1 /* Native-dependent code for OpenBSD/powerpc. 2 3 Copyright (C) 2004-2019 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 "gdbcore.h" 22 #include "inferior.h" 23 #include "regcache.h" 24 25 #include <sys/types.h> 26 #include <sys/ptrace.h> 27 #include <sys/signal.h> 28 #include <machine/frame.h> 29 #include <machine/pcb.h> 30 #include <machine/reg.h> 31 32 #include "ppc-tdep.h" 33 #include "ppc-obsd-tdep.h" 34 #include "inf-ptrace.h" 35 #include "obsd-nat.h" 36 #include "bsd-kvm.h" 37 38 struct ppc_obsd_nat_target final : public obsd_nat_target 39 { 40 void fetch_registers (struct regcache *, int) override; 41 void store_registers (struct regcache *, int) override; 42 }; 43 44 static ppc_obsd_nat_target the_ppc_obsd_nat_target; 45 46 /* OpenBSD/powerpc didn't have PT_GETFPREGS/PT_SETFPREGS until release 47 4.0. On older releases the floating-point registers are handled by 48 PT_GETREGS/PT_SETREGS, but fpscr wasn't available.. */ 49 50 #ifdef PT_GETFPREGS 51 52 /* Returns true if PT_GETFPREGS fetches this register. */ 53 54 static int 55 getfpregs_supplies (struct gdbarch *gdbarch, int regnum) 56 { 57 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); 58 59 /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating 60 point registers. Traditionally, GDB's register set has still 61 listed the floating point registers for such machines, so this 62 code is harmless. However, the new E500 port actually omits the 63 floating point registers entirely from the register set --- they 64 don't even have register numbers assigned to them. 65 66 It's not clear to me how best to update this code, so this assert 67 will alert the first person to encounter the NetBSD/E500 68 combination to the problem. */ 69 gdb_assert (ppc_floating_point_unit_p (gdbarch)); 70 71 return ((regnum >= tdep->ppc_fp0_regnum 72 && regnum < tdep->ppc_fp0_regnum + ppc_num_fprs) 73 || regnum == tdep->ppc_fpscr_regnum); 74 } 75 76 #endif /* PT_GETFPREGS */ 77 78 /* Fetch register REGNUM from the inferior. If REGNUM is -1, do this 79 for all registers. */ 80 81 void 82 ppc_obsd_nat_target::fetch_registers (struct regcache *regcache, int regnum) 83 { 84 struct reg regs; 85 pid_t pid = regcache->ptid ().pid (); 86 87 if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) ®s, 0) == -1) 88 perror_with_name (_("Couldn't get registers")); 89 90 ppc_supply_gregset (&ppcobsd_gregset, regcache, -1, 91 ®s, sizeof regs); 92 #ifndef PT_GETFPREGS 93 ppc_supply_fpregset (&ppcobsd_gregset, regcache, -1, 94 ®s, sizeof regs); 95 #endif 96 97 #ifdef PT_GETFPREGS 98 if (regnum == -1 99 || getfpregs_supplies (regcache->arch (), regnum)) 100 { 101 struct fpreg fpregs; 102 103 if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1) 104 perror_with_name (_("Couldn't get floating point status")); 105 106 ppc_supply_fpregset (&ppcobsd_fpregset, regcache, -1, 107 &fpregs, sizeof fpregs); 108 } 109 #endif 110 } 111 112 /* Store register REGNUM back into the inferior. If REGNUM is -1, do 113 this for all registers. */ 114 115 void 116 ppc_obsd_nat_target::store_registers (struct regcache *regcache, int regnum) 117 { 118 struct reg regs; 119 pid_t pid = regcache->ptid ().pid (); 120 121 if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) ®s, 0) == -1) 122 perror_with_name (_("Couldn't get registers")); 123 124 ppc_collect_gregset (&ppcobsd_gregset, regcache, 125 regnum, ®s, sizeof regs); 126 #ifndef PT_GETFPREGS 127 ppc_collect_fpregset (&ppcobsd_gregset, regcache, 128 regnum, ®s, sizeof regs); 129 #endif 130 131 if (ptrace (PT_SETREGS, pid, (PTRACE_TYPE_ARG3) ®s, 0) == -1) 132 perror_with_name (_("Couldn't write registers")); 133 134 #ifdef PT_GETFPREGS 135 if (regnum == -1 136 || getfpregs_supplies (regcache->arch (), regnum)) 137 { 138 struct fpreg fpregs; 139 140 if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1) 141 perror_with_name (_("Couldn't get floating point status")); 142 143 ppc_collect_fpregset (&ppcobsd_fpregset, regcache, 144 regnum, &fpregs, sizeof fpregs); 145 146 if (ptrace (PT_SETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1) 147 perror_with_name (_("Couldn't write floating point status")); 148 } 149 #endif 150 } 151 152 153 static int 154 ppcobsd_supply_pcb (struct regcache *regcache, struct pcb *pcb) 155 { 156 struct gdbarch *gdbarch = regcache->arch (); 157 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); 158 struct switchframe sf; 159 struct callframe cf; 160 int i, regnum; 161 162 /* The following is true for OpenBSD 3.7: 163 164 The pcb contains %r1 (the stack pointer) at the point of the 165 context switch in cpu_switch(). At that point we have a stack 166 frame as described by `struct switchframe', and below that a call 167 frame as described by `struct callframe'. From this information 168 we reconstruct the register state as it would look when we are in 169 cpu_switch(). */ 170 171 /* The stack pointer shouldn't be zero. */ 172 if (pcb->pcb_sp == 0) 173 return 0; 174 175 read_memory (pcb->pcb_sp, (gdb_byte *)&sf, sizeof sf); 176 regcache->raw_supply (gdbarch_sp_regnum (gdbarch), &sf.sp); 177 regcache->raw_supply (tdep->ppc_cr_regnum, &sf.cr); 178 regcache->raw_supply (tdep->ppc_gp0_regnum + 2, &sf.fixreg2); 179 for (i = 0, regnum = tdep->ppc_gp0_regnum + 13; i < 19; i++, regnum++) 180 regcache->raw_supply (regnum, &sf.fixreg[i]); 181 182 read_memory (sf.sp, (gdb_byte *)&cf, sizeof cf); 183 regcache->raw_supply (gdbarch_pc_regnum (gdbarch), &cf.lr); 184 regcache->raw_supply (tdep->ppc_gp0_regnum + 30, &cf.r30); 185 regcache->raw_supply (tdep->ppc_gp0_regnum + 31, &cf.r31); 186 187 return 1; 188 } 189 190 void 191 _initialize_ppcobsd_nat (void) 192 { 193 add_inf_child_target (&the_ppc_obsd_nat_target); 194 195 /* General-purpose registers. */ 196 ppcobsd_reg_offsets.r0_offset = offsetof (struct reg, gpr); 197 ppcobsd_reg_offsets.gpr_size = 4; 198 ppcobsd_reg_offsets.xr_size = 4; 199 ppcobsd_reg_offsets.pc_offset = offsetof (struct reg, pc); 200 ppcobsd_reg_offsets.ps_offset = offsetof (struct reg, ps); 201 ppcobsd_reg_offsets.cr_offset = offsetof (struct reg, cnd); 202 ppcobsd_reg_offsets.lr_offset = offsetof (struct reg, lr); 203 ppcobsd_reg_offsets.ctr_offset = offsetof (struct reg, cnt); 204 ppcobsd_reg_offsets.xer_offset = offsetof (struct reg, xer); 205 ppcobsd_reg_offsets.mq_offset = offsetof (struct reg, mq); 206 207 /* Floating-point registers. */ 208 ppcobsd_reg_offsets.f0_offset = offsetof (struct reg, fpr); 209 ppcobsd_reg_offsets.fpscr_offset = -1; 210 #ifdef PT_GETFPREGS 211 ppcobsd_fpreg_offsets.f0_offset = offsetof (struct fpreg, fpr); 212 ppcobsd_fpreg_offsets.fpscr_offset = offsetof (struct fpreg, fpscr); 213 ppcobsd_fpreg_offsets.fpscr_size = 4; 214 #endif 215 216 /* Support debugging kernel virtual memory images. */ 217 bsd_kvm_add_target (ppcobsd_supply_pcb); 218 } 219