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c877c8e6 | 1 | /* Target-dependent code for GDB, the GNU debugger. |
4e052eda | 2 | |
6aba47ca DJ |
3 | Copyright (C) 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997, |
4 | 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 | |
76a9d10f | 5 | Free Software Foundation, Inc. |
c877c8e6 KB |
6 | |
7 | This file is part of GDB. | |
8 | ||
9 | This program is free software; you can redistribute it and/or modify | |
10 | it under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 2 of the License, or | |
12 | (at your option) any later version. | |
13 | ||
14 | This program is distributed in the hope that it will be useful, | |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with this program; if not, write to the Free Software | |
197e01b6 EZ |
21 | Foundation, Inc., 51 Franklin Street, Fifth Floor, |
22 | Boston, MA 02110-1301, USA. */ | |
c877c8e6 KB |
23 | |
24 | #include "defs.h" | |
25 | #include "frame.h" | |
26 | #include "inferior.h" | |
27 | #include "symtab.h" | |
28 | #include "target.h" | |
29 | #include "gdbcore.h" | |
30 | #include "gdbcmd.h" | |
31 | #include "symfile.h" | |
32 | #include "objfiles.h" | |
4e052eda | 33 | #include "regcache.h" |
fd0407d6 | 34 | #include "value.h" |
4be87837 | 35 | #include "osabi.h" |
f9be684a | 36 | #include "regset.h" |
6ded7999 | 37 | #include "solib-svr4.h" |
9aa1e687 | 38 | #include "ppc-tdep.h" |
61a65099 KB |
39 | #include "trad-frame.h" |
40 | #include "frame-unwind.h" | |
a8f60bfc | 41 | #include "tramp-frame.h" |
9aa1e687 | 42 | |
a2d356b0 DJ |
43 | /* The following instructions are used in the signal trampoline code |
44 | on GNU/Linux PPC. The kernel used to use magic syscalls 0x6666 and | |
45 | 0x7777 but now uses the sigreturn syscalls. We check for both. */ | |
46 | #define INSTR_LI_R0_0x6666 0x38006666 | |
47 | #define INSTR_LI_R0_0x7777 0x38007777 | |
48 | #define INSTR_LI_R0_NR_sigreturn 0x38000077 | |
49 | #define INSTR_LI_R0_NR_rt_sigreturn 0x380000AC | |
50 | ||
51 | #define INSTR_SC 0x44000002 | |
c877c8e6 KB |
52 | |
53 | /* Since the *-tdep.c files are platform independent (i.e, they may be | |
54 | used to build cross platform debuggers), we can't include system | |
55 | headers. Therefore, details concerning the sigcontext structure | |
56 | must be painstakingly rerecorded. What's worse, if these details | |
57 | ever change in the header files, they'll have to be changed here | |
58 | as well. */ | |
59 | ||
60 | /* __SIGNAL_FRAMESIZE from <asm/ptrace.h> */ | |
61 | #define PPC_LINUX_SIGNAL_FRAMESIZE 64 | |
62 | ||
63 | /* From <asm/sigcontext.h>, offsetof(struct sigcontext_struct, regs) == 0x1c */ | |
64 | #define PPC_LINUX_REGS_PTR_OFFSET (PPC_LINUX_SIGNAL_FRAMESIZE + 0x1c) | |
65 | ||
66 | /* From <asm/sigcontext.h>, | |
67 | offsetof(struct sigcontext_struct, handler) == 0x14 */ | |
68 | #define PPC_LINUX_HANDLER_PTR_OFFSET (PPC_LINUX_SIGNAL_FRAMESIZE + 0x14) | |
69 | ||
70 | /* From <asm/ptrace.h>, values for PT_NIP, PT_R1, and PT_LNK */ | |
71 | #define PPC_LINUX_PT_R0 0 | |
72 | #define PPC_LINUX_PT_R1 1 | |
73 | #define PPC_LINUX_PT_R2 2 | |
74 | #define PPC_LINUX_PT_R3 3 | |
75 | #define PPC_LINUX_PT_R4 4 | |
76 | #define PPC_LINUX_PT_R5 5 | |
77 | #define PPC_LINUX_PT_R6 6 | |
78 | #define PPC_LINUX_PT_R7 7 | |
79 | #define PPC_LINUX_PT_R8 8 | |
80 | #define PPC_LINUX_PT_R9 9 | |
81 | #define PPC_LINUX_PT_R10 10 | |
82 | #define PPC_LINUX_PT_R11 11 | |
83 | #define PPC_LINUX_PT_R12 12 | |
84 | #define PPC_LINUX_PT_R13 13 | |
85 | #define PPC_LINUX_PT_R14 14 | |
86 | #define PPC_LINUX_PT_R15 15 | |
87 | #define PPC_LINUX_PT_R16 16 | |
88 | #define PPC_LINUX_PT_R17 17 | |
89 | #define PPC_LINUX_PT_R18 18 | |
90 | #define PPC_LINUX_PT_R19 19 | |
91 | #define PPC_LINUX_PT_R20 20 | |
92 | #define PPC_LINUX_PT_R21 21 | |
93 | #define PPC_LINUX_PT_R22 22 | |
94 | #define PPC_LINUX_PT_R23 23 | |
95 | #define PPC_LINUX_PT_R24 24 | |
96 | #define PPC_LINUX_PT_R25 25 | |
97 | #define PPC_LINUX_PT_R26 26 | |
98 | #define PPC_LINUX_PT_R27 27 | |
99 | #define PPC_LINUX_PT_R28 28 | |
100 | #define PPC_LINUX_PT_R29 29 | |
101 | #define PPC_LINUX_PT_R30 30 | |
102 | #define PPC_LINUX_PT_R31 31 | |
103 | #define PPC_LINUX_PT_NIP 32 | |
104 | #define PPC_LINUX_PT_MSR 33 | |
105 | #define PPC_LINUX_PT_CTR 35 | |
106 | #define PPC_LINUX_PT_LNK 36 | |
107 | #define PPC_LINUX_PT_XER 37 | |
108 | #define PPC_LINUX_PT_CCR 38 | |
109 | #define PPC_LINUX_PT_MQ 39 | |
110 | #define PPC_LINUX_PT_FPR0 48 /* each FP reg occupies 2 slots in this space */ | |
111 | #define PPC_LINUX_PT_FPR31 (PPC_LINUX_PT_FPR0 + 2*31) | |
112 | #define PPC_LINUX_PT_FPSCR (PPC_LINUX_PT_FPR0 + 2*32 + 1) | |
113 | ||
9aa1e687 | 114 | static int ppc_linux_at_sigtramp_return_path (CORE_ADDR pc); |
50c9bd31 | 115 | |
c877c8e6 KB |
116 | /* Determine if pc is in a signal trampoline... |
117 | ||
ca557f44 | 118 | Ha! That's not what this does at all. wait_for_inferior in |
fcf70625 AC |
119 | infrun.c calls get_frame_type() in order to detect entry into a |
120 | signal trampoline just after delivery of a signal. But on | |
d7bd68ca AC |
121 | GNU/Linux, signal trampolines are used for the return path only. |
122 | The kernel sets things up so that the signal handler is called | |
123 | directly. | |
c877c8e6 KB |
124 | |
125 | If we use in_sigtramp2() in place of in_sigtramp() (see below) | |
126 | we'll (often) end up with stop_pc in the trampoline and prev_pc in | |
127 | the (now exited) handler. The code there will cause a temporary | |
128 | breakpoint to be set on prev_pc which is not very likely to get hit | |
129 | again. | |
130 | ||
131 | If this is confusing, think of it this way... the code in | |
132 | wait_for_inferior() needs to be able to detect entry into a signal | |
