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/tmp/gdb-7.10/gdb/ppcobsd-tdep.c
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1 /* Target-dependent code for OpenBSD/powerpc.
2 
3  Copyright (C) 2004-2015 Free Software Foundation, Inc.
4 
5  This file is part of GDB.
6 
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 3 of the License, or
10  (at your option) any later version.
11 
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.
16 
17  You should have received a copy of the GNU General Public License
18  along with this program. If not, see <http://www.gnu.org/licenses/>. */
19 
20 #include "defs.h"
21 #include "arch-utils.h"
22 #include "frame.h"
23 #include "frame-unwind.h"
24 #include "gdbtypes.h"
25 #include "osabi.h"
26 #include "regcache.h"
27 #include "regset.h"
28 #include "symtab.h"
29 #include "trad-frame.h"
30 
31 #include "ppc-tdep.h"
32 #include "ppcobsd-tdep.h"
33 #include "solib-svr4.h"
34 
35 /* Register offsets from <machine/reg.h>. */
38 
39 
40 /* Core file support. */
41 
42 /* Supply register REGNUM in the general-purpose register set REGSET
43  from the buffer specified by GREGS and LEN to register cache
44  REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
45 
46 void
48  struct regcache *regcache, int regnum,
49  const void *gregs, size_t len)
50 {
51  ppc_supply_gregset (regset, regcache, regnum, gregs, len);
52  ppc_supply_fpregset (regset, regcache, regnum, gregs, len);
53 }
54 
55 /* Collect register REGNUM in the general-purpose register set
56  REGSET, from register cache REGCACHE into the buffer specified by
57  GREGS and LEN. If REGNUM is -1, do this for all registers in
58  REGSET. */
59 
60 void
62  const struct regcache *regcache, int regnum,
63  void *gregs, size_t len)
64 {
65  ppc_collect_gregset (regset, regcache, regnum, gregs, len);
66  ppc_collect_fpregset (regset, regcache, regnum, gregs, len);
67 }
68 
69 /* OpenBSD/powerpc register set. */
70 
71 const struct regset ppcobsd_gregset =
72 {
75 };
76 
77 const struct regset ppcobsd_fpregset =
78 {
81 };
82 
83 /* Iterate over core file register note sections. */
84 
85 static void
88  void *cb_data,
89  const struct regcache *regcache)
90 {
91  cb (".reg", 412, &ppcobsd_gregset, NULL, cb_data);
92 }
93 
94 
95 /* Signal trampolines. */
96 
97 /* Since OpenBSD 3.2, the sigtramp routine is mapped at a random page
98  in virtual memory. The randomness makes it somewhat tricky to
99  detect it, but fortunately we can rely on the fact that the start
100  of the sigtramp routine is page-aligned. We recognize the
101  trampoline by looking for the code that invokes the sigreturn
102  system call. The offset where we can find that code varies from
103  release to release.
104 
105  By the way, the mapping mentioned above is read-only, so you cannot
106  place a breakpoint in the signal trampoline. */
107 
108 /* Default page size. */
109 static const int ppcobsd_page_size = 4096;
110 
111 /* Offset for sigreturn(2). */
112 static const int ppcobsd_sigreturn_offset[] = {
113  0x98, /* OpenBSD 3.8 */
114  0x0c, /* OpenBSD 3.2 */
115  -1
116 };
117 
118 static int
120  struct frame_info *this_frame,
121  void **this_cache)
122 {
123  struct gdbarch *gdbarch = get_frame_arch (this_frame);
124  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
125  CORE_ADDR pc = get_frame_pc (this_frame);
126  CORE_ADDR start_pc = (pc & ~(ppcobsd_page_size - 1));
127  const int *offset;
128  const char *name;
129 
130  find_pc_partial_function (pc, &name, NULL, NULL);
131  if (name)
132  return 0;
133 
134  for (offset = ppcobsd_sigreturn_offset; *offset != -1; offset++)
135  {
136  gdb_byte buf[2 * PPC_INSN_SIZE];
137  unsigned long insn;
138 
