1 /* Target-dependent code for Linux running on PA-RISC, for GDB.
3 Copyright 2004 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
26 #include "solib-svr4.h"
27 #include "glibc-tdep.h"
28 #include "frame-unwind.h"
29 #include "trad-frame.h"
30 #include "dwarf2-frame.h"
31 #include "hppa-tdep.h"
34 /* Convert DWARF register number REG to the appropriate register
35 number used by GDB. */
37 hppa_dwarf_reg_to_regnum (int reg
)
39 /* registers 0 - 31 are the same in both sets */
43 /* dwarf regs 32 to 85 are fpregs 4 - 31 */
44 if (reg
>= 32 && reg
<= 85)
45 return HPPA_FP4_REGNUM
+ (reg
- 32);
47 warning ("Unmapped DWARF Register #%d encountered\n", reg
);
53 hppa_linux_target_write_pc (CORE_ADDR v
, ptid_t ptid
)
55 /* Probably this should be done by the kernel, but it isn't. */
56 write_register_pid (HPPA_PCOQ_HEAD_REGNUM
, v
| 0x3, ptid
);
57 write_register_pid (HPPA_PCOQ_TAIL_REGNUM
, (v
+ 4) | 0x3, ptid
);
60 /* An instruction to match. */
63 unsigned int data
; /* See if it matches this.... */
64 unsigned int mask
; /* ... with this mask. */
67 /* See bfd/elf32-hppa.c */
68 static struct insn_pattern hppa_long_branch_stub
[] = {
70 { 0x20200000, 0xffe00000 },
71 /* be,n RR'xxx(%sr4,%r1) */
72 { 0xe0202002, 0xffe02002 },
76 static struct insn_pattern hppa_long_branch_pic_stub
[] = {
78 { 0xe8200000, 0xffe00000 },
79 /* addil LR'xxx - ($PIC_pcrel$0 - 4), %r1 */
80 { 0x28200000, 0xffe00000 },
81 /* be,n RR'xxxx - ($PIC_pcrel$0 - 8)(%sr4, %r1) */
82 { 0xe0202002, 0xffe02002 },
86 static struct insn_pattern hppa_import_stub
[] = {
87 /* addil LR'xxx, %dp */
88 { 0x2b600000, 0xffe00000 },
89 /* ldw RR'xxx(%r1), %r21 */
90 { 0x48350000, 0xffffb000 },
92 { 0xeaa0c000, 0xffffffff },
93 /* ldw RR'xxx+4(%r1), %r19 */
94 { 0x48330000, 0xffffb000 },
98 static struct insn_pattern hppa_import_pic_stub
[] = {
99 /* addil LR'xxx,%r19 */
100 { 0x2a600000, 0xffe00000 },
101 /* ldw RR'xxx(%r1),%r21 */
102 { 0x48350000, 0xffffb000 },
104 { 0xeaa0c000, 0xffffffff },
105 /* ldw RR'xxx+4(%r1),%r19 */
106 { 0x48330000, 0xffffb000 },
110 static struct insn_pattern hppa_plt_stub
[] = {
111 /* b,l 1b, %r20 - 1b is 3 insns before here */
112 { 0xea9f1fdd, 0xffffffff },
113 /* depi 0,31,2,%r20 */
114 { 0xd6801c1e, 0xffffffff },
118 static struct insn_pattern hppa_sigtramp
[] = {
119 /* ldi 0, %r25 or ldi 1, %r25 */
120 { 0x34190000, 0xfffffffd },
121 /* ldi __NR_rt_sigreturn, %r20 */
122 { 0x3414015a, 0xffffffff },
123 /* be,l 0x100(%sr2, %r0), %sr0, %r31 */
124 { 0xe4008200, 0xffffffff },
126 { 0x08000240, 0xffffffff },
130 #define HPPA_MAX_INSN_PATTERN_LEN (4)
132 /* Return non-zero if the instructions at PC match the series
133 described in PATTERN, or zero otherwise. PATTERN is an array of
134 'struct insn_pattern' objects, terminated by an entry whose mask is
137 When the match is successful, fill INSN[i] with what PATTERN[i]
140 insns_match_pattern (CORE_ADDR pc
,
141 struct insn_pattern
*pattern
,
147 for (i
= 0; pattern
[i
].mask
; i
++)
149 insn
[i
] = read_memory_unsigned_integer (npc
, 4);
150 if ((insn
[i
] & pattern
[i
].mask
) == pattern
[i
].data
)
159 hppa_linux_in_dyncall (CORE_ADDR pc
)
161 static CORE_ADDR dyncall
= 0;
163 /* FIXME: if we switch exec files, dyncall should be reinitialized */
166 struct minimal_symbol
*minsym
;
168 minsym
= lookup_minimal_symbol ("$$dyncall", NULL
, NULL
);
170 dyncall
= SYMBOL_VALUE_ADDRESS (minsym
);
175 return pc
== dyncall
;
178 /* There are several kinds of "trampolines" that we need to deal with:
179 - long branch stubs: these are inserted by the linker when a branch
180 target is too far away for a branch insn to reach
181 - plt stubs: these should go into the .plt section, so are easy to find
182 - import stubs: used to call from object to shared lib or shared lib to
183 shared lib; these go in regular text sections. In fact the linker tries
184 to put them throughout the code because branches have limited reachability.
