| 1 | /* Machine-dependent hooks for the unix child process stratum. This |
| 2 | code is for the HP PA-RISC cpu. |
| 3 | |
| 4 | Copyright 1986, 1987, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1998, |
| 5 | 1999, 2000, 2001 Free Software Foundation, Inc. |
| 6 | |
| 7 | Contributed by the Center for Software Science at the |
| 8 | University of Utah (pa-gdb-bugs@cs.utah.edu). |
| 9 | |
| 10 | This file is part of GDB. |
| 11 | |
| 12 | This program is free software; you can redistribute it and/or modify |
| 13 | it under the terms of the GNU General Public License as published by |
| 14 | the Free Software Foundation; either version 2 of the License, or |
| 15 | (at your option) any later version. |
| 16 | |
| 17 | This program is distributed in the hope that it will be useful, |
| 18 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | GNU General Public License for more details. |
| 21 | |
| 22 | You should have received a copy of the GNU General Public License |
| 23 | along with this program; if not, write to the Free Software |
| 24 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 25 | Boston, MA 02111-1307, USA. */ |
| 26 | |
| 27 | #include "defs.h" |
| 28 | #include "inferior.h" |
| 29 | #include "target.h" |
| 30 | #include "regcache.h" |
| 31 | #include <sys/ptrace.h> |
| 32 | |
| 33 | /* Use an extra level of indirection for ptrace calls. |
| 34 | This lets us breakpoint usefully on call_ptrace. It also |
| 35 | allows us to pass an extra argument to ptrace without |
| 36 | using an ANSI-C specific macro. */ |
| 37 | |
| 38 | #define ptrace call_ptrace |
| 39 | |
| 40 | #if !defined (offsetof) |
| 41 | #define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER) |
| 42 | #endif |
| 43 | |
| 44 | /* U_REGS_OFFSET is the offset of the registers within the u area. */ |
| 45 | #if !defined (U_REGS_OFFSET) |
| 46 | #define U_REGS_OFFSET \ |
| 47 | ptrace (PT_READ_U, inferior_pid, \ |
| 48 | (PTRACE_ARG3_TYPE) (offsetof (struct user, u_ar0)), 0) \ |
| 49 | - KERNEL_U_ADDR |
| 50 | #endif |
| 51 | |
| 52 | /* Fetch one register. */ |
| 53 | |
| 54 | static void |
| 55 | fetch_register (int regno) |
| 56 | { |
| 57 | register unsigned int regaddr; |
| 58 | char buf[MAX_REGISTER_RAW_SIZE]; |
| 59 | register int i; |
| 60 | |
| 61 | /* Offset of registers within the u area. */ |
| 62 | unsigned int offset; |
| 63 | |
| 64 | offset = U_REGS_OFFSET; |
| 65 | |
| 66 | regaddr = register_addr (regno, offset); |
| 67 | for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int)) |
| 68 | { |
| 69 | errno = 0; |
| 70 | *(int *) &buf[i] = ptrace (PT_RUREGS, inferior_pid, |
| 71 | (PTRACE_ARG3_TYPE) regaddr, 0); |
| 72 | regaddr += sizeof (int); |
| 73 | if (errno != 0) |
| 74 | { |
| 75 | /* Warning, not error, in case we are attached; sometimes the |
| 76 | kernel doesn't let us at the registers. */ |
| 77 | char *err = safe_strerror (errno); |
| 78 | char *msg = alloca (strlen (err) + 128); |
| 79 | sprintf (msg, "reading register %s: %s", REGISTER_NAME (regno), err); |
| 80 | warning (msg); |
| 81 | goto error_exit; |
| 82 | } |
| 83 | } |
| 84 | supply_register (regno, buf); |
| 85 | error_exit:; |
| 86 | } |
| 87 | |
| 88 | /* Fetch all registers, or just one, from the child process. */ |
| 89 | |
| 90 | void |
| 91 | fetch_inferior_registers (int regno) |
| 92 | { |
| 93 | if (regno == -1) |
| 94 | for (regno = 0; regno < NUM_REGS; regno++) |
| 95 | fetch_register (regno); |
| 96 | else |
| 97 | fetch_register (regno); |
| 98 | } |
| 99 | |
| 100 | /* Store our register values back into the inferior. |
| 101 | If REGNO is -1, do this for all registers. |
| 102 | Otherwise, REGNO specifies which register (so we can save time). */ |
| 103 | |
| 104 | void |
| 105 | store_inferior_registers (int regno) |
| 106 | { |
