gdb/aarch64-fbsd-tdep.c

   1 /* Target-dependent code for FreeBSD/aarch64.
   2
   3    Copyright (C) 2017-2020 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 /* Register maps.  */
  33
  34 static const struct regcache_map_entry aarch64_fbsd_gregmap[] =
  35   {
  36     { 30, AARCH64_X0_REGNUM, 8 }, /* x0 ... x29 */
  37     { 1, AARCH64_LR_REGNUM, 8 },
  38     { 1, AARCH64_SP_REGNUM, 8 },
  39     { 1, AARCH64_PC_REGNUM, 8 },
  40     { 1, AARCH64_CPSR_REGNUM, 4 },
  41     { 0 }
  42   };
  43
  44 static const struct regcache_map_entry aarch64_fbsd_fpregmap[] =
  45   {
  46     { 32, AARCH64_V0_REGNUM, 16 }, /* v0 ... v31 */
  47     { 1, AARCH64_FPSR_REGNUM, 4 },
  48     { 1, AARCH64_FPCR_REGNUM, 4 },
  49     { 0 }
  50   };
  51
  52 /* In a signal frame, sp points to a 'struct sigframe' which is
  53    defined as:
  54
  55    struct sigframe {
  56            siginfo_t    sf_si;
  57            ucontext_t   sf_uc;
  58    };
  59
  60    ucontext_t is defined as:
  61
  62    struct __ucontext {
  63            sigset_t     uc_sigmask;
  64            mcontext_t   uc_mcontext;
  65            ...
  66    };
  67
  68    The mcontext_t contains the general purpose register set followed
  69    by the floating point register set.  The floating point register
  70    set is only valid if the _MC_FP_VALID flag is set in mc_flags.  */
  71
  72 #define AARCH64_SIGFRAME_UCONTEXT_OFFSET        80
  73 #define AARCH64_UCONTEXT_MCONTEXT_OFFSET        16
  74 #define AARCH64_MCONTEXT_FPREGS_OFFSET          272
  75 #define AARCH64_MCONTEXT_FLAGS_OFFSET           800
  76 #define AARCH64_MCONTEXT_FLAG_FP_VALID          0x1
  77
  78 /* Implement the "init" method of struct tramp_frame.  */
  79
  80 static void
  81 aarch64_fbsd_sigframe_init (const struct tramp_frame *self,
  82                              struct frame_info *this_frame,
  83                              struct trad_frame_cache *this_cache,
  84                              CORE_ADDR func)
  85 {
  86   struct gdbarch *gdbarch = get_frame_arch (this_frame);
  87   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  88   CORE_ADDR sp = get_frame_register_unsigned (this_frame, AARCH64_SP_REGNUM);
  89   CORE_ADDR mcontext_addr
  90     = (sp
  91        + AARCH64_SIGFRAME_UCONTEXT_OFFSET
  92        + AARCH64_UCONTEXT_MCONTEXT_OFFSET);
  93   gdb_byte buf[4];
  94
  95   trad_frame_set_reg_regmap (this_cache, aarch64_fbsd_gregmap, mcontext_addr,
  96                              regcache_map_entry_size (aarch64_fbsd_gregmap));
  97
  98   if (target_read_memory (mcontext_addr + AARCH64_MCONTEXT_FLAGS_OFFSET, buf,
  99                           4) == 0
 100       && (extract_unsigned_integer (buf, 4, byte_order)
 101           & AARCH64_MCONTEXT_FLAG_FP_VALID))
 102     trad_frame_set_reg_regmap (this_cache, aarch64_fbsd_fpregmap,
 103                                mcontext_addr + AARCH64_MCONTEXT_FPREGS_OFFSET,
 104                                regcache_map_entry_size (aarch64_fbsd_fpregmap));
 105
 106   trad_frame_set_id (this_cache, frame_id_build (sp, func));
 107 }
 108
 109 static const struct tramp_frame aarch64_fbsd_sigframe =
 110 {
 111   SIGTRAMP_FRAME,
 112   4,
 113   {
 114     {0x910003e0, ULONGEST_MAX},         /* mov  x0, sp  */
 115     {0x91014000, ULONGEST_MAX},         /* add  x0, x0, #SF_UC  */
 116     {0xd2803428, ULONGEST_MAX},         /* mov  x8, #SYS_sigreturn  */
 117     {0xd4000001, ULONGEST_MAX},         /* svc  0x0  */
 118     {TRAMP_SENTINEL_INSN, ULONGEST_MAX}
 119   },
 120   aarch64_fbsd_sigframe_init
 121 };
 122
 123 /* Register set definitions.  */
 124
 125 const struct regset aarch64_fbsd_gregset =
 126   {
 127     aarch64_fbsd_gregmap,
 128     regcache_supply_regset, regcache_collect_regset
 129   };
 130
 131 const struct regset aarch64_fbsd_fpregset =
 132   {
 133     aarch64_fbsd_fpregmap,
 134     regcache_supply_regset, regcache_collect_regset
 135   };
 136
 137 /* Implement the "regset_from_core_section" gdbarch method.  */
 138
 139 static void
 140 aarch64_fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
 141                                            iterate_over_regset_sections_cb *cb,
 142                                            void *cb_data,
 143                                            const struct regcache *regcache)
 144 {
 145   cb (".reg", AARCH64_FBSD_SIZEOF_GREGSET, AARCH64_FBSD_SIZEOF_GREGSET,
 146       &aarch64_fbsd_gregset, NULL, cb_data);
 147   cb (".reg2", AARCH64_FBSD_SIZEOF_FPREGSET, AARCH64_FBSD_SIZEOF_FPREGSET,
 148       &aarch64_fbsd_fpregset, NULL, cb_data);
 149 }
 150
 151 /* Implement the 'init_osabi' method of struct gdb_osabi_handler.  */
 152
 153 static void
 154 aarch64_fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 155 {
 156   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 157
 158   /* Generic FreeBSD support.  */
 159   fbsd_init_abi (info, gdbarch);
 160
 161   set_solib_svr4_fetch_link_map_offsets (gdbarch,
 162                                          svr4_lp64_fetch_link_map_offsets);
 163
 164   tramp_frame_prepend_unwinder (gdbarch, &aarch64_fbsd_sigframe);
 165
 166   /* Enable longjmp.  */
 167   tdep->jb_pc = 13;
 168
 169   set_gdbarch_iterate_over_regset_sections
 170     (gdbarch, aarch64_fbsd_iterate_over_regset_sections);
 171 }
 172
 173 void
 174 _initialize_aarch64_fbsd_tdep (void)
 175 {
 176   gdbarch_register_osabi (bfd_arch_aarch64, 0, GDB_OSABI_FREEBSD,
 177                           aarch64_fbsd_init_abi);
 178 }