | /* Check if ADDR points to a function descriptor. */ |
800 | if (s && strcmp (s->the_bfd_section->name, ".opd") == 0) | |
b6591e8b | 801 | return get_target_memory_unsigned (targ, addr, 8); |
9b540880 AC |
802 | |
803 | return addr; | |
02631ec0 JB |
804 | } |
805 | ||
f9be684a AC |
806 | static void |
807 | right_supply_register (struct regcache *regcache, int wordsize, int regnum, | |
808 | const bfd_byte *buf) | |
809 | { | |
810 | regcache_raw_supply (regcache, regnum, | |
23a6d369 | 811 | (buf + wordsize - register_size (current_gdbarch, regnum))); |
f9be684a AC |
812 | } |
813 | ||
814 | /* Extract the register values found in the WORDSIZED ABI GREGSET, | |
815 | storing their values in REGCACHE. Note that some are left-aligned, | |
816 | while others are right aligned. */ | |
817 | ||
2fda4977 | 818 | void |
f9be684a AC |
819 | ppc_linux_supply_gregset (struct regcache *regcache, |
820 | int regnum, const void *gregs, size_t size, | |
821 | int wordsize) | |
2fda4977 DJ |
822 | { |
823 | int regi; | |
f9be684a AC |
824 | struct gdbarch *regcache_arch = get_regcache_arch (regcache); |
825 | struct gdbarch_tdep *regcache_tdep = gdbarch_tdep (regcache_arch); | |
826 | const bfd_byte *buf = gregs; | |
2fda4977 | 827 | |
063715bf | 828 | for (regi = 0; regi < ppc_num_gprs; regi++) |
cdf2c5f5 JB |
829 | right_supply_register (regcache, wordsize, |
830 | regcache_tdep->ppc_gp0_regnum + regi, | |
831 | buf + wordsize * regi); | |
f9be684a AC |
832 | |
833 | right_supply_register (regcache, wordsize, gdbarch_pc_regnum (regcache_arch), | |
834 | buf + wordsize * PPC_LINUX_PT_NIP); | |
835 | right_supply_register (regcache, wordsize, regcache_tdep->ppc_lr_regnum, | |
836 | buf + wordsize * PPC_LINUX_PT_LNK); | |
837 | regcache_raw_supply (regcache, regcache_tdep->ppc_cr_regnum, | |
838 | buf + wordsize * PPC_LINUX_PT_CCR); | |
839 | regcache_raw_supply (regcache, regcache_tdep->ppc_xer_regnum, | |
840 | buf + wordsize * PPC_LINUX_PT_XER); | |
841 | regcache_raw_supply (regcache, regcache_tdep->ppc_ctr_regnum, | |
842 | buf + wordsize * PPC_LINUX_PT_CTR); | |
843 | if (regcache_tdep->ppc_mq_regnum != -1) | |
844 | right_supply_register (regcache, wordsize, regcache_tdep->ppc_mq_regnum, | |
845 | buf + wordsize * PPC_LINUX_PT_MQ); | |
846 | right_supply_register (regcache, wordsize, regcache_tdep->ppc_ps_regnum, | |
847 | buf + wordsize * PPC_LINUX_PT_MSR); | |
848 | } | |
849 | ||
850 | static void | |
851 | ppc32_linux_supply_gregset (const struct regset *regset, | |
852 | struct regcache *regcache, | |
853 | int regnum, const void *gregs, size_t size) | |
854 | { | |
855 | ppc_linux_supply_gregset (regcache, regnum, gregs, size, 4); | |
2fda4977 DJ |
856 | } |
857 | ||
f9be684a AC |
858 | static struct regset ppc32_linux_gregset = { |
859 | NULL, ppc32_linux_supply_gregset | |
860 | }; | |
861 | ||
862 | static void | |
863 | ppc64_linux_supply_gregset (const struct regset *regset, | |
864 | struct regcache * regcache, | |
865 | int regnum, const void *gregs, size_t size) | |
866 | { | |
867 | ppc_linux_supply_gregset (regcache, regnum, gregs, size, 8); | |
868 | } | |
869 | ||
870 | static struct regset ppc64_linux_gregset = { | |
871 | NULL, ppc64_linux_supply_gregset | |
872 | }; | |
873 | ||
2fda4977 | 874 | void |
f9be684a AC |
875 | ppc_linux_supply_fpregset (const struct regset *regset, |
876 | struct regcache * regcache, | |
877 | int regnum, const void *fpset, size_t size) | |
2fda4977 DJ |
878 | { |
879 | int regi; | |
f9be684a AC |
880 | struct gdbarch *regcache_arch = get_regcache_arch (regcache); |
