| 1 | /* Target-dependent code for the MIPS architecture running on IRIX, |
| 2 | for GDB, the GNU Debugger. |
| 3 | |
| 4 | Copyright (C) 2002, 2007-2012 Free Software Foundation, Inc. |
| 5 | |
| 6 | This file is part of GDB. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 3 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 20 | |
| 21 | #include "defs.h" |
| 22 | #include "osabi.h" |
| 23 | #include "gdb_string.h" |
| 24 | #include "solib.h" |
| 25 | #include "solib-irix.h" |
| 26 | #include "elf-bfd.h" |
| 27 | #include "mips-tdep.h" |
| 28 | #include "trad-frame.h" |
| 29 | #include "tramp-frame.h" |
| 30 | |
| 31 | static void |
| 32 | mips_irix_elf_osabi_sniff_abi_tag_sections (bfd *abfd, asection *sect, |
| 33 | void *obj) |
| 34 | { |
| 35 | enum gdb_osabi *os_ident_ptr = obj; |
| 36 | const char *name; |
| 37 | unsigned int sectsize; |
| 38 | |
| 39 | name = bfd_get_section_name (abfd, sect); |
| 40 | sectsize = bfd_section_size (abfd, sect); |
| 41 | |
| 42 | if (strncmp (name, ".MIPS.", 6) == 0 && sectsize > 0) |
| 43 | { |
| 44 | /* The presence of a section named with a ".MIPS." prefix is |
| 45 | indicative of an IRIX binary. */ |
| 46 | *os_ident_ptr = GDB_OSABI_IRIX; |
| 47 | } |
| 48 | } |
| 49 | |
| 50 | static enum gdb_osabi |
| 51 | mips_irix_elf_osabi_sniffer (bfd *abfd) |
| 52 | { |
| 53 | unsigned int elfosabi; |
| 54 | enum gdb_osabi osabi = GDB_OSABI_UNKNOWN; |
| 55 | |
| 56 | /* If the generic sniffer gets a hit, return and let other sniffers |
| 57 | get a crack at it. */ |
| 58 | bfd_map_over_sections (abfd, |
| 59 | generic_elf_osabi_sniff_abi_tag_sections, |
| 60 | &osabi); |
| 61 | if (osabi != GDB_OSABI_UNKNOWN) |
| 62 | return GDB_OSABI_UNKNOWN; |
| 63 | |
| 64 | elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI]; |
| 65 | |
| 66 | if (elfosabi == ELFOSABI_NONE) |
| 67 | { |
| 68 | /* When elfosabi is ELFOSABI_NONE (0), then the ELF structures in the |
| 69 | file are conforming to the base specification for that machine |
| 70 | (there are no OS-specific extensions). In order to determine the |
| 71 | real OS in use we must look for OS notes that have been added. |
| 72 | |
| 73 | For IRIX, we simply look for sections named with .MIPS. as |
| 74 | prefixes. */ |
| 75 | bfd_map_over_sections (abfd, |
| 76 | mips_irix_elf_osabi_sniff_abi_tag_sections, |
| 77 | &osabi); |
| 78 | } |
| 79 | return osabi; |
| 80 | } |
| 81 | |
| 82 | /* Unwinding past the signal handler on mips-irix. |
| 83 | |
| 84 | Note: The following has only been tested with N32, but can probably |
| 85 | be made to work with a small number of adjustments. |
| 86 | |
| 87 | On mips-irix, the sigcontext_t structure is stored at the base |
| 88 | of the frame established by the _sigtramp function. The definition |
| 89 | of this structure can be found in <sys/signal.h> (comments have been |
| 90 | C++'ified to avoid a collision with the C-style comment delimiters |
| 91 | used by this comment): |
| 92 | |
| 93 | typedef struct sigcontext { |
