gdb/aarch64-fbsd-tdep.c

   1 /* Target-dependent code for FreeBSD/aarch64.
   2
   3    Copyright (C) 2017-2018 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
  22 #include "gdbarch.h"
  23 #include "fbsd-tdep.h"
  24 #include "aarch64-tdep.h"
  25 #include "aarch64-fbsd-tdep.h"
  26 #include "osabi.h"
  27 #include "solib-svr4.h"
  28 #include "target.h"
  29 #include "tramp-frame.h"
  30 #include "trad-frame.h"
  31
  32 /* In a signal frame, sp points to a 'struct sigframe' which is
  33    defined as:
  34
  35    struct sigframe {
  36            siginfo_t    sf_si;
  37            ucontext_t   sf_uc;
  38    };
  39
  40    ucontext_t is defined as:
  41
  42    struct __ucontext {
  43            sigset_t     uc_sigmask;
  44            mcontext_t   uc_mcontext;
  45            ...
  46    };
  47
  48    The mcontext_t contains the general purpose register set followed
  49    by the floating point register set.  The floating point register
  50    set is only valid if the _MC_FP_VALID flag is set in mc_flags.  */
  51
  52 #define AARCH64_MCONTEXT_REG_SIZE               8
  53 #define AARCH64_MCONTEXT_FPREG_SIZE             16
  54 #define AARCH64_SIGFRAME_UCONTEXT_OFFSET        80
  55 #define AARCH64_UCONTEXT_MCONTEXT_OFFSET        16
  56 #define AARCH64_MCONTEXT_FPREGS_OFFSET          272
  57 #define AARCH64_MCONTEXT_FLAGS_OFFSET           800
  58 #define AARCH64_MCONTEXT_FLAG_FP_VALID          0x1
  59
  60 /* Implement the "init" method of struct tramp_frame.  */
  61
  62 static void
  63 aarch64_fbsd_sigframe_init (const struct tramp_frame *self,
  64                              struct frame_info *this_frame,
  65                              struct trad_frame_cache *this_cache,
  66                              CORE_ADDR func)
  67 {
  68   struct gdbarch *gdbarch = get_frame_arch (this_frame);
  69   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  70   CORE_ADDR sp = get_frame_register_unsigned (this_frame, AARCH64_SP_REGNUM);
  71   CORE_ADDR mcontext_addr =
  72     sp
  73     + AARCH64_SIGFRAME_UCONTEXT_OFFSET
  74     + AARCH64_UCONTEXT_MCONTEXT_OFFSET;
  75   gdb_byte buf[4];
  76   int i;
  77
  78   for (i = 0; i < 30; i++)
  79     {
  80       trad_frame_set_reg_addr (this_cache,
  81                                AARCH64_X0_REGNUM + i,
  82                                mcontext_addr + i * AARCH64_MCONTEXT_REG_SIZE);
  83     }
  84   trad_frame_set_reg_addr (this_cache, AARCH64_LR_REGNUM,
  85                            mcontext_addr + 30 * AARCH64_MCONTEXT_REG_SIZE);
  86   trad_frame_set_reg_addr (this_cache, AARCH64_SP_REGNUM,
  87                            mcontext_addr + 31 * AARCH64_MCONTEXT_REG_SIZE);
  88   trad_frame_set_reg_addr (this_cache, AARCH64_PC_REGNUM,
  89                            mcontext_addr + 32 * AARCH64_MCONTEXT_REG_SIZE);
  90   trad_frame_set_reg_addr (this_cache, AARCH64_CPSR_REGNUM,
  91                            mcontext_addr + 33 * AARCH64_MCONTEXT_REG_SIZE);
  92
  93   if (target_read_memory (mcontext_addr + AARCH64_MCONTEXT_FLAGS_OFFSET, buf,
  94                           4) == 0
  95       && (extract_unsigned_integer (buf, 4, byte_order)
  96           & AARCH64_MCONTEXT_FLAG_FP_VALID))
  97     {
  98       for (i = 0; i < 32; i++)
  99         {
 100           trad_frame_set_reg_addr (this_cache, AARCH64_V0_REGNUM + i,
 101                                    mcontext_addr
 102                                    + AARCH64_MCONTEXT_FPREGS_OFFSET
 103                                    + i * AARCH64_MCONTEXT_FPREG_SIZE);