881 | struct gdbarch_tdep *regcache_tdep = gdbarch_tdep (regcache_arch); | |
882 | const bfd_byte *buf = fpset; | |
2fda4977 | 883 | |
383f0f5b JB |
884 | if (! ppc_floating_point_unit_p (regcache_arch)) |
885 | return; | |
886 | ||
887 | for (regi = 0; regi < ppc_num_fprs; regi++) | |
366f009f JB |
888 | regcache_raw_supply (regcache, |
889 | regcache_tdep->ppc_fp0_regnum + regi, | |
890 | buf + 8 * regi); | |
2fda4977 | 891 | |
383f0f5b JB |
892 | /* The FPSCR is stored in the low order word of the last |
893 | doubleword in the fpregset. */ | |
f9be684a | 894 | regcache_raw_supply (regcache, regcache_tdep->ppc_fpscr_regnum, |
383f0f5b | 895 | buf + 8 * 32 + 4); |
2fda4977 DJ |
896 | } |
897 | ||
f9be684a | 898 | static struct regset ppc_linux_fpregset = { NULL, ppc_linux_supply_fpregset }; |
2fda4977 | 899 | |
f9be684a AC |
900 | static const struct regset * |
901 | ppc_linux_regset_from_core_section (struct gdbarch *core_arch, | |
902 | const char *sect_name, size_t sect_size) | |
2fda4977 | 903 | { |
f9be684a AC |
904 | struct gdbarch_tdep *tdep = gdbarch_tdep (core_arch); |
905 | if (strcmp (sect_name, ".reg") == 0) | |
2fda4977 | 906 | { |
f9be684a AC |
907 | if (tdep->wordsize == 4) |
908 | return &ppc32_linux_gregset; | |
2fda4977 | 909 | else |
f9be684a | 910 | return &ppc64_linux_gregset; |
2fda4977 | 911 | } |
f9be684a AC |
912 | if (strcmp (sect_name, ".reg2") == 0) |
913 | return &ppc_linux_fpregset; | |
914 | return NULL; | |
2fda4977 DJ |
915 | } |
916 | ||
a8f60bfc AC |
917 | static void |
918 | ppc_linux_sigtramp_cache (struct frame_info *next_frame, | |
919 | struct trad_frame_cache *this_cache, | |
920 | CORE_ADDR func, LONGEST offset, | |
921 | int bias) | |
922 | { | |
923 | CORE_ADDR base; | |
924 | CORE_ADDR regs; | |
925 | CORE_ADDR gpregs; | |
926 | CORE_ADDR fpregs; | |
927 | int i; | |
928 | struct gdbarch *gdbarch = get_frame_arch (next_frame); | |
929 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
930 | ||
931 | base = frame_unwind_register_unsigned (next_frame, SP_REGNUM); | |
932 | if (bias > 0 && frame_pc_unwind (next_frame) != func) | |
933 | /* See below, some signal trampolines increment the stack as their | |
934 | first instruction, need to compensate for that. */ | |
935 | base -= bias; | |
936 | ||
937 | /* Find the address of the register buffer pointer. */ | |
938 | regs = base + offset; | |
939 | /* Use that to find the address of the corresponding register | |
940 | buffers. */ | |
941 | gpregs = read_memory_unsigned_integer (regs, tdep->wordsize); | |
942 | fpregs = gpregs + 48 * tdep->wordsize; | |
943 | ||
944 | /* General purpose. */ | |
945 | for (i = 0; i < 32; i++) | |
946 | { | |
947 | int regnum = i + tdep->ppc_gp0_regnum; | |
948 | trad_frame_set_reg_addr (this_cache, regnum, gpregs + i * tdep->wordsize); | |
949 | } | |
950 | trad_frame_set_reg_addr (this_cache, PC_REGNUM, gpregs + 32 * tdep->wordsize); | |
951 | trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, | |
952 | gpregs + 35 * tdep->wordsize); | |
953 | trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, | |
954 | gpregs + 36 * tdep->wordsize); | |
955 | trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, | |
956 | gpregs + 37 * tdep->wordsize); | |
957 | trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, | |
958 | gpregs + 38 * tdep->wordsize); | |
959 | ||
960 | /* Floating point registers. */ | |
961 | for (i = 0; i < 32; i++) | |
962 | { | |
963 | int regnum = i + FP0_REGNUM; | |