133 | trampoline just after a signal is delivered, not after the handler | |
134 | has been run. | |
135 | ||
136 | So, we define in_sigtramp() below to return 1 if the following is | |
137 | true: | |
138 | ||
139 | 1) The previous frame is a real signal trampoline. | |
140 | ||
141 | - and - | |
142 | ||
143 | 2) pc is at the first or second instruction of the corresponding | |
144 | handler. | |
145 | ||
146 | Why the second instruction? It seems that wait_for_inferior() | |
147 | never sees the first instruction when single stepping. When a | |
148 | signal is delivered while stepping, the next instruction that | |
149 | would've been stepped over isn't, instead a signal is delivered and | |
150 | the first instruction of the handler is stepped over instead. That | |
fcf70625 AC |
151 | puts us on the second instruction. (I added the test for the first |
152 | instruction long after the fact, just in case the observed behavior | |
153 | is ever fixed.) */ | |
c877c8e6 KB |
154 | |
155 | int | |
156 | ppc_linux_in_sigtramp (CORE_ADDR pc, char *func_name) | |
157 | { | |
158 | CORE_ADDR lr; | |
159 | CORE_ADDR sp; | |
160 | CORE_ADDR tramp_sp; | |
50fd1280 | 161 | gdb_byte buf[4]; |
c877c8e6 KB |
162 | CORE_ADDR handler; |
163 | ||
2188cbdd | 164 | lr = read_register (gdbarch_tdep (current_gdbarch)->ppc_lr_regnum); |
c877c8e6 KB |
165 | if (!ppc_linux_at_sigtramp_return_path (lr)) |
166 | return 0; | |
167 | ||
168 | sp = read_register (SP_REGNUM); | |
169 | ||
170 | if (target_read_memory (sp, buf, sizeof (buf)) != 0) | |
171 | return 0; | |
172 | ||
173 | tramp_sp = extract_unsigned_integer (buf, 4); | |
174 | ||
175 | if (target_read_memory (tramp_sp + PPC_LINUX_HANDLER_PTR_OFFSET, buf, | |
176 | sizeof (buf)) != 0) | |
177 | return 0; | |
178 | ||
179 | handler = extract_unsigned_integer (buf, 4); | |
180 | ||
181 | return (pc == handler || pc == handler + 4); | |
182 | } | |
183 | ||
39efb398 | 184 | static int |
a2d356b0 DJ |
185 | insn_is_sigreturn (unsigned long pcinsn) |
186 | { | |
187 | switch(pcinsn) | |
188 | { | |
189 | case INSTR_LI_R0_0x6666: | |
190 | case INSTR_LI_R0_0x7777: | |
191 | case INSTR_LI_R0_NR_sigreturn: | |
192 | case INSTR_LI_R0_NR_rt_sigreturn: | |
193 | return 1; | |
194 | default: | |
195 | return 0; | |
196 | } | |
197 | } | |
198 | ||
c877c8e6 KB |
199 | /* |
200 | * The signal handler trampoline is on the stack and consists of exactly | |
201 | * two instructions. The easiest and most accurate way of determining | |
202 | * whether the pc is in one of these trampolines is by inspecting the | |
203 | * instructions. It'd be faster though if we could find a way to do this | |
204 | * via some simple address comparisons. | |
205 | */ | |
9aa1e687 | 206 | static int |
c877c8e6 KB |
207 | ppc_linux_at_sigtramp_return_path (CORE_ADDR pc) |
208 | { | |
50fd1280 | 209 | gdb_byte buf[12]; |
c877c8e6 KB |
210 | unsigned long pcinsn; |
211 | if (target_read_memory (pc - 4, buf, sizeof (buf)) != 0) | |
212 | return 0; | |
213 | ||
214 | /* extract the instruction at the pc */ | |
215 | pcinsn = extract_unsigned_integer (buf + 4, 4); | |
216 | ||
217 | return ( | |
a2d356b0 | 218 | (insn_is_sigreturn (pcinsn) |
c877c8e6 KB |
219 | && extract_unsigned_integer (buf + 8, 4) == INSTR_SC) |
220 | || | |
221 | (pcinsn == INSTR_SC | |
a2d356b0 | 222 | && insn_is_sigreturn (extract_unsigned_integer (buf, 4)))); |
c877c8e6 KB |
223 | } |
224 | ||
6974274f | 225 | static CORE_ADDR |
c877c8e6 KB |
226 | ppc_linux_skip_trampoline_code (CORE_ADDR pc) |
227 | { | |
50fd1280 | 228 | gdb_byte buf[4]; |
c877c8e6 KB |
229 | struct obj_section *sect; |
230 | struct objfile *objfile; | |
231 | unsigned long insn; | |
232 | CORE_ADDR plt_start = 0; | |
233 | CORE_ADDR symtab = 0; | |
234 | CORE_ADDR strtab = 0; | |
235 | int num_slots = -1; | |
236 | int reloc_index = -1; | |
237 | CORE_ADDR plt_table; | |
238 | CORE_ADDR reloc; | |
239 | CORE_ADDR sym; | |
240 | long symidx; | |
241 | char symname[1024]; | |
242 | struct minimal_symbol *msymbol; | |
243 | ||
244 | /* Find the section pc is in; return if not in .plt */ | |
245 | sect = find_pc_section (pc); | |
246 | if (!sect || strcmp (sect->the_bfd_section->name, ".plt") != 0) | |
247 | return 0; | |
248 | ||
249 | objfile = sect->objfile; | |
250 | ||
251 | /* Pick up the instruction at pc. It had better be of the | |
252 | form | |
253 | li r11, IDX | |
254 | ||
255 | where IDX is an index into the plt_table. */ | |
256 | ||
257 | if (target_read_memory (pc, buf, 4) != 0) | |
258 | return 0; | |
259 | insn = extract_unsigned_integer (buf, 4); | |
260 | ||
261 | if ((insn & 0xffff0000) != 0x39600000 /* li r11, VAL */ ) | |
262 | return 0; | |
263 | ||
264 | reloc_index = (insn << 16) >> 16; | |
265 | ||
266 | /* Find the objfile that pc is in and obtain the information | |
267 | necessary for finding the symbol name. */ | |
268 | for (sect = objfile->sections; sect < objfile->sections_end; ++sect) | |
269 | { | |
270 | const char *secname = sect->the_bfd_section->name; | |
271 | if (strcmp (secname, ".plt") == 0) | |
272 | plt_start = sect->addr; | |
273 | else if (strcmp (secname, ".rela.plt") == 0) | |
274 | num_slots = ((int) sect->endaddr - (int) sect->addr) / 12; | |
275 | else if (strcmp (secname, ".dynsym") == 0) | |
276 | symtab = sect->addr; | |
277 | else if (strcmp (secname, ".dynstr") == 0) | |
278 | strtab = sect->addr; | |
279 | } | |
280 | ||
281 | /* Make sure we have all the information we need. */ | |
282 | if (plt_start == 0 || num_slots == -1 || symtab == 0 || strtab == 0) | |
283 | return 0; | |
284 | ||
285 | /* Compute the value of the plt table */ | |
286 | plt_table = plt_start + 72 + 8 * num_slots; | |
287 | ||
288 | /* Get address of the relocation entry (Elf32_Rela) */ | |
289 | if (target_read_memory (plt_table + reloc_index, buf, 4) != 0) | |
