1/* GNU/Linux/PowerPC specific low level interface, for the in-process 2 agent library for GDB. 3 4 Copyright (C) 2016-2020 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 "arch/ppc-linux-tdesc.h" 25#include "linux-ppc-tdesc-init.h" 26#include <elf.h> 27#ifdef HAVE_GETAUXVAL 28#include <sys/auxv.h> 29#endif 30 31/* These macros define the position of registers in the buffer collected 32 by the fast tracepoint jump pad. */ 33#define FT_CR_R0 0 34#define FT_CR_CR 32 35#define FT_CR_XER 33 36#define FT_CR_LR 34 37#define FT_CR_CTR 35 38#define FT_CR_PC 36 39#define FT_CR_GPR(n) (FT_CR_R0 + (n)) 40 41static const int ppc_ft_collect_regmap[] = { 42 /* GPRs */ 43 FT_CR_GPR (0), FT_CR_GPR (1), FT_CR_GPR (2), 44 FT_CR_GPR (3), FT_CR_GPR (4), FT_CR_GPR (5), 45 FT_CR_GPR (6), FT_CR_GPR (7), FT_CR_GPR (8), 46 FT_CR_GPR (9), FT_CR_GPR (10), FT_CR_GPR (11), 47 FT_CR_GPR (12), FT_CR_GPR (13), FT_CR_GPR (14), 48 FT_CR_GPR (15), FT_CR_GPR (16), FT_CR_GPR (17), 49 FT_CR_GPR (18), FT_CR_GPR (19), FT_CR_GPR (20), 50 FT_CR_GPR (21), FT_CR_GPR (22), FT_CR_GPR (23), 51 FT_CR_GPR (24), FT_CR_GPR (25), FT_CR_GPR (26), 52 FT_CR_GPR (27), FT_CR_GPR (28), FT_CR_GPR (29), 53 FT_CR_GPR (30), FT_CR_GPR (31), 54 /* FPRs - not collected. */ 55 -1, -1, -1, -1, -1, -1, -1, -1, 56 -1, -1, -1, -1, -1, -1, -1, -1, 57 -1, -1, -1, -1, -1, -1, -1, -1, 58 -1, -1, -1, -1, -1, -1, -1, -1, 59 FT_CR_PC, /* PC */ 60 -1, /* MSR */ 61 FT_CR_CR, /* CR */ 62 FT_CR_LR, /* LR */ 63 FT_CR_CTR, /* CTR */ 64 FT_CR_XER, /* XER */ 65 -1, /* FPSCR */ 66}; 67 68#define PPC_NUM_FT_COLLECT_GREGS \ 69 (sizeof (ppc_ft_collect_regmap) / sizeof(ppc_ft_collect_regmap[0])) 70 71/* Supply registers collected by the fast tracepoint jump pad. 72 BUF is the second argument we pass to gdb_collect in jump pad. */ 73 74void 75supply_fast_tracepoint_registers (struct regcache *regcache, 76 const unsigned char *buf) 77{ 78 int i; 79 80 for (i = 0; i < PPC_NUM_FT_COLLECT_GREGS; i++) 81 { 82 if (ppc_ft_collect_regmap[i] == -1) 83 continue; 84 supply_register (regcache, i, 85 ((char *) buf) 86 + ppc_ft_collect_regmap[i] * sizeof (long)); 87 } 88} 89 90/* Return the value of register REGNUM. RAW_REGS is collected buffer 91 by jump pad. This function is called by emit_reg. */ 92 93ULONGEST 94get_raw_reg (const unsigned char *raw_regs, int regnum) 95{ 96 if (regnum >= PPC_NUM_FT_COLLECT_GREGS) 97 return 0; 98 if (ppc_ft_collect_regmap[regnum] == -1) 99 return 0; 100 101 return *(unsigned long *) (raw_regs 102 + ppc_ft_collect_regmap[regnum] * sizeof (long)); 103} 104 105/* Allocate buffer for the jump pads. The branch instruction has a reach 106 of +/- 32MiB, and the executable is loaded at 0x10000000 (256MiB). 107 108 64-bit: To maximize the area of executable that can use tracepoints, 109 try allocating at 0x10000000 - size initially, decreasing until we hit 110 a free area. 111 112 32-bit: ld.so loads dynamic libraries right below the executable, so 113 we cannot depend on that area (dynamic libraries can be quite large). 114 Instead, aim right after the executable - at sbrk(0). This will 115 cause future brk to fail, and malloc will fallback to mmap. */ 116 117void * 118alloc_jump_pad_buffer (size_t size) 119{ 120#ifdef __powerpc64__ 121 uintptr_t addr; 122 uintptr_t exec_base = getauxval (AT_PHDR); 123 int pagesize; 124 void *res; 125 126 if (exec_base == 0) 127 exec_base = 0x10000000; 128 129 pagesize = sysconf (_SC_PAGE_SIZE); 130 if (pagesize == -1) 131 perror_with_name ("sysconf"); 132 133 addr = exec_base - size; 134 135 /* size should already be page-aligned, but this can't hurt. */ 136 addr &= ~(pagesize - 1); 137 138 /* Search for a free area. If we hit 0, we're out of luck. */ 139 for (; addr; addr -= pagesize) 140 { 141 /* No MAP_FIXED - we don't want to zap someone's mapping. */ 142 res = mmap ((void *) addr, size, 143 PROT_READ | PROT_WRITE | PROT_EXEC, 144 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 145 146 /* If we got what we wanted, return. */ 147 if ((uintptr_t) res == addr) 148 return res; 149 150 /* If we got a mapping, but at a wrong address, undo it. */ 151 if (res != MAP_FAILED) 152 munmap (res, size); 153 } 154 155 return NULL; 156#else 157 void *target = sbrk (0); 158 void *res = mmap (target, size, PROT_READ | PROT_WRITE | PROT_EXEC, 159 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 160 161 if (res == target) 162 return res; 163 164 if (res != MAP_FAILED) 165 munmap (res, size); 166 167 return NULL; 168#endif 169} 170 171/* Return target_desc to use for IPA, given the tdesc index passed by 172 gdbserver. */ 173 174const struct target_desc * 175get_ipa_tdesc (int idx) 176{ 177 switch (idx) 178 { 179#ifdef __powerpc64__ 180 case PPC_TDESC_BASE: 181 return tdesc_powerpc_64l; 182 case PPC_TDESC_ALTIVEC: 183 return tdesc_powerpc_altivec64l; 184 case PPC_TDESC_VSX: 185 return tdesc_powerpc_vsx64l; 186 case PPC_TDESC_ISA205: 187 return tdesc_powerpc_isa205_64l; 188 case PPC_TDESC_ISA205_ALTIVEC: 189 return tdesc_powerpc_isa205_altivec64l; 190 case PPC_TDESC_ISA205_VSX: 191 return tdesc_powerpc_isa205_vsx64l; 192 case PPC_TDESC_ISA205_PPR_DSCR_VSX: 193 return tdesc_powerpc_isa205_ppr_dscr_vsx64l; 194 case PPC_TDESC_ISA207_VSX: 195 return tdesc_powerpc_isa207_vsx64l; 196 case PPC_TDESC_ISA207_HTM_VSX: 197 return tdesc_powerpc_isa207_htm_vsx64l; 198#else 199 case PPC_TDESC_BASE: 200 return tdesc_powerpc_32l; 201 case PPC_TDESC_ALTIVEC: 202 return tdesc_powerpc_altivec32l; 203 case PPC_TDESC_VSX: 204 return tdesc_powerpc_vsx32l; 205 case PPC_TDESC_ISA205: 206 return tdesc_powerpc_isa205_32l; 207 case PPC_TDESC_ISA205_ALTIVEC: 208 return tdesc_powerpc_isa205_altivec32l; 209 case PPC_TDESC_ISA205_VSX: 210 return tdesc_powerpc_isa205_vsx32l; 211 case PPC_TDESC_ISA205_PPR_DSCR_VSX: 212 return tdesc_powerpc_isa205_ppr_dscr_vsx32l; 213 case PPC_TDESC_ISA207_VSX: 214 return tdesc_powerpc_isa207_vsx32l; 215 case PPC_TDESC_ISA207_HTM_VSX: 216 return tdesc_powerpc_isa207_htm_vsx32l; 217 case PPC_TDESC_E500: 218 return tdesc_powerpc_e500l; 219#endif 220 default: 221 internal_error (__FILE__, __LINE__, 222 "unknown ipa tdesc index: %d", idx); 223#ifdef __powerpc64__ 224 return tdesc_powerpc_64l; 225#else 226 return tdesc_powerpc_32l; 227#endif 228 } 229} 230 231 232/* Initialize ipa_tdesc and others. */ 233 234void 235initialize_low_tracepoint (void) 236{ 237#ifdef __powerpc64__ 238 init_registers_powerpc_64l (); 239 init_registers_powerpc_altivec64l (); 240 init_registers_powerpc_vsx64l (); 241 init_registers_powerpc_isa205_64l (); 242 init_registers_powerpc_isa205_altivec64l (); 243 init_registers_powerpc_isa205_vsx64l (); 244 init_registers_powerpc_isa205_ppr_dscr_vsx64l (); 245 init_registers_powerpc_isa207_vsx64l (); 246 init_registers_powerpc_isa207_htm_vsx64l (); 247#else 248 init_registers_powerpc_32l (); 249 init_registers_powerpc_altivec32l (); 250 init_registers_powerpc_vsx32l (); 251 init_registers_powerpc_isa205_32l (); 252 init_registers_powerpc_isa205_altivec32l (); 253 init_registers_powerpc_isa205_vsx32l (); 254 init_registers_powerpc_isa205_ppr_dscr_vsx32l (); 255 init_registers_powerpc_isa207_vsx32l (); 256 init_registers_powerpc_isa207_htm_vsx32l (); 257 init_registers_powerpc_e500l (); 258#endif 259} 260