| 94 | __uint32_t sc_regmask; // regs to restore in sigcleanup |
| 95 | __uint32_t sc_status; // cp0 status register |
| 96 | __uint64_t sc_pc; // pc at time of signal |
| 97 | // General purpose registers |
| 98 | __uint64_t sc_regs[32]; // processor regs 0 to 31 |
| 99 | // Floating point coprocessor state |
| 100 | __uint64_t sc_fpregs[32]; // fp regs 0 to 31 |
| 101 | __uint32_t sc_ownedfp; // fp has been used |
| 102 | __uint32_t sc_fpc_csr; // fpu control and status reg |
| 103 | __uint32_t sc_fpc_eir; // fpu exception instruction reg |
| 104 | // implementation/revision |
| 105 | __uint32_t sc_ssflags; // signal stack state to restore |
| 106 | __uint64_t sc_mdhi; // Multiplier hi and low regs |
| 107 | __uint64_t sc_mdlo; |
| 108 | // System coprocessor registers at time of signal |
| 109 | __uint64_t sc_cause; // cp0 cause register |
| 110 | __uint64_t sc_badvaddr; // cp0 bad virtual address |
| 111 | __uint64_t sc_triggersave; // state of graphics trigger (SGI) |
| 112 | sigset_t sc_sigset; // signal mask to restore |
| 113 | __uint64_t sc_fp_rounded_result; // for Ieee 754 support |
| 114 | __uint64_t sc_pad[31]; |
| 115 | } sigcontext_t; |
| 116 | |
| 117 | The following macros provide the offset of some of the fields |
| 118 | used to retrieve the value of the registers before the signal |
| 119 | was raised. */ |
| 120 | |
| 121 | /* The size of the sigtramp frame. The sigtramp frame base can then |
| 122 | be computed by adding this size to the SP. */ |
| 123 | #define SIGTRAMP_FRAME_SIZE 48 |
| 124 | /* The offset in sigcontext_t where the PC is saved. */ |
| 125 | #define SIGCONTEXT_PC_OFF 8 |
| 126 | /* The offset in sigcontext_t where the GP registers are saved. */ |
| 127 | #define SIGCONTEXT_REGS_OFF (SIGCONTEXT_PC_OFF + 8) |
| 128 | /* The offset in sigcontext_t where the FP regsiters are saved. */ |
| 129 | #define SIGCONTEXT_FPREGS_OFF (SIGCONTEXT_REGS_OFF + 32 * 8) |
| 130 | /* The offset in sigcontext_t where the FP CSR register is saved. */ |
| 131 | #define SIGCONTEXT_FPCSR_OFF (SIGCONTEXT_FPREGS_OFF + 32 * 8 + 4) |
| 132 | /* The offset in sigcontext_t where the multiplier hi register is saved. */ |
| 133 | #define SIGCONTEXT_HI_OFF (SIGCONTEXT_FPCSR_OFF + 2 * 4) |
| 134 | /* The offset in sigcontext_t where the multiplier lo register is saved. */ |
| 135 | #define SIGCONTEXT_LO_OFF (SIGCONTEXT_HI_OFF + 4) |
| 136 | |
| 137 | /* Implement the "init" routine in struct tramp_frame for the N32 ABI |
| 138 | on mips-irix. */ |
| 139 | static void |
| 140 | mips_irix_n32_tramp_frame_init (const struct tramp_frame *self, |
| 141 | struct frame_info *this_frame, |
| 142 | struct trad_frame_cache *this_cache, |
| 143 | CORE_ADDR func) |
| 144 | { |
| 145 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
| 146 | const int num_regs = gdbarch_num_regs (gdbarch); |
| 147 | int sp_cooked_regno = num_regs + MIPS_SP_REGNUM; |
| 148 | const CORE_ADDR sp = get_frame_register_signed (this_frame, sp_cooked_regno); |
| 149 | const CORE_ADDR sigcontext_base = sp + 48; |
