/* Motorola m68k native support for GNU/Linux. Copyright (C) 1996-2018 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 3 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, see <http://www.gnu.org/licenses/>. */ #include "defs.h" #include "frame.h" #include "inferior.h" #include "language.h" #include "gdbcore.h" #include "regcache.h" #include "target.h" #include "linux-nat.h" #include "m68k-tdep.h" #include <sys/dir.h> #include <signal.h> #include "nat/gdb_ptrace.h" #include <sys/user.h> #include <sys/ioctl.h> #include <fcntl.h> #include <sys/procfs.h> #ifdef HAVE_SYS_REG_H #include <sys/reg.h> #endif #include <sys/file.h> #include <sys/stat.h> #include "floatformat.h" /* Prototypes for supply_gregset etc. */ #include "gregset.h" /* Defines ps_err_e, struct ps_prochandle. */ #include "gdb_proc_service.h" #include "inf-ptrace.h" #ifndef PTRACE_GET_THREAD_AREA #define PTRACE_GET_THREAD_AREA 25 #endif class m68k_linux_nat_target final : public linux_nat_target { public: /* Add our register access methods. */ void fetch_registers (struct regcache *, int) override; void store_registers (struct regcache *, int) override; }; static m68k_linux_nat_target the_m68k_linux_nat_target; /* This table must line up with gdbarch_register_name in "m68k-tdep.c". */ static const int regmap[] = { PT_D0, PT_D1, PT_D2, PT_D3, PT_D4, PT_D5, PT_D6, PT_D7, PT_A0, PT_A1, PT_A2, PT_A3, PT_A4, PT_A5, PT_A6, PT_USP, PT_SR, PT_PC, /* PT_FP0, ..., PT_FP7 */ 21, 24, 27, 30, 33, 36, 39, 42, /* PT_FPCR, PT_FPSR, PT_FPIAR */ 45, 46, 47 }; /* Which ptrace request retrieves which registers? These apply to the corresponding SET requests as well. */ #define NUM_GREGS (18) #define MAX_NUM_REGS (NUM_GREGS + 11) static int getregs_supplies (int regno) { return 0 <= regno && regno < NUM_GREGS; } static int getfpregs_supplies (int regno) { return M68K_FP0_REGNUM <= regno && regno <= M68K_FPI_REGNUM; } /* Does the current host support the GETREGS request? */ static int have_ptrace_getregs = #ifdef HAVE_PTRACE_GETREGS 1 #else 0 #endif ; /* Fetching registers directly from the U area, one at a time. */ /* Fetch one register. */ static void fetch_register (struct regcache *regcache, int regno) { struct gdbarch *gdbarch = regcache->arch (); long regaddr, val; int i; gdb_byte buf[M68K_MAX_REGISTER_SIZE]; pid_t tid = get_ptrace_pid (regcache->ptid ()); regaddr = 4 * regmap[regno]; for (i = 0; i < register_size (gdbarch, regno); i += sizeof (long)) { errno = 0; val = ptrace (PTRACE_PEEKUSER, tid, regaddr, 0); memcpy (&buf[i], &val, sizeof (long)); regaddr += sizeof (long); if (errno != 0) error (_("Couldn't read register %s (#%d): %s."), gdbarch_register_name (gdbarch, regno), regno, safe_strerror (errno)); } regcache->raw_supply (regno, buf); } /* Fetch register values from the inferior. If REGNO is negative, do this for all registers. Otherwise, REGNO specifies which register (so we can save time). */ static void old_fetch_inferior_registers (struct regcache *regcache, int regno) { if (regno >= 0) { fetch_register (regcache, regno); } else { for (regno = 0; regno < gdbarch_num_regs (regcache->arch ()); regno++) { fetch_register (regcache, regno); } } } /* Store one register. */ static void store_register (const struct regcache *regcache, int regno) { struct gdbarch *gdbarch = regcache->arch (); long regaddr, val; int i; gdb_byte buf[M68K_MAX_REGISTER_SIZE]; pid_t tid = get_ptrace_pid (regcache->ptid ()); regaddr = 4 * regmap[regno]; /* Put the contents of regno into a local buffer. */ regcache->raw_collect (regno, buf); /* Store the local buffer into the inferior a chunk at the time. */ for (i = 0; i < register_size (gdbarch, regno); i += sizeof (long)) { errno = 0; memcpy (&val, &buf[i], sizeof (long)); ptrace (PTRACE_POKEUSER, tid, regaddr, val); regaddr += sizeof (long); if (errno != 0) error (_("Couldn't write register %s (#%d): %s."), gdbarch_register_name (gdbarch, regno), regno, safe_strerror (errno)); } } /* Store our register values back into the