139  if (!safe_frame_unwind_memory (this_frame, start_pc + *offset,
140  buf, sizeof buf))
141  continue;
142 
143  /* Check for "li r0,SYS_sigreturn". */
144  insn = extract_unsigned_integer (buf, PPC_INSN_SIZE, byte_order);
145  if (insn != 0x38000067)
146  continue;
147 
148  /* Check for "sc". */
150  PPC_INSN_SIZE, byte_order);
151  if (insn != 0x44000002)
152  continue;
153 
154  return 1;
155  }
156 
157  return 0;
158 }
159 
160 static struct trad_frame_cache *
162 {
163  struct gdbarch *gdbarch = get_frame_arch (this_frame);
164  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
165  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
166  struct trad_frame_cache *cache;
167  CORE_ADDR addr, base, func;
168  gdb_byte buf[PPC_INSN_SIZE];
169  unsigned long insn, sigcontext_offset;
170  int i;
171 
172  if (*this_cache)
173  return *this_cache;
174 
175  cache = trad_frame_cache_zalloc (this_frame);
176  *this_cache = cache;
177 
178  func = get_frame_pc (this_frame);
179  func &= ~(ppcobsd_page_size - 1);
180  if (!safe_frame_unwind_memory (this_frame, func, buf, sizeof buf))
181  return cache;
182 
183  /* Calculate the offset where we can find `struct sigcontext'. We
184  base our calculation on the amount of stack space reserved by the
185  first instruction of the signal trampoline. */
186  insn = extract_unsigned_integer (buf, PPC_INSN_SIZE, byte_order);
187  sigcontext_offset = (0x10000 - (insn & 0x0000ffff)) + 8;
188 
189  base = get_frame_register_unsigned (this_frame, gdbarch_sp_regnum (gdbarch));
190  addr = base + sigcontext_offset + 2 * tdep->wordsize;
191  for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
192  {
193  int regnum = i + tdep->ppc_gp0_regnum;
194  trad_frame_set_reg_addr (cache, regnum, addr);
195  }
196  trad_frame_set_reg_addr (cache, tdep->ppc_lr_regnum, addr);
197  addr += tdep->wordsize;
198  trad_frame_set_reg_addr (cache, tdep->ppc_cr_regnum, addr);
199  addr += tdep->wordsize;
200  trad_frame_set_reg_addr (cache, tdep->ppc_xer_regnum, addr);
201  addr += tdep->wordsize;
202  trad_frame_set_reg_addr (cache, tdep->ppc_ctr_regnum, addr);
203  addr += tdep->wordsize;
204  trad_frame_set_reg_addr (cache, gdbarch_pc_regnum (gdbarch), addr);
205  /* SRR0? */
206  addr += tdep->wordsize;
207 
208  /* Construct the frame ID using the function start. */
209  trad_frame_set_id (cache, frame_id_build (base, func));
210 
211  return cache;
212 }
213 
214 static void
216  void **this_cache, struct frame_id *this_id)
217 {
218  struct trad_frame_cache *cache =
219  ppcobsd_sigtramp_frame_cache (this_frame, this_cache);
220 
221  trad_frame_get_id (cache, this_id);
222 }
223 
224 static struct value *
226  void **this_cache, int regnum)
227 {
228  struct trad_frame_cache *cache =
229  ppcobsd_sigtramp_frame_cache (this_frame, this_cache);
230 
231  return trad_frame_get_register (cache, this_frame, regnum);
232 }
233 
234 static const struct frame_unwind ppcobsd_sigtramp_frame_unwind = {
239  NULL,
241 };
242 
243 
244 static void
246 {
247  /* OpenBSD doesn't support the 128-bit `long double' from the psABI. */
248  set_gdbarch_long_double_bit (gdbarch, 64);
250 
251  /* OpenBSD currently uses a broken GCC. */
253 
254  /* OpenBSD uses SVR4-style shared libraries. */
257 
260 
261  frame_unwind_append_unwinder (gdbarch, &ppcobsd_sigtramp_frame_unwind);
262 }
263 
264 
265 /* OpenBSD uses uses the traditional NetBSD core file format, even for
266  ports that use ELF. */
267 #define GDB_OSABI_NETBSD_CORE GDB_OSABI_OPENBSD_ELF
268 
269 static enum gdb_osabi
271 {
272  if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
273  return GDB_OSABI_NETBSD_CORE;
274 
275  return GDB_OSABI_UNKNOWN;
276 }
277 
278 
