1 /* Target-dependent code for GNU/Linux SPARC.
3 Copyright (C) 2003, 2004, 2005, 2007 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., 51 Franklin Street, Fifth Floor,
20 Boston, MA 02110-1301, USA. */
23 #include "dwarf2-frame.h"
25 #include "frame-unwind.h"
32 #include "solib-svr4.h"
34 #include "trad-frame.h"
35 #include "tramp-frame.h"
37 #include "sparc-tdep.h"
39 /* Signal trampoline support. */
41 static void sparc32_linux_sigframe_init (const struct tramp_frame
*self
,
42 struct frame_info
*next_frame
,
43 struct trad_frame_cache
*this_cache
,
46 /* GNU/Linux has two flavors of signals. Normal signal handlers, and
47 "realtime" (RT) signals. The RT signals can provide additional
48 information to the signal handler if the SA_SIGINFO flag is set
49 when establishing a signal handler using `sigaction'. It is not
50 unlikely that future versions of GNU/Linux will support SA_SIGINFO
51 for normal signals too. */
53 /* When the sparc Linux kernel calls a signal handler and the
54 SA_RESTORER flag isn't set, the return address points to a bit of
55 code on the stack. This code checks whether the PC appears to be
56 within this bit of code.
58 The instruction sequence for normal signals is encoded below.
59 Checking for the code sequence should be somewhat reliable, because
60 the effect is to call the system call sigreturn. This is unlikely
61 to occur anywhere other than a signal trampoline. */
63 static const struct tramp_frame sparc32_linux_sigframe
=
68 { 0x821020d8, -1 }, /* mov __NR_sugreturn, %g1 */
69 { 0x91d02010, -1 }, /* ta 0x10 */
70 { TRAMP_SENTINEL_INSN
, -1 }
72 sparc32_linux_sigframe_init
75 /* The instruction sequence for RT signals is slightly different. The
76 effect is to call the system call rt_sigreturn. */
78 static const struct tramp_frame sparc32_linux_rt_sigframe
=
83 { 0x82102065, -1 }, /* mov __NR_rt_sigreturn, %g1 */
84 { 0x91d02010, -1 }, /* ta 0x10 */
85 { TRAMP_SENTINEL_INSN
, -1 }
87 sparc32_linux_sigframe_init
91 sparc32_linux_sigframe_init (const struct tramp_frame
*self
,
92 struct frame_info
*next_frame
,
93 struct trad_frame_cache
*this_cache
,
96 CORE_ADDR base
, addr
, sp_addr
;
99 base
= frame_unwind_register_unsigned (next_frame
, SPARC_O1_REGNUM
);
100 if (self
== &sparc32_linux_rt_sigframe
)
103 /* Offsets from <bits/sigcontext.h>. */
105 trad_frame_set_reg_addr (this_cache
, SPARC32_PSR_REGNUM
, base
+ 0);
106 trad_frame_set_reg_addr (this_cache
, SPARC32_PC_REGNUM
, base
+ 4);
107 trad_frame_set_reg_addr (this_cache
, SPARC32_NPC_REGNUM
, base
+ 8);
108 trad_frame_set_reg_addr (this_cache
, SPARC32_Y_REGNUM
, base
+ 12);
110 /* Since %g0 is always zero, keep the identity encoding. */
112 sp_addr
= base
+ 16 + ((SPARC_SP_REGNUM
- SPARC_G0_REGNUM
) * 4);
113 for (regnum
= SPARC_G1_REGNUM
; regnum
<= SPARC_O7_REGNUM
; regnum
++)
115 trad_frame_set_reg_addr (this_cache
, regnum
, addr
);
119 base
= frame_unwind_register_unsigned (next_frame
, SPARC_SP_REGNUM
);
120 addr
= get_frame_memory_unsigned (next_frame
, sp_addr
, 4);
122 for (regnum
= SPARC_L0_REGNUM
; regnum
<= SPARC_I7_REGNUM
; regnum
++)
124 trad_frame_set_reg_addr (this_cache
, regnum
, addr
);
127 trad_frame_set_id (this_cache
, frame_id_build (base
, func
));
130 /* Return the address of a system call's alternative return
134 sparc32_linux_step_trap (struct frame_info
*frame
, unsigned long insn
)
136 if (insn
== 0x91d02010)
138 ULONGEST sc_num
= get_frame_register_unsigned (frame
, SPARC_G1_REGNUM
);
140 /* __NR_rt_sigreturn is 101 and __NR_sigreturn is 216 */
141 if (sc_num
== 101 || sc_num
== 216)
143 ULONGEST sp
, pc_offset
;
145 sp
= get_frame_register_unsigned (frame
, SPARC_SP_REGNUM
);
147 /* The kernel puts the sigreturn registers on the stack,
148 and this is where the signal unwinding state is take from
149 when returning from a signal.