| 107 | register unsigned int regaddr; |
| 108 | char buf[80]; |
| 109 | register int i; |
| 110 | unsigned int offset = U_REGS_OFFSET; |
| 111 | int scratch; |
| 112 | |
| 113 | if (regno >= 0) |
| 114 | { |
| 115 | if (CANNOT_STORE_REGISTER (regno)) |
| 116 | return; |
| 117 | regaddr = register_addr (regno, offset); |
| 118 | errno = 0; |
| 119 | if (regno == PCOQ_HEAD_REGNUM || regno == PCOQ_TAIL_REGNUM) |
| 120 | { |
| 121 | scratch = *(int *) ®isters[REGISTER_BYTE (regno)] | 0x3; |
| 122 | ptrace (PT_WUREGS, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, |
| 123 | scratch); |
| 124 | if (errno != 0) |
| 125 | { |
| 126 | /* Error, even if attached. Failing to write these two |
| 127 | registers is pretty serious. */ |
| 128 | sprintf (buf, "writing register number %d", regno); |
| 129 | perror_with_name (buf); |
| 130 | } |
| 131 | } |
| 132 | else |
| 133 | for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int)) |
| 134 | { |
| 135 | errno = 0; |
| 136 | ptrace (PT_WUREGS, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, |
| 137 | *(int *) ®isters[REGISTER_BYTE (regno) + i]); |
| 138 | if (errno != 0) |
| 139 | { |
| 140 | /* Warning, not error, in case we are attached; sometimes the |
| 141 | kernel doesn't let us at the registers. */ |
| 142 | char *err = safe_strerror (errno); |
| 143 | char *msg = alloca (strlen (err) + 128); |
| 144 | sprintf (msg, "writing register %s: %s", |
| 145 | REGISTER_NAME (regno), err); |
| 146 | warning (msg); |
| 147 | return; |
| 148 | } |
| 149 | regaddr += sizeof (int); |
| 150 | } |
| 151 | } |
| 152 | else |
| 153 | for (regno = 0; regno < NUM_REGS; regno++) |
| 154 | store_inferior_registers (regno); |
| 155 | } |
| 156 | |
| 157 | /* PT_PROT is specific to the PA BSD kernel and isn't documented |
| 158 | anywhere (except here). |
| 159 | |
| 160 | PT_PROT allows one to enable/disable the data memory break bit |
| 161 | for pages of memory in an inferior process. This bit is used |
| 162 | to cause "Data memory break traps" to occur when the appropriate |
| 163 | page is written to. |
| 164 | |
| 165 | The arguments are as follows: |
| 166 | |
| 167 | PT_PROT -- The ptrace action to perform. |
| 168 | |
| 169 | INFERIOR_PID -- The pid of the process who's page table entries |
| 170 | will be modified. |
| 171 | |
| 172 | PT_ARGS -- The *address* of a 3 word block of memory which has |
| 173 | additional information: |
| 174 | |
| 175 | word 0 -- The start address to watch. This should be a page-aligned |
| 176 | address. |
| 177 | |
| 178 | word 1 -- The ending address to watch. Again, this should be a |
| 179 | page aligned address. |
| 180 | |
| 181 | word 2 -- Nonzero to enable the data memory break bit on the |
| 182 | given address range or zero to disable the data memory break |
| 183 | bit on the given address range. |
| 184 | |
| 185 | This call may fail if the given addresses are not valid in the inferior |
| 186 | process. This most often happens when restarting a program which |
| 187 | has watchpoints inserted on heap or stack memory. */ |
| 188 | |
| 189 | #define PT_PROT 21 |
| 190 | |
| 191 | int |
| 192 | hppa_set_watchpoint (int addr, int len, int flag) |
| 193 | { |
| 194 | int pt_args[3]; |
| 195 | pt_args[0] = addr; |
| 196 | pt_args[1] = addr + len; |
| 197 | pt_args[2] = flag; |
| 198 | |
| 199 | /* Mask off the lower 12 bits since we want to work on a page basis. */ |
| 200 | pt_args[0] >>= 12; |
| 201 | pt_args[1] >>= 12; |
| 202 | |
| 203 | /* Rounding adjustments. */ |
| 204 | pt_args[1] -= pt_args[0]; |
| 205 | pt_args[1]++; |
| 206 | |
| 207 | /* Put the lower 12 bits back as zero. */ |
| 208 | pt_args[0] <<= 12; |
| 209 | pt_args[1] <<= 12; |
| 210 | |
| 211 | /* Do it. */ |
| 212 | return ptrace (PT_PROT, inferior_pid, (PTRACE_ARG3_TYPE) pt_args, 0); |
| 213 | } |