1 /* Target-dependent code for GNU/Linux SPARC.
3 Copyright (C) 2003, 2004, 2005, 2007, 2008 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/>. */
21 #include "dwarf2-frame.h"
23 #include "frame-unwind.h"
30 #include "solib-svr4.h"
32 #include "trad-frame.h"
33 #include "tramp-frame.h"
35 #include "sparc-tdep.h"
37 /* Signal trampoline support. */
39 static void sparc32_linux_sigframe_init (const struct tramp_frame
*self
,
40 struct frame_info
*this_frame
,
41 struct trad_frame_cache
*this_cache
,
44 /* GNU/Linux has two flavors of signals. Normal signal handlers, and
45 "realtime" (RT) signals. The RT signals can provide additional
46 information to the signal handler if the SA_SIGINFO flag is set
47 when establishing a signal handler using `sigaction'. It is not
48 unlikely that future versions of GNU/Linux will support SA_SIGINFO
49 for normal signals too. */
51 /* When the sparc Linux kernel calls a signal handler and the
52 SA_RESTORER flag isn't set, the return address points to a bit of
53 code on the stack. This code checks whether the PC appears to be
54 within this bit of code.
56 The instruction sequence for normal signals is encoded below.
57 Checking for the code sequence should be somewhat reliable, because
58 the effect is to call the system call sigreturn. This is unlikely
59 to occur anywhere other than a signal trampoline. */
61 static const struct tramp_frame sparc32_linux_sigframe
=
66 { 0x821020d8, -1 }, /* mov __NR_sugreturn, %g1 */
67 { 0x91d02010, -1 }, /* ta 0x10 */
68 { TRAMP_SENTINEL_INSN
, -1 }
70 sparc32_linux_sigframe_init
73 /* The instruction sequence for RT signals is slightly different. The
74 effect is to call the system call rt_sigreturn. */
76 static const struct tramp_frame sparc32_linux_rt_sigframe
=
81 { 0x82102065, -1 }, /* mov __NR_rt_sigreturn, %g1 */
82 { 0x91d02010, -1 }, /* ta 0x10 */
83 { TRAMP_SENTINEL_INSN
, -1 }
85 sparc32_linux_sigframe_init
89 sparc32_linux_sigframe_init (const struct tramp_frame
*self
,
90 struct frame_info
*this_frame
,
91 struct trad_frame_cache
*this_cache
,
94 CORE_ADDR base
, addr
, sp_addr
;
97 base
= get_frame_register_unsigned (this_frame
, SPARC_O1_REGNUM
);
98 if (self
== &sparc32_linux_rt_sigframe
)
101 /* Offsets from <bits/sigcontext.h>. */
103 trad_frame_set_reg_addr (this_cache
, SPARC32_PSR_REGNUM
, base
+ 0);
104 trad_frame_set_reg_addr (this_cache
, SPARC32_PC_REGNUM
, base
+ 4);
105 trad_frame_set_reg_addr (this_cache
, SPARC32_NPC_REGNUM
, base
+ 8);
106 trad_frame_set_reg_addr (this_cache
, SPARC32_Y_REGNUM
, base
+ 12);
108 /* Since %g0 is always zero, keep the identity encoding. */
110 sp_addr
= base
+ 16 + ((SPARC_SP_REGNUM
- SPARC_G0_REGNUM
) * 4);
111 for (regnum
= SPARC_G1_REGNUM
; regnum
<= SPARC_O7_REGNUM
; regnum
++)
113 trad_frame_set_reg_addr (this_cache
, regnum
, addr
);
117 base
= get_frame_register_unsigned (this_frame
, SPARC_SP_REGNUM
);
118 addr
= get_frame_memory_unsigned (this_frame
, sp_addr
, 4);
120 for (regnum
= SPARC_L0_REGNUM
; regnum
<= SPARC_I7_REGNUM
; regnum
++)
122 trad_frame_set_reg_addr (this_cache
, regnum
, addr
);
125 trad_frame_set_id (this_cache
, frame_id_build (base
, func
));
128 /* Return the address of a system call's alternative return
132 sparc32_linux_step_trap (struct frame_info
*frame
, unsigned long insn
)
134 if (insn
== 0x91d02010)
136 ULONGEST sc_num
= get_frame_register_unsigned (frame
, SPARC_G1_REGNUM
);
138 /* __NR_rt_sigreturn is 101 and __NR_sigreturn is 216 */
139 if (sc_num
== 101 || sc_num
== 216)
141 ULONGEST sp
, pc_offset
;
143 sp
= get_frame_register_unsigned (frame
, SPARC_SP_REGNUM
);
145 /* The kernel puts the sigreturn registers on the stack,
146 and this is where the signal unwinding state is take from
147 when returning from a signal.
