1 /* Target-dependent code for OpenBSD/sparc.
3 Copyright (C) 2004-2021 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 3 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, see <http://www.gnu.org/licenses/>. */
22 #include "frame-unwind.h"
27 #include "trad-frame.h"
30 #include "obsd-tdep.h"
31 #include "sparc-tdep.h"
32 #include "solib-svr4.h"
33 #include "bsd-uthread.h"
36 /* Signal trampolines. */
38 /* The OpenBSD kernel maps the signal trampoline at some random
39 location in user space, which means that the traditional BSD way of
40 detecting it won't work.
42 The signal trampoline will be mapped at an address that is page
43 aligned. We recognize the signal trampoline by looking for the
44 sigreturn system call. */
46 static const int sparc32obsd_page_size
= 4096;
49 sparc32obsd_pc_in_sigtramp (CORE_ADDR pc
, const char *name
)
51 CORE_ADDR start_pc
= (pc
& ~(sparc32obsd_page_size
- 1));
57 /* Check for "restore %g0, SYS_sigreturn, %g1". */
58 insn
= sparc_fetch_instruction (start_pc
+ 0xec);
59 if (insn
!= 0x83e82067)
62 /* Check for "t ST_SYSCALL". */
63 insn
= sparc_fetch_instruction (start_pc
+ 0xf4);
64 if (insn
!= 0x91d02000)
70 static struct sparc_frame_cache
*
71 sparc32obsd_sigtramp_frame_cache (struct frame_info
*this_frame
,
74 struct sparc_frame_cache
*cache
;
78 return (struct sparc_frame_cache
*) *this_cache
;
80 cache
= sparc_frame_cache (this_frame
, this_cache
);
81 gdb_assert (cache
== *this_cache
);
83 /* If we couldn't find the frame's function, we're probably dealing
84 with an on-stack signal trampoline. */
87 cache
->pc
= get_frame_pc (this_frame
);
88 cache
->pc
&= ~(sparc32obsd_page_size
- 1);
90 /* Since we couldn't find the frame's function, the cache was
91 initialized under the assumption that we're frameless. */
92 sparc_record_save_insn (cache
);
93 addr
= get_frame_register_unsigned (this_frame
, SPARC_FP_REGNUM
);
97 cache
->saved_regs
= sparc32nbsd_sigcontext_saved_regs (this_frame
);
103 sparc32obsd_sigtramp_frame_this_id (struct frame_info
*this_frame
,
105 struct frame_id
*this_id
)
107 struct sparc_frame_cache
*cache
=
108 sparc32obsd_sigtramp_frame_cache (this_frame
, this_cache
);
110 (*this_id
) = frame_id_build (cache
->base
, cache
->pc
);
113 static struct value
*
114 sparc32obsd_sigtramp_frame_prev_register (struct frame_info
*this_frame
,
115 void **this_cache
, int regnum
)
117 struct sparc_frame_cache
*cache
=
118 sparc32obsd_sigtramp_frame_cache (this_frame
, this_cache
);
120 return trad_frame_get_prev_register (this_frame
, cache
->saved_regs
, regnum
);
124 sparc32obsd_sigtramp_frame_sniffer (const struct frame_unwind
*self
,
125 struct frame_info
*this_frame
,
128 CORE_ADDR pc
= get_frame_pc (this_frame
);
131 find_pc_partial_function (pc
, &name
, NULL
, NULL
);
132 if (sparc32obsd_pc_in_sigtramp (pc
, name
))
137 static const struct frame_unwind sparc32obsd_sigtramp_frame_unwind
=
140 default_frame_unwind_stop_reason
,
141 sparc32obsd_sigtramp_frame_this_id
,
142 sparc32obsd_sigtramp_frame_prev_register
,
144 sparc32obsd_sigtramp_frame_sniffer
149 /* Offset wthin the thread structure where we can find %fp and %i7. */
150 #define SPARC32OBSD_UTHREAD_FP_OFFSET 128