185 We use the same mechanism as ppc64 to recognize the stub insn patterns.
186 - $$dyncall: similar to hpux, hppa-linux uses $$dyncall for indirect function
187 calls. $$dyncall is exported by libgcc.a */
189 hppa_linux_in_solib_call_trampoline (CORE_ADDR pc
, char *name
)
191 unsigned int insn
[HPPA_MAX_INSN_PATTERN_LEN
];
194 r
= in_plt_section (pc
, name
)
195 || hppa_linux_in_dyncall (pc
)
196 || insns_match_pattern (pc
, hppa_import_stub
, insn
)
197 || insns_match_pattern (pc
, hppa_import_pic_stub
, insn
)
198 || insns_match_pattern (pc
, hppa_long_branch_stub
, insn
)
199 || insns_match_pattern (pc
, hppa_long_branch_pic_stub
, insn
);
205 hppa_linux_skip_trampoline_code (CORE_ADDR pc
)
207 unsigned int insn
[HPPA_MAX_INSN_PATTERN_LEN
];
210 /* dyncall handles both PLABELs and direct addresses */
211 if (hppa_linux_in_dyncall (pc
))
213 pc
= (CORE_ADDR
) read_register (22);
215 /* PLABELs have bit 30 set; if it's a PLABEL, then dereference it */
217 pc
= (CORE_ADDR
) read_memory_integer (pc
& ~0x3, TARGET_PTR_BIT
/ 8);
222 dp_rel
= pic_rel
= 0;
223 if ((dp_rel
= insns_match_pattern (pc
, hppa_import_stub
, insn
))
224 || (pic_rel
= insns_match_pattern (pc
, hppa_import_pic_stub
, insn
)))
226 /* Extract the target address from the addil/ldw sequence. */
227 pc
= hppa_extract_21 (insn
[0]) + hppa_extract_14 (insn
[1]);
230 pc
+= (CORE_ADDR
) read_register (27);
232 pc
+= (CORE_ADDR
) read_register (19);
237 if (in_plt_section (pc
, NULL
))
239 pc
= (CORE_ADDR
) read_memory_integer (pc
, TARGET_PTR_BIT
/ 8);
241 /* if the plt slot has not yet been resolved, the target will
243 if (in_plt_section (pc
, NULL
))
245 /* Sanity check: are we pointing to the plt stub? */
246 if (insns_match_pattern (pc
, hppa_plt_stub
, insn
))
248 /* this should point to the fixup routine */
249 pc
= (CORE_ADDR
) read_memory_integer (pc
+ 8, TARGET_PTR_BIT
/ 8);
253 error ("Cannot resolve plt stub at 0x%s\n",
265 /* (This is derived from MD_FALLBACK_FRAME_STATE_FOR in gcc.)
267 Unfortunately, because of various bugs and changes to the kernel,
268 we have several cases to deal with.
270 In 2.4, the signal trampoline is 4 bytes, and pc should point directly at
271 the beginning of the trampoline and struct rt_sigframe.
