| 1 | /* Target-dependent code for the IA-64 for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright (C) 2000-2014 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 | #include "ia64-tdep.h" |
| 22 | #include "arch-utils.h" |
| 23 | #include "gdbcore.h" |
| 24 | #include "regcache.h" |
| 25 | #include "osabi.h" |
| 26 | #include "solib-svr4.h" |
| 27 | #include "symtab.h" |
| 28 | #include "linux-tdep.h" |
| 29 | |
| 30 | #include <ctype.h> |
| 31 | |
| 32 | /* The sigtramp code is in a non-readable (executable-only) region |
| 33 | of memory called the ``gate page''. The addresses in question |
| 34 | were determined by examining the system headers. They are |
| 35 | overly generous to allow for different pages sizes. */ |
| 36 | |
| 37 | #define GATE_AREA_START 0xa000000000000100LL |
| 38 | #define GATE_AREA_END 0xa000000000020000LL |
| 39 | |
| 40 | /* Offset to sigcontext structure from frame of handler. */ |
| 41 | #define IA64_LINUX_SIGCONTEXT_OFFSET 192 |
| 42 | |
| 43 | static int |
| 44 | ia64_linux_pc_in_sigtramp (CORE_ADDR pc) |
| 45 | { |
| 46 | return (pc >= (CORE_ADDR) GATE_AREA_START && pc < (CORE_ADDR) GATE_AREA_END); |
| 47 | } |
| 48 | |
| 49 | /* IA-64 GNU/Linux specific function which, given a frame address and |
| 50 | a register number, returns the address at which that register may be |
| 51 | found. 0 is returned for registers which aren't stored in the |
| 52 | sigcontext structure. */ |
| 53 | |
| 54 | static CORE_ADDR |
| 55 | ia64_linux_sigcontext_register_address (struct gdbarch *gdbarch, |
| 56 | CORE_ADDR sp, int regno) |
| 57 | { |
| 58 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 59 | gdb_byte buf[8]; |
| 60 | CORE_ADDR sigcontext_addr = 0; |
| 61 | |
| 62 | /* The address of the sigcontext area is found at offset 16 in the |
| 63 | sigframe. */ |
| 64 | read_memory (sp + 16, buf, 8); |
| 65 | sigcontext_addr = extract_unsigned_integer (buf, 8, byte_order); |
| 66 | |
| 67 | if (IA64_GR0_REGNUM <= regno && regno <= IA64_GR31_REGNUM) |
| 68 | return sigcontext_addr + 200 + 8 * (regno - IA64_GR0_REGNUM); |
| 69 | else if (IA64_BR0_REGNUM <= regno && regno <= IA64_BR7_REGNUM) |
| 70 | return sigcontext_addr + 136 + 8 * (regno - IA64_BR0_REGNUM); |
| 71 | else if (IA64_FR0_REGNUM <= regno && regno <= IA64_FR127_REGNUM) |
| 72 | return sigcontext_addr + 464 + 16 * (regno - IA64_FR0_REGNUM); |
| 73 | else |
| 74 | switch (regno) |
| 75 | { |
| 76 | case IA64_IP_REGNUM : |
| 77 | return sigcontext_addr + 40; |
| 78 | case IA64_CFM_REGNUM : |
| 79 | return sigcontext_addr + 48; |
| 80 | case IA64_PSR_REGNUM : |
| 81 | return sigcontext_addr + 56; /* user mask only */ |
| 82 | /* sc_ar_rsc is provided, from which we could compute bspstore, but |
| 83 | I don't think it's worth it. Anyway, if we want it, it's at offset |
| 84 | 64. */ |
| 85 | case IA64_BSP_REGNUM : |
| 86 | return sigcontext_addr + 72; |
| 87 | case IA64_RNAT_REGNUM : |
| 88 | return sigcontext_addr + 80; |
| 89 | case IA64_CCV_REGNUM : |
| 90 | return sigcontext_addr + 88; |
| 91 | case IA64_UNAT_REGNUM : |
| 92 | return sigcontext_addr + 96; |
| 93 | case IA64_FPSR_REGNUM : |
| 94 | return sigcontext_addr + 104; |
| 95 | case IA64_PFS_REGNUM : |
| 96 | return sigcontext_addr + 112; |
| 97 | case IA64_LC_REGNUM : |
| 98 | return sigcontext_addr + 120; |
| 99 | case IA64_PR_REGNUM : |
| 100 | return sigcontext_addr + 128; |
| 101 | default : |
