Initial revision

1 files changed, 638 insertions, 0 deletions

diff --git a/gdb/infptrace.c b/gdb/infptrace.c
new file mode 100644
index 00000000000..1db7223ea3b
--- /dev/null
+++ b/gdb/infptrace.c
@@ -0,0 +1,638 @@
+/* Low level Unix child interface to ptrace, for GDB when running under Unix.
+   Copyright 1988, 89, 90, 91, 92, 93, 94, 95, 96, 1998 
+   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 "target.h"
+#include "gdb_string.h"
+#include "wait.h"
+#include "command.h"
+
+#ifdef USG
+#include <sys/types.h>
+#endif
+
+#include <sys/param.h>
+#include <sys/dir.h>
+#include <signal.h>
+#include <sys/ioctl.h>
+
+#ifdef HAVE_PTRACE_H
+# include <ptrace.h>
+#else
+# ifdef HAVE_SYS_PTRACE_H
+#  include <sys/ptrace.h>
+# endif
+#endif
+
+#if !defined (PT_READ_I)
+#define PT_READ_I	1	/* Read word from text space */
+#endif
+#if !defined (PT_READ_D)
+#define	PT_READ_D	2	/* Read word from data space */
+#endif
+#if !defined (PT_READ_U)
+#define PT_READ_U	3	/* Read word from kernel user struct */
+#endif
+#if !defined (PT_WRITE_I)
+#define PT_WRITE_I	4	/* Write word to text space */
+#endif
+#if !defined (PT_WRITE_D)
+#define PT_WRITE_D	5	/* Write word to data space */
+#endif
+#if !defined (PT_WRITE_U)
+#define PT_WRITE_U	6	/* Write word to kernel user struct */
+#endif
+#if !defined (PT_CONTINUE)
+#define PT_CONTINUE	7	/* Continue after signal */
+#endif
+#if !defined (PT_STEP)
+#define PT_STEP		9	/* Set flag for single stepping */
+#endif
+#if !defined (PT_KILL)
+#define PT_KILL		8	/* Send child a SIGKILL signal */
+#endif
+
+#ifndef PT_ATTACH
+#define PT_ATTACH PTRACE_ATTACH
+#endif
+#ifndef PT_DETACH
+#define PT_DETACH PTRACE_DETACH
+#endif
+
+#include "gdbcore.h"
+#ifndef	NO_SYS_FILE
+#include <sys/file.h>
+#endif
+#if 0
+/* Don't think this is used anymore.  On the sequent (not sure whether it's
+   dynix or ptx or both), it is included unconditionally by sys/user.h and
+   not protected against multiple inclusion.  */
+#include "gdb_stat.h"
+#endif
+
+#if !defined (FETCH_INFERIOR_REGISTERS)
+#include <sys/user.h>		/* Probably need to poke the user structure */
+#if defined (KERNEL_U_ADDR_BSD)
+#include <a.out.h>		/* For struct nlist */
+#endif /* KERNEL_U_ADDR_BSD.  */
+#endif /* !FETCH_INFERIOR_REGISTERS */
+
+#if !defined (CHILD_XFER_MEMORY)
+static void udot_info PARAMS ((char *, int));
+#endif
+
+#if !defined (FETCH_INFERIOR_REGISTERS)
+static void fetch_register PARAMS ((int));
+static void store_register PARAMS ((int));
+#endif
+
+void _initialize_kernel_u_addr PARAMS ((void));
+void _initialize_infptrace PARAMS ((void));
+
+
+/* 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;
+     PTRACE_ARG3_TYPE addr;
+     int data;
+{
+  int pt_status = 0;
+
+#if 0
+  int saved_errno;
+
