1 /* Native-dependent code for DragonFly/i386. 2 3 Copyright (C) 2001-2013 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 "inferior.h" 22 #include "regcache.h" 23 #include "target.h" 24 #include "gregset.h" 25 26 #include <sys/types.h> 27 #include <sys/procfs.h> 28 #include <sys/ptrace.h> 29 #include <sys/sysctl.h> 30 31 #include "fbsd-nat.h" 32 #include "i386-tdep.h" 33 #include "i386-nat.h" 34 #include "i386bsd-nat.h" 35 36 #ifdef DFLY_PCB_SUPPLY 37 /* Resume execution of the inferior process. If STEP is nonzero, 38 single-step it. If SIGNAL is nonzero, give it that signal. */ 39 40 static void 41 i386dfly_resume (struct target_ops *ops, 42 ptid_t ptid, int step, enum gdb_signal signal) 43 { 44 pid_t pid = ptid_get_pid (ptid); 45 int request = PT_STEP; 46 47 if (pid == -1) 48 /* Resume all threads. This only gets used in the non-threaded 49 case, where "resume all threads" and "resume inferior_ptid" are 50 the same. */ 51 pid = ptid_get_pid (inferior_ptid); 52 53 if (!step) 54 { 55 struct regcache *regcache = get_current_regcache (); 56 ULONGEST eflags; 57 58 /* Workaround for a bug in FreeBSD. Make sure that the trace 59 flag is off when doing a continue. There is a code path 60 through the kernel which leaves the flag set when it should 61 have been cleared. If a process has a signal pending (such 62 as SIGALRM) and we do a PT_STEP, the process never really has 63 a chance to run because the kernel needs to notify the 64 debugger that a signal is being sent. Therefore, the process 65 never goes through the kernel's trap() function which would 66 normally clear it. */ 67 68 regcache_cooked_read_unsigned (regcache, I386_EFLAGS_REGNUM, 69 &eflags); 70 if (eflags & 0x0100) 71 regcache_cooked_write_unsigned (regcache, I386_EFLAGS_REGNUM, 72 eflags & ~0x0100); 73 74 request = PT_CONTINUE; 75 } 76 77 /* An addres of (caddr_t) 1 tells ptrace to continue from where it 78 was. (If GDB wanted it to start some other way, we have already 79 written a new PC value to the child.) */ 80 if (ptrace (request, pid, (caddr_t) 1, 81 gdb_signal_to_host (signal)) == -1) 82 perror_with_name (("ptrace")); 83 } 84 85 86 /* Transfering the registers between GDB, inferiors and core files. */ 87 88 /* Fill GDB's register array with the general-purpose register values 89 in *GREGSETP. */ 90 91 void 92 supply_gregset (struct regcache *regcache, const gregset_t *gregsetp) 93 { 94 i386bsd_supply_gregset (regcache, gregsetp); 95 } 96 97 /* Fill register REGNUM (if it is a general-purpose register) in 98 *GREGSETPS with the value in GDB's register array. If REGNUM is -1, 99 do this for all registers. */ 100 101 void 102 fill_gregset (const struct regcache *regcache, gdb_gregset_t *gregsetp, int regnum) 103 { 104 i386bsd_collect_gregset (regcache, gregsetp, regnum); 105 } 106 107 #include "i387-tdep.h" 108 109 /* Fill GDB's register array with the floating-point register values 110 in *FPREGSETP. */ 111 112 void 113 supply_fpregset (struct regcache *regcache, const fpregset_t *fpregsetp) 114 { 115 i387_supply_fsave (regcache, -1, fpregsetp); 116 } 117 118 /* Fill register REGNUM (if it is a floating-point register) in 119 *FPREGSETP with the value in GDB's register array. If REGNUM is -1, 120 do this for all registers. */ 