/* Intel 386 native support for System V systems (pre-SVR4). Copyright 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2002 Free Software Foundation, Inc. This file is part of GDB. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include "defs.h" #ifdef HAVE_PTRACE_H #include #else #ifdef HAVE_SYS_PTRACE_H #include #endif #endif #include "frame.h" #include "inferior.h" #include "language.h" #include "gdbcore.h" #include #include #include #include #include #include #ifdef TARGET_HAS_HARDWARE_WATCHPOINTS #include #endif #include #include "gdb_stat.h" #ifdef HAVE_SYS_REG_H #include #endif #include "floatformat.h" #include "target.h" #include "i386-tdep.h" /* Mapping between the general-purpose registers in `struct user' format and GDB's register array layout. */ static int regmap[] = { EAX, ECX, EDX, EBX, UESP, EBP, ESI, EDI, EIP, EFL, CS, SS, DS, ES, FS, GS, }; /* Support for the user struct. */ /* Return the address of register REGNUM. BLOCKEND is the value of u.u_ar0, and points to the place where GS is stored. */ CORE_ADDR register_u_addr (CORE_ADDR blockend, int regnum) { struct user u; CORE_ADDR fpstate; if (i386_fp_regnum_p (regnum)) { #ifdef KSTKSZ /* SCO, and others? */ blockend += 4 * (SS + 1) - KSTKSZ; fpstate = blockend + ((char *) &u.u_fps.u_fpstate - (char *) &u); return (fpstate + 0x1c + 10 * (regnum - FP0_REGNUM)); #else fpstate = blockend + ((char *) &u.i387.st_space - (char *) &u); return (fpstate + 10 * (regnum - FP0_REGNUM)); #endif } return (blockend + 4 * regmap[regnum]); } /* Return the size of the user struct. */ int kernel_u_size (void) { return (sizeof (struct user)); } #ifdef TARGET_HAS_HARDWARE_WATCHPOINTS #if !defined (offsetof) #define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER) #endif /* Record the value of the debug control register. */ static int debug_control_mirror; /* Record which address associates with which register. */ static CORE_ADDR address_lookup[DR_LASTADDR - DR_FIRSTADDR + 1]; static int i386_insert_aligned_watchpoint (int, CORE_ADDR, CORE_ADDR, int, int); static int i386_insert_nonaligned_watchpoint (int, CORE_ADDR, CORE_ADDR, int, int); /* Insert a watchpoint. */ int i386_insert_watchpoint (int pid, CORE_ADDR addr, int len, int rw) { return i386_insert_aligned_watchpoint (pid, addr, addr, len, rw); } static int i386_insert_aligned_watchpoint (int pid, CORE_ADDR waddr, CORE_ADDR addr, int len, int rw) { int i; int read_write_bits, len_bits; int free_debug_register; int register_number; /* Look for a free debug register. */ for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++) { if (address_lookup[i - DR_FIRSTADDR] == 0) break; } /* No more debug registers! */ if (i > DR_LASTADDR) return -1; read_write_bits = (rw & 1) ? DR_RW_READ : DR_RW_WRITE; if (len == 1) len_bits = DR_LEN_1; else if (len == 2) { if (addr % 2) return i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw); len_bits = DR_LEN_2; } else if (len == 4) { if (addr % 4) return i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw); len_bits = DR_LEN_4; } else return i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw); free_debug_register = i; register_number = free_debug_register - DR_FIRSTADDR; debug_control_mirror |= ((read_write_bits | len_bits) << (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * register_number)); debug_control_mirror |= (1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * register_number)); debug_control_mirror |= DR_LOCAL_SLOWDOWN; debug_control_mirror &= ~DR_CONTROL_RESERVED; ptrace (6, pid, offsetof (struct user, u_debugreg[DR_CONTROL]), debug_control_mirror); ptrace (6, pid, offsetof (struct user, u_debugreg[free_debug_register]), addr); /* Record where we came from. */ address_lookup[register_number] = addr; return 0; } static int i386_insert_nonaligned_watchpoint (int pid, CORE_ADDR waddr, CORE_ADDR addr, int len, int rw) { int align; int size; int rv; static int size_try_array[4][4] = { { 1, 1, 1, 1 }, /* trying size one */ { 2, 1, 2, 1 }, /* trying size two */ { 2, 1, 2, 1 }, /* trying size three */ { 4, 1, 2, 1 } /* trying size four */ }; rv = 0; while (len > 0) { align = addr % 4; /* Four is the maximum length for 386. */ size = size_try_array[len > 4 ? 3 : len - 1][align]; rv = i386_insert_aligned_watchpoint (pid, waddr, addr, size, rw); if (rv) { i386_remove_watchpoint (pid, waddr, size); return rv; } addr += size; len -= size; } return rv; } /* Remove a watchpoint. */ int i386_remove_watchpoint (int pid, CORE_ADDR addr, int len) { int i; int register_number; for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++) { register_number = i - DR_FIRSTADDR; if (address_lookup[register_number] == addr) { debug_control_mirror &= ~(1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * register_number)); address_lookup[register_number] = 0; } } ptrace (6, pid, offsetof (struct user, u_debugreg[DR_CONTROL]), debug_control_mirror); ptrace (6, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0); return 0; } /* Check if stopped by a watchpoint. */ CORE_ADDR i386_stopped_by_watchpoint (int pid) { int i; int status; status = ptrace (3, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0); ptrace (6, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0); for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++) { if (status & (1 << (i - DR_FIRSTADDR))) return address_lookup[i - DR_FIRSTADDR]; } return 0; } #endif /* TARGET_HAS_HARDWARE_WATCHPOINTS */