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Diffstat (limited to 'gdb/infptrace.c')
-rw-r--r-- | gdb/infptrace.c | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/gdb/infptrace.c b/gdb/infptrace.c new file mode 100644 index 0000000..03bb271 --- /dev/null +++ b/gdb/infptrace.c @@ -0,0 +1,397 @@ +/* Low level Unix child interface to ptrace, for GDB when running under Unix. + Copyright (C) 1988, 1989, 1990, 1991 Free Software Foundation, Inc. + +This file is part of GDB. + +GDB 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 1, or (at your option) +any later version. + +GDB 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 GDB; see the file COPYING. If not, write to +the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#include <stdio.h> +#include "defs.h" +#include "param.h" +#include "frame.h" +#include "inferior.h" +#include "target.h" + +#ifdef USG +#include <sys/types.h> +#endif + +#include <sys/param.h> +#include <sys/dir.h> +#include <signal.h> +#include <sys/ioctl.h> +#include <sys/ptrace.h> +#if !defined (PT_KILL) +#define PT_KILL 8 +#define PT_STEP 9 +#define PT_CONTINUE 7 +#define PT_READ_U 3 +#define PT_WRITE_U 6 +#define PT_READ_I 1 +#define PT_WRITE_I 4 +/* The Following Change is for a Sun */ +#define PT_WRITE_D 4 +#endif /* No PT_KILL. */ + +#ifndef PT_ATTACH +#define PT_ATTACH PTRACE_ATTACH +#endif +#ifndef PT_DETACH +#define PT_DETACH PTRACE_DETACH +#endif + +#include "gdbcore.h" +#include <sys/user.h> /* After a.out.h */ +#include <sys/file.h> +#include <sys/stat.h> + +/* This function simply calls ptrace with the given arguments. + It exists so that all calls to ptrace are isolated in this + machine-dependent file. */ +int +call_ptrace (request, pid, addr, data) + int request, pid, *addr, data; +{ + return ptrace (request, pid, addr, data); +} + +#ifdef DEBUG_PTRACE +/* For the rest of the file, use an extra level of indirection */ +/* This lets us breakpoint usefully on call_ptrace. */ +#define ptrace call_ptrace +#endif + +/* This is used when GDB is exiting. It gives less chance of error.*/ + +void +kill_inferior_fast () +{ + if (inferior_pid == 0) + return; + ptrace (PT_KILL, inferior_pid, 0, 0); + wait ((int *)0); +} + +void +kill_inferior (args, from_tty) + char *args; + int from_tty; +{ + kill_inferior_fast (); + target_mourn_inferior (); +} + +/* Resume execution of the inferior process. + If STEP is nonzero, single-step it. + If SIGNAL is nonzero, give it that signal. */ + +void +child_resume (step, signal) + int step; + int signal; +{ + errno = 0; + /* An address of (int *)1 tells it to continue from where it was. + (If GDB wanted it to start some other way, we have already written + a new PC value to the child.) */ + if (step) + { +#if defined (NO_SINGLE_STEP) + single_step (signal); +#else /* Have single step. */ + ptrace (PT_STEP, inferior_pid, (int *)1, signal); +#endif /* Have single step. */ + } + else + ptrace (PT_CONTINUE, inferior_pid, (int *)1, signal); + if (errno) + perror_with_name ("ptrace"); +} + +#ifdef ATTACH_DETACH +/* Nonzero if we are debugging an attached process rather than + an inferior. */ +extern int attach_flag; + +/* Start debugging the process whose number is PID. */ +int +attach (pid) + int pid; +{ + errno = 0; + ptrace (PT_ATTACH, pid, 0, 0); + if (errno) + perror_with_name ("ptrace"); + attach_flag = 1; + return pid; +} + +/* Stop debugging the process whose number is PID + and continue it with signal number SIGNAL. + SIGNAL = 0 means just continue it. */ + +void +detach (signal) + int signal; +{ + errno = 0; + ptrace (PT_DETACH, inferior_pid, 1, signal); + if (errno) + perror_with_name ("ptrace"); + attach_flag = 0; +} +#endif /* ATTACH_DETACH */ + +#if !defined (FETCH_INFERIOR_REGISTERS) + +/* KERNEL_U_ADDR is the amount to subtract from u.u_ar0 + to get the offset in the core file of the register values. */ +#if defined (KERNEL_U_ADDR_BSD) +/* Get kernel_u_addr using BSD-style nlist(). */ +CORE_ADDR kernel_u_addr; + +void +_initialize_kernel_u_addr () +{ + struct nlist names[2]; + + names[0].n_un.n_name = "_u"; + names[1].n_un.n_name = NULL; + if (nlist ("/vmunix", names) == 0) + kernel_u_addr = names[0].n_value; + else + fatal ("Unable to get kernel u area address."); +} +#endif /* KERNEL_U_ADDR_BSD. */ + +#if defined (KERNEL_U_ADDR_HPUX) +/* Get kernel_u_addr using HPUX-style nlist(). */ +CORE_ADDR kernel_u_addr; + +struct hpnlist { + char * n_name; + long n_value; + unsigned char n_type; + unsigned char n_length; + short n_almod; + short n_unused; +}; +static struct hpnlist nl[] = {{ "_u", -1, }, { (char *) 0, }}; + +/* read the value of the u area from the hp-ux kernel */ +void _initialize_kernel_u_addr () +{ + struct user u; + nlist ("/hp-ux", &nl); + kernel_u_addr = nl[0].n_value; +} +#endif /* KERNEL_U_ADDR_HPUX. */ + +#if !defined (offsetof) +#define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER) +#endif + +/* U_REGS_OFFSET is the offset of the registers within