+  printf ("call_ptrace(request=%d, pid=%d, addr=0x%x, data=0x%x)",
+	  request, pid, addr, data);
+#endif
+#if defined(PT_SETTRC)
+  /* If the parent can be told to attach to us, try to do it.  */
+  if (request == PT_SETTRC) {
+    errno = 0;
+    pt_status = ptrace (PT_SETTRC, pid, addr, data
+#if defined (FIVE_ARG_PTRACE)
+                       /* Deal with HPUX 8.0 braindamage.  We never use the
+                          calls which require the fifth argument.  */
+                       , 0
+#endif
+                       );
+
+     if (errno) perror_with_name ("ptrace");
+#if 0
+     printf (" = %d\n", pt_status);
+#endif
+     if (pt_status < 0)
+         return pt_status;
+     else
+         return parent_attach_all (pid, addr, data);
+  }
+#endif
+
+#if defined(PT_CONTIN1)
+  /* On HPUX, PT_CONTIN1 is a form of continue that preserves pending
+     signals.  If it's available, use it.  */
+  if (request == PT_CONTINUE)
+    request = PT_CONTIN1;
+#endif
+
+#if defined(PT_SINGLE1)
+  /* On HPUX, PT_SINGLE1 is a form of step that preserves pending
+     signals.  If it's available, use it.  */
+  if (request == PT_STEP)
+    request = PT_SINGLE1;
+#endif
+
+#if 0
+  saved_errno = errno;
+  errno = 0;
+#endif
+  pt_status = ptrace (request, pid, addr, data
+#if defined (FIVE_ARG_PTRACE)
+		 /* Deal with HPUX 8.0 braindamage.  We never use the
+		    calls which require the fifth argument.  */
+		 , 0
+#endif
+		 );
+#if 0
+  if (errno)
+    printf (" [errno = %d]", errno);
+
+  errno = saved_errno;
+  printf (" = 0x%x\n", pt_status);
+#endif
+  return pt_status;
+}
+
+
+#if defined (DEBUG_PTRACE) || defined (FIVE_ARG_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
+
+/* Wait for a process to finish, possibly running a target-specific
+   hook before returning.  */
+
+int
+ptrace_wait (pid, status)
+    int pid;
+    int *status;
+{
+  int wstate;
+
+  wstate = wait (status);
+  target_post_wait (wstate, *status);
+  return wstate;
+}
+
+void
+kill_inferior ()
+{
+  int status;
+
+  if (inferior_pid == 0)
+    return;
+
+  /* This once used to call "kill" to kill the inferior just in case
+     the inferior was still running.  As others have noted in the past
+     (kingdon) there shouldn't be any way to get here if the inferior
+     is still running -- else there's a major problem elsewere in gdb
+     and it needs to be fixed.
+
+     The kill call causes problems under hpux10, so it's been removed;
+     if this causes problems we'll deal with them as they arise.  */
+  ptrace (PT_KILL, inferior_pid, (PTRACE_ARG3_TYPE) 0, 0);
+  ptrace_wait (0, &status);
+  target_mourn_inferior ();
+}
+
+#ifndef CHILD_RESUME
+
+/* Resume execution of the inferior process.
+   If STEP is nonzero, single-step it.
