gdb/loongarch-linux-tdep.c

   1 /* Target-dependent code for GNU/Linux on LoongArch processors.
   2
   3    Copyright (C) 2022 Free Software Foundation, Inc.
   4    Contributed by Loongson Ltd.
   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 "glibc-tdep.h"
  23 #include "inferior.h"
  24 #include "linux-tdep.h"
  25 #include "loongarch-tdep.h"
  26 #include "solib-svr4.h"
  27 #include "target-descriptions.h"
  28 #include "trad-frame.h"
  29 #include "tramp-frame.h"
  30
  31 /* Unpack an elf_gregset_t into GDB's register cache.  */
  32
  33 static void
  34 loongarch_supply_gregset (const struct regset *r,
  35                           struct regcache *regcache, int regno,
  36                           const void *gprs, size_t len)
  37 {
  38   loongarch_gdbarch_tdep *tdep
  39     = (loongarch_gdbarch_tdep *) gdbarch_tdep (regcache->arch ());
  40   auto regs = tdep->regs;
  41
  42   int regsize = register_size (regcache->arch (), regs.r);
  43   const gdb_byte *buf = nullptr;
  44
  45   if (regno == -1)
  46     {
  47       /* Set $r0 = 0.  */
  48       regcache->raw_supply_zeroed (regs.r);
  49
  50       for (int i = 1; i < 32; i++)
  51         {
  52           buf = (const gdb_byte*) gprs + regsize * i;
  53           regcache->raw_supply (regs.r + i, (const void *) buf);
  54         }
  55
  56       /* Size base (pc) = regsize * regs.pc.  */
  57       buf = (const gdb_byte*) gprs + regsize * regs.pc;
  58       regcache->raw_supply (regs.pc, (const void *) buf);
  59
  60       /* Size base (badv) = regsize * regs.badv.  */
  61       buf = (const gdb_byte*) gprs + regsize * regs.badv;
  62       regcache->raw_supply (regs.badv, (const void *) buf);
  63     }
  64   else if (regs.r == regno)
  65     regcache->raw_supply_zeroed (regno);
  66   else if ((regs.r < regno && regno < regs.r + 32)
  67            || regs.pc == regno || regs.badv == regno)
  68     {
  69       /* Offset offset (regno) = regsize * (regno - regs.r).  */
  70       buf = (const gdb_byte*) gprs + regsize * (regno - regs.r);
  71       regcache->raw_supply (regno, (const void *) buf);
  72     }
  73 }
  74
  75 /* Pack the GDB's register cache value into an elf_gregset_t.  */
  76
  77 static void
  78 loongarch_fill_gregset (const struct regset *r,
  79                         const struct regcache *regcache, int regno,
  80                         void *gprs, size_t len)
  81 {
  82   loongarch_gdbarch_tdep *tdep
  83     = (loongarch_gdbarch_tdep *) gdbarch_tdep (regcache->arch ());
  84   auto regs = tdep->regs;
  85   int regsize = register_size (regcache->arch (), regs.r);
  86   gdb_byte *buf = nullptr;
  87
  88   if (regno == -1)
  89     {
  90       for (int i = 0; i < 32; i++)
  91         {
  92           buf = (gdb_byte *) gprs + regsize * i;
  93           regcache->raw_collect (regs.r + i, (void *) buf);
  94         }
  95
  96       /* Size base (pc) = regsize * regs.pc.  */
  97       buf = (gdb_byte *) gprs + regsize * regs.pc;
  98       regcache->raw_collect (regs.pc, (void *) buf);
  99
 100       /* Size base (badv) = regsize * regs.badv.  */
 101       buf = (gdb_byte *) gprs + regsize * regs.badv;
 102       regcache->raw_collect (regs.badv, (void *) buf);
 103     }
 104   else if ((regs.r <= regno && regno < regs.r + 32)
 105            || regs.pc == regno || regs.badv == regno)
 106     {
 107       /* Offset offset (regno) = regsize * (regno - regs.r).  */
 108       buf = (gdb_byte *) gprs + regsize * (regno - regs.r);