121 122 void 123 fill_fpregset (const struct regcache *regcache, gdb_fpregset_t *fpregsetp, int regnum) 124 { 125 i387_collect_fsave (regcache, regnum, fpregsetp); 126 } 127 128 129 /* Support for debugging kernel virtual memory images. */ 130 131 #include <sys/types.h> 132 #include <machine/pcb.h> 133 134 #include "bsd-kvm.h" 135 136 static int 137 i386dfly_supply_pcb (struct regcache *regcache, struct pcb *pcb) 138 { 139 /* The following is true for FreeBSD 4.7: 140 141 The pcb contains %eip, %ebx, %esp, %ebp, %esi, %edi and %gs. 142 This accounts for all callee-saved registers specified by the 143 psABI and then some. Here %esp contains the stack pointer at the 144 point just after the call to cpu_switch(). From this information 145 we reconstruct the register state as it would look when we just 146 returned from cpu_switch(). */ 147 148 /* The stack pointer shouldn't be zero. */ 149 if (pcb->pcb_esp == 0) 150 return 0; 151 152 pcb->pcb_esp += 4; 153 regcache_raw_supply (regcache, I386_EDI_REGNUM, &pcb->pcb_edi); 154 regcache_raw_supply (regcache, I386_ESI_REGNUM, &pcb->pcb_esi); 155 regcache_raw_supply (regcache, I386_EBP_REGNUM, &pcb->pcb_ebp); 156 regcache_raw_supply (regcache, I386_ESP_REGNUM, &pcb->pcb_esp); 157 regcache_raw_supply (regcache, I386_EBX_REGNUM, &pcb->pcb_ebx); 158 regcache_raw_supply (regcache, I386_EIP_REGNUM, &pcb->pcb_eip); 159 regcache_raw_supply (regcache, I386_GS_REGNUM, &pcb->pcb_gs); 160 161 return 1; 162 } 163 #endif /* DFLY_PCB_SUPPLY */ 164 165 166 /* Prevent warning from -Wmissing-prototypes. */ 167 void _initialize_i386dfly_nat (void); 168 169 void 170 _initialize_i386dfly_nat (void) 171 { 172 struct target_ops *t; 173 174 /* Add some extra features to the common *BSD/i386 target. */ 175 t = i386bsd_target (); 176 177 #ifdef HAVE_PT_GETDBREGS 178 179 i386_use_watchpoints (t); 180 181 i386_dr_low.set_control = i386bsd_dr_set_control; 182 i386_dr_low.set_addr = i386bsd_dr_set_addr; 183 i386_dr_low.get_addr = i386bsd_dr_get_addr; 184 i386_dr_low.get_status = i386bsd_dr_get_status; 185 i386_dr_low.get_control = i386bsd_dr_get_control; 186 i386_set_debug_register_length (4); 187 188 #endif /* HAVE_PT_GETDBREGS */ 189 190 191 t->to_pid_to_exec_file = fbsd_pid_to_exec_file; 192 t->to_find_memory_regions = fbsd_find_memory_regions; 193 t->to_make_corefile_notes = fbsd_make_corefile_notes; 194 add_target (t); 195 196 #ifdef DFLY_PCB_SUPPLY 197 /* Support debugging kernel virtual memory images. */ 198 bsd_kvm_add_target (i386dfly_supply_pcb); 199 #endif 200 201 /* DragonFly provides a kern.ps_strings sysctl that we can use to 202 locate the sigtramp. That way we can still recognize a sigtramp 203 if its location is changed in a new kernel. Of course this is 204 still based on the assumption that the sigtramp is placed 205 directly under the location where the program arguments and 206 environment can be found. */ 207 #ifdef KERN_PS_STRINGS 208 { 209 int mib[2]; 210 u_long ps_strings; 211 size_t len; 212 213 mib[0] = CTL_KERN; 214 mib[1] = KERN_PS_STRINGS; 215 len = sizeof (ps_strings); 216 if (sysctl (mib, 2, &ps_strings, &len, NULL, 0) == 0) 217 { 218 i386dfly_sigtramp_start_addr = ps_strings - 128; 219 i386dfly_sigtramp_end_addr = ps_strings; 220 } 221 } 222 #endif 223 } 224