279 /* Provide a prototype to silence -Wmissing-prototypes. */
280 void _initialize_ppcobsd_tdep (void);
281 
282 void
284 {
285  /* BFD doesn't set a flavour for NetBSD style a.out core files. */
286  gdbarch_register_osabi_sniffer (bfd_arch_powerpc, bfd_target_unknown_flavour,
288 
289  gdbarch_register_osabi (bfd_arch_rs6000, 0, GDB_OSABI_OPENBSD_ELF,
291  gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_OPENBSD_ELF,
293 
294  /* Avoid initializing the register offsets again if they were
295  already initailized by ppcobsd-nat.c. */
297  {
298  /* General-purpose registers. */
309 
310  /* Floating-point registers. */
313 
314  /* AltiVec registers. */
318  }
319 
321  {
322  /* Floating-point registers. */
326  }
327 }
#define GDB_OSABI_NETBSD_CORE
Definition: ppcobsd-tdep.c:267
static const int ppcobsd_sigreturn_offset[]
Definition: ppcobsd-tdep.c:112
static struct value * ppcobsd_sigtramp_frame_prev_register(struct frame_info *this_frame, void **this_cache, int regnum)
Definition: ppcobsd-tdep.c:225
ULONGEST extract_unsigned_integer(const gdb_byte *, int, enum bfd_endian)
Definition: findvar.c:84
static void ppcobsd_sigtramp_frame_this_id(struct frame_info *this_frame, void **this_cache, struct frame_id *this_id)
Definition: ppcobsd-tdep.c:215
void trad_frame_set_reg_addr(struct trad_frame_cache *this_trad_cache, int regnum, CORE_ADDR addr)
Definition: trad-frame.c:119
static int ppcobsd_sigtramp_frame_sniffer(const struct frame_unwind *self, struct frame_info *this_frame, void **this_cache)
Definition: ppcobsd-tdep.c:119
struct frame_id frame_id_build(CORE_ADDR stack_addr, CORE_ADDR code_addr)
Definition: frame.c:554
enum return_value_convention ppc_sysv_abi_broken_return_value(struct gdbarch *gdbarch, struct value *function, struct type *valtype, struct regcache *regcache, gdb_byte *readbuf, const gdb_byte *writebuf)
CORE_ADDR get_frame_pc(struct frame_info *frame)
Definition: frame.c:2217
bfd_vma CORE_ADDR
Definition: common-types.h:41
const struct floatformat * floatformats_ieee_double[BFD_ENDIAN_UNKNOWN]
Definition: gdbtypes.c:74
static struct trad_frame_cache * ppcobsd_sigtramp_frame_cache(struct frame_info *this_frame, void **this_cache)
Definition: ppcobsd-tdep.c:161
int ppc_lr_regnum
Definition: ppc-tdep.h:218
void(* func)(char *)
static void ppcobsd_iterate_over_regset_sections(struct gdbarch *gdbarch, iterate_over_regset_sections_cb *cb, void *cb_data, const struct regcache *regcache)
Definition: ppcobsd-tdep.c:86
void ppc_supply_fpregset(const struct regset *regset, struct regcache *regcache, int regnum, const void *fpregs, size_t len)
Definition: rs6000-tdep.c:550
void trad_frame_set_id(struct trad_frame_cache *this_trad_cache, struct frame_id this_id)
Definition: trad-frame.c:164
struct ppc_reg_offsets ppcobsd_reg_offsets
Definition: ppcobsd-tdep.c:36
void gdbarch_register_osabi_sniffer(enum bfd_architecture arch, enum bfd_flavour flavour, enum gdb_osabi(*sniffer_fn)(bfd *))
Definition: osabi.c:225
struct link_map_offsets * svr4_ilp32_fetch_link_map_offsets(void)
Definition: solib-svr4.c:3149
int ppc_cr_regnum
Definition: ppc-tdep.h:217
struct gdbarch_tdep * gdbarch_tdep(struct gdbarch *gdbarch)
Definition: gdbarch.c:1402
void frame_unwind_append_unwinder(struct gdbarch *gdbarch, const struct frame_unwind *unwinder)
Definition: frame-unwind.c:78
void ppcobsd_collect_gregset(const struct regset *regset, const struct regcache *regcache, int regnum, void *gregs, size_t len)
Definition: ppcobsd-tdep.c:61
Definition: regset.h:34
void trad_frame_get_id(struct trad_frame_cache *this_trad_cache, struct frame_id *this_id)
Definition: trad-frame.c:171
const char *const name
Definition: aarch64-tdep.c:68
