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3379287a | 1 | /* Target-dependent code for GNU/Linux on Alpha. |
0b302171 | 2 | Copyright (C) 2002-2003, 2007-2012 Free Software Foundation, Inc. |
3379287a JT |
3 | |
4 | This file is part of GDB. | |
5 | ||
6 | This program is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 8 | the Free Software Foundation; either version 3 of the License, or |
3379287a JT |
9 | (at your option) any later version. |
10 | ||
11 | This program is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 17 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
3379287a JT |
18 | |
19 | #include "defs.h" | |
5868c862 | 20 | #include "frame.h" |
d2427a71 | 21 | #include "gdb_assert.h" |
b02f9d57 | 22 | #include "gdb_string.h" |
f1a559ae | 23 | #include "osabi.h" |
b2756930 | 24 | #include "solib-svr4.h" |
982e9687 | 25 | #include "symtab.h" |
b02f9d57 UW |
26 | #include "regset.h" |
27 | #include "regcache.h" | |
a5ee0f0c | 28 | #include "linux-tdep.h" |
3379287a JT |
29 | #include "alpha-tdep.h" |
30 | ||
d2427a71 RH |
31 | /* Under GNU/Linux, signal handler invocations can be identified by |
32 | the designated code sequence that is used to return from a signal | |
3379287a | 33 | handler. In particular, the return address of a signal handler |
d2427a71 RH |
34 | points to a sequence that copies $sp to $16, loads $0 with the |
35 | appropriate syscall number, and finally enters the kernel. | |
36 | ||
37 | This is somewhat complicated in that: | |
38 | (1) the expansion of the "mov" assembler macro has changed over | |
39 | time, from "bis src,src,dst" to "bis zero,src,dst", | |
40 | (2) the kernel has changed from using "addq" to "lda" to load the | |
41 | syscall number, | |
42 | (3) there is a "normal" sigreturn and an "rt" sigreturn which | |
0963b4bd | 43 | has a different stack layout. */ |
d2427a71 RH |
44 | |
45 | static long | |
e17a4113 | 46 | alpha_linux_sigtramp_offset_1 (struct gdbarch *gdbarch, CORE_ADDR pc) |
3379287a | 47 | { |
e17a4113 | 48 | switch (alpha_read_insn (gdbarch, pc)) |
d2427a71 RH |
49 | { |
50 | case 0x47de0410: /* bis $30,$30,$16 */ | |
51 | case 0x47fe0410: /* bis $31,$30,$16 */ | |
52 | return 0; | |
3379287a | 53 | |
d2427a71 RH |
54 | case 0x43ecf400: /* addq $31,103,$0 */ |
55 | case 0x201f0067: /* lda $0,103($31) */ | |
56 | case 0x201f015f: /* lda $0,351($31) */ | |
57 | return 4; | |
58 | ||
59 | case 0x00000083: /* call_pal callsys */ | |
60 | return 8; | |
3379287a | 61 | |
3379287a JT |
62 | default: |
63 | return -1; | |
64 | } | |
d2427a71 RH |
65 | } |
66 | ||
67 | static LONGEST | |
e17a4113 | 68 | alpha_linux_sigtramp_offset (struct gdbarch *gdbarch, CORE_ADDR pc) |
d2427a71 RH |
69 | { |
70 | long i, off; | |
71 | ||
72 | if (pc & 3) | |
73 | return -1; | |
74 | ||
75 | /* Guess where we might be in the sequence. */ | |
e17a4113 | 76 | off = alpha_linux_sigtramp_offset_1 (gdbarch, pc); |
d2427a71 RH |
77 | if (off < 0) |
78 | return -1; | |
79 | ||
80 | /* Verify that the other two insns of the sequence are as we expect. */ | |
3379287a | 81 | pc -= off; |
d2427a71 | 82 | for (i = 0; i < 12; i += 4) |
3379287a | 83 | { |