inferior. If REGNO is negative, do this for all registers. Otherwise, REGNO specifies which register (so we can save time). */ static void old_store_inferior_registers (const struct regcache *regcache, int regno) { if (regno >= 0) { store_register (regcache, regno); } else { for (regno = 0; regno < gdbarch_num_regs (regcache->arch ()); regno++) { store_register (regcache, regno); } } } /* Given a pointer to a general register set in /proc format (elf_gregset_t *), unpack the register contents and supply them as gdb's idea of the current register values. */ void supply_gregset (struct regcache *regcache, const elf_gregset_t *gregsetp) { struct gdbarch *gdbarch = regcache->arch (); const elf_greg_t *regp = (const elf_greg_t *) gregsetp; int regi; for (regi = M68K_D0_REGNUM; regi <= gdbarch_sp_regnum (gdbarch); regi++) regcache->raw_supply (regi, ®p[regmap[regi]]); regcache->raw_supply (gdbarch_ps_regnum (gdbarch), ®p[PT_SR]); regcache->raw_supply (gdbarch_pc_regnum (gdbarch), ®p[PT_PC]); } /* Fill register REGNO (if it is a general-purpose register) in *GREGSETPS with the value in GDB's register array. If REGNO is -1, do this for all registers. */ void fill_gregset (const struct regcache *regcache, elf_gregset_t *gregsetp, int regno) { elf_greg_t *regp = (elf_greg_t *) gregsetp; int i; for (i = 0; i < NUM_GREGS; i++) if (regno == -1 || regno == i) regcache->raw_collect (i, regp + regmap[i]); } #ifdef HAVE_PTRACE_GETREGS /* Fetch all general-purpose registers from process/thread TID and store their values in GDB's register array. */ static void fetch_regs (struct regcache *regcache, int tid) { elf_gregset_t regs; if (ptrace (PTRACE_GETREGS, tid, 0, (int) ®s) < 0) { if (errno == EIO) { /* The kernel we're running on doesn't support the GETREGS request. Reset `have_ptrace_getregs'. */ have_ptrace_getregs = 0; return; } perror_with_name (_("Couldn't get registers")); } supply_gregset (regcache, (const elf_gregset_t *) ®s); } /* Store all valid general-purpose registers in GDB's register array into the process/thread specified by TID. */ static void store_regs (const struct regcache *regcache, int tid, int regno) { elf_gregset_t regs; if (ptrace (PTRACE_GETREGS, tid, 0, (int) ®s) < 0) perror_with_name (_("Couldn't get registers")); fill_gregset (regcache, ®s, regno); if (ptrace (PTRACE_SETREGS, tid, 0, (int) ®s) < 0) perror_with_name (_("Couldn't write registers")); } #else static void fetch_regs (struct regcache *regcache, int tid) { } static void store_regs (const struct regcache *regcache, int tid, int regno) { } #endif /* Transfering floating-point registers between GDB, inferiors and cores. */ /* What is the address of fpN within the floating-point register set F? */ #define FPREG_ADDR(f, n) (&(f)->fpregs[(n) * 3]) /* Fill GDB's register array with the floating-point register values in *FPREGSETP. */ void supply_fpregset (struct regcache *regcache, const elf_fpregset_t *fpregsetp) { struct gdbarch *gdbarch = regcache->arch (); int regi; for (regi = gdbarch_fp0_regnum (gdbarch); regi < gdbarch_fp0_regnum (gdbarch) + 8; regi++) regcache->raw_supply (regi, FPREG_ADDR (fpregsetp, regi - gdbarch_fp0_regnum (gdbarch))); regcache->raw_supply (M68K_FPC_REGNUM, &fpregsetp->fpcntl[0]); regcache->raw_supply (M68K_FPS_REGNUM, &fpregsetp->fpcntl[1]); regcache->raw_supply (M68K_FPI_REGNUM, &fpregsetp->fpcntl[2]); } /* Fill register REGNO (if it is a floating-point register) in *FPREGSETP with the value in GDB's register array. If REGNO is -1, do this for all registers. */ void fill_fpregset (const struct regcache *regcache, elf_fpregset_t *fpregsetp, int regno) { struct gdbarch *gdbarch = regcache->arch (); int i; /* Fill in the floating-point registers. */ for (i = gdbarch_fp0_regnum (gdbarch); i < gdbarch_fp0_regnum (gdbarch) + 8; i++) if (regno == -1 || regno == i) regcache->raw_collect (i, FPREG_ADDR (fpregsetp, i - gdbarch_fp0_regnum (gdbarch))); /* Fill in the floating-point control registers. */ for (i = M68K_FPC_REGNUM; i <= M68K_FPI_REGNUM; i++) if (regno == -1 || regno == i) regcache->raw_collect (i, &fpregsetp->fpcntl[i - M68K_FPC_REGNUM]); } #ifdef HAVE_PTRACE_GETREGS /* Fetch all floating-point registers from process/thread TID and store thier values in GDB's register array. */ static void fetch_fpregs (struct regcache *regcache, int tid) { elf_fpregset_t fpregs; if (ptrace (PTRACE_GETFPREGS, tid, 0, (int) &fpregs) < 0) perror_with_name (_("Couldn't get floating point status")); supply_fpregset (regcache, (const elf_fpregset_t *) &fpregs); } /* Store all valid floating-point registers in GDB's register array into the process/thread specified by TID. */ static void store_fpregs (const struct regcache *regcache, int tid, int regno) { elf_fpregset_t fpregs; if (ptrace (PTRACE_GETFPREGS, tid, 0, (int) &fpregs) < 0) perror_with_name (_("Couldn't get floating point status")); fill_fpregset (regcache, &fpregs, regno); if (ptrace (PTRACE_SETFPREGS, tid, 0, (int) &fpregs) < 0) perror_with_name (_("Couldn't write floating point status")); } #else static void fetch_fpregs (struct regcache *regcache, int tid) { } static void store_fpregs (const struct regcache *regcache, int tid, int regno) { } #endif /* Transferring arbitrary registers between GDB and inferior. */ /* Fetch register REGNO from the child process. If REGNO is -1, do this for all registers (including the floating point and SSE registers). */ void m68k_linux_nat_target::fetch_registers (struct regcache *regcache, int regno) { pid_t tid; /* Use the old method of peeking around in `struct user' if the GETREGS request isn't available. */ if (! have_ptrace_getregs) { old_fetch_inferior_registers (regcache, regno); return; } tid = get_ptrace_pid (regcache->ptid ()); /* Use the PTRACE_GETFPXREGS request whenever possible, since it transfers more registers in one system call, and we'll cache the results. But remember that fetch_fpxregs can fail, and return zero. */ if (regno == -1) { fetch_regs (regcache, tid); /* The call above might reset `have_ptrace_getregs'. */ if (! have_ptrace_getregs) { old_fetch_inferior_registers (regcache, -1); return; } fetch_fpregs (regcache, tid); return; } if (getregs_supplies (regno)) { fetch_regs (regcache, tid); return; } if (getfpregs_supplies (regno)) { fetch_fpregs (regcache, tid); return; } internal_error (__FILE__, __LINE__, _("Got request for bad register number %d."), regno); } /* Store register REGNO back into the child process. If REGNO is -1, do this for all registers (including the floating point and SSE registers). */ void m68k_linux_nat_target::store_registers (struct regcache *regcache, int regno) { pid_t tid; /* Use the old method of poking around in `struct user' if the SETREGS request isn't available. */ if (! have_ptrace_getregs) { old_store_inferior_registers (regcache, regno); return; } tid = get_ptrace_pid (regcache->ptid ()); /* Use the PTRACE_SETFPREGS requests whenever possible, since it transfers more registers in one system call. But remember that store_fpregs can fail, and return zero. */ if (regno == -1) { store_regs (regcache, tid, regno); store_fpregs (regcache, tid, regno); return; } if (getregs_supplies (regno)) { store_regs (regcache, tid, regno); return; } if (getfpregs_supplies (regno)) { store_fpregs (regcache, tid, regno); return; } internal_error (__FILE__, __LINE__, _("Got request to store bad register number %d."), regno); } /* Fetch the thread-local storage pointer for libthread_db. */ ps_err_e ps_get_thread_area (struct ps_prochandle *ph, lwpid_t lwpid, int idx, void **base) { if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) < 0) return PS_ERR; /* IDX is the bias from the thread pointer to the beginning of the thread descriptor. It has to be subtracted due to implementation quirks in libthread_db. */ *base = (char *) *base - idx; return PS_OK; } void _initialize_m68k_linux_nat (void) { /* Register the target. */ linux_target = &the_m68k_linux_nat_target; add_inf_child_target (&the_m68k_linux_nat_target); }