the u area. */ +#if !defined (U_REGS_OFFSET) +#define U_REGS_OFFSET \ + ptrace (PT_READ_U, inferior_pid, \ + (int *)(offsetof (struct user, u_ar0)), 0) - KERNEL_U_ADDR +#endif + +/* Fetch one register. */ +static void +fetch_register (regno) + int regno; +{ + register unsigned int regaddr; + char buf[MAX_REGISTER_RAW_SIZE]; + register int i; + + /* Offset of registers within the u area. */ + unsigned int offset = U_REGS_OFFSET; + + regaddr = register_addr (regno, offset); + for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int)) + { + *(int *) &buf[i] = ptrace (PT_READ_U, inferior_pid, (int *)regaddr, 0); + regaddr += sizeof (int); + } + supply_register (regno, buf); +} + +/* Fetch all registers, or just one, from the child process. + We should check for errors, but we don't. FIXME. */ + +int +fetch_inferior_registers (regno) + int regno; +{ + if (regno == -1) + for (regno = 0; regno < NUM_REGS; regno++) + fetch_register (regno); + else + fetch_register (regno); + return 0; +} + +/* Registers we shouldn't try to store. */ +#if !defined (CANNOT_STORE_REGISTER) +#define CANNOT_STORE_REGISTER(regno) 0 +#endif + +/* Store our register values back into the inferior. + If REGNO is -1, do this for all registers. + Otherwise, REGNO specifies which register (so we can save time). */ + +int +store_inferior_registers (regno) + int regno; +{ + register unsigned int regaddr; + char buf[80]; + extern char registers[]; + register int i; + int result = 0; + + unsigned int offset = U_REGS_OFFSET; + + if (regno >= 0) + { + regaddr = register_addr (regno, offset); + for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(int)) + { + errno = 0; + ptrace (PT_WRITE_U, inferior_pid, (int *)regaddr, + *(int *) ®isters[REGISTER_BYTE (regno) + i]); + if (errno != 0) + { + sprintf (buf, "writing register number %d(%d)", regno, i); + perror_with_name (buf); + result = -1; + } + regaddr += sizeof(int); + } + } + else + { + for (regno = 0; regno < NUM_REGS; regno++) + { + if (CANNOT_STORE_REGISTER (regno)) + continue; + regaddr = register_addr (regno, offset); + for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(int)) + { + errno = 0; + ptrace (PT_WRITE_U, inferior_pid, (int *)regaddr, + *(int *) ®isters[REGISTER_BYTE (regno) + i]); + if (errno != 0) + { + sprintf (buf, "writing register number %d(%d)", regno, i); + perror_with_name (buf); + result = -1; + } + regaddr += sizeof(int); + } + } + } + return result; +} +#endif /* !defined (FETCH_INFERIOR_REGISTERS). */ + +/* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory + in the NEW_SUN_PTRACE case. + It ought to be straightforward. But it appears that writing did + not write the data that I specified. I cannot understand where + it got the data that it actually did write. */ + +/* Copy LEN bytes to or from inferior's memory starting at MEMADDR + to debugger memory starting at MYADDR. Copy to inferior if + WRITE is nonzero. + + Returns the length copied, which is either the LEN argument or zero. + This xfer function does not do partial moves, since child_ops + doesn't allow memory operations to cross below us in the target stack + anyway. */ + +int +child_xfer_memory (memaddr, myaddr, len, write) + CORE_ADDR memaddr; + char *myaddr; + int len; + int write; +{ + register int i; + /* Round starting address down to longword boundary. */ + register CORE_ADDR addr = memaddr & - sizeof (int); + /* Round ending address up; get number of longwords that makes. */ + register int count + = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int); + /* Allocate buffer of that many longwords. */ + register int *buffer = (int *) alloca (count * sizeof (int)); + + if (write) + { + /* Fill start and end extra bytes of buffer with existing memory data. */ + + if (addr != memaddr || len < (int)sizeof (int)) { + /* Need part of initial word -- fetch it. */ + buffer[0] = ptrace (PT_READ_I, inferior_pid, (int *)addr, 0); + } + + if (count > 1) /* FIXME, avoid if even boundary */ + { + buffer[count - 1] + = ptrace (PT_READ_I, inferior_pid, + (int *)(addr + (count - 1) * sizeof (int)), 0); + } + + /* Copy data to be written over corresponding part of buffer */ + + bcopy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len); + + /* Write the entire buffer. */ + + for (i = 0; i < count; i++, addr += sizeof (int)) + { + errno = 0; + ptrace (PT_WRITE_D, inferior_pid, (int *)addr, buffer[i]); + if (errno) + { + /* Using the appropriate one (I or D) is necessary for + Gould NP1, at least. */ + errno = 0; + ptrace (PT_WRITE_I, inferior_pid, (int *)addr, buffer[i]); + } + if (errno) + return 0; + } + } + else + { + /* Read all the longwords */ + for (i = 0; i < count; i++, addr += sizeof (int)) + { + errno = 0; + buffer[i] = ptrace (PT_READ_I, inferior_pid, (int *)addr, 0); + if (errno) + return 0; + QUIT; + } + + /* Copy appropriate bytes out of the buffer. */ + bcopy ((char *) buffer + (memaddr & (sizeof (int) - 1)), myaddr, len); + } + return len; +} |