void ppc_collect_gregset(const struct regset *regset, const struct regcache *regcache, int regnum, void *gregs, size_t len)
Definition: rs6000-tdep.c:663
int gdbarch_sp_regnum(struct gdbarch *gdbarch)
Definition: gdbarch.c:1981
int safe_frame_unwind_memory(struct frame_info *this_frame, CORE_ADDR addr, gdb_byte *buf, int len)
Definition: frame.c:2525
#define PPC_INSN_SIZE
Definition: ppc-tdep.h:327
int ppc_gp0_regnum
Definition: ppc-tdep.h:214
enum bfd_endian gdbarch_byte_order(struct gdbarch *gdbarch)
Definition: gdbarch.c:1420
void set_solib_svr4_fetch_link_map_offsets(struct gdbarch *gdbarch, struct link_map_offsets *(*flmo)(void))
Definition: solib-svr4.c:3108
int find_pc_partial_function(CORE_ADDR pc, const char **name, CORE_ADDR *address, CORE_ADDR *endaddr)
Definition: blockframe.c:321
void ppcobsd_supply_gregset(const struct regset *regset, struct regcache *regcache, int regnum, const void *gregs, size_t len)
Definition: ppcobsd-tdep.c:47
struct ppc_reg_offsets ppcobsd_fpreg_offsets
Definition: ppcobsd-tdep.c:37
void ppc_collect_fpregset(const struct regset *regset, const struct regcache *regcache, int regnum, void *fpregs, size_t len)
Definition: rs6000-tdep.c:710
struct trad_frame_cache * trad_frame_cache_zalloc(struct frame_info *this_frame)
Definition: trad-frame.c:36
int regnum
Definition: aarch64-tdep.c:69
void( iterate_over_regset_sections_cb)(const char *sect_name, int size, const struct regset *regset, const char *human_name, void *cb_data)
Definition: gdbarch.h:98
ULONGEST get_frame_register_unsigned(struct frame_info *frame, int regnum)
Definition: frame.c:1194
struct frame_info * this_frame
Definition: trad-frame.c:29
Definition: value.c:172
static void ppcobsd_init_abi(struct gdbarch_info info, struct gdbarch *gdbarch)
Definition: ppcobsd-tdep.c:245
struct frame_id this_id
Definition: trad-frame.c:32
bfd_byte gdb_byte
Definition: common-types.h:38
int ppc_ctr_regnum
Definition: ppc-tdep.h:219
int wordsize
Definition: ppc-tdep.h:206
int offset
Definition: agent.c:65
int ppc_xer_regnum
Definition: ppc-tdep.h:220
static enum gdb_osabi ppcobsd_core_osabi_sniffer(bfd *abfd)
Definition: ppcobsd-tdep.c:270
enum unwind_stop_reason default_frame_unwind_stop_reason(struct frame_info *this_frame, void **this_cache)
Definition: frame-unwind.c:180
void set_gdbarch_long_double_bit(struct gdbarch *gdbarch, int long_double_bit)
Definition: gdbarch.c:1667
void set_gdbarch_return_value(struct gdbarch *gdbarch, gdbarch_return_value_ftype return_value)
Definition: gdbarch.c:2556
int gdbarch_pc_regnum(struct gdbarch *gdbarch)
Definition: gdbarch.c:1998
void set_gdbarch_long_double_format(struct gdbarch *gdbarch, const struct floatformat **long_double_format)
Definition: gdbarch.c:1683
static const int ppcobsd_page_size
Definition: ppcobsd-tdep.c:109
void _initialize_ppcobsd_tdep(void)
Definition: ppcobsd-tdep.c:283
void set_gdbarch_iterate_over_regset_sections(struct gdbarch *gdbarch, gdbarch_iterate_over_regset_sections_ftype iterate_over_regset_sections)
Definition: gdbarch.c:3398
struct value * trad_frame_get_register(struct trad_frame_cache *this_trad_cache, struct frame_info *this_frame, int regnum)
Definition: trad-frame.c:155
enum bfd_endian byte_order
Definition: gdbarch.c:128
void gdbarch_register_osabi(enum bfd_architecture arch, unsigned long machine, enum gdb_osabi osabi, void(*init_osabi)(struct gdbarch_info, struct gdbarch *))
Definition: osabi.c:148
void ppc_supply_gregset(const struct regset *regset, struct regcache *regcache, int regnum, const void *gregs, size_t len)
Definition: rs6000-tdep.c:505
struct gdbarch * get_frame_arch(struct frame_info *this_frame)
Definition: frame.c:2535
gdb_osabi
Definition: defs.h:540
const ULONGEST const LONGEST len
Definition: target.h:309