| 1 | /* Target-dependent code for the IA-64 for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright (C) 2000, 2004, 2005, 2007, 2008 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 | |
| 29 | /* The sigtramp code is in a non-readable (executable-only) region |
| 30 | of memory called the ``gate page''. The addresses in question |
| 31 | were determined by examining the system headers. They are |
| 32 | overly generous to allow for different pages sizes. */ |
| 33 | |
| 34 | #define GATE_AREA_START 0xa000000000000100LL |
| 35 | #define GATE_AREA_END 0xa000000000020000LL |
| 36 | |
| 37 | /* Offset to sigcontext structure from frame of handler */ |
| 38 | #define IA64_LINUX_SIGCONTEXT_OFFSET 192 |
| 39 | |
| 40 | static int |
| 41 | ia64_linux_pc_in_sigtramp (CORE_ADDR pc) |
| 42 | { |
| 43 | return (pc >= (CORE_ADDR) GATE_AREA_START && pc < (CORE_ADDR) GATE_AREA_END); |
| 44 | } |
| 45 | |
| 46 | /* IA-64 GNU/Linux specific function which, given a frame address and |
| 47 | a register number, returns the address at which that register may be |
| 48 | found. 0 is returned for registers which aren't stored in the the |
| 49 | sigcontext structure. */ |
| 50 | |
| 51 | static CORE_ADDR |
| 52 | ia64_linux_sigcontext_register_address (CORE_ADDR sp, int regno) |
| 53 | { |
| 54 | char buf[8]; |
| 55 | CORE_ADDR sigcontext_addr = 0; |
| 56 | |
| 57 | /* The address of the sigcontext area is found at offset 16 in the sigframe. */ |
| 58 | read_memory (sp + 16, buf, 8); |
| 59 | sigcontext_addr = extract_unsigned_integer (buf, 8); |
| 60 | |
| 61 | if (IA64_GR0_REGNUM <= regno && regno <= IA64_GR31_REGNUM) |
| 62 | return sigcontext_addr + 200 + 8 * (regno - IA64_GR0_REGNUM); |
| 63 | else if (IA64_BR0_REGNUM <= regno && regno <= IA64_BR7_REGNUM) |
| 64 | return sigcontext_addr + 136 + 8 * (regno - IA64_BR0_REGNUM); |
| 65 | else if (IA64_FR0_REGNUM <= regno && regno <= IA64_FR127_REGNUM) |
| 66 | return sigcontext_addr + 464 + 16 * (regno - IA64_FR0_REGNUM); |
| 67 | else |
| 68 | switch (regno) |
| 69 | { |
| 70 | case IA64_IP_REGNUM : |
| 71 | return sigcontext_addr + 40; |
| 72 | case IA64_CFM_REGNUM : |
| 73 | return sigcontext_addr + 48; |
| 74 | case IA64_PSR_REGNUM : |
| 75 | return sigcontext_addr + 56; /* user mask only */ |
| 76 | /* sc_ar_rsc is provided, from which we could compute bspstore, but |
| 77 | I don't think it's worth it. Anyway, if we want it, it's at offset |
| 78 | 64 */ |
| 79 | case IA64_BSP_REGNUM : |
| 80 | return sigcontext_addr + 72; |
| 81 | case IA64_RNAT_REGNUM : |
| 82 | return sigcontext_addr + 80; |
| 83 | case IA64_CCV_REGNUM : |
| 84 | return sigcontext_addr + 88; |
| 85 | case IA64_UNAT_REGNUM : |
| 86 | return sigcontext_addr + 96; |
| 87 | case IA64_FPSR_REGNUM : |
| 88 | return sigcontext_addr + 104; |
| 89 | case IA64_PFS_REGNUM : |
| 90 | return sigcontext_addr + 112; |
| 91 | case IA64_LC_REGNUM : |
| 92 | return sigcontext_addr + 120; |
| 93 | case IA64_PR_REGNUM : |
| 94 | return sigcontext_addr + 128; |
| 95 | default : |
| 96 | return 0; |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | static void |
| 101 | ia64_linux_write_pc (struct regcache *regcache, CORE_ADDR pc) |
| 102 | { |
| 103 | ia64_write_pc (regcache, pc); |
| 104 | |
| 105 | /* We must be careful with modifying the instruction-pointer: if we |
| 106 | just interrupt a system call, the kernel would ordinarily try to |
| 107 | restart it when we resume the inferior, which typically results |
| 108 | in SIGSEGV or SIGILL. We prevent this by clearing r10, which |
| 109 | will tell the kernel that r8 does NOT contain a valid error code |
| 110 | and hence it will skip system-call restart. |
| 111 | |
| 112 | The clearing of r10 is safe as long as ia64_write_pc() is only |
| 113 | called as part of setting up an inferior call. */ |
| 114 | regcache_cooked_write_unsigned (regcache, IA64_GR10_REGNUM, 0); |
| 115 | } |
| 116 | |
| 117 | static void |
| 118 | ia64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 119 | { |
| 120 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 121 | |
| 122 | /* Set the method of obtaining the sigcontext addresses at which |
| 123 | registers are saved. */ |
| 124 | tdep->sigcontext_register_address = ia64_linux_sigcontext_register_address; |
| 125 | |
| 126 | /* Set the pc_in_sigtramp method. */ |
| 127 | tdep->pc_in_sigtramp = ia64_linux_pc_in_sigtramp; |
| 128 | |
| 129 | set_gdbarch_write_pc (gdbarch, ia64_linux_write_pc); |
| 130 | |
| 131 | set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); |
| 132 | |
| 133 | set_solib_svr4_fetch_link_map_offsets |
| 134 | (gdbarch, svr4_lp64_fetch_link_map_offsets); |
| 135 | |
| 136 | /* Enable TLS support. */ |
| 137 | set_gdbarch_fetch_tls_load_module_address (gdbarch, |
| 138 | svr4_fetch_objfile_link_map); |
| 139 | } |
| 140 | |
| 141 | void |
| 142 | _initialize_ia64_linux_tdep (void) |
| 143 | { |
| 144 | gdbarch_register_osabi (bfd_arch_ia64, 0, GDB_OSABI_LINUX, |
| 145 | ia64_linux_init_abi); |
| 146 | } |