149 For __NR_sigreturn, this register area sits 96 bytes from
150 the base of the stack. The saved PC sits 4 bytes into the
151 sigreturn register save area.
153 For __NR_rt_sigreturn a siginfo_t, which is 128 bytes, sits
154 right before the sigreturn register save area. */
160 return read_memory_unsigned_integer (sp
+ pc_offset
, 4);
168 const struct sparc_gregset sparc32_linux_core_gregset
=
183 sparc32_linux_supply_core_gregset (const struct regset
*regset
,
184 struct regcache
*regcache
,
185 int regnum
, const void *gregs
, size_t len
)
187 sparc32_supply_gregset (&sparc32_linux_core_gregset
, regcache
, regnum
, gregs
);
191 sparc32_linux_collect_core_gregset (const struct regset
*regset
,
192 const struct regcache
*regcache
,
193 int regnum
, void *gregs
, size_t len
)
195 sparc32_collect_gregset (&sparc32_linux_core_gregset
, regcache
, regnum
, gregs
);
199 sparc32_linux_supply_core_fpregset (const struct regset
*regset
,
200 struct regcache
*regcache
,
201 int regnum
, const void *fpregs
, size_t len
)
203 sparc32_supply_fpregset (regcache
, regnum
, fpregs
);
207 sparc32_linux_collect_core_fpregset (const struct regset
*regset
,
208 const struct regcache
*regcache
,
209 int regnum
, void *fpregs
, size_t len
)
211 sparc32_collect_fpregset (regcache
, regnum
, fpregs
);
214 /* Set the program counter for process PTID to PC. */
216 #define PSR_SYSCALL 0x00004000
219 sparc_linux_write_pc (struct regcache
*regcache
, CORE_ADDR pc
)
221 struct gdbarch_tdep
*tdep
= gdbarch_tdep (get_regcache_arch (regcache
));
224 regcache_cooked_write_unsigned (regcache
, tdep
->pc_regnum
, pc
);
225 regcache_cooked_write_unsigned (regcache
, tdep
->npc_regnum
, pc
+ 4);
227 /* Clear the "in syscall" bit to prevent the kernel from
228 messing with the PCs we just installed, if we happen to be
229 within an interrupted system call that the kernel wants to
232 Note that after we return from the dummy call, the PSR et al.
233 registers will be automatically restored, and the kernel
234 continues to restart the system call at this point. */
235 regcache_cooked_read_unsigned (regcache
, SPARC32_PSR_REGNUM
, &psr
);
237 regcache_cooked_write_unsigned (regcache
, SPARC32_PSR_REGNUM
, psr
);
243 sparc32_linux_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
245 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
247 tdep
->gregset
= regset_alloc (gdbarch
, sparc32_linux_supply_core_gregset
,
248 sparc32_linux_collect_core_gregset
);
249 tdep
->sizeof_gregset
= 152;
251 tdep
->fpregset
= regset_alloc (gdbarch
, sparc32_linux_supply_core_fpregset
,
252 sparc32_linux_collect_core_fpregset
);
253 tdep
->sizeof_fpregset
= 396;
255 tramp_frame_prepend_unwinder (gdbarch
, &sparc32_linux_sigframe
);
256 tramp_frame_prepend_unwinder (gdbarch
, &sparc32_linux_rt_sigframe
);
258 /* GNU/Linux has SVR4-style shared libraries... */
259 set_gdbarch_skip_trampoline_code (gdbarch
, find_solib_trampoline_target
);
260 set_solib_svr4_fetch_link_map_offsets
261 (gdbarch
, svr4_ilp32_fetch_link_map_offsets
);
263 /* ...which means that we need some special handling when doing
264 prologue analysis. */
265 tdep
->plt_entry_size
= 12;
267 /* Enable TLS support. */
268 set_gdbarch_fetch_tls_load_module_address (gdbarch
,
269 svr4_fetch_objfile_link_map
);
271 /* Make sure we can single-step over signal return system calls. */
272 tdep
->step_trap
= sparc32_linux_step_trap
;
274 /* Hook in the DWARF CFI frame unwinder. */
275 dwarf2_append_unwinders (gdbarch
);
277 set_gdbarch_write_pc (gdbarch
, sparc_linux_write_pc
);
280 /* Provide a prototype to silence -Wmissing-prototypes. */
281 extern void _initialize_sparc_linux_tdep (void);
284 _initialize_sparc_linux_tdep (void)
286 gdbarch_register_osabi (bfd_arch_sparc
, 0, GDB_OSABI_LINUX
,
287 sparc32_linux_init_abi
);