290 | return 0; | |
7c0b4a20 | 291 | reloc = extract_unsigned_integer (buf, 4); |
c877c8e6 KB |
292 | |
293 | sect = find_pc_section (reloc); | |
294 | if (!sect) | |
295 | return 0; | |
296 | ||
297 | if (strcmp (sect->the_bfd_section->name, ".text") == 0) | |
298 | return reloc; | |
299 | ||
300 | /* Now get the r_info field which is the relocation type and symbol | |
301 | index. */ | |
302 | if (target_read_memory (reloc + 4, buf, 4) != 0) | |
303 | return 0; | |
304 | symidx = extract_unsigned_integer (buf, 4); | |
305 | ||
306 | /* Shift out the relocation type leaving just the symbol index */ | |
307 | /* symidx = ELF32_R_SYM(symidx); */ | |
308 | symidx = symidx >> 8; | |
309 | ||
310 | /* compute the address of the symbol */ | |
311 | sym = symtab + symidx * 4; | |
312 | ||
313 | /* Fetch the string table index */ | |
314 | if (target_read_memory (sym, buf, 4) != 0) | |
315 | return 0; | |
316 | symidx = extract_unsigned_integer (buf, 4); | |
317 | ||
318 | /* Fetch the string; we don't know how long it is. Is it possible | |
319 | that the following will fail because we're trying to fetch too | |
320 | much? */ | |
50fd1280 AC |
321 | if (target_read_memory (strtab + symidx, (gdb_byte *) symname, |
322 | sizeof (symname)) != 0) | |
c877c8e6 KB |
323 | return 0; |
324 | ||
325 | /* This might not work right if we have multiple symbols with the | |
326 | same name; the only way to really get it right is to perform | |
327 | the same sort of lookup as the dynamic linker. */ | |
5520a790 | 328 | msymbol = lookup_minimal_symbol_text (symname, NULL); |
c877c8e6 KB |
329 | if (!msymbol) |
330 | return 0; | |
331 | ||
332 | return SYMBOL_VALUE_ADDRESS (msymbol); | |
333 | } | |
334 | ||
122a33de KB |
335 | /* ppc_linux_memory_remove_breakpoints attempts to remove a breakpoint |
336 | in much the same fashion as memory_remove_breakpoint in mem-break.c, | |
337 | but is careful not to write back the previous contents if the code | |
338 | in question has changed in between inserting the breakpoint and | |
339 | removing it. | |
340 | ||
341 | Here is the problem that we're trying to solve... | |
342 | ||
343 | Once upon a time, before introducing this function to remove | |
344 | breakpoints from the inferior, setting a breakpoint on a shared | |
345 | library function prior to running the program would not work | |
346 | properly. In order to understand the problem, it is first | |
347 | necessary to understand a little bit about dynamic linking on | |
348 | this platform. | |
349 | ||
350 | A call to a shared library function is accomplished via a bl | |
351 | (branch-and-link) instruction whose branch target is an entry | |
352 | in the procedure linkage table (PLT). The PLT in the object | |
353 | file is uninitialized. To gdb, prior to running the program, the | |
354 | entries in the PLT are all zeros. | |
355 | ||
356 | Once the program starts running, the shared libraries are loaded | |
357 | and the procedure linkage table is initialized, but the entries in | |
358 | the table are not (necessarily) resolved. Once a function is | |
359 | actually called, the code in the PLT is hit and the function is | |
360 | resolved. In order to better illustrate this, an example is in | |
361 | order; the following example is from the gdb testsuite. | |
362 | ||
363 | We start the program shmain. | |
364 | ||
365 | [kev@arroyo testsuite]$ ../gdb gdb.base/shmain | |
366 | [...] | |
367 | ||
368 | We place two breakpoints, one on shr1 and the other on main. | |
369 | ||
370 | (gdb) b shr1 | |
371 | Breakpoint 1 at 0x100409d4 | |
372 | (gdb) b main | |
373 | Breakpoint 2 at 0x100006a0: file gdb.base/shmain.c, line 44. | |
374 | ||
375 | Examine the instruction (and the immediatly following instruction) | |
376 | upon which the breakpoint was placed. Note that the PLT entry | |
377 | for shr1 contains zeros. | |
378 | ||
379 | (gdb) x/2i 0x100409d4 | |
380 | 0x100409d4 <shr1>: .long 0x0 | |
381 | 0x100409d8 <shr1+4>: .long 0x0 | |
382 | ||
383 | Now run 'til main. | |
384 | ||
385 | (gdb) r | |
386 | Starting program: gdb.base/shmain | |
387 | Breakpoint 1 at 0xffaf790: file gdb.base/shr1.c, line 19. | |
388 | ||
389 | Breakpoint 2, main () | |
390 | at gdb.base/shmain.c:44 | |
391 | 44 g = 1; | |
392 | ||
393 | Examine the PLT again. Note that the loading of the shared | |
394 | library has initialized the PLT to code which loads a constant | |
395 | (which I think is an index into the GOT) into r11 and then | |
396 | branchs a short distance to the code which actually does the | |
397 | resolving. | |
398 | ||
399 | (gdb) x/2i 0x100409d4 | |
400 | 0x100409d4 <shr1>: li r11,4 | |
401 | 0x100409d8 <shr1+4>: b 0x10040984 <sg+4> | |
402 | (gdb) c | |
403 | Continuing. | |
404 | ||
405 | Breakpoint 1, shr1 (x=1) | |
406 | at gdb.base/shr1.c:19 | |
407 | 19 l = 1; | |
408 | ||
409 | Now we've hit the breakpoint at shr1. (The breakpoint was | |
410 | reset from the PLT entry to the actual shr1 function after the | |
411 | shared library was loaded.) Note that the PLT entry has been | |
412 | resolved to contain a branch that takes us directly to shr1. | |
413 | (The real one, not the PLT entry.) | |
414 | ||
415 | (gdb) x/2i 0x100409d4 | |
416 | 0x100409d4 <shr1>: b 0xffaf76c <shr1> | |
417 | 0x100409d8 <shr1+4>: b 0x10040984 <sg+4> | |
418 | ||
419 | The thing to note here is that the PLT entry for shr1 has been | |
420 | changed twice. | |
421 | ||
422 | Now the problem should be obvious. GDB places a breakpoint (a | |
423 | trap instruction) on the zero value of the PLT entry for shr1. | |
424 | Later on, after the shared library had been loaded and the PLT | |
425 | initialized, GDB gets a signal indicating this fact and attempts | |
426 | (as it always does when it stops) to remove all the breakpoints. | |