+   If SIGNAL is nonzero, give it that signal.  */
+
+void
+child_resume (pid, step, signal)
+     int pid;
+     int step;
+     enum target_signal signal;
+{
+  errno = 0;
+
+  if (pid == -1)
+    /* Resume all threads.  */
+    /* I think this only gets used in the non-threaded case, where "resume
+       all threads" and "resume inferior_pid" are the same.  */
+    pid = inferior_pid;
+
+  /* An address of (PTRACE_ARG3_TYPE)1 tells ptrace 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 this system does not support PT_STEP, a higher level function will
+     have called single_step() to transmute the step request into a
+     continue request (by setting breakpoints on all possible successor
+     instructions), so we don't have to worry about that here.  */
+
+  if (step)
+    {
+      if (SOFTWARE_SINGLE_STEP_P)
+	abort();  /* Make sure this doesn't happen. */
+      else
+	ptrace (PT_STEP,     pid, (PTRACE_ARG3_TYPE) 1,
+		target_signal_to_host (signal));
+    }
+  else
+    ptrace (PT_CONTINUE, pid, (PTRACE_ARG3_TYPE) 1,
+	    target_signal_to_host (signal));
+
+  if (errno)
+    perror_with_name ("ptrace");
+}
+#endif /* CHILD_RESUME */
+
+
+#ifdef ATTACH_DETACH
+/* Start debugging the process whose number is PID.  */
+int
+attach (pid)
+     int pid;
+{
+  errno = 0;
+  ptrace (PT_ATTACH, pid, (PTRACE_ARG3_TYPE) 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, (PTRACE_ARG3_TYPE) 1, signal);
+  if (errno)
+    perror_with_name ("ptrace");
+  attach_flag = 0;
+}
+#endif /* ATTACH_DETACH */
+
+/* Default the type of the ptrace transfer to int.  */
+#ifndef PTRACE_XFER_TYPE
+#define PTRACE_XFER_TYPE int
+#endif
+
+/* 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) && !defined (FETCH_INFERIOR_REGISTERS)
+/* Get kernel_u_addr using BSD-style nlist().  */
+CORE_ADDR kernel_u_addr;
+#endif /* KERNEL_U_ADDR_BSD.  */
+
+void
+_initialize_kernel_u_addr ()
+{
+#if defined (KERNEL_U_ADDR_BSD) && !defined (FETCH_INFERIOR_REGISTERS)
+  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 (FETCH_INFERIOR_REGISTERS)
+
+#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, \
+	  (PTRACE_ARG3_TYPE) (offsetof (struct user, u_ar0)), 0) \
+    - KERNEL_U_ADDR
+#endif
+
+/* Registers we shouldn't try to fetch.  */
+#if !defined (CANNOT_FETCH_REGISTER)
+#define CANNOT_FETCH_REGISTER(regno) 0
+#endif
+
+/* Fetch one register.  */
+
+static void
+fetch_register (regno)
+     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];
+
+  if (CANNOT_FETCH_REGISTER (regno))
+    {
+      memset (buf, '\0', REGISTER_RAW_SIZE (regno));	/* Supply zeroes */
+      supply_register (regno, buf);
+      return;
+    }
+
+  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, inferior_pid,
+					      (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
+fetch_inferior_registers (regno)
+     int regno;
+{
+  if (regno >= 0)
+    {
+      fetch_register (regno);
+    }
+  else
+    {
+      for (regno = 0; regno < ARCH_NUM_REGS; regno++)
+	{
+	  fetch_register (regno);
+	}
+    }
+}
+
+/* Registers we shouldn't try to store.  */
+#if !defined (CANNOT_STORE_REGISTER)
+#define CANNOT_STORE_REGISTER(regno) 0
+#endif
+
+/* Store one register. */
+
+static void
+store_register (regno)
+     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.  */
+
+  if (CANNOT_STORE_REGISTER (regno))
+    {
+      return;
+    }
+
+  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 (PT_WRITE_U, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
+	      *(PTRACE_XFER_TYPE *) &registers[REGISTER_BYTE (regno) + 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
+store_inferior_registers (regno)
+     int regno;
+{
+  if (regno >= 0)
+    {
+      store_register (regno);
+    }
+  else
+    {
+      for (regno = 0; regno < ARCH_NUM_REGS; regno++)
+	{
+	  store_register (regno);
+	}
+    }
+}
+#endif /* !defined (FETCH_INFERIOR_REGISTERS).  */
+
+
