gdb/gdbserver/linux-amd64-ipa.c

   1 /* GNU/Linux/x86-64 specific low level interface, for the in-process
   2    agent library for GDB.
   3
   4    Copyright (C) 2010-2016 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 "server.h"
  22 #include <sys/mman.h>
  23 #include "tracepoint.h"
  24 #include "linux-x86-tdesc.h"
  25
  26 /* Defined in auto-generated file amd64-linux.c.  */
  27 void init_registers_amd64_linux (void);
  28 extern const struct target_desc *tdesc_amd64_linux;
  29
  30 /* fast tracepoints collect registers.  */
  31
  32 #define FT_CR_RIP 0
  33 #define FT_CR_EFLAGS 1
  34 #define FT_CR_R8 2
  35 #define FT_CR_R9 3
  36 #define FT_CR_R10 4
  37 #define FT_CR_R11 5
  38 #define FT_CR_R12 6
  39 #define FT_CR_R13 7
  40 #define FT_CR_R14 8
  41 #define FT_CR_R15 9
  42 #define FT_CR_RAX 10
  43 #define FT_CR_RBX 11
  44 #define FT_CR_RCX 12
  45 #define FT_CR_RDX 13
  46 #define FT_CR_RSI 14
  47 #define FT_CR_RDI 15
  48 #define FT_CR_RBP 16
  49 #define FT_CR_RSP 17
  50
  51 static const int x86_64_ft_collect_regmap[] = {
  52   FT_CR_RAX * 8, FT_CR_RBX * 8, FT_CR_RCX * 8, FT_CR_RDX * 8,
  53   FT_CR_RSI * 8, FT_CR_RDI * 8, FT_CR_RBP * 8, FT_CR_RSP * 8,
  54   FT_CR_R8 * 8,  FT_CR_R9 * 8,  FT_CR_R10 * 8, FT_CR_R11 * 8,
  55   FT_CR_R12 * 8, FT_CR_R13 * 8, FT_CR_R14 * 8, FT_CR_R15 * 8,
  56   FT_CR_RIP * 8, FT_CR_EFLAGS * 8
  57 };
  58
  59 #define X86_64_NUM_FT_COLLECT_GREGS \
  60   (sizeof (x86_64_ft_collect_regmap) / sizeof(x86_64_ft_collect_regmap[0]))
  61
  62 void
  63 supply_fast_tracepoint_registers (struct regcache *regcache,
  64                                   const unsigned char *buf)
  65 {
  66   int i;
  67
  68   for (i = 0; i < X86_64_NUM_FT_COLLECT_GREGS; i++)
  69     supply_register (regcache, i,
  70                      ((char *) buf) + x86_64_ft_collect_regmap[i]);
  71 }
  72
  73 ULONGEST
  74 get_raw_reg (const unsigned char *raw_regs, int regnum)
  75 {
  76   if (regnum >= X86_64_NUM_FT_COLLECT_GREGS)
  77     return 0;
  78
  79   return *(ULONGEST *) (raw_regs + x86_64_ft_collect_regmap[regnum]);
  80 }
  81
  82 #ifdef HAVE_UST
  83
  84 #include <ust/processor.h>
  85
  86 /* "struct registers" is the UST object type holding the registers at
  87    the time of the static tracepoint marker call.  This doesn't
  88    contain RIP, but we know what it must have been (the marker
  89    address).  */
  90
  91 #define ST_REGENTRY(REG)                        \
  92   {                                             \
  93     offsetof (struct registers, REG),           \
  94     sizeof (((struct registers *) NULL)->REG)   \
  95   }
  96
  97 static struct
  98 {
  99   int offset;
 100   int size;
 101 } x86_64_st_collect_regmap[] =
 102   {
 103     ST_REGENTRY(rax),
 104     ST_REGENTRY(rbx),
 105     ST_REGENTRY(rcx),
 106     ST_REGENTRY(rdx),
 107     ST_REGENTRY(rsi),
 108     ST_REGENTRY(rdi),
 109     ST_REGENTRY(rbp),
 110     ST_REGENTRY(rsp),
 111     ST_REGENTRY(r8),
 112     ST_REGENTRY(r9),
 113     ST_REGENTRY(r10),
 114     ST_REGENTRY(r11),
 115     ST_REGENTRY(r12),
 116     ST_REGENTRY(r13),
 117     ST_REGENTRY(r14),
 118     ST_REGENTRY(r15),
 119     { -1, 0 },
 120     ST_REGENTRY(rflags),
 121     ST_REGENTRY(cs),
 122     ST_REGENTRY(ss),
 123   };
 124
 125 #define X86_64_NUM_ST_COLLECT_GREGS \
 126   (sizeof (x86_64_st_collect_regmap) / sizeof (x86_64_st_collect_regmap[0]))
 127
 128 /* GDB's RIP register number.  */
 129 #define AMD64_RIP_REGNUM 16
 130
 131 void
 132 supply_static_tracepoint_registers (struct regcache *regcache,
 133                                     const unsigned char *buf,
 134                                     CORE_ADDR pc)
 135 {
 136   int i;
 137   unsigned long newpc = pc;
 138
 139   supply_register (regcache, AMD64_RIP_REGNUM, &newpc);
 140
 141   for (i = 0; i < X86_64_NUM_ST_COLLECT_GREGS; i++)
 142     if (x86_64_st_collect_regmap[i].offset != -1)
 143       {
 144         switch (x86_64_st_collect_regmap[i].size)
 145           {
 146           case 8:
 147             supply_register (regcache, i,
 148                              ((char *) buf)
 149                              + x86_64_st_collect_regmap[i].offset);