151 For __NR_sigreturn, this register area sits 96 bytes from
152 the base of the stack. The saved PC sits 4 bytes into the
153 sigreturn register save area.
155 For __NR_rt_sigreturn a siginfo_t, which is 128 bytes, sits
156 right before the sigreturn register save area. */
162 return read_memory_unsigned_integer (sp
+ pc_offset
, 4);
170 const struct sparc_gregset sparc32_linux_core_gregset
=
185 sparc32_linux_supply_core_gregset (const struct regset
*regset
,
186 struct regcache
*regcache
,
187 int regnum
, const void *gregs
, size_t len
)
189 sparc32_supply_gregset (&sparc32_linux_core_gregset
, regcache
, regnum
, gregs
);
193 sparc32_linux_collect_core_gregset (const struct regset
*regset
,
194 const struct regcache
*regcache
,
195 int regnum
, void *gregs
, size_t len
)
197 sparc32_collect_gregset (&sparc32_linux_core_gregset
, regcache
, regnum
, gregs
);
201 sparc32_linux_supply_core_fpregset (const struct regset
*regset
,
202 struct regcache
*regcache
,
203 int regnum
, const void *fpregs
, size_t len
)
205 sparc32_supply_fpregset (regcache
, regnum
, fpregs
);
209 sparc32_linux_collect_core_fpregset (const struct regset
*regset
,
210 const struct regcache
*regcache
,
211 int regnum
, void *fpregs
, size_t len
)
213 sparc32_collect_fpregset (regcache
, regnum
, fpregs
);
219 sparc32_linux_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
221 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
223 tdep
->gregset
= regset_alloc (gdbarch
, sparc32_linux_supply_core_gregset
,
224 sparc32_linux_collect_core_gregset
);
225 tdep
->sizeof_gregset
= 152;
227 tdep
->fpregset
= regset_alloc (gdbarch
, sparc32_linux_supply_core_fpregset
,
228 sparc32_linux_collect_core_fpregset
);
229 tdep
->sizeof_fpregset
= 396;
231 tramp_frame_prepend_unwinder (gdbarch
, &sparc32_linux_sigframe
);
232 tramp_frame_prepend_unwinder (gdbarch
, &sparc32_linux_rt_sigframe
);
234 /* GNU/Linux has SVR4-style shared libraries... */
235 set_gdbarch_skip_trampoline_code (gdbarch
, find_solib_trampoline_target
);
236 set_solib_svr4_fetch_link_map_offsets
237 (gdbarch
, svr4_ilp32_fetch_link_map_offsets
);
239 /* ...which means that we need some special handling when doing
240 prologue analysis. */
241 tdep
->plt_entry_size
= 12;
243 /* GNU/Linux doesn't support the 128-bit `long double' from the psABI. */
244 set_gdbarch_long_double_bit (gdbarch
, 64);
245 set_gdbarch_long_double_format (gdbarch
, floatformats_ieee_double
);
247 /* Enable TLS support. */
248 set_gdbarch_fetch_tls_load_module_address (gdbarch
,
249 svr4_fetch_objfile_link_map
);
251 /* Make sure we can single-step over signal return system calls. */
252 tdep
->step_trap
= sparc32_linux_step_trap
;
254 /* Hook in the DWARF CFI frame unwinder. */
255 frame_unwind_append_sniffer (gdbarch
, dwarf2_frame_sniffer
);
258 /* Provide a prototype to silence -Wmissing-prototypes. */
259 extern void _initialize_sparc_linux_tdep (void);
262 _initialize_sparc_linux_tdep (void)
264 gdbarch_register_osabi (bfd_arch_sparc
, 0, GDB_OSABI_LINUX
,
265 sparc32_linux_init_abi
);