d2427a71 RH |
84 | if (i == off) |
85 | continue; | |
e17a4113 | 86 | if (alpha_linux_sigtramp_offset_1 (gdbarch, pc + i) != i) |
d2427a71 | 87 | return -1; |
3379287a | 88 | } |
3379287a | 89 | |
d2427a71 | 90 | return off; |
3379287a JT |
91 | } |
92 | ||
6c72f9f9 | 93 | static int |
e17a4113 UW |
94 | alpha_linux_pc_in_sigtramp (struct gdbarch *gdbarch, |
95 | CORE_ADDR pc, char *func_name) | |
6c72f9f9 | 96 | { |
e17a4113 | 97 | return alpha_linux_sigtramp_offset (gdbarch, pc) >= 0; |
6c72f9f9 JT |
98 | } |
99 | ||
5868c862 | 100 | static CORE_ADDR |
94afd7a6 | 101 | alpha_linux_sigcontext_addr (struct frame_info *this_frame) |
5868c862 | 102 | { |
e17a4113 | 103 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
d2427a71 RH |
104 | CORE_ADDR pc; |
105 | ULONGEST sp; | |
106 | long off; | |
107 | ||
94afd7a6 UW |
108 | pc = get_frame_pc (this_frame); |
109 | sp = get_frame_register_unsigned (this_frame, ALPHA_SP_REGNUM); | |
d2427a71 | 110 | |
e17a4113 | 111 | off = alpha_linux_sigtramp_offset (gdbarch, pc); |
d2427a71 RH |
112 | gdb_assert (off >= 0); |
113 | ||
114 | /* __NR_rt_sigreturn has a couple of structures on the stack. This is: | |
115 | ||
116 | struct rt_sigframe { | |
117 | struct siginfo info; | |
118 | struct ucontext uc; | |
119 | }; | |
120 | ||
0963b4bd MS |
121 | offsetof (struct rt_sigframe, uc.uc_mcontext); */ |
122 | ||
e17a4113 | 123 | if (alpha_read_insn (gdbarch, pc - off + 4) == 0x201f015f) |
d2427a71 RH |
124 | return sp + 176; |
125 | ||
126 | /* __NR_sigreturn has the sigcontext structure at the top of the stack. */ | |
127 | return sp; | |
5868c862 JT |
128 | } |
129 | ||
b02f9d57 UW |
130 | /* Supply register REGNUM from the buffer specified by GREGS and LEN |
131 | in the general-purpose register set REGSET to register cache | |
132 | REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */ | |
133 | ||
134 | static void | |
135 | alpha_linux_supply_gregset (const struct regset *regset, | |
136 | struct regcache *regcache, | |
137 | int regnum, const void *gregs, size_t len) | |
138 | { | |
139 | const gdb_byte *regs = gregs; | |
140 | int i; | |
141 | gdb_assert (len >= 32 * 8); | |
142 | ||
143 | for (i = 0; i < ALPHA_ZERO_REGNUM; i++) | |
144 | { | |
145 | if (regnum == i || regnum == -1) | |
146 | regcache_raw_supply (regcache, i, regs + i * 8); | |
147 | } | |
148 | ||
149 | if (regnum == ALPHA_PC_REGNUM || regnum == -1) | |
150 | regcache_raw_supply (regcache, ALPHA_PC_REGNUM, regs + 31 * 8); | |
151 | ||
152 | if (regnum == ALPHA_UNIQUE_REGNUM || regnum == -1) | |
153 | regcache_raw_supply (regcache, ALPHA_UNIQUE_REGNUM, | |
154 | len >= 33 * 8 ? regs + 32 * 8 : NULL); | |
155 | } | |
156 | ||
157 | /* Supply register REGNUM from the buffer specified by FPREGS and LEN | |
158 | in the floating-point register set REGSET to register cache | |
159 | REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */ | |
160 | ||
161 | static void | |
162 | alpha_linux_supply_fpregset (const struct regset *regset, | |
163 | struct regcache *regcache, | |
164 | int regnum, const void *fpregs, size_t len) | |
165 | { | |
166 | const gdb_byte *regs = fpregs; | |