 150             break;
 151           case 2:
 152             {
 153               unsigned long reg
 154                 = * (short *) (((char *) buf)
 155                                + x86_64_st_collect_regmap[i].offset);
 156               reg &= 0xffff;
 157               supply_register (regcache, i, &reg);
 158             }
 159             break;
 160           default:
 161             internal_error (__FILE__, __LINE__,
 162                             "unhandled register size: %d",
 163                             x86_64_st_collect_regmap[i].size);
 164             break;
 165           }
 166       }
 167 }
 168
 169 #endif /* HAVE_UST */
 170
 171 /* Return target_desc to use for IPA, given the tdesc index passed by
 172    gdbserver.  */
 173
 174 const struct target_desc *
 175 get_ipa_tdesc (int idx)
 176 {
 177 #if defined __ILP32__
 178   switch (idx)
 179     {
 180     case X86_TDESC_SSE:
 181       return tdesc_x32_linux;
 182     case X86_TDESC_AVX:
 183       return tdesc_x32_avx_linux;
 184     case X86_TDESC_AVX512:
 185       return tdesc_x32_avx512_linux;
 186     default:
 187       break;
 188     }
 189 #else
 190   switch (idx)
 191     {
 192     case X86_TDESC_SSE:
 193       return tdesc_amd64_linux;
 194     case X86_TDESC_AVX:
 195       return tdesc_amd64_avx_linux;
 196     case X86_TDESC_MPX:
 197       return tdesc_amd64_mpx_linux;
 198     case X86_TDESC_AVX_MPX:
 199       return tdesc_amd64_avx_mpx_linux;
 200     case X86_TDESC_AVX512:
 201       return tdesc_amd64_avx512_linux;
 202     }
 203 #endif
 204
 205   internal_error (__FILE__, __LINE__,
 206                   "unknown ipa tdesc index: %d", idx);
 207 }
 208
 209 /* Allocate buffer for the jump pads.  The branch instruction has a
 210    reach of +/- 31-bit, and the executable is loaded at low addresses.
 211
 212    64-bit: Use MAP_32BIT to allocate in the first 2GB.  Shared
 213    libraries, being allocated at the top, are unfortunately out of
 214    luck.
 215
 216    x32: Since MAP_32BIT is 64-bit only, do the placement manually.
 217    Try allocating at '0x80000000 - SIZE' initially, decreasing until
 218    we hit a free area.  This ensures the executable is fully covered,
 219    and is as close as possible to the shared libraries, which are
 220    usually mapped at the top of the first 4GB of the address space.
 221 */
 222
 223 void *
 224 alloc_jump_pad_buffer (size_t size)
 225 {
 226 #if __ILP32__
 227   uintptr_t addr;
 228   int pagesize;
 229
 230   pagesize = sysconf (_SC_PAGE_SIZE);
 231   if (pagesize == -1)
 232     perror_with_name ("sysconf");
 233
 234   addr = 0x80000000 - size;
 235
 236   /* size should already be page-aligned, but this can't hurt.  */
 237   addr &= ~(pagesize - 1);
 238
 239   /* Search for a free area.  If we hit 0, we're out of luck.  */
 240   for (; addr; addr -= pagesize)
 241     {
 242       void *res;
 243
 244       /* No MAP_FIXED - we don't want to zap someone's mapping.  */
 245       res = mmap ((void *) addr, size,
 246                   PROT_READ | PROT_WRITE | PROT_EXEC,
 247                   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 248
 249       /* If we got what we wanted, return.  */
 250       if ((uintptr_t) res == addr)
 251         return res;
 252
 253       /* If we got a mapping, but at a wrong address, undo it.  */
 254       if (res != MAP_FAILED)
 255         munmap (res, size);
 256     }
 257
 258   return NULL;
 259 #else
 260   void *res = mmap (NULL, size, PROT_READ | PROT_WRITE | PROT_EXEC,
 261                     MAP_PRIVATE | MAP_ANONYMOUS | MAP_32BIT, -1, 0);
 262
 263   if (res == MAP_FAILED)
 264     return NULL;
 265
 266   return res;
 267 #endif
 268 }
 269
 270 void
 271 initialize_low_tracepoint (void)
 272 {
 273 #if defined __ILP32__
 274   init_registers_x32_linux ();
 275   init_registers_x32_avx_linux ();
 276   init_registers_x32_avx512_linux ();
 277 #else
 278   init_registers_amd64_linux ();
 279   init_registers_amd64_avx_linux ();
 280   init_registers_amd64_avx_mpx_linux ();
 281   init_registers_amd64_mpx_linux ();
 282   init_registers_amd64_avx512_linux ();
 283 #endif
 284 }