273 In <= 2.6.5-rc2-pa3, the signal trampoline is 9 bytes, and pc points at
274 the 4th word in the trampoline structure. This is wrong, it should point
275 at the 5th word. This is fixed in 2.6.5-rc2-pa4.
277 To detect these cases, we first take pc, align it to 64-bytes
278 to get the beginning of the signal frame, and then check offsets 0, 4
279 and 5 to see if we found the beginning of the trampoline. This will
280 tell us how to locate the sigcontext structure.
282 Note that with a 2.4 64-bit kernel, the signal context is not properly
283 passed back to userspace so the unwind will not work correctly. */
285 hppa_linux_sigtramp_find_sigcontext (CORE_ADDR sp
)
287 unsigned int dummy
[HPPA_MAX_INSN_PATTERN_LEN
];
290 /* offsets to try to find the trampoline */
291 static int pcoffs
[] = { 0, 4*4, 5*4 };
292 /* offsets to the rt_sigframe structure */
293 static int sfoffs
[] = { 4*4, 10*4, 10*4 };
295 /* rt_sigreturn trampoline:
296 3419000x ldi 0, %r25 or ldi 1, %r25 (x = 0 or 2)
297 3414015a ldi __NR_rt_sigreturn, %r20
298 e4008200 be,l 0x100(%sr2, %r0), %sr0, %r31
301 for (try = 0; try < ARRAY_SIZE (pcoffs
); try++)
303 if (insns_match_pattern (sp
+ pcoffs
[try], hppa_sigtramp
, dummy
))
313 /* sp + sfoffs[try] points to a struct rt_sigframe, which contains
314 a struct siginfo and a struct ucontext. struct ucontext contains
315 a struct sigcontext. Return an offset to this sigcontext here. Too
316 bad we cannot include system specific headers :-(.
317 sizeof(struct siginfo) == 128
318 offsetof(struct ucontext, uc_mcontext) == 24. */
319 return sp
+ sfoffs
[try] + 128 + 24;
322 struct hppa_linux_sigtramp_unwind_cache
325 struct trad_frame_saved_reg
*saved_regs
;
328 static struct hppa_linux_sigtramp_unwind_cache
*
329 hppa_linux_sigtramp_frame_unwind_cache (struct frame_info
*next_frame
,
332 struct gdbarch
*gdbarch
= get_frame_arch (next_frame
);
333 struct hppa_linux_sigtramp_unwind_cache
*info
;
334 CORE_ADDR sp
, pc
, scptr
;
340 info
= FRAME_OBSTACK_ZALLOC (struct hppa_linux_sigtramp_unwind_cache
);
342 info
->saved_regs
= trad_frame_alloc_saved_regs (next_frame
);
344 pc
= frame_pc_unwind (next_frame
);
346 scptr
= hppa_linux_sigtramp_find_sigcontext (sp
);
348 /* structure of struct sigcontext:
351 unsigned long sc_flags;
352 unsigned long sc_gr[32];
353 unsigned long long sc_fr[32];
354 unsigned long sc_iasq[2];
355 unsigned long sc_iaoq[2];
356 unsigned long sc_sar; */
361 /* GR[0] is the psw, we don't restore that. */
364 /* General registers. */
365 for (i
= 1; i
< 32; i
++)
367 info
->saved_regs
[HPPA_R0_REGNUM
+ i
].addr
= scptr
;
374 /* FP regs; FP0-3 are not restored. */
377 for (i
= 4; i
< 32; i
++)
379 info
->saved_regs
[HPPA_FP0_REGNUM
+ (i
* 2)].addr
= scptr
;
381 info
->saved_regs
[HPPA_FP0_REGNUM
+ (i
* 2) + 1].addr
= scptr
;
386 info
->saved_regs
[HPPA_PCSQ_HEAD_REGNUM
].addr
= scptr
;
388 info
->saved_regs
[HPPA_PCSQ_TAIL_REGNUM
].addr
= scptr
;
391 info
->saved_regs
[HPPA_PCOQ_HEAD_REGNUM
].addr
= scptr
;
393 info
->saved_regs
[HPPA_PCOQ_TAIL_REGNUM
].addr
= scptr
;
396 info
->base
= read_memory_unsigned_integer (
397 info
->saved_regs
[HPPA_SP_REGNUM
].addr
, 4);
403 hppa_linux_sigtramp_frame_this_id (struct frame_info