| 150 | const struct mips_regnum *regs = mips_regnum (gdbarch); |
| 151 | int ireg; |
| 152 | |
| 153 | trad_frame_set_reg_addr (this_cache, regs->pc + gdbarch_num_regs (gdbarch), |
| 154 | sigcontext_base + SIGCONTEXT_PC_OFF); |
| 155 | |
| 156 | for (ireg = 1; ireg < 32; ireg++) |
| 157 | trad_frame_set_reg_addr (this_cache, ireg + MIPS_ZERO_REGNUM + num_regs, |
| 158 | sigcontext_base + SIGCONTEXT_REGS_OFF + ireg * 8); |
| 159 | |
| 160 | for (ireg = 0; ireg < 32; ireg++) |
| 161 | trad_frame_set_reg_addr (this_cache, ireg + regs->fp0 + num_regs, |
| 162 | sigcontext_base + SIGCONTEXT_FPREGS_OFF |
| 163 | + ireg * 8); |
| 164 | |
| 165 | trad_frame_set_reg_addr (this_cache, regs->fp_control_status + num_regs, |
| 166 | sigcontext_base + SIGCONTEXT_FPCSR_OFF); |
| 167 | |
| 168 | trad_frame_set_reg_addr (this_cache, regs->hi + num_regs, |
| 169 | sigcontext_base + SIGCONTEXT_HI_OFF); |
| 170 | |
| 171 | trad_frame_set_reg_addr (this_cache, regs->lo + num_regs, |
| 172 | sigcontext_base + SIGCONTEXT_LO_OFF); |
| 173 | |
| 174 | trad_frame_set_id (this_cache, frame_id_build (sigcontext_base, func)); |
| 175 | } |
| 176 | |
| 177 | /* The tramp_frame structure describing sigtramp frames on mips-irix N32. |
| 178 | |
| 179 | Note that the list of instructions below is pretty much a pure dump |
| 180 | of function _sigtramp on mips-irix. A few instructions are actually |
| 181 | not tested (mask set to 0), because a portion of these instructions |
| 182 | contain an address which changes due to relocation. We could use |
| 183 | a smarter mask that checks the instrutction code alone, but given |
| 184 | the number of instructions already being checked, this seemed |
| 185 | unnecessary. */ |
| 186 | |
| 187 | static const struct tramp_frame mips_irix_n32_tramp_frame = |
| 188 | { |
| 189 | SIGTRAMP_FRAME, |
| 190 | 4, |
| 191 | { |
| 192 | { 0x3c0c8000, -1 }, /* lui t0,0x8000 */ |
| 193 | { 0x27bdffd0, -1 }, /* addiu sp,sp,-48 */ |
| 194 | { 0x008c6024, -1 }, /* and t0,a0,t0 */ |
| 195 | { 0xffa40018, -1 }, /* sd a0,24(sp) */ |
| 196 | { 0x00000000, 0 }, /* beqz t0,0xfaefcb8 <_sigtramp+40> */ |
| 197 | { 0xffa60028, -1 }, /* sd a2,40(sp) */ |
| 198 | { 0x01806027, -1 }, /* nor t0,t0,zero */ |
| 199 | { 0xffa00020, -1 }, /* sd zero,32(sp) */ |
| 200 | { 0x00000000, 0 }, /* b 0xfaefcbc <_sigtramp+44> */ |
| 201 | { 0x008c2024, -1 }, /* and a0,a0,t0 */ |
| 202 | { 0xffa60020, -1 }, /* sd a2,32(sp) */ |
| 203 | { 0x03e0c025, -1 }, /* move t8,ra */ |
| 204 | { 0x00000000, 0 }, /* bal 0xfaefcc8 <_sigtramp+56> */ |
| 205 | { 0x00000000, -1 }, /* nop */ |
| 206 | { 0x3c0c0007, -1 }, /* lui t0,0x7 */ |
| 207 | { 0x00e0c825, -1 }, /* move t9,a3 */ |
| 208 | { 0x658c80fc, -1 }, /* daddiu t0,t0,-32516 */ |
| 209 | { 0x019f602d, -1 }, /* daddu t0,t0,ra */ |
| 210 | { 0x0300f825, -1 }, /* move ra,t8 */ |
| 211 | { 0x8d8c9880, -1 }, /* lw t0,-26496(t0) */ |
| 212 | { 0x8d8c0000, -1 }, /* lw t0,0(t0) */ |
| 213 | { 0x8d8d0000, -1 }, /* lw t1,0(t0) */ |
| 214 | { 0xffac0008, -1 }, /* sd t0,8(sp) */ |
| 215 | { 0x0320f809, -1 }, /* jalr t9 */ |