| 102 | return 0; |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | static void |
| 107 | ia64_linux_write_pc (struct regcache *regcache, CORE_ADDR pc) |
| 108 | { |
| 109 | ia64_write_pc (regcache, pc); |
| 110 | |
| 111 | /* We must be careful with modifying the instruction-pointer: if we |
| 112 | just interrupt a system call, the kernel would ordinarily try to |
| 113 | restart it when we resume the inferior, which typically results |
| 114 | in SIGSEGV or SIGILL. We prevent this by clearing r10, which |
| 115 | will tell the kernel that r8 does NOT contain a valid error code |
| 116 | and hence it will skip system-call restart. |
| 117 | |
| 118 | The clearing of r10 is safe as long as ia64_write_pc() is only |
| 119 | called as part of setting up an inferior call. */ |
| 120 | regcache_cooked_write_unsigned (regcache, IA64_GR10_REGNUM, 0); |
| 121 | } |
| 122 | |
| 123 | /* Implementation of `gdbarch_stap_is_single_operand', as defined in |
| 124 | gdbarch.h. */ |
| 125 | |
| 126 | static int |
| 127 | ia64_linux_stap_is_single_operand (struct gdbarch *gdbarch, const char *s) |
| 128 | { |
| 129 | return ((isdigit (*s) && s[1] == '[' && s[2] == 'r') /* Displacement. */ |
| 130 | || *s == 'r' /* Register value. */ |
| 131 | || isdigit (*s)); /* Literal number. */ |
| 132 | } |
| 133 | |
| 134 | static void |
| 135 | ia64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 136 | { |
| 137 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 138 | static const char *const stap_register_prefixes[] = { "r", NULL }; |
| 139 | static const char *const stap_register_indirection_prefixes[] = { "[", |
| 140 | NULL }; |
| 141 | static const char *const stap_register_indirection_suffixes[] = { "]", |
| 142 | NULL }; |
| 143 | |
| 144 | linux_init_abi (info, gdbarch); |
| 145 | |
| 146 | /* Set the method of obtaining the sigcontext addresses at which |
| 147 | registers are saved. */ |
| 148 | tdep->sigcontext_register_address = ia64_linux_sigcontext_register_address; |
| 149 | |
| 150 | /* Set the pc_in_sigtramp method. */ |
| 151 | tdep->pc_in_sigtramp = ia64_linux_pc_in_sigtramp; |
| 152 | |
| 153 | set_gdbarch_write_pc (gdbarch, ia64_linux_write_pc); |
| 154 | |
| 155 | set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); |
| 156 | |
| 157 | set_solib_svr4_fetch_link_map_offsets |
| 158 | (gdbarch, svr4_lp64_fetch_link_map_offsets); |
| 159 | |
| 160 | /* Enable TLS support. */ |
| 161 | set_gdbarch_fetch_tls_load_module_address (gdbarch, |
| 162 | svr4_fetch_objfile_link_map); |
| 163 | |
| 164 | /* SystemTap related. */ |
| 165 | set_gdbarch_stap_register_prefixes (gdbarch, stap_register_prefixes); |
| 166 | set_gdbarch_stap_register_indirection_prefixes (gdbarch, |
| 167 | stap_register_indirection_prefixes); |
| 168 | set_gdbarch_stap_register_indirection_suffixes (gdbarch, |
| 169 | stap_register_indirection_suffixes); |
| 170 | set_gdbarch_stap_gdb_register_prefix (gdbarch, "r"); |
| 171 | set_gdbarch_stap_is_single_operand (gdbarch, |
| 172 | ia64_linux_stap_is_single_operand); |
| 173 | } |
| 174 | |
| 175 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 176 | extern initialize_file_ftype _initialize_ia64_linux_tdep; |
| 177 | |
| 178 | void |
| 179 | _initialize_ia64_linux_tdep (void) |
| 180 | { |
| 181 | gdbarch_register_osabi (bfd_arch_ia64, 0, GDB_OSABI_LINUX, |
| 182 | ia64_linux_init_abi); |
| 183 | } |