427 | ||
428 | The breakpoint removal was causing the former contents (a zero | |
429 | word) to be written back to the now initialized PLT entry thus | |
430 | destroying a portion of the initialization that had occurred only a | |
431 | short time ago. When execution continued, the zero word would be | |
432 | executed as an instruction an an illegal instruction trap was | |
433 | generated instead. (0 is not a legal instruction.) | |
434 | ||
435 | The fix for this problem was fairly straightforward. The function | |
436 | memory_remove_breakpoint from mem-break.c was copied to this file, | |
437 | modified slightly, and renamed to ppc_linux_memory_remove_breakpoint. | |
438 | In tm-linux.h, MEMORY_REMOVE_BREAKPOINT is defined to call this new | |
439 | function. | |
440 | ||
441 | The differences between ppc_linux_memory_remove_breakpoint () and | |
442 | memory_remove_breakpoint () are minor. All that the former does | |
443 | that the latter does not is check to make sure that the breakpoint | |
444 | location actually contains a breakpoint (trap instruction) prior | |
445 | to attempting to write back the old contents. If it does contain | |
446 | a trap instruction, we allow the old contents to be written back. | |
447 | Otherwise, we silently do nothing. | |
448 | ||
449 | The big question is whether memory_remove_breakpoint () should be | |
450 | changed to have the same functionality. The downside is that more | |
451 | traffic is generated for remote targets since we'll have an extra | |
452 | fetch of a memory word each time a breakpoint is removed. | |
453 | ||
454 | For the time being, we'll leave this self-modifying-code-friendly | |
455 | version in ppc-linux-tdep.c, but it ought to be migrated somewhere | |
456 | else in the event that some other platform has similar needs with | |
457 | regard to removing breakpoints in some potentially self modifying | |
458 | code. */ | |
482ca3f5 | 459 | int |
8181d85f | 460 | ppc_linux_memory_remove_breakpoint (struct bp_target_info *bp_tgt) |
482ca3f5 | 461 | { |
8181d85f | 462 | CORE_ADDR addr = bp_tgt->placed_address; |
f4f9705a | 463 | const unsigned char *bp; |
482ca3f5 KB |
464 | int val; |
465 | int bplen; | |
50fd1280 | 466 | gdb_byte old_contents[BREAKPOINT_MAX]; |
482ca3f5 KB |
467 | |
468 | /* Determine appropriate breakpoint contents and size for this address. */ | |
469 | bp = BREAKPOINT_FROM_PC (&addr, &bplen); | |
470 | if (bp == NULL) | |
8a3fe4f8 | 471 | error (_("Software breakpoints not implemented for this target.")); |
482ca3f5 KB |
472 | |
473 | val = target_read_memory (addr, old_contents, bplen); | |
474 | ||
475 | /* If our breakpoint is no longer at the address, this means that the | |
476 | program modified the code on us, so it is wrong to put back the | |
477 | old value */ | |
478 | if (val == 0 && memcmp (bp, old_contents, bplen) == 0) | |
8181d85f | 479 | val = target_write_memory (addr, bp_tgt->shadow_contents, bplen); |
482ca3f5 KB |
480 | |
481 | return val; | |
482 | } | |
6ded7999 | 483 | |
b9ff3018 AC |
484 | /* For historic reasons, PPC 32 GNU/Linux follows PowerOpen rather |
485 | than the 32 bit SYSV R4 ABI structure return convention - all | |
486 | structures, no matter their size, are put in memory. Vectors, | |
487 | which were added later, do get returned in a register though. */ | |
488 | ||
05580c65 AC |
489 | static enum return_value_convention |
490 | ppc_linux_return_value (struct gdbarch *gdbarch, struct type *valtype, | |
50fd1280 AC |
491 | struct regcache *regcache, gdb_byte *readbuf, |
492 | const gdb_byte *writebuf) | |
b9ff3018 | 493 | { |
05580c65 AC |
494 | if ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT |
495 | || TYPE_CODE (valtype) == TYPE_CODE_UNION) | |
496 | && !((TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 8) | |
497 | && TYPE_VECTOR (valtype))) | |
498 | return RETURN_VALUE_STRUCT_CONVENTION; | |
499 | else | |
475b6ddd AC |
500 | return ppc_sysv_abi_return_value (gdbarch, valtype, regcache, readbuf, |
501 | writebuf); | |
b9ff3018 AC |
502 | } |
503 | ||
f470a70a JB |
504 | /* Macros for matching instructions. Note that, since all the |
505 | operands are masked off before they're or-ed into the instruction, | |
506 | you can use -1 to make masks. */ | |
507 | ||
508 | #define insn_d(opcd, rts, ra, d) \ | |
509 | ((((opcd) & 0x3f) << 26) \ | |
510 | | (((rts) & 0x1f) << 21) \ | |
511 | | (((ra) & 0x1f) << 16) \ | |
512 | | ((d) & 0xffff)) | |
513 | ||
514 | #define insn_ds(opcd, rts, ra, d, xo) \ | |
515 | ((((opcd) & 0x3f) << 26) \ | |
516 | | (((rts) & 0x1f) << 21) \ | |
517 | | (((ra) & 0x1f) << 16) \ | |
518 | | ((d) & 0xfffc) \ | |
519 | | ((xo) & 0x3)) | |
520 | ||
521 | #define insn_xfx(opcd, rts, spr, xo) \ | |
522 | ((((opcd) & 0x3f) << 26) \ | |
523 | | (((rts) & 0x1f) << 21) \ | |
524 | | (((spr) & 0x1f) << 16) \ | |
525 | | (((spr) & 0x3e0) << 6) \ | |
526 | | (((xo) & 0x3ff) << 1)) | |
527 | ||
528 | /* Read a PPC instruction from memory. PPC instructions are always | |
529 | big-endian, no matter what endianness the program is running in, so | |
530 | we can't use read_memory_integer or one of its friends here. */ | |
531 | static unsigned int | |
532 | read_insn (CORE_ADDR pc) | |
533 | { | |
534 | unsigned char buf[4]; | |
535 | ||
536 | read_memory (pc, buf, 4); | |
537 | return (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3]; | |
538 | } | |
539 | ||
540 | ||
541 | /* An instruction to match. */ | |
542 | struct insn_pattern | |
543 | { | |
544 | unsigned int mask; /* mask the insn with this... */ | |
545 | unsigned int data; /* ...and see if it matches this. */ | |
546 | int optional; /* If non-zero, this insn may be absent. */ | |
547 | }; | |
548 | ||
549 | /* Return non-zero if the instructions at PC match the series | |