| 216 | { 0xffad0010, -1 }, /* sd t1,16(sp) */ |
| 217 | { 0xdfad0010, -1 }, /* ld t1,16(sp) */ |
| 218 | { 0xdfac0008, -1 }, /* ld t0,8(sp) */ |
| 219 | { 0xad8d0000, -1 }, /* sw t1,0(t0) */ |
| 220 | { 0xdfa40020, -1 }, /* ld a0,32(sp) */ |
| 221 | { 0xdfa50028, -1 }, /* ld a1,40(sp) */ |
| 222 | { 0xdfa60018, -1 }, /* ld a2,24(sp) */ |
| 223 | { 0x24020440, -1 }, /* li v0,1088 */ |
| 224 | { 0x0000000c, -1 }, /* syscall */ |
| 225 | { TRAMP_SENTINEL_INSN, -1 } |
| 226 | }, |
| 227 | mips_irix_n32_tramp_frame_init |
| 228 | }; |
| 229 | |
| 230 | /* Implement the "init" routine in struct tramp_frame for the stack-based |
| 231 | trampolines used on mips-irix. */ |
| 232 | |
| 233 | static void |
| 234 | mips_irix_n32_stack_tramp_frame_init (const struct tramp_frame *self, |
| 235 | struct frame_info *this_frame, |
| 236 | struct trad_frame_cache *this_cache, |
| 237 | CORE_ADDR func) |
| 238 | { |
| 239 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
| 240 | const int num_regs = gdbarch_num_regs (gdbarch); |
| 241 | int sp_cooked_regno = num_regs + MIPS_SP_REGNUM; |
| 242 | const CORE_ADDR sp = get_frame_register_signed (this_frame, sp_cooked_regno); |
| 243 | |
| 244 | /* The previous frame's PC is stored in RA. */ |
| 245 | trad_frame_set_reg_realreg (this_cache, gdbarch_pc_regnum (gdbarch), |
| 246 | num_regs + MIPS_RA_REGNUM); |
| 247 | |
| 248 | trad_frame_set_id (this_cache, frame_id_build (sp, func)); |
| 249 | } |
| 250 | |
| 251 | /* A tramp_frame structure describing the stack-based trampoline |
| 252 | used on mips-irix. These trampolines are created on the stack |
| 253 | before being called. */ |
| 254 | |
| 255 | static const struct tramp_frame mips_irix_n32_stack_tramp_frame = |
| 256 | { |
| 257 | SIGTRAMP_FRAME, |
| 258 | 4, |
| 259 | { |
| 260 | { 0x8f210000, 0xffff0000 }, /* lw at, N(t9) */ |
| 261 | { 0x8f2f0000, 0xffff0000 }, /* lw t3, M(t9) */ |
| 262 | { 0x00200008, 0xffffffff }, /* jr at */ |
| 263 | { 0x0020c82d, 0xffffffff }, /* move t9, at */ |
| 264 | { TRAMP_SENTINEL_INSN, -1 } |
| 265 | }, |
| 266 | mips_irix_n32_stack_tramp_frame_init |
| 267 | }; |
| 268 | |
| 269 | static void |
| 270 | mips_irix_init_abi (struct gdbarch_info info, |
| 271 | struct gdbarch *gdbarch) |
| 272 | { |
| 273 | set_solib_ops (gdbarch, &irix_so_ops); |
| 274 | tramp_frame_prepend_unwinder (gdbarch, &mips_irix_n32_stack_tramp_frame); |
| 275 | tramp_frame_prepend_unwinder (gdbarch, &mips_irix_n32_tramp_frame); |
| 276 | } |
| 277 | |
| 278 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 279 | extern initialize_file_ftype _initialize_mips_irix_tdep; |
| 280 | |
| 281 | void |
| 282 | _initialize_mips_irix_tdep (void) |
| 283 | { |
| 284 | /* Register an ELF OS ABI sniffer for IRIX binaries. */ |
| 285 | gdbarch_register_osabi_sniffer (bfd_arch_mips, |
| 286 | bfd_target_elf_flavour, |
| 287 | mips_irix_elf_osabi_sniffer); |
| 288 | |
| 289 | gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_IRIX, |
| 290 | mips_irix_init_abi); |
| 291 | } |