964 | trad_frame_set_reg_addr (this_cache, regnum, fpregs + i * tdep->wordsize); | |
965 | } | |
966 | trad_frame_set_reg_addr (this_cache, tdep->ppc_fpscr_regnum, | |
967 | fpregs + 32 * tdep->wordsize); | |
968 | trad_frame_set_id (this_cache, frame_id_build (base, func)); | |
969 | } | |
970 | ||
971 | static void | |
972 | ppc32_linux_sigaction_cache_init (const struct tramp_frame *self, | |
973 | struct frame_info *next_frame, | |
974 | struct trad_frame_cache *this_cache, | |
975 | CORE_ADDR func) | |
976 | { | |
977 | ppc_linux_sigtramp_cache (next_frame, this_cache, func, | |
978 | 0xd0 /* Offset to ucontext_t. */ | |
979 | + 0x30 /* Offset to .reg. */, | |
980 | 0); | |
981 | } | |
982 | ||
983 | static void | |
984 | ppc64_linux_sigaction_cache_init (const struct tramp_frame *self, | |
985 | struct frame_info *next_frame, | |
986 | struct trad_frame_cache *this_cache, | |
987 | CORE_ADDR func) | |
988 | { | |
989 | ppc_linux_sigtramp_cache (next_frame, this_cache, func, | |
990 | 0x80 /* Offset to ucontext_t. */ | |
991 | + 0xe0 /* Offset to .reg. */, | |
992 | 128); | |
993 | } | |
994 | ||
995 | static void | |
996 | ppc32_linux_sighandler_cache_init (const struct tramp_frame *self, | |
997 | struct frame_info *next_frame, | |
998 | struct trad_frame_cache *this_cache, | |
999 | CORE_ADDR func) | |
1000 | { | |
1001 | ppc_linux_sigtramp_cache (next_frame, this_cache, func, | |
1002 | 0x40 /* Offset to ucontext_t. */ | |
1003 | + 0x1c /* Offset to .reg. */, | |
1004 | 0); | |
1005 | } | |
1006 | ||
1007 | static void | |
1008 | ppc64_linux_sighandler_cache_init (const struct tramp_frame *self, | |
1009 | struct frame_info *next_frame, | |
1010 | struct trad_frame_cache *this_cache, | |
1011 | CORE_ADDR func) | |
1012 | { | |
1013 | ppc_linux_sigtramp_cache (next_frame, this_cache, func, | |
1014 | 0x80 /* Offset to struct sigcontext. */ | |
1015 | + 0x38 /* Offset to .reg. */, | |
1016 | 128); | |
1017 | } | |
1018 | ||
1019 | static struct tramp_frame ppc32_linux_sigaction_tramp_frame = { | |
1020 | SIGTRAMP_FRAME, | |
1021 | 4, | |
1022 | { | |
1023 | { 0x380000ac, -1 }, /* li r0, 172 */ | |
1024 | { 0x44000002, -1 }, /* sc */ | |
1025 | { TRAMP_SENTINEL_INSN }, | |
1026 | }, | |
1027 | ppc32_linux_sigaction_cache_init | |
1028 | }; | |
1029 | static struct tramp_frame ppc64_linux_sigaction_tramp_frame = { | |
1030 | SIGTRAMP_FRAME, | |
1031 | 4, | |
1032 | { | |
1033 | { 0x38210080, -1 }, /* addi r1,r1,128 */ | |
1034 | { 0x380000ac, -1 }, /* li r0, 172 */ | |
1035 | { 0x44000002, -1 }, /* sc */ | |
1036 | { TRAMP_SENTINEL_INSN }, | |
1037 | }, | |
1038 | ppc64_linux_sigaction_cache_init | |
1039 | }; | |
1040 | static struct tramp_frame ppc32_linux_sighandler_tramp_frame = { | |
1041 | SIGTRAMP_FRAME, | |
1042 | 4, | |
1043 | { | |
1044 | { 0x38000077, -1 }, /* li r0,119 */ | |
1045 | { 0x44000002, -1 }, /* sc */ | |
1046 | { TRAMP_SENTINEL_INSN }, | |
1047 | }, | |
1048 | ppc32_linux_sighandler_cache_init | |
1049 | }; | |
1050 | static struct tramp_frame ppc64_linux_sighandler_tramp_frame = { | |
1051 | SIGTRAMP_FRAME, | |
1052 | 4, | |
1053 | { | |
1054 | { 0x38210080, -1 }, /* addi r1,r1,128 */ | |
1055 | { 0x38000077, -1 }, /* li r0,119 */ | |
1056 | { 0x44000002, -1 }, /* sc */ | |
1057 | { TRAMP_SENTINEL_INSN }, | |
1058 | }, | |
1059 | ppc64_linux_sighandler_cache_init | |
1060 | }; | |
1061 | ||
7b112f9c JT |
1062 | static void |
1063 | ppc_linux_init_abi (struct gdbarch_info info, | |
1064 | struct gdbarch *gdbarch) | |
1065 | { | |
1066 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