550 | described in PATTERN, or zero otherwise. PATTERN is an array of | |
551 | 'struct insn_pattern' objects, terminated by an entry whose mask is | |
552 | zero. | |
553 | ||
554 | When the match is successful, fill INSN[i] with what PATTERN[i] | |
555 | matched. If PATTERN[i] is optional, and the instruction wasn't | |
556 | present, set INSN[i] to 0 (which is not a valid PPC instruction). | |
557 | INSN should have as many elements as PATTERN. Note that, if | |
558 | PATTERN contains optional instructions which aren't present in | |
559 | memory, then INSN will have holes, so INSN[i] isn't necessarily the | |
560 | i'th instruction in memory. */ | |
561 | static int | |
562 | insns_match_pattern (CORE_ADDR pc, | |
563 | struct insn_pattern *pattern, | |
564 | unsigned int *insn) | |
565 | { | |
566 | int i; | |
567 | ||
568 | for (i = 0; pattern[i].mask; i++) | |
569 | { | |
570 | insn[i] = read_insn (pc); | |
571 | if ((insn[i] & pattern[i].mask) == pattern[i].data) | |
572 | pc += 4; | |
573 | else if (pattern[i].optional) | |
574 | insn[i] = 0; | |
575 | else | |
576 | return 0; | |
577 | } | |
578 | ||
579 | return 1; | |
580 | } | |
581 | ||
582 | ||
583 | /* Return the 'd' field of the d-form instruction INSN, properly | |
584 | sign-extended. */ | |
585 | static CORE_ADDR | |
586 | insn_d_field (unsigned int insn) | |
587 | { | |
588 | return ((((CORE_ADDR) insn & 0xffff) ^ 0x8000) - 0x8000); | |
589 | } | |
590 | ||
591 | ||
592 | /* Return the 'ds' field of the ds-form instruction INSN, with the two | |
593 | zero bits concatenated at the right, and properly | |
594 | sign-extended. */ | |
595 | static CORE_ADDR | |
596 | insn_ds_field (unsigned int insn) | |
597 | { | |
598 | return ((((CORE_ADDR) insn & 0xfffc) ^ 0x8000) - 0x8000); | |
599 | } | |
600 | ||
601 | ||
e538d2d7 | 602 | /* If DESC is the address of a 64-bit PowerPC GNU/Linux function |
d64558a5 JB |
603 | descriptor, return the descriptor's entry point. */ |
604 | static CORE_ADDR | |
605 | ppc64_desc_entry_point (CORE_ADDR desc) | |
606 | { | |
607 | /* The first word of the descriptor is the entry point. */ | |
608 | return (CORE_ADDR) read_memory_unsigned_integer (desc, 8); | |
609 | } | |
610 | ||
611 | ||
f470a70a JB |
612 | /* Pattern for the standard linkage function. These are built by |
613 | build_plt_stub in elf64-ppc.c, whose GLINK argument is always | |
614 | zero. */ | |
615 | static struct insn_pattern ppc64_standard_linkage[] = | |
616 | { | |
617 | /* addis r12, r2, <any> */ | |
618 | { insn_d (-1, -1, -1, 0), insn_d (15, 12, 2, 0), 0 }, | |
619 | ||
620 | /* std r2, 40(r1) */ | |
621 | { -1, insn_ds (62, 2, 1, 40, 0), 0 }, | |
622 | ||
623 | /* ld r11, <any>(r12) */ | |
624 | { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 0 }, | |
625 | ||
626 | /* addis r12, r12, 1 <optional> */ | |
627 | { insn_d (-1, -1, -1, -1), insn_d (15, 12, 2, 1), 1 }, | |
628 | ||
629 | /* ld r2, <any>(r12) */ | |
630 | { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 12, 0, 0), 0 }, | |
631 | ||
632 | /* addis r12, r12, 1 <optional> */ | |
633 | { insn_d (-1, -1, -1, -1), insn_d (15, 12, 2, 1), 1 }, | |
634 | ||
635 | /* mtctr r11 */ | |
636 | { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467), | |
637 | 0 }, | |
638 | ||
639 | /* ld r11, <any>(r12) */ | |
640 | { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 0 }, | |
641 | ||
642 | /* bctr */ | |
643 | { -1, 0x4e800420, 0 }, | |
644 | ||
645 | { 0, 0, 0 } | |
646 | }; | |
647 | #define PPC64_STANDARD_LINKAGE_LEN \ | |
648 | (sizeof (ppc64_standard_linkage) / sizeof (ppc64_standard_linkage[0])) | |
649 | ||
f470a70a JB |
650 | /* When the dynamic linker is doing lazy symbol resolution, the first |
651 | call to a function in another object will go like this: | |
652 | ||
653 | - The user's function calls the linkage function: | |
654 | ||
655 | 100007c4: 4b ff fc d5 bl 10000498 | |
656 | 100007c8: e8 41 00 28 ld r2,40(r1) | |
657 | ||
658 | - The linkage function loads the entry point (and other stuff) from | |
659 | the function descriptor in the PLT, and jumps to it: | |
660 | ||
661 | 10000498: 3d 82 00 00 addis r12,r2,0 | |
662 | 1000049c: f8 41 00 28 std r2,40(r1) | |
663 | 100004a0: e9 6c 80 98 ld r11,-32616(r12) | |
664 | 100004a4: e8 4c 80 a0 ld r2,-32608(r12) | |
665 | 100004a8: 7d 69 03 a6 mtctr r11 | |
666 | 100004ac: e9 6c 80 a8 ld r11,-32600(r12) | |
667 | 100004b0: 4e 80 04 20 bctr | |
668 | ||
669 | - But since this is the first time that PLT entry has been used, it | |
670 | sends control to its glink entry. That loads the number of the | |
671 | PLT entry and jumps to the common glink0 code: | |
672 | ||
673 | 10000c98: 38 00 00 00 li r0,0 | |
674 | 10000c9c: 4b ff ff dc b 10000c78 | |
675 | ||
676 | - The common glink0 code then transfers control to the dynamic | |
677 | linker's fixup code: | |
678 | ||
679 | 10000c78: e8 41 00 28 ld r2,40(r1) | |
680 | 10000c7c: 3d 82 00 00 addis r12,r2,0 | |
681 | 10000c80: e9 6c 80 80 ld r11,-32640(r12) | |
682 | 10000c84: e8 4c 80 88 ld r2,-32632(r12) | |
683 | 10000c88: 7d 69 03 a6 mtctr r11 | |
684 | 10000c8c: e9 6c 80 90 ld r11,-32624(r12) | |
685 | 10000c90: 4e 80 04 20 bctr | |
686 | ||
687 | Eventually, this code will figure out how to skip all of this, | |
688 | including the dynamic linker. At the moment, we just get through | |
689 | the linkage function. */ | |
690 | ||
691 | /* If the current thread is about to execute a series of instructions | |
692 | at PC matching the ppc64_standard_linkage pattern, and INSN is the result | |
693 | from that pattern match, return the code address to which the | |
694 | standard linkage function will send them. (This doesn't deal with | |
695 | dynamic linker lazy symbol resolution stubs.) */ | |
696 | static CORE_ADDR | |
