1 /* Target-dependent code for GNU/Linux UltraSPARC. 2 3 Copyright (C) 2003-2014 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 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. 11 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. 16 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/>. */ 19 20 #include "defs.h" 21 #include "frame.h" 22 #include "frame-unwind.h" 23 #include "dwarf2-frame.h" 24 #include "regset.h" 25 #include "regcache.h" 26 #include "gdbarch.h" 27 #include "gdbcore.h" 28 #include "osabi.h" 29 #include "solib-svr4.h" 30 #include "symtab.h" 31 #include "trad-frame.h" 32 #include "tramp-frame.h" 33 #include "xml-syscall.h" 34 #include "linux-tdep.h" 35 36 /* The syscall's XML filename for sparc 64-bit. */ 37 #define XML_SYSCALL_FILENAME_SPARC64 "syscalls/sparc64-linux.xml" 38 39 #include "sparc64-tdep.h" 40 41 /* Signal trampoline support. */ 42 43 static void sparc64_linux_sigframe_init (const struct tramp_frame *self, 44 struct frame_info *this_frame, 45 struct trad_frame_cache *this_cache, 46 CORE_ADDR func); 47 48 /* See sparc-linux-tdep.c for details. Note that 64-bit binaries only 49 use RT signals. */ 50 51 static const struct tramp_frame sparc64_linux_rt_sigframe = 52 { 53 SIGTRAMP_FRAME, 54 4, 55 { 56 { 0x82102065, -1 }, /* mov __NR_rt_sigreturn, %g1 */ 57 { 0x91d0206d, -1 }, /* ta 0x6d */ 58 { TRAMP_SENTINEL_INSN, -1 } 59 }, 60 sparc64_linux_sigframe_init 61 }; 62 63 static void 64 sparc64_linux_sigframe_init (const struct tramp_frame *self, 65 struct frame_info *this_frame, 66 struct trad_frame_cache *this_cache, 67 CORE_ADDR func) 68 { 69 CORE_ADDR base, addr, sp_addr; 70 int regnum; 71 72 base = get_frame_register_unsigned (this_frame, SPARC_O1_REGNUM); 73 base += 128; 74 75 /* Offsets from <bits/sigcontext.h>. */ 76 77 /* Since %g0 is always zero, keep the identity encoding. */ 78 addr = base + 8; 79 sp_addr = base + ((SPARC_SP_REGNUM - SPARC_G0_REGNUM) * 8); 80 for (regnum = SPARC_G1_REGNUM; regnum <= SPARC_O7_REGNUM; regnum++) 81 { 82 trad_frame_set_reg_addr (this_cache, regnum, addr); 83 addr += 8; 84 } 85 86 trad_frame_set_reg_addr (this_cache, SPARC64_STATE_REGNUM, addr + 0); 87 trad_frame_set_reg_addr (this_cache, SPARC64_PC_REGNUM, addr + 8); 88 trad_frame_set_reg_addr (this_cache, SPARC64_NPC_REGNUM, addr + 16); 89 trad_frame_set_reg_addr (this_cache, SPARC64_Y_REGNUM, addr + 24); 90 trad_frame_set_reg_addr (this_cache, SPARC64_FPRS_REGNUM, addr + 28); 91 92 base = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM); 93 if (base & 1) 94 base += BIAS; 95 96 addr = get_frame_memory_unsigned (this_frame, sp_addr, 8); 97 if (addr & 1) 98 addr += BIAS; 99 100 for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++) 101 { 102 trad_frame_set_reg_addr (this_cache, regnum, addr); 103 addr += 8; 104 } 105 trad_frame_set_id (this_cache, frame_id_build (base, func)); 106 } 107 108 /* Return the address of a system call's alternative return 109 address. */ 110 111 static CORE_ADDR 112 sparc64_linux_step_trap (struct frame_info *frame, unsigned long insn) 113 { 114 if (insn == 0x91d0206d) 115 { 116 struct gdbarch *gdbarch = get_frame_arch (frame); 117 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); 118 119 ULONGEST sp = get_frame_register_unsigned (frame, SPARC_SP_REGNUM); 120 if (sp & 1) 121 sp += BIAS; 122 123 /* The kernel puts the sigreturn registers on the stack, 124 and this is where the signal unwinding state is take from 125 when returning from a signal. 