167 | int i; | |
168 | gdb_assert (len >= 32 * 8); | |
169 | ||
170 | for (i = ALPHA_FP0_REGNUM; i < ALPHA_FP0_REGNUM + 31; i++) | |
171 | { | |
172 | if (regnum == i || regnum == -1) | |
173 | regcache_raw_supply (regcache, i, regs + (i - ALPHA_FP0_REGNUM) * 8); | |
174 | } | |
175 | ||
176 | if (regnum == ALPHA_FPCR_REGNUM || regnum == -1) | |
6afb1f32 | 177 | regcache_raw_supply (regcache, ALPHA_FPCR_REGNUM, regs + 31 * 8); |
b02f9d57 UW |
178 | } |
179 | ||
180 | static struct regset alpha_linux_gregset = | |
181 | { | |
182 | NULL, | |
183 | alpha_linux_supply_gregset | |
184 | }; | |
185 | ||
186 | static struct regset alpha_linux_fpregset = | |
187 | { | |
188 | NULL, | |
189 | alpha_linux_supply_fpregset | |
190 | }; | |
191 | ||
192 | /* Return the appropriate register set for the core section identified | |
193 | by SECT_NAME and SECT_SIZE. */ | |
194 | ||
63807e1d | 195 | static const struct regset * |
b02f9d57 UW |
196 | alpha_linux_regset_from_core_section (struct gdbarch *gdbarch, |
197 | const char *sect_name, size_t sect_size) | |
198 | { | |
199 | if (strcmp (sect_name, ".reg") == 0 && sect_size >= 32 * 8) | |
200 | return &alpha_linux_gregset; | |
201 | ||
202 | if (strcmp (sect_name, ".reg2") == 0 && sect_size >= 32 * 8) | |
203 | return &alpha_linux_fpregset; | |
204 | ||
205 | return NULL; | |
206 | } | |
207 | ||
3379287a | 208 | static void |
baa490c4 | 209 | alpha_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
3379287a | 210 | { |
d2427a71 RH |
211 | struct gdbarch_tdep *tdep; |
212 | ||
a5ee0f0c PA |
213 | linux_init_abi (info, gdbarch); |
214 | ||
f1a559ae | 215 | /* Hook into the DWARF CFI frame unwinder. */ |
baa490c4 | 216 | alpha_dwarf2_init_abi (info, gdbarch); |
f1a559ae RH |
217 | |
218 | /* Hook into the MDEBUG frame unwinder. */ | |
d2427a71 | 219 | alpha_mdebug_init_abi (info, gdbarch); |
36a6271d | 220 | |
d2427a71 | 221 | tdep = gdbarch_tdep (gdbarch); |
36a6271d | 222 | tdep->dynamic_sigtramp_offset = alpha_linux_sigtramp_offset; |
5868c862 | 223 | tdep->sigcontext_addr = alpha_linux_sigcontext_addr; |
f2524b93 | 224 | tdep->pc_in_sigtramp = alpha_linux_pc_in_sigtramp; |
accc6d1f JT |
225 | tdep->jb_pc = 2; |
226 | tdep->jb_elt_size = 8; | |
b2756930 | 227 | |
982e9687 UW |
228 | set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); |
229 | ||
8d005789 UW |
230 | set_solib_svr4_fetch_link_map_offsets |
231 | (gdbarch, svr4_lp64_fetch_link_map_offsets); | |
232 | ||
b2756930 KB |
233 | /* Enable TLS support. */ |
234 | set_gdbarch_fetch_tls_load_module_address (gdbarch, | |
235 | svr4_fetch_objfile_link_map); | |
b02f9d57 UW |
236 | |
237 | set_gdbarch_regset_from_core_section | |
238 | (gdbarch, alpha_linux_regset_from_core_section); | |
3379287a JT |
239 | } |
240 | ||
63807e1d PA |
241 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
242 | extern initialize_file_ftype _initialize_alpha_linux_tdep; | |
243 | ||
3379287a JT |
244 | void |
245 | _initialize_alpha_linux_tdep (void) | |
246 | { | |
05816f70 | 247 | gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_LINUX, |
70f80edf | 248 | alpha_linux_init_abi); |
3379287a | 249 | } |