697 | ppc64_standard_linkage_target (CORE_ADDR pc, unsigned int *insn) | |
698 | { | |
699 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); | |
700 | ||
701 | /* The address of the function descriptor this linkage function | |
702 | references. */ | |
703 | CORE_ADDR desc | |
704 | = ((CORE_ADDR) read_register (tdep->ppc_gp0_regnum + 2) | |
705 | + (insn_d_field (insn[0]) << 16) | |
706 | + insn_ds_field (insn[2])); | |
707 | ||
708 | /* The first word of the descriptor is the entry point. Return that. */ | |
d64558a5 | 709 | return ppc64_desc_entry_point (desc); |
f470a70a JB |
710 | } |
711 | ||
712 | ||
713 | /* Given that we've begun executing a call trampoline at PC, return | |
714 | the entry point of the function the trampoline will go to. */ | |
715 | static CORE_ADDR | |
716 | ppc64_skip_trampoline_code (CORE_ADDR pc) | |
717 | { | |
718 | unsigned int ppc64_standard_linkage_insn[PPC64_STANDARD_LINKAGE_LEN]; | |
719 | ||
720 | if (insns_match_pattern (pc, ppc64_standard_linkage, | |
721 | ppc64_standard_linkage_insn)) | |
722 | return ppc64_standard_linkage_target (pc, ppc64_standard_linkage_insn); | |
723 | else | |
724 | return 0; | |
725 | } | |
726 | ||
727 | ||
e2d0e7eb AC |
728 | /* Support for CONVERT_FROM_FUNC_PTR_ADDR (ARCH, ADDR, TARG) on PPC64 |
729 | GNU/Linux. | |
02631ec0 JB |
730 | |
731 | Usually a function pointer's representation is simply the address | |
e538d2d7 JB |
732 | of the function. On GNU/Linux on the 64-bit PowerPC however, a |
733 | function pointer is represented by a pointer to a TOC entry. This | |
734 | TOC entry contains three words, the first word is the address of | |
735 | the function, the second word is the TOC pointer (r2), and the | |
736 | third word is the static chain value. Throughout GDB it is | |
737 | currently assumed that a function pointer contains the address of | |
738 | the function, which is not easy to fix. In addition, the | |
739 | conversion of a function address to a function pointer would | |
740 | require allocation of a TOC entry in the inferior's memory space, | |
741 | with all its drawbacks. To be able to call C++ virtual methods in | |
742 | the inferior (which are called via function pointers), | |
743 | find_function_addr uses this function to get the function address | |
744 | from a function pointer. */ | |
02631ec0 | 745 | |
9b540880 AC |
746 | /* If ADDR points at what is clearly a function descriptor, transform |
747 | it into the address of the corresponding function. Be | |
748 | conservative, otherwize GDB will do the transformation on any | |
749 | random addresses such as occures when there is no symbol table. */ | |
02631ec0 JB |
750 | |
751 | static CORE_ADDR | |
e2d0e7eb AC |
752 | ppc64_linux_convert_from_func_ptr_addr (struct gdbarch *gdbarch, |
753 | CORE_ADDR addr, | |
754 | struct target_ops *targ) | |
02631ec0 | 755 | { |
b6591e8b | 756 | struct section_table *s = target_section_by_addr (targ, addr); |
02631ec0 | 757 | |
9b540880 AC |
758 | /* Check if ADDR points to a function descriptor. */ |
759 | if (s && strcmp (s->the_bfd_section->name, ".opd") == 0) | |
b6591e8b | 760 | return get_target_memory_unsigned (targ, addr, 8); |
9b540880 AC |
761 | |
762 | return addr; | |
02631ec0 JB |
763 | } |
764 | ||
f9be684a AC |
765 | static void |
766 | right_supply_register (struct regcache *regcache, int wordsize, int regnum, | |
767 | const bfd_byte *buf) | |
768 | { | |
769 | regcache_raw_supply (regcache, regnum, | |
23a6d369 | 770 | (buf + wordsize - register_size (current_gdbarch, regnum))); |
f9be684a AC |
771 | } |
772 | ||
773 | /* Extract the register values found in the WORDSIZED ABI GREGSET, | |
774 | storing their values in REGCACHE. Note that some are left-aligned, | |
775 | while others are right aligned. */ | |
776 | ||
2fda4977 | 777 | void |
f9be684a AC |
778 | ppc_linux_supply_gregset (struct regcache *regcache, |
779 | int regnum, const void *gregs, size_t size, | |
780 | int wordsize) | |
2fda4977 DJ |
781 | { |
782 | int regi; | |
f9be684a AC |
783 | struct gdbarch *regcache_arch = get_regcache_arch (regcache); |
784 | struct gdbarch_tdep *regcache_tdep = gdbarch_tdep (regcache_arch); | |
785 | const bfd_byte *buf = gregs; | |
2fda4977 | 786 | |
063715bf | 787 | for (regi = 0; regi < ppc_num_gprs; regi++) |
cdf2c5f5 JB |
788 | right_supply_register (regcache, wordsize, |
789 | regcache_tdep->ppc_gp0_regnum + regi, | |
790 | buf + wordsize * regi); | |
f9be684a AC |
791 | |
792 | right_supply_register (regcache, wordsize, gdbarch_pc_regnum (regcache_arch), | |
793 | buf + wordsize * PPC_LINUX_PT_NIP); | |
794 | right_supply_register (regcache, wordsize, regcache_tdep->ppc_lr_regnum, | |
795 | buf + wordsize * PPC_LINUX_PT_LNK); | |
796 | regcache_raw_supply (regcache, regcache_tdep->ppc_cr_regnum, | |
797 | buf + wordsize * PPC_LINUX_PT_CCR); | |
798 | regcache_raw_supply (regcache, regcache_tdep->ppc_xer_regnum, | |
799 | buf + wordsize * PPC_LINUX_PT_XER); | |
800 | regcache_raw_supply (regcache, regcache_tdep->ppc_ctr_regnum, | |
801 | buf + wordsize * PPC_LINUX_PT_CTR); | |
802 | if (regcache_tdep->ppc_mq_regnum != -1) | |
803 | right_supply_register (regcache, wordsize, regcache_tdep->ppc_mq_regnum, | |
804 | buf + wordsize * PPC_LINUX_PT_MQ); | |
805 | right_supply_register (regcache, wordsize, regcache_tdep->ppc_ps_regnum, | |
806 | buf + wordsize * PPC_LINUX_PT_MSR); | |
807 | } | |
808 | ||
809 | static void | |
810 | ppc32_linux_supply_gregset (const struct regset *regset, | |
811 | struct regcache *regcache, | |
812 | int regnum, const void *gregs, size_t size) | |
813 | { | |
814 | ppc_linux_supply_gregset (regcache, regnum, gregs, size, 4); | |
2fda4977 DJ |
815 | } |
816 | ||
f9be684a AC |
817 | static struct regset ppc32_linux_gregset = { |
818 | NULL, ppc32_linux_supply_gregset | |