1067 | ||
0598a43c AC |
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 uses | |
1071 | eight-byte long doubles. GCC only recently got 128-bit long | |
1072 | double support on PPC, so it may be changing soon. The | |
1073 | Linux[sic] Standards Base says that programs that use 'long | |
1074 | double' on PPC GNU/Linux are non-conformant. */ | |
1075 | /* NOTE: cagney/2005-01-25: True for both 32- and 64-bit. */ | |
1076 | set_gdbarch_long_double_bit (gdbarch, 8 * TARGET_CHAR_BIT); | |
1077 | ||
7b112f9c JT |
1078 | if (tdep->wordsize == 4) |
1079 | { | |
b9ff3018 AC |
1080 | /* Until November 2001, gcc did not comply with the 32 bit SysV |
1081 | R4 ABI requirement that structures less than or equal to 8 | |
1082 | bytes should be returned in registers. Instead GCC was using | |
1083 | the the AIX/PowerOpen ABI - everything returned in memory | |
1084 | (well ignoring vectors that is). When this was corrected, it | |
1085 | wasn't fixed for GNU/Linux native platform. Use the | |
1086 | PowerOpen struct convention. */ | |
05580c65 | 1087 | set_gdbarch_return_value (gdbarch, ppc_linux_return_value); |
b9ff3018 | 1088 | |
7b112f9c JT |
1089 | set_gdbarch_memory_remove_breakpoint (gdbarch, |
1090 | ppc_linux_memory_remove_breakpoint); | |
61a65099 | 1091 | |
f470a70a | 1092 | /* Shared library handling. */ |
f470a70a JB |
1093 | set_gdbarch_skip_trampoline_code (gdbarch, |
1094 | ppc_linux_skip_trampoline_code); | |
7b112f9c JT |
1095 | set_solib_svr4_fetch_link_map_offsets |
1096 | (gdbarch, ppc_linux_svr4_fetch_link_map_offsets); | |
a8f60bfc AC |
1097 | |
1098 | /* Trampolines. */ | |
1099 | tramp_frame_prepend_unwinder (gdbarch, &ppc32_linux_sigaction_tramp_frame); | |
1100 | tramp_frame_prepend_unwinder (gdbarch, &ppc32_linux_sighandler_tramp_frame); | |
7b112f9c | 1101 | } |
f470a70a JB |
1102 | |
1103 | if (tdep->wordsize == 8) | |
1104 | { | |
e538d2d7 | 1105 | /* Handle PPC64 GNU/Linux function pointers (which are really |
02631ec0 JB |
1106 | function descriptors). */ |
1107 | set_gdbarch_convert_from_func_ptr_addr | |
1108 | (gdbarch, ppc64_linux_convert_from_func_ptr_addr); | |
f470a70a | 1109 | set_gdbarch_skip_trampoline_code (gdbarch, ppc64_skip_trampoline_code); |
9ea97f2a | 1110 | |
fb318ff7 DJ |
1111 | /* Shared library handling. */ |
1112 | set_solib_svr4_fetch_link_map_offsets | |
1113 | (gdbarch, svr4_lp64_fetch_link_map_offsets); | |
1114 | ||
a8f60bfc AC |
1115 | /* Trampolines. */ |
1116 | tramp_frame_prepend_unwinder (gdbarch, &ppc64_linux_sigaction_tramp_frame); | |
1117 | tramp_frame_prepend_unwinder (gdbarch, &ppc64_linux_sighandler_tramp_frame); | |
f470a70a | 1118 | } |
f9be684a | 1119 | set_gdbarch_regset_from_core_section (gdbarch, ppc_linux_regset_from_core_section); |
b2756930 KB |
1120 | |
1121 | /* Enable TLS support. */ | |
1122 | set_gdbarch_fetch_tls_load_module_address (gdbarch, | |
1123 | svr4_fetch_objfile_link_map); | |
7b112f9c JT |
1124 | } |
1125 | ||
1126 | void | |
1127 | _initialize_ppc_linux_tdep (void) | |
1128 | { | |
0a0a4ac3 AC |
1129 | /* Register for all sub-familes of the POWER/PowerPC: 32-bit and |
1130 | 64-bit PowerPC, and the older rs6k. */ | |
1131 | gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc, GDB_OSABI_LINUX, | |
1132 | ppc_linux_init_abi); | |
1133 | gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc64, GDB_OSABI_LINUX, | |
1134 | ppc_linux_init_abi); | |
1135 | gdbarch_register_osabi (bfd_arch_rs6000, bfd_mach_rs6k, GDB_OSABI_LINUX, | |
1136 | ppc_linux_init_abi); | |
7b112f9c | 1137 | } |