 109       regcache->raw_collect (regno, (void *) buf);
 110     }
 111 }
 112
 113 /* Register set definitions.  */
 114
 115 const struct regset loongarch_gregset =
 116 {
 117   nullptr,
 118   loongarch_supply_gregset,
 119   loongarch_fill_gregset,
 120 };
 121
 122 /* Implement the "init" method of struct tramp_frame.  */
 123
 124 #define LOONGARCH_RT_SIGFRAME_UCONTEXT_OFFSET   128
 125 #define LOONGARCH_UCONTEXT_SIGCONTEXT_OFFSET    176
 126
 127 static void
 128 loongarch_linux_rt_sigframe_init (const struct tramp_frame *self,
 129                                   struct frame_info *this_frame,
 130                                   struct trad_frame_cache *this_cache,
 131                                   CORE_ADDR func)
 132 {
 133   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 134   loongarch_gdbarch_tdep *tdep = (loongarch_gdbarch_tdep *) gdbarch_tdep (gdbarch);
 135   auto regs = tdep->regs;
 136
 137   CORE_ADDR frame_sp = get_frame_sp (this_frame);
 138   CORE_ADDR sigcontext_base = (frame_sp + LOONGARCH_RT_SIGFRAME_UCONTEXT_OFFSET
 139                                + LOONGARCH_UCONTEXT_SIGCONTEXT_OFFSET);
 140
 141   trad_frame_set_reg_addr (this_cache, regs.pc, sigcontext_base);
 142   for (int i = 0; i < 32; i++)
 143     trad_frame_set_reg_addr (this_cache, regs.r + i, sigcontext_base + 8 + i * 8);
 144
 145   trad_frame_set_id (this_cache, frame_id_build (frame_sp, func));
 146 }
 147
 148 /* li.w    a7, __NR_rt_sigreturn  */
 149 #define LOONGARCH_INST_LIW_A7_RT_SIGRETURN      0x03822c0b
 150 /* syscall 0  */
 151 #define LOONGARCH_INST_SYSCALL                  0x002b0000
 152
 153 static const struct tramp_frame loongarch_linux_rt_sigframe =
 154 {
 155   SIGTRAMP_FRAME,
 156   4,
 157   {
 158     { LOONGARCH_INST_LIW_A7_RT_SIGRETURN, ULONGEST_MAX },
 159     { LOONGARCH_INST_SYSCALL, ULONGEST_MAX },
 160     { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 161   },
 162   loongarch_linux_rt_sigframe_init,
 163   NULL
 164 };
 165
 166 /* Initialize LoongArch Linux ABI info.  */
 167
 168 static void
 169 loongarch_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 170 {
 171   linux_init_abi (info, gdbarch, 0);
 172
 173   set_solib_svr4_fetch_link_map_offsets (gdbarch,
 174                                          info.bfd_arch_info->bits_per_address == 32
 175                                          ? linux_ilp32_fetch_link_map_offsets
 176                                          : linux_lp64_fetch_link_map_offsets);
 177
 178   /* GNU/Linux uses SVR4-style shared libraries.  */
 179   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 180
 181   /* GNU/Linux uses the dynamic linker included in the GNU C Library.  */
 182   set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
 183
 184   /* Enable TLS support.  */
 185   set_gdbarch_fetch_tls_load_module_address (gdbarch, svr4_fetch_objfile_link_map);
 186
 187   /* Prepend tramp frame unwinder for signal.  */
 188   tramp_frame_prepend_unwinder (gdbarch, &loongarch_linux_rt_sigframe);
 189 }
 190
 191 /* Initialize LoongArch Linux target support.  */
 192
 193 void _initialize_loongarch_linux_tdep ();
 194 void
 195 _initialize_loongarch_linux_tdep ()
 196 {
 197   gdbarch_register_osabi (bfd_arch_loongarch, bfd_mach_loongarch32,
 198                           GDB_OSABI_LINUX, loongarch_linux_init_abi);
 199   gdbarch_register_osabi (bfd_arch_loongarch, bfd_mach_loongarch64,
 200                           GDB_OSABI_LINUX, loongarch_linux_init_abi);
 201 }