819 | }; | |
820 | ||
821 | static void | |
822 | ppc64_linux_supply_gregset (const struct regset *regset, | |
823 | struct regcache * regcache, | |
824 | int regnum, const void *gregs, size_t size) | |
825 | { | |
826 | ppc_linux_supply_gregset (regcache, regnum, gregs, size, 8); | |
827 | } | |
828 | ||
829 | static struct regset ppc64_linux_gregset = { | |
830 | NULL, ppc64_linux_supply_gregset | |
831 | }; | |
832 | ||
2fda4977 | 833 | void |
f9be684a AC |
834 | ppc_linux_supply_fpregset (const struct regset *regset, |
835 | struct regcache * regcache, | |
836 | int regnum, const void *fpset, size_t size) | |
2fda4977 DJ |
837 | { |
838 | int regi; | |
f9be684a AC |
839 | struct gdbarch *regcache_arch = get_regcache_arch (regcache); |
840 | struct gdbarch_tdep *regcache_tdep = gdbarch_tdep (regcache_arch); | |
841 | const bfd_byte *buf = fpset; | |
2fda4977 | 842 | |
383f0f5b JB |
843 | if (! ppc_floating_point_unit_p (regcache_arch)) |
844 | return; | |
845 | ||
846 | for (regi = 0; regi < ppc_num_fprs; regi++) | |
366f009f JB |
847 | regcache_raw_supply (regcache, |
848 | regcache_tdep->ppc_fp0_regnum + regi, | |
849 | buf + 8 * regi); | |
2fda4977 | 850 | |
383f0f5b JB |
851 | /* The FPSCR is stored in the low order word of the last |
852 | doubleword in the fpregset. */ | |
f9be684a | 853 | regcache_raw_supply (regcache, regcache_tdep->ppc_fpscr_regnum, |
383f0f5b | 854 | buf + 8 * 32 + 4); |
2fda4977 DJ |
855 | } |
856 | ||
f9be684a | 857 | static struct regset ppc_linux_fpregset = { NULL, ppc_linux_supply_fpregset }; |
2fda4977 | 858 | |
f9be684a AC |
859 | static const struct regset * |
860 | ppc_linux_regset_from_core_section (struct gdbarch *core_arch, | |
861 | const char *sect_name, size_t sect_size) | |
2fda4977 | 862 | { |
f9be684a AC |
863 | struct gdbarch_tdep *tdep = gdbarch_tdep (core_arch); |
864 | if (strcmp (sect_name, ".reg") == 0) | |
2fda4977 | 865 | { |
f9be684a AC |
866 | if (tdep->wordsize == 4) |
867 | return &ppc32_linux_gregset; | |
2fda4977 | 868 | else |
f9be684a | 869 | return &ppc64_linux_gregset; |
2fda4977 | 870 | } |
f9be684a AC |
871 | if (strcmp (sect_name, ".reg2") == 0) |
872 | return &ppc_linux_fpregset; | |
873 | return NULL; | |
2fda4977 DJ |
874 | } |
875 | ||
a8f60bfc AC |
876 | static void |
877 | ppc_linux_sigtramp_cache (struct frame_info *next_frame, | |
878 | struct trad_frame_cache *this_cache, | |
879 | CORE_ADDR func, LONGEST offset, | |
880 | int bias) | |
881 | { | |
882 | CORE_ADDR base; | |
883 | CORE_ADDR regs; | |
884 | CORE_ADDR gpregs; | |
885 | CORE_ADDR fpregs; | |
886 | int i; | |
887 | struct gdbarch *gdbarch = get_frame_arch (next_frame); | |
888 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
889 | ||
890 | base = frame_unwind_register_unsigned (next_frame, SP_REGNUM); | |
891 | if (bias > 0 && frame_pc_unwind (next_frame) != func) | |
892 | /* See below, some signal trampolines increment the stack as their | |
893 | first instruction, need to compensate for that. */ | |
894 | base -= bias; | |
895 | ||
896 | /* Find the address of the register buffer pointer. */ | |
897 | regs = base + offset; | |
898 | /* Use that to find the address of the corresponding register | |
899 | buffers. */ | |
900 | gpregs = read_memory_unsigned_integer (regs, tdep->wordsize); | |
901 | fpregs = gpregs + 48 * tdep->wordsize; | |
902 | ||
903 | /* General purpose. */ | |
904 | for (i = 0; i < 32; i++) | |
905 | { | |
906 | int regnum = i + tdep->ppc_gp0_regnum; | |
907 | trad_frame_set_reg_addr (this_cache, regnum, gpregs + i * tdep->wordsize); | |
908 | } | |
909 | trad_frame_set_reg_addr (this_cache, PC_REGNUM, gpregs + 32 * tdep->wordsize); | |
910 | trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, | |
911 | gpregs + 35 * tdep->wordsize); | |
912 | trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, | |
913 | gpregs + 36 * tdep->wordsize); | |
914 | trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, | |
915 | gpregs + 37 * tdep->wordsize); | |
916 | trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, | |
917 | gpregs + 38 * tdep->wordsize); | |
918 | ||
60f140f9 PG |
919 | if (ppc_floating_point_unit_p (gdbarch)) |
920 | { | |
921 | /* Floating point registers. */ | |
922 | for (i = 0; i < 32; i++) | |
923 | { | |
924 | int regnum = i + FP0_REGNUM; | |
925 | trad_frame_set_reg_addr (this_cache, regnum, | |
926 | fpregs + i * tdep->wordsize); | |
927 | } | |
928 | trad_frame_set_reg_addr (this_cache, tdep->ppc_fpscr_regnum, | |
4019046a | 929 | fpregs + 32 * tdep->wordsize); |
60f140f9 | 930 | } |
a8f60bfc AC |
931 | trad_frame_set_id (this_cache, frame_id_build (base, func)); |
932 | } | |
933 | ||
934 | static void | |
935 | ppc32_linux_sigaction_cache_init (const struct tramp_frame *self, | |
936 | struct frame_info *next_frame, | |
937 | struct trad_frame_cache *this_cache, | |
938 | CORE_ADDR func) | |
939 | { | |
940 | ppc_linux_sigtramp_cache (next_frame, this_cache, func, | |
941 | 0xd0 /* Offset to ucontext_t. */ | |
942 | + 0x30 /* Offset to .reg. */, | |
943 | 0); | |
944 | } | |
945 | ||
946 | static void | |
947 | ppc64_linux_sigaction_cache_init (const struct tramp_frame *self, | |
948 | struct frame_info *next_frame, | |
949 | struct trad_frame_cache *this_cache, | |
950 | CORE_ADDR func) | |
951 | { | |
952 | ppc_linux_sigtramp_cache (next_frame, this_cache, func, | |
953 | 0x80 /* Offset to ucontext_t. */ | |
954 | + 0xe0 /* Offset to .reg. */, | |
955 | 128); | |
956 | } | |
957 | ||
958 | static void | |
959 | ppc32_linux_sighandler_cache_init (const struct tramp_frame *self, | |
960 | struct frame_info *next_frame, | |
961 | struct trad_frame_cache *this_cache, | |
962 | CORE_ADDR func) | |
963 | { | |
964 | ppc_linux_sigtramp_cache (next_frame, this_cache, func, | |