+#if !defined (CHILD_XFER_MEMORY)
+/* 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, target)
+     CORE_ADDR memaddr;
+     char *myaddr;
+     int len;
+     int write;
+     struct target_ops *target;		/* ignored */
+{
+  register int i;
+  /* Round starting address down to longword boundary.  */
+  register CORE_ADDR addr = memaddr & - sizeof (PTRACE_XFER_TYPE);
+  /* Round ending address up; get number of longwords that makes.  */
+  register int count
+    = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
+      / sizeof (PTRACE_XFER_TYPE);
+  /* Allocate buffer of that many longwords.  */
+  register PTRACE_XFER_TYPE *buffer
+    = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
+
+  if (write)
+    {
+      /* Fill start and end extra bytes of buffer with existing memory data.  */
+
+      if (addr != memaddr || len < (int) sizeof (PTRACE_XFER_TYPE)) {
+	/* Need part of initial word -- fetch it.  */
+        buffer[0] = ptrace (PT_READ_I, inferior_pid, (PTRACE_ARG3_TYPE) addr,
+			    0);
+      }
+
+      if (count > 1)		/* FIXME, avoid if even boundary */
+	{
+	  buffer[count - 1]
+	    = ptrace (PT_READ_I, inferior_pid,
+		      ((PTRACE_ARG3_TYPE)
+		       (addr + (count - 1) * sizeof (PTRACE_XFER_TYPE))),
+		      0);
+	}
+
+      /* Copy data to be written over corresponding part of buffer */
+
+      memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
+	      myaddr,
+	      len);
+
+      /* Write the entire buffer.  */
+
+      for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
+	{
+	  errno = 0;
+	  ptrace (PT_WRITE_D, inferior_pid, (PTRACE_ARG3_TYPE) 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, (PTRACE_ARG3_TYPE) addr,
+		      buffer[i]);
+	    }
+	  if (errno)
+	    return 0;
+	}
+#ifdef CLEAR_INSN_CACHE
+      CLEAR_INSN_CACHE();
+#endif
+    }
+  else
+    {
+      /* Read all the longwords */
+      for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
+	{
+	  errno = 0;
+	  buffer[i] = ptrace (PT_READ_I, inferior_pid,
+			      (PTRACE_ARG3_TYPE) addr, 0);
+	  if (errno)
+	    return 0;
+	  QUIT;
+	}
+
+      /* Copy appropriate bytes out of the buffer.  */
+      memcpy (myaddr,
+	      (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
+	      len);
+    }
+  return len;
+}
+
+
+static void
+udot_info (dummy1, dummy2)
+     char *dummy1;
+     int dummy2;
+{
+#if defined (KERNEL_U_SIZE)
+  int udot_off;		/* Offset into user struct */
+  int udot_val;		/* Value from user struct at udot_off */
+  char mess[128];	/* For messages */
+#endif
+
+   if (!target_has_execution)
+     {
+       error ("The program is not being run.");
+     }
+
+#if !defined (KERNEL_U_SIZE)
+
+  /* Adding support for this command is easy.  Typically you just add a
+     routine, called "kernel_u_size" that returns the size of the user
+     struct, to the appropriate *-nat.c file and then add to the native
+     config file "#define KERNEL_U_SIZE kernel_u_size()" */
+  error ("Don't know how large ``struct user'' is in this version of gdb.");
+
+#else
+
+  for (udot_off = 0; udot_off < KERNEL_U_SIZE; udot_off += sizeof (udot_val))
+    {
+      if ((udot_off % 24) == 0)
+	{
+	  if (udot_off > 0)
+	    {
+	      printf_filtered ("\n");
+	    }
+	  printf_filtered ("%04x:", udot_off);
+	}
+      udot_val = ptrace (PT_READ_U, inferior_pid, (PTRACE_ARG3_TYPE) udot_off, 0);
+      if (errno != 0)
+	{
+	  sprintf (mess, "\nreading user struct at offset 0x%x", udot_off);
+	  perror_with_name (mess);
+	}
+      /* Avoid using nonportable (?) "*" in print specs */
+      printf_filtered (sizeof (int) == 4 ? " 0x%08x" : " 0x%16x", udot_val);
+    }
+  printf_filtered ("\n");
+
+#endif
+}
+#endif /* !defined (CHILD_XFER_MEMORY).  */
+
+
+void
+_initialize_infptrace ()
+{
+#if !defined (CHILD_XFER_MEMORY)
+  add_info ("udot", udot_info,
+	    "Print contents of kernel ``struct user'' for current child.");
+#endif
+}