 104         }
 105       trad_frame_set_reg_addr (this_cache, AARCH64_FPSR_REGNUM,
 106                                mcontext_addr + AARCH64_MCONTEXT_FPREGS_OFFSET
 107                                + 32 * AARCH64_MCONTEXT_FPREG_SIZE);
 108       trad_frame_set_reg_addr (this_cache, AARCH64_FPCR_REGNUM,
 109                                mcontext_addr + AARCH64_MCONTEXT_FPREGS_OFFSET
 110                                + 32 * AARCH64_MCONTEXT_FPREG_SIZE + 4);
 111     }
 112
 113   trad_frame_set_id (this_cache, frame_id_build (sp, func));
 114 }
 115
 116 static const struct tramp_frame aarch64_fbsd_sigframe =
 117 {
 118   SIGTRAMP_FRAME,
 119   4,
 120   {
 121     {0x910003e0, -1},           /* mov  x0, sp  */
 122     {0x91014000, -1},           /* add  x0, x0, #SF_UC  */
 123     {0xd2803428, -1},           /* mov  x8, #SYS_sigreturn  */
 124     {0xd4000001, -1},           /* svc  0x0  */
 125     {TRAMP_SENTINEL_INSN, -1}
 126   },
 127   aarch64_fbsd_sigframe_init
 128 };
 129
 130 /* Register maps.  */
 131
 132 static const struct regcache_map_entry aarch64_fbsd_gregmap[] =
 133   {
 134     { 30, AARCH64_X0_REGNUM, 8 }, /* x0 ... x29 */
 135     { 1, AARCH64_LR_REGNUM, 8 },
 136     { 1, AARCH64_SP_REGNUM, 8 },
 137     { 1, AARCH64_PC_REGNUM, 8 },
 138     { 1, AARCH64_CPSR_REGNUM, 4 },
 139     { 0 }
 140   };
 141
 142 static const struct regcache_map_entry aarch64_fbsd_fpregmap[] =
 143   {
 144     { 32, AARCH64_V0_REGNUM, 16 }, /* v0 ... v31 */
 145     { 1, AARCH64_FPSR_REGNUM, 4 },
 146     { 1, AARCH64_FPCR_REGNUM, 4 },
 147     { 0 }
 148   };
 149
 150 /* Register set definitions.  */
 151
 152 const struct regset aarch64_fbsd_gregset =
 153   {
 154     aarch64_fbsd_gregmap,
 155     regcache_supply_regset, regcache_collect_regset
 156   };
 157
 158 const struct regset aarch64_fbsd_fpregset =
 159   {
 160     aarch64_fbsd_fpregmap,
 161     regcache_supply_regset, regcache_collect_regset
 162   };
 163
 164 /* Implement the "regset_from_core_section" gdbarch method.  */
 165
 166 static void
 167 aarch64_fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
 168                                            iterate_over_regset_sections_cb *cb,
 169                                            void *cb_data,
 170                                            const struct regcache *regcache)
 171 {
 172   cb (".reg", AARCH64_FBSD_SIZEOF_GREGSET, AARCH64_FBSD_SIZEOF_GREGSET,
 173       &aarch64_fbsd_gregset, NULL, cb_data);
 174   cb (".reg2", AARCH64_FBSD_SIZEOF_FPREGSET, AARCH64_FBSD_SIZEOF_FPREGSET,
 175       &aarch64_fbsd_fpregset, NULL, cb_data);
 176 }
 177
 178 /* Implement the 'init_osabi' method of struct gdb_osabi_handler.  */
 179
 180 static void
 181 aarch64_fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 182 {
 183   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 184
 185   /* Generic FreeBSD support.  */
 186   fbsd_init_abi (info, gdbarch);
 187
 188   set_solib_svr4_fetch_link_map_offsets (gdbarch,
 189                                          svr4_lp64_fetch_link_map_offsets);
 190
 191   tramp_frame_prepend_unwinder (gdbarch, &aarch64_fbsd_sigframe);
 192
 193   /* Enable longjmp.  */
 194   tdep->jb_pc = 13;
 195
 196   set_gdbarch_iterate_over_regset_sections
 197     (gdbarch, aarch64_fbsd_iterate_over_regset_sections);
 198 }
 199
 200 void
 201 _initialize_aarch64_fbsd_tdep (void)
 202 {
 203   gdbarch_register_osabi (bfd_arch_aarch64, 0, GDB_OSABI_FREEBSD,
 204                           aarch64_fbsd_init_abi);
 205 }