/* Motorola m68k native support for GNU/Linux. Copyright 1996, 1998, 2000, 2001, 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" #include "frame.h" #include "inferior.h" #include "language.h" #include "gdbcore.h" #include "regcache.h" #ifdef USG #include #endif #include #include #include #include #include #include #include #include #ifdef HAVE_SYS_REG_H #include #endif #include #include "gdb_stat.h" #include "floatformat.h" #include "target.h" /* This table must line up with REGISTER_NAMES in tm-m68k.h */ 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) int getregs_supplies (int regno) { return 0 <= regno && regno < NUM_GREGS; } int getfpregs_supplies (int regno) { return FP0_REGNUM <= regno && regno <= FPI_REGNUM; } /* Does the current host support the GETREGS request? */ int have_ptrace_getregs = #ifdef HAVE_PTRACE_GETREGS 1 #else 0 #endif ; /* BLOCKEND is the value of u.u_ar0, and points to the place where GS is stored. */ int m68k_linux_register_u_addr (int blockend, int regnum) { return (blockend + 4 * regmap[regnum]); } /* Fetching registers directly from the U area, one at a time. */ /* FIXME: This duplicates code from `inptrace.c'. The problem is that we define FETCH_INFERIOR_REGISTERS since we want to use our own versions of {fetch,store}_inferior_registers that use the GETREGS request. This means that the code in `infptrace.c' is #ifdef'd out. But we need to fall back on that code when GDB is running on top of a kernel that doesn't support the GETREGS request. */ #ifndef PT_READ_U #define PT_READ_U PTRACE_PEEKUSR #endif #ifndef PT_WRITE_U #define PT_WRITE_U PTRACE_POKEUSR #endif /* Default the type of the ptrace transfer to int. */ #ifndef PTRACE_XFER_TYPE #define PTRACE_XFER_TYPE int #endif /* Fetch one register. */ static void fetch_register (int regno) { /* This isn't really an address. But ptrace thinks of it as one. */ CORE_ADDR regaddr; char mess[128]; /* For messages */ register int i; unsigned int offset; /* Offset of registers within the u area. */ char buf[MAX_REGISTER_RAW_SIZE]; int tid; if (CANNOT_FETCH_REGISTER (regno)) { memset (buf, '\0', REGISTER_RAW_SIZE (regno)); /* Supply zeroes */ supply_register (regno, buf); return; } /* Overload thread id onto process id */ if ((tid = TIDGET (inferior_ptid)) == 0) tid = PIDGET (inferior_ptid); /* no thread id, just use process id */ offset = U_REGS_OFFSET; regaddr = register_addr (regno, offset); for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE)) { errno = 0; *(PTRACE_XFER_TYPE *) & buf[i] = ptrace (PT_READ_U, tid, (PTRACE_ARG3_TYPE) regaddr, 0); regaddr += sizeof (PTRACE_XFER_TYPE); if (errno != 0) { sprintf (mess, "reading register %s (#%d)", REGISTER_NAME (regno), regno); perror_with_name (mess); } } supply_register (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). */ void old_fetch_inferior_registers (int regno) { if (regno >= 0) { fetch_register (regno); } else { for (regno = 0; regno < NUM_REGS; regno++) { fetch_register (regno); } } } /* Store one register. */ static void store_register (int regno) { /* This isn't really an address. But ptrace thinks of it as one. */ CORE_ADDR regaddr; char mess[128]; /* For messages */ register int i; unsigned int offset; /* Offset of registers within the u area. */ int tid; char *buf = alloca (MAX_REGISTER_RAW_SIZE); if (CANNOT_STORE_REGISTER (regno)) { return; } /* Overload thread id onto process id */ if ((tid = TIDGET (inferior_ptid)) == 0) tid = PIDGET (inferior_ptid); /* no thread id, just use process id */ offset = U_REGS_OFFSET; regaddr = register_addr (regno, offset); /* Put the contents of regno into a local buffer */ regcache_collect (regno, buf); /* Store the local buffer into the inferior a chunk at the time. */ for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE)) { errno = 0; ptrace (PT_WRITE_U, tid, (PTRACE_ARG3_TYPE) regaddr, *(PTRACE_XFER_TYPE *) (buf + i)); regaddr += sizeof (PTRACE_XFER_TYPE); if (errno != 0) { sprintf (mess, "writing register %s (#%d)", REGISTER_NAME (regno), regno); perror_with_name (mess); } } } /* 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). */ void old_store_inferior_registers (int regno) { if (regno >= 0) { store_register (regno); } else { for (regno = 0; regno < NUM_REGS; regno++) { store_register (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. */ /* Note both m68k-tdep.c and m68klinux-nat.c contain definitions for supply_gregset and supply_fpregset. The definitions in m68k-tdep.c are valid if USE_PROC_FS is defined. Otherwise, the definitions in m68klinux-nat.c will be used. This is a bit of a hack. The supply_* routines do not belong in *_tdep.c files. But, there are several lynx ports that currently depend on these definitions. */ #ifndef USE_PROC_FS /* Prototypes for supply_gregset etc. */ #include "gregset.h" void supply_gregset (elf_gregset_t *gregsetp) { elf_greg_t *regp = (elf_greg_t *) gregsetp; int regi; for (regi = D0_REGNUM; regi <= SP_REGNUM; regi++) supply_register (regi, (char *) ®p[regmap[regi]]); supply_register (PS_REGNUM, (char *) ®p[PT_SR]); supply_register (PC_REGNUM, (char *) ®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 (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_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 (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 (®s); } /* Store all valid general-purpose registers in GDB's register array into the process/thread specified by TID. */ static void store_regs (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 (®s, regno); if (ptrace (PTRACE_SETREGS, tid, 0, (int) ®s) < 0) perror_with_name ("Couldn't write registers"); } #else static void fetch_regs (int tid) {} static void store_regs (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) ((char *) &(f)->fpregs[(n) * 3]) /* Fill GDB's register array with the floating-point register values in *FPREGSETP. */ void supply_fpregset (elf_fpregset_t *fpregsetp) { int regi; for (regi = FP0_REGNUM; regi < FPC_REGNUM; regi++) supply_register (regi, FPREG_ADDR (fpregsetp, regi - FP0_REGNUM)); supply_register (FPC_REGNUM, (char *) &fpregsetp->fpcntl[0]); supply_register (FPS_REGNUM, (char *) &fpregsetp->fpcntl[1]); supply_register (FPI_REGNUM, (char *) &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 (elf_fpregset_t *fpregsetp, int regno) { int i; /* Fill in the floating-point registers. */ for (i = FP0_REGNUM; i < FP0_REGNUM + 8; i++) if (regno == -1 || regno == i) regcache_collect (regno, FPREG_ADDR (fpregsetp, regno - FP0_REGNUM)); /* Fill in the floating-point control registers. */ for (i = FPC_REGNUM; i <= FPI_REGNUM; i++) if (regno == -1 || regno == i) regcache_collect (regno, (char *) &fpregsetp->fpcntl[regno - 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 (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 (&fpregs); } /* Store all valid floating-point registers in GDB's register array into the process/thread specified by TID. */ static void store_fpregs (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 (&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 (int tid) {} static void store_fpregs (int tid, int regno) {} #endif #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 fetch_inferior_registers (int regno) { int 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 (regno); return; } /* GNU/Linux LWP ID's are process ID's. */ if ((tid = TIDGET (inferior_ptid)) == 0) tid = PIDGET (inferior_ptid); /* Not a threaded program. */ /* 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 (tid); /* The call above might reset `have_ptrace_getregs'. */ if (! have_ptrace_getregs) { old_fetch_inferior_registers (-1); return; } fetch_fpregs (tid); return; } if (getregs_supplies (regno)) { fetch_regs (tid); return; } if (getfpregs_supplies (regno)) { fetch_fpregs (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 store_inferior_registers (int regno) { int 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 (regno); return; } /* GNU/Linux LWP ID's are process ID's. */ if ((tid = TIDGET (inferior_ptid)) == 0) tid = PIDGET (inferior_ptid); /* Not a threaded program. */ /* 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 (tid, regno); store_fpregs (tid, regno); return; } if (getregs_supplies (regno)) { store_regs (tid, regno); return; } if (getfpregs_supplies (regno)) { store_fpregs (tid, regno); return; } internal_error (__FILE__, __LINE__, "Got request to store bad register number %d.", regno); } /* Interpreting register set info found in core files. */ /* Provide registers to GDB from a core file. (We can't use the generic version of this function in core-regset.c, because we need to use elf_gregset_t