965 | 0x40 /* Offset to ucontext_t. */ | |
966 | + 0x1c /* Offset to .reg. */, | |
967 | 0); | |
968 | } | |
969 | ||
970 | static void | |
971 | ppc64_linux_sighandler_cache_init (const struct tramp_frame *self, | |
972 | struct frame_info *next_frame, | |
973 | struct trad_frame_cache *this_cache, | |
974 | CORE_ADDR func) | |
975 | { | |
976 | ppc_linux_sigtramp_cache (next_frame, this_cache, func, | |
977 | 0x80 /* Offset to struct sigcontext. */ | |
978 | + 0x38 /* Offset to .reg. */, | |
979 | 128); | |
980 | } | |
981 | ||
982 | static struct tramp_frame ppc32_linux_sigaction_tramp_frame = { | |
983 | SIGTRAMP_FRAME, | |
984 | 4, | |
985 | { | |
986 | { 0x380000ac, -1 }, /* li r0, 172 */ | |
987 | { 0x44000002, -1 }, /* sc */ | |
988 | { TRAMP_SENTINEL_INSN }, | |
989 | }, | |
990 | ppc32_linux_sigaction_cache_init | |
991 | }; | |
992 | static struct tramp_frame ppc64_linux_sigaction_tramp_frame = { | |
993 | SIGTRAMP_FRAME, | |
994 | 4, | |
995 | { | |
996 | { 0x38210080, -1 }, /* addi r1,r1,128 */ | |
997 | { 0x380000ac, -1 }, /* li r0, 172 */ | |
998 | { 0x44000002, -1 }, /* sc */ | |
999 | { TRAMP_SENTINEL_INSN }, | |
1000 | }, | |
1001 | ppc64_linux_sigaction_cache_init | |
1002 | }; | |
1003 | static struct tramp_frame ppc32_linux_sighandler_tramp_frame = { | |
1004 | SIGTRAMP_FRAME, | |
1005 | 4, | |
1006 | { | |
1007 | { 0x38000077, -1 }, /* li r0,119 */ | |
1008 | { 0x44000002, -1 }, /* sc */ | |
1009 | { TRAMP_SENTINEL_INSN }, | |
1010 | }, | |
1011 | ppc32_linux_sighandler_cache_init | |
1012 | }; | |
1013 | static struct tramp_frame ppc64_linux_sighandler_tramp_frame = { | |
1014 | SIGTRAMP_FRAME, | |
1015 | 4, | |
1016 | { | |
1017 | { 0x38210080, -1 }, /* addi r1,r1,128 */ | |
1018 | { 0x38000077, -1 }, /* li r0,119 */ | |
1019 | { 0x44000002, -1 }, /* sc */ | |
1020 | { TRAMP_SENTINEL_INSN }, | |
1021 | }, | |
1022 | ppc64_linux_sighandler_cache_init | |
1023 | }; | |
1024 | ||
7b112f9c JT |
1025 | static void |
1026 | ppc_linux_init_abi (struct gdbarch_info info, | |
1027 | struct gdbarch *gdbarch) | |
1028 | { | |
1029 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
1030 | ||
0598a43c AC |
1031 | /* NOTE: jimb/2004-03-26: The System V ABI PowerPC Processor |
1032 | Supplement says that long doubles are sixteen bytes long. | |
1033 | However, as one of the known warts of its ABI, PPC GNU/Linux uses | |
1034 | eight-byte long doubles. GCC only recently got 128-bit long | |
1035 | double support on PPC, so it may be changing soon. The | |
1036 | Linux[sic] Standards Base says that programs that use 'long | |
1037 | double' on PPC GNU/Linux are non-conformant. */ | |
1038 | /* NOTE: cagney/2005-01-25: True for both 32- and 64-bit. */ | |
1039 | set_gdbarch_long_double_bit (gdbarch, 8 * TARGET_CHAR_BIT); | |
1040 | ||
7b112f9c JT |
1041 | if (tdep->wordsize == 4) |
1042 | { | |
b9ff3018 AC |
1043 | /* Until November 2001, gcc did not comply with the 32 bit SysV |
1044 | R4 ABI requirement that structures less than or equal to 8 | |
1045 | bytes should be returned in registers. Instead GCC was using | |
1046 | the the AIX/PowerOpen ABI - everything returned in memory | |
1047 | (well ignoring vectors that is). When this was corrected, it | |
1048 | wasn't fixed for GNU/Linux native platform. Use the | |
1049 | PowerOpen struct convention. */ | |
05580c65 | 1050 | set_gdbarch_return_value (gdbarch, ppc_linux_return_value); |
b9ff3018 | 1051 | |
7b112f9c JT |
1052 | set_gdbarch_memory_remove_breakpoint (gdbarch, |
1053 | ppc_linux_memory_remove_breakpoint); | |
61a65099 | 1054 | |
f470a70a | 1055 | /* Shared library handling. */ |
f470a70a JB |
1056 | set_gdbarch_skip_trampoline_code (gdbarch, |
1057 | ppc_linux_skip_trampoline_code); | |
7b112f9c | 1058 | set_solib_svr4_fetch_link_map_offsets |
76a9d10f | 1059 | (gdbarch, svr4_ilp32_fetch_link_map_offsets); |
a8f60bfc AC |
1060 | |
1061 | /* Trampolines. */ | |
1062 | tramp_frame_prepend_unwinder (gdbarch, &ppc32_linux_sigaction_tramp_frame); | |
1063 | tramp_frame_prepend_unwinder (gdbarch, &ppc32_linux_sighandler_tramp_frame); | |
7b112f9c | 1064 | } |
f470a70a JB |
1065 | |
1066 | if (tdep->wordsize == 8) | |
1067 | { | |
e538d2d7 | 1068 | /* Handle PPC64 GNU/Linux function pointers (which are really |
02631ec0 JB |
1069 | function descriptors). */ |
1070 | set_gdbarch_convert_from_func_ptr_addr | |
1071 | (gdbarch, ppc64_linux_convert_from_func_ptr_addr); | |
f470a70a | 1072 | set_gdbarch_skip_trampoline_code (gdbarch, ppc64_skip_trampoline_code); |
9ea97f2a | 1073 | |
fb318ff7 DJ |
1074 | /* Shared library handling. */ |
1075 | set_solib_svr4_fetch_link_map_offsets | |
1076 | (gdbarch, svr4_lp64_fetch_link_map_offsets); | |
1077 | ||
a8f60bfc AC |
1078 | /* Trampolines. */ |
1079 | tramp_frame_prepend_unwinder (gdbarch, &ppc64_linux_sigaction_tramp_frame); | |
1080 | tramp_frame_prepend_unwinder (gdbarch, &ppc64_linux_sighandler_tramp_frame); | |
f470a70a | 1081 | } |
f9be684a | 1082 | set_gdbarch_regset_from_core_section (gdbarch, ppc_linux_regset_from_core_section); |
b2756930 KB |
1083 | |
1084 | /* Enable TLS support. */ | |
1085 | set_gdbarch_fetch_tls_load_module_address (gdbarch, | |
1086 | svr4_fetch_objfile_link_map); | |
7b112f9c JT |
1087 | } |
1088 | ||
1089 | void | |
1090 | _initialize_ppc_linux_tdep (void) | |
1091 | { | |
0a0a4ac3 AC |
1092 | /* Register for all sub-familes of the POWER/PowerPC: 32-bit and |
1093 | 64-bit PowerPC, and the older rs6k. */ | |
1094 | gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc, GDB_OSABI_LINUX, | |
1095 | ppc_linux_init_abi); | |
1096 | gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc64, GDB_OSABI_LINUX, | |
1097 | ppc_linux_init_abi); | |
1098 | gdbarch_register_osabi (bfd_arch_rs6000, bfd_mach_rs6k, GDB_OSABI_LINUX, | |
1099 | ppc_linux_init_abi); | |
7b112f9c | 1100 | } |