*next_frame
,
404 void **this_prologue_cache
,
405 struct frame_id
*this_id
)
407 struct hppa_linux_sigtramp_unwind_cache
*info
408 = hppa_linux_sigtramp_frame_unwind_cache (next_frame
, this_prologue_cache
);
409 *this_id
= frame_id_build (info
->base
, frame_pc_unwind (next_frame
));
413 hppa_linux_sigtramp_frame_prev_register (struct frame_info
*next_frame
,
414 void **this_prologue_cache
,
415 int regnum
, int *optimizedp
,
416 enum lval_type
*lvalp
,
418 int *realnump
, void *bufferp
)
420 struct hppa_linux_sigtramp_unwind_cache
*info
421 = hppa_linux_sigtramp_frame_unwind_cache (next_frame
, this_prologue_cache
);
422 int pcoqt
= (regnum
== HPPA_PCOQ_TAIL_REGNUM
);
425 regnum
= HPPA_PCOQ_HEAD_REGNUM
;
427 trad_frame_prev_register (next_frame
, info
->saved_regs
, regnum
,
428 optimizedp
, lvalp
, addrp
, realnump
, bufferp
);
431 store_unsigned_integer (bufferp
, 4,
432 extract_unsigned_integer (bufferp
, 4) + 4);
435 static const struct frame_unwind hppa_linux_sigtramp_frame_unwind
= {
437 hppa_linux_sigtramp_frame_this_id
,
438 hppa_linux_sigtramp_frame_prev_register
441 /* hppa-linux always uses "new-style" rt-signals. The signal handler's return
442 address should point to a signal trampoline on the stack. The signal
443 trampoline is embedded in a rt_sigframe structure that is aligned on
444 the stack. We take advantage of the fact that sp must be 64-byte aligned,
445 and the trampoline is small, so by rounding down the trampoline address
446 we can find the beginning of the struct rt_sigframe. */
447 static const struct frame_unwind
*
448 hppa_linux_sigtramp_unwind_sniffer (struct frame_info
*next_frame
)
450 CORE_ADDR pc
= frame_pc_unwind (next_frame
);
451 CORE_ADDR sp
= (pc
& ~63);
453 if (hppa_linux_sigtramp_find_sigcontext (sp
))
454 return &hppa_linux_sigtramp_frame_unwind
;
459 /* Forward declarations. */
460 extern initialize_file_ftype _initialize_hppa_linux_tdep
;
463 hppa_linux_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
465 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
467 /* Linux is always ELF. */
470 set_gdbarch_write_pc (gdbarch
, hppa_linux_target_write_pc
);
472 frame_unwind_append_sniffer (gdbarch
, hppa_linux_sigtramp_unwind_sniffer
);
474 /* GNU/Linux uses SVR4-style shared libraries. */
475 set_solib_svr4_fetch_link_map_offsets
476 (gdbarch
, svr4_ilp32_fetch_link_map_offsets
);
478 set_gdbarch_in_solib_call_trampoline
479 (gdbarch
, hppa_linux_in_solib_call_trampoline
);
480 set_gdbarch_skip_trampoline_code
481 (gdbarch
, hppa_linux_skip_trampoline_code
);
483 /* GNU/Linux uses the dynamic linker included in the GNU C Library. */
484 set_gdbarch_skip_solib_resolver (gdbarch
, glibc_skip_solib_resolver
);
487 /* Dwarf-2 unwinding support. Not yet working. */
488 set_gdbarch_dwarf_reg_to_regnum (gdbarch
, hppa_dwarf_reg_to_regnum
);
489 set_gdbarch_dwarf2_reg_to_regnum (gdbarch
, hppa_dwarf_reg_to_regnum
);
490 frame_unwind_append_sniffer (gdbarch
, dwarf2_frame_sniffer
);
491 frame_base_append_sniffer (gdbarch
, dwarf2_frame_base_sniffer
);
496 _initialize_hppa_linux_tdep (void)
498 gdbarch_register_osabi (bfd_arch_hppa
, 0, GDB_OSABI_LINUX
, hppa_linux_init_abi
);