126 127 A siginfo_t sits 192 bytes from the base of the stack. This 128 siginfo_t is 128 bytes, and is followed by the sigreturn 129 register save area. The saved PC sits at a 136 byte offset 130 into there. */ 131 132 return read_memory_unsigned_integer (sp + 192 + 128 + 136, 133 8, byte_order); 134 } 135 136 return 0; 137 } 138 139 140 const struct sparc_gregset sparc64_linux_core_gregset = 141 { 142 32 * 8, /* %tstate */ 143 33 * 8, /* %tpc */ 144 34 * 8, /* %tnpc */ 145 35 * 8, /* %y */ 146 -1, /* %wim */ 147 -1, /* %tbr */ 148 1 * 8, /* %g1 */ 149 16 * 8, /* %l0 */ 150 8, /* y size */ 151 }; 152 153 154 static void 155 sparc64_linux_supply_core_gregset (const struct regset *regset, 156 struct regcache *regcache, 157 int regnum, const void *gregs, size_t len) 158 { 159 sparc64_supply_gregset (&sparc64_linux_core_gregset, 160 regcache, regnum, gregs); 161 } 162 163 static void 164 sparc64_linux_collect_core_gregset (const struct regset *regset, 165 const struct regcache *regcache, 166 int regnum, void *gregs, size_t len) 167 { 168 sparc64_collect_gregset (&sparc64_linux_core_gregset, 169 regcache, regnum, gregs); 170 } 171 172 static void 173 sparc64_linux_supply_core_fpregset (const struct regset *regset, 174 struct regcache *regcache, 175 int regnum, const void *fpregs, size_t len) 176 { 177 sparc64_supply_fpregset (&sparc64_bsd_fpregset, regcache, regnum, fpregs); 178 } 179 180 static void 181 sparc64_linux_collect_core_fpregset (const struct regset *regset, 182 const struct regcache *regcache, 183 int regnum, void *fpregs, size_t len) 184 { 185 sparc64_collect_fpregset (&sparc64_bsd_fpregset, regcache, regnum, fpregs); 186 } 187 188 /* Set the program counter for process PTID to PC. */ 189 190 #define TSTATE_SYSCALL 0x0000000000000020ULL 191 192 static void 193 sparc64_linux_write_pc (struct regcache *regcache, CORE_ADDR pc) 194 { 195 struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache)); 196 ULONGEST state; 197 198 regcache_cooked_write_unsigned (regcache, tdep->pc_regnum, pc); 199 regcache_cooked_write_unsigned (regcache, tdep->npc_regnum, pc + 4); 200 201 /* Clear the "in syscall" bit to prevent the kernel from 202 messing with the PCs we just installed, if we happen to be 203 within an interrupted system call that the kernel wants to 204 restart. 205 206 Note that after we return from the dummy call, the TSTATE et al. 207 registers will be automatically restored, and the kernel 208 continues to restart the system call at this point. */ 209 regcache_cooked_read_unsigned (regcache, SPARC64_STATE_REGNUM, &state); 210 state &= ~TSTATE_SYSCALL; 211 regcache_cooked_write_unsigned (regcache, SPARC64_STATE_REGNUM, state); 212 } 213 214 static LONGEST 215 sparc64_linux_get_syscall_number (struct gdbarch *gdbarch, 216 ptid_t ptid) 217 { 218 struct regcache *regcache = get_thread_regcache (ptid); 219 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); 220 /* The content of a register. */ 221 gdb_byte buf[8]; 222 /* The result. */ 223 LONGEST ret; 224 225 /* Getting the system call number from the register. 