instead of gregset_t.) CORE_REG_SECT points to an array of bytes, which are the contents of a `note' from a core file which BFD thinks might contain register contents. CORE_REG_SIZE is its size. WHICH says which register set corelow suspects this is: 0 --- the general-purpose register set, in elf_gregset_t format 2 --- the floating-point register set, in elf_fpregset_t format REG_ADDR isn't used on GNU/Linux. */ static void fetch_core_registers (char *core_reg_sect, unsigned core_reg_size, int which, CORE_ADDR reg_addr) { elf_gregset_t gregset; elf_fpregset_t fpregset; switch (which) { case 0: if (core_reg_size != sizeof (gregset)) warning ("Wrong size gregset in core file."); else { memcpy (&gregset, core_reg_sect, sizeof (gregset)); supply_gregset (&gregset); } break; case 2: if (core_reg_size != sizeof (fpregset)) warning ("Wrong size fpregset in core file."); else { memcpy (&fpregset, core_reg_sect, sizeof (fpregset)); supply_fpregset (&fpregset); } break; default: /* We've covered all the kinds of registers we know about here, so this must be something we wouldn't know what to do with anyway. Just ignore it. */ break; } } int kernel_u_size (void) { return (sizeof (struct user)); } /* Check whether insn1 and insn2 are parts of a signal trampoline. */ #define IS_SIGTRAMP(insn1, insn2) \ (/* addaw #20,sp; moveq #119,d0; trap #0 */ \ (insn1 == 0xdefc0014 && insn2 == 0x70774e40) \ /* moveq #119,d0; trap #0 */ \ || insn1 == 0x70774e40) #define IS_RT_SIGTRAMP(insn1, insn2) \ (/* movel #173,d0; trap #0 */ \ (insn1 == 0x203c0000 && insn2 == 0x00ad4e40) \ /* moveq #82,d0; notb d0; trap #0 */ \ || (insn1 == 0x70524600 && (insn2 >> 16) == 0x4e40)) /* Return non-zero if PC points into the signal trampoline. For the sake of m68k_linux_frame_saved_pc we also distinguish between non-RT and RT signal trampolines. */ int m68k_linux_in_sigtramp (CORE_ADDR pc) { CORE_ADDR sp; char buf[12]; unsigned long insn0, insn1, insn2; if (read_memory_nobpt (pc - 4, buf, sizeof (buf))) return 0; insn1 = extract_unsigned_integer (buf + 4, 4); insn2 = extract_unsigned_integer (buf + 8, 4); if (IS_SIGTRAMP (insn1, insn2)) return 1; if (IS_RT_SIGTRAMP (insn1, insn2)) return 2; insn0 = extract_unsigned_integer (buf, 4); if (IS_SIGTRAMP (insn0, insn1)) return 1; if (IS_RT_SIGTRAMP (insn0, insn1)) return 2; insn0 = (insn0 << 16) | (insn1 >> 16); insn1 = (insn1 << 16) | (insn2 >> 16); if (IS_SIGTRAMP (insn0, insn1)) return 1; if (IS_RT_SIGTRAMP (insn0, insn1)) return 2; return 0; } /* Offset to saved PC in sigcontext, from . */ #define SIGCONTEXT_PC_OFFSET 26 /* Offset to saved PC in ucontext, from . */ #define UCONTEXT_PC_OFFSET 88 /* Get saved user PC for sigtramp from sigcontext or ucontext. */ static CORE_ADDR m68k_linux_sigtramp_saved_pc (struct frame_info *frame) { CORE_ADDR sigcontext_addr; char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT]; int ptrbytes = TARGET_PTR_BIT / TARGET_CHAR_BIT; int sigcontext_offs = (2 * TARGET_INT_BIT) / TARGET_CHAR_BIT; /* Get sigcontext address, it is the third parameter on the stack. */ if (frame->next) sigcontext_addr = read_memory_integer (FRAME_ARGS_ADDRESS (frame->next) + FRAME_ARGS_SKIP + sigcontext_offs, ptrbytes); else sigcontext_addr = read_memory_integer (read_register (SP_REGNUM) + sigcontext_offs, ptrbytes); /* Don't cause a memory_error when accessing sigcontext in case the stack layout has changed or the stack is corrupt. */ if (m68k_linux_in_sigtramp (frame->pc) == 2) target_read_memory (sigcontext_addr + UCONTEXT_PC_OFFSET, buf, ptrbytes); else target_read_memory (sigcontext_addr + SIGCONTEXT_PC_OFFSET, buf, ptrbytes); return extract_unsigned_integer (buf, ptrbytes); } /* Return the saved program counter for FRAME. */ CORE_ADDR m68k_linux_frame_saved_pc (struct frame_info *frame) { if ((get_frame_type (frame) == SIGTRAMP_FRAME)) return m68k_linux_sigtramp_saved_pc (frame); return read_memory_integer (frame->frame + 4, 4); } /* Register that we are able to handle GNU/Linux ELF core file formats. */ static struct core_fns linux_elf_core_fns = { bfd_target_elf_flavour, /* core_flavour */ default_check_format, /* check_format */ default_core_sniffer, /* core_sniffer */ fetch_core_registers, /* core_read_registers */ NULL /* next */ }; void _initialize_m68k_linux_nat (void) { add_core_fns (&linux_elf_core_fns); }