151 #define SPARC32OBSD_UTHREAD_PC_OFFSET 132
154 sparc32obsd_supply_uthread (struct regcache
*regcache
,
155 int regnum
, CORE_ADDR addr
)
157 struct gdbarch
*gdbarch
= regcache
->arch ();
158 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
159 CORE_ADDR fp
, fp_addr
= addr
+ SPARC32OBSD_UTHREAD_FP_OFFSET
;
162 /* This function calls functions that depend on the global current thread. */
163 gdb_assert (regcache
->ptid () == inferior_ptid
);
165 gdb_assert (regnum
>= -1);
167 fp
= read_memory_unsigned_integer (fp_addr
, 4, byte_order
);
168 if (regnum
== SPARC_SP_REGNUM
|| regnum
== -1)
170 store_unsigned_integer (buf
, 4, byte_order
, fp
);
171 regcache
->raw_supply (SPARC_SP_REGNUM
, buf
);
173 if (regnum
== SPARC_SP_REGNUM
)
177 if (regnum
== SPARC32_PC_REGNUM
|| regnum
== SPARC32_NPC_REGNUM
180 CORE_ADDR i7
, i7_addr
= addr
+ SPARC32OBSD_UTHREAD_PC_OFFSET
;
182 i7
= read_memory_unsigned_integer (i7_addr
, 4, byte_order
);
183 if (regnum
== SPARC32_PC_REGNUM
|| regnum
== -1)
185 store_unsigned_integer (buf
, 4, byte_order
, i7
+ 8);
186 regcache
->raw_supply (SPARC32_PC_REGNUM
, buf
);
188 if (regnum
== SPARC32_NPC_REGNUM
|| regnum
== -1)
190 store_unsigned_integer (buf
, 4, byte_order
, i7
+ 12);
191 regcache
->raw_supply (SPARC32_NPC_REGNUM
, buf
);
194 if (regnum
== SPARC32_PC_REGNUM
|| regnum
== SPARC32_NPC_REGNUM
)
198 sparc_supply_rwindow (regcache
, fp
, regnum
);
202 sparc32obsd_collect_uthread(const struct regcache
*regcache
,
203 int regnum
, CORE_ADDR addr
)
205 struct gdbarch
*gdbarch
= regcache
->arch ();
206 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
210 /* This function calls functions that depend on the global current thread. */
211 gdb_assert (regcache
->ptid () == inferior_ptid
);
213 gdb_assert (regnum
>= -1);
215 if (regnum
== SPARC_SP_REGNUM
|| regnum
== -1)
217 CORE_ADDR fp_addr
= addr
+ SPARC32OBSD_UTHREAD_FP_OFFSET
;
219 regcache
->raw_collect (SPARC_SP_REGNUM
, buf
);
220 write_memory (fp_addr
,buf
, 4);
223 if (regnum
== SPARC32_PC_REGNUM
|| regnum
== -1)
225 CORE_ADDR i7
, i7_addr
= addr
+ SPARC32OBSD_UTHREAD_PC_OFFSET
;
227 regcache
->raw_collect (SPARC32_PC_REGNUM
, buf
);
228 i7
= extract_unsigned_integer (buf
, 4, byte_order
) - 8;
229 write_memory_unsigned_integer (i7_addr
, 4, byte_order
, i7
);
231 if (regnum
== SPARC32_PC_REGNUM
)
235 regcache
->raw_collect (SPARC_SP_REGNUM
, buf
);
236 sp
= extract_unsigned_integer (buf
, 4, byte_order
);
237 sparc_collect_rwindow (regcache
, sp
, regnum
);
242 sparc32obsd_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
244 /* OpenBSD/sparc is very similar to NetBSD/sparc ELF. */
245 sparc32nbsd_init_abi (info
, gdbarch
);
247 set_gdbarch_skip_solib_resolver (gdbarch
, obsd_skip_solib_resolver
);
249 frame_unwind_append_unwinder (gdbarch
, &sparc32obsd_sigtramp_frame_unwind
);
251 /* OpenBSD provides a user-level threads implementation. */
252 bsd_uthread_set_supply_uthread (gdbarch
, sparc32obsd_supply_uthread
);
253 bsd_uthread_set_collect_uthread (gdbarch
, sparc32obsd_collect_uthread
);
256 void _initialize_sparc32obsd_tdep ();
258 _initialize_sparc32obsd_tdep ()
260 gdbarch_register_osabi (bfd_arch_sparc
, 0, GDB_OSABI_OPENBSD
,
261 sparc32obsd_init_abi
);