226 When dealing with the sparc architecture, this information 227 is stored at the %g1 register. */ 228 regcache_cooked_read (regcache, SPARC_G1_REGNUM, buf); 229 230 ret = extract_signed_integer (buf, 8, byte_order); 231 232 return ret; 233 } 234 235 236 /* Implement the "get_longjmp_target" gdbarch method. */ 237 238 static int 239 sparc64_linux_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc) 240 { 241 struct gdbarch *gdbarch = get_frame_arch (frame); 242 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); 243 CORE_ADDR jb_addr; 244 gdb_byte buf[8]; 245 246 jb_addr = get_frame_register_unsigned (frame, SPARC_O0_REGNUM); 247 248 /* setjmp and longjmp in SPARC64 are implemented in glibc using the 249 setcontext and getcontext system calls respectively. These 250 system calls operate on ucontext_t structures, which happen to 251 partially have the same structure than jmp_buf. However the 252 ucontext returned by getcontext, and thus the jmp_buf structure 253 returned by setjmp, contains the context of the trap instruction 254 in the glibc __[sig]setjmp wrapper, not the context of the user 255 code calling setjmp. 256 257 %o7 in the jmp_buf structure is stored at offset 18*8 in the 258 mc_gregs array, which is itself located at offset 32 into 259 jmp_buf. See bits/setjmp.h. This register contains the address 260 of the 'call setjmp' instruction in user code. 261 262 In order to determine the longjmp target address in the 263 initiating frame we need to examine the call instruction itself, 264 in particular whether the annul bit is set. If it is not set 265 then we need to jump over the instruction at the delay slot. */ 266 267 if (target_read_memory (jb_addr + 32 + (18 * 8), buf, 8)) 268 return 0; 269 270 *pc = extract_unsigned_integer (buf, 8, gdbarch_byte_order (gdbarch)); 271 272 if (!sparc_is_annulled_branch_insn (*pc)) 273 *pc += 4; /* delay slot insn */ 274 *pc += 4; /* call insn */ 275 276 return 1; 277 } 278 279 280 281 static void 282 sparc64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) 283 { 284 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); 285 286 linux_init_abi (info, gdbarch); 287 288 tdep->gregset = regset_alloc (gdbarch, sparc64_linux_supply_core_gregset, 289 sparc64_linux_collect_core_gregset); 290 tdep->sizeof_gregset = 288; 291 292 tdep->fpregset = regset_alloc (gdbarch, sparc64_linux_supply_core_fpregset, 293 sparc64_linux_collect_core_fpregset); 294 tdep->sizeof_fpregset = 280; 295 296 tramp_frame_prepend_unwinder (gdbarch, &sparc64_linux_rt_sigframe); 297 298 /* Hook in the DWARF CFI frame unwinder. */ 299 dwarf2_append_unwinders (gdbarch); 300 301 sparc64_init_abi (info, gdbarch); 302 303 /* GNU/Linux has SVR4-style shared libraries... */ 304 set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); 305 set_solib_svr4_fetch_link_map_offsets 306 (gdbarch, svr4_lp64_fetch_link_map_offsets); 307 308 /* ...which means that we need some special handling when doing 309 prologue analysis. */ 310 tdep->plt_entry_size = 16; 311 312 /* Enable TLS support. */ 313 set_gdbarch_fetch_tls_load_module_address (gdbarch, 314 svr4_fetch_objfile_link_map); 315 316 /* Make sure we can single-step over signal return system calls. */ 317 tdep->step_trap = sparc64_linux_step_trap; 318 319 /* Make sure we can single-step over longjmp calls. */ 320 set_gdbarch_get_longjmp_target (gdbarch, sparc64_linux_get_longjmp_target); 321 322 set_gdbarch_write_pc (gdbarch, sparc64_linux_write_pc); 323 324 /* Functions for 'catch syscall'. */ 325 set_xml_syscall_file_name (XML_SYSCALL_FILENAME_SPARC64); 326 set_gdbarch_get_syscall_number (gdbarch, 327 sparc64_linux_get_syscall_number); 328 } 329 330 331 /* Provide a prototype to silence -Wmissing-prototypes. */ 332 extern void _initialize_sparc64_linux_tdep (void); 333 334 void 335 _initialize_sparc64_linux_tdep (void) 336 { 337 gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9, 338 GDB_OSABI_LINUX, sparc64_linux_init_abi); 339 } 340