Initial creation of sourceware repositorygdb-4_18-branchpoint

1 files changed, 451 insertions, 0 deletions

diff --git a/gdb/gdbserver/low-linux.c b/gdb/gdbserver/low-linux.c
new file mode 100644
index 0000000..1060210
--- /dev/null
+++ b/gdb/gdbserver/low-linux.c
@@ -0,0 +1,451 @@
+/* Low level interface to ptrace, for the remote server for GDB.
+   Copyright (C) 1995, 1996 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 <sys/wait.h>
+#include "frame.h"
+#include "inferior.h"
+
+#include <stdio.h>
+#include <sys/param.h>
+#include <sys/dir.h>
+#include <sys/user.h>
+#include <signal.h>
+#include <sys/ioctl.h>
+#if 0
+#include <sgtty.h>
+#endif
+#include <fcntl.h>
+
+/***************Begin MY defs*********************/
+int quit_flag = 0;
+char registers[REGISTER_BYTES];
+
+/* Index within `registers' of the first byte of the space for
+   register N.  */
+
+
+char buf2[MAX_REGISTER_RAW_SIZE];
+/***************End MY defs*********************/
+
+#include <sys/ptrace.h>
+
+#if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 1)
+#include <sys/reg.h>
+#endif
+
+extern char **environ;
+extern int errno;
+extern int inferior_pid;
+void quit (), perror_with_name ();
+int query ();
+
+/* Start an inferior process and returns its pid.
+   ALLARGS is a vector of program-name and args.
+   ENV is the environment vector to pass.  */
+
+int
+create_inferior (program, allargs)
+     char *program;
+     char **allargs;
+{
+  int pid;
+
+  pid = fork ();
+  if (pid < 0)
+    perror_with_name ("fork");
+
+  if (pid == 0)
+    {
+      ptrace (PTRACE_TRACEME, 0, 0, 0);
+
+      execv (program, allargs);
+
+      fprintf (stderr, "Cannot exec %s: %s.\n", program,
+	       errno < sys_nerr ? sys_errlist[errno] : "unknown error");
+      fflush (stderr);
+      _exit (0177);
+    }
+
+  return pid;
+}
+
+/* Kill the inferior process.  Make us have no inferior.  */
+
+void
+kill_inferior ()
+{
+  if (inferior_pid == 0)
+    return;
+  ptrace (PTRACE_KILL, inferior_pid, 0, 0);
+  wait (0);
+  /*************inferior_died ();****VK**************/
+}
+
+/* Return nonzero if the given thread is still alive.  */
+int
+mythread_alive (pid)
+     int pid;
+{
+  return 1;
+}
+
+/* Wait for process, returns status */
+
+unsigned char
+mywait (status)
+     char *status;
+{
+  int pid;
+  union wait w;
+
+  pid = wait (&w);
+  if (pid != inferior_pid)
+    perror_with_name ("wait");
+
+  if (WIFEXITED (w))
+    {
+      fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
+      *status = 'W';
+      return ((unsigned char) WEXITSTATUS (w));
+    }
+  else if (!WIFSTOPPED (w))
+    {
+      fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
+      *status = 'X';
+      return ((unsigned char) WTERMSIG (w));
+    }
+
+  fetch_inferior_registers (0);
+
+  *status = 'T';
+  return ((unsigned char) WSTOPSIG (w));
+}
+
+/* Resume execution of the inferior process.
+   If STEP is nonzero, single-step it.
+   If SIGNAL is nonzero, give it that signal.  */
+
+void
+myresume (step, signal)
+     int step;
+     int signal;
+{
+  errno = 0;
+  ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, inferior_pid, 1, signal);
+  if (errno)
+    perror_with_name ("ptrace");
+}
+
+
+#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
+
+#ifndef TARGET_M68K
+/* this table must line up with REGISTER_NAMES in tm-i386v.h */
+/* symbols like 'EAX' come from <sys/reg.h> */
+static int regmap[] = 
+{
+  EAX, ECX, EDX, EBX,
+  UESP, EBP, ESI, EDI,
+  EIP, EFL, CS, SS,
+  DS, ES, FS, GS,
+};
+
+int
+i386_register_u_addr (blockend, regnum)
+     int blockend;
+     int regnum;
+{
+#if 0
+  /* this will be needed if fp registers are reinstated */
+  /* for now, you can look at them with 'info float'
+   * sys5 wont let you change them with ptrace anyway
+   */
+  if (regnum >= FP0_REGNUM && regnum <= FP7_REGNUM) 
+    {
+      int ubase, fpstate;
+      struct user u;
+      ubase = blockend + 4 * (SS + 1) - KSTKSZ;
+      fpstate = ubase + ((char *)&u.u_fpstate - (char *)&u);
+      return (fpstate + 0x1c + 10 * (regnum - FP0_REGNUM));
+    } 
+  else
+#endif
+    return (blockend + 4 * regmap[regnum]);
+  
+}
+#else /* TARGET_M68K */
+/* This table must line up with REGISTER_NAMES in tm-m68k.h */
+static int regmap[] = 
+{
+#ifdef PT_D0
+  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,
+#else
+  14, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15,
+  17, 18,
+#endif
+#ifdef PT_FP0
+  PT_FP0, PT_FP1, PT_FP2, PT_FP3, PT_FP4, PT_FP5, PT_FP6, PT_FP7,
+  PT_FPCR, PT_FPSR, PT_FPIAR
+#else
+  21, 24, 27, 30, 33, 36, 39, 42, 45, 46, 47
+#endif
+};
+
+/* BLOCKEND is the value of u.u_ar0, and points to the place where GS
+   is stored.  */
+
+int
+m68k_linux_register_u_addr (blockend, regnum)
+     int blockend;
+     int regnum;
+{
+    return (blockend + 4 * regmap[regnum]);
+}
+#endif
+
+CORE_ADDR
+register_addr (regno, blockend)
+     int regno;
+     CORE_ADDR blockend;
+{
+  CORE_ADDR addr;
+
+  if (regno < 0 || regno >= ARCH_NUM_REGS)
+    error ("Invalid register number %d.", regno);
+
+  REGISTER_U_ADDR (addr, blockend, regno);
+
+  return addr;
+}
+
+/* Fetch one register.  */
+
+static void
+fetch_register (regno)
+     int regno;
+{
+  register unsigned int regaddr;
+  register int i;
+
+  /* Offset of registers within the u area.  */
+  unsigned int offset;
+
+  offset = U_REGS_OFFSET;
+
+  regaddr = register_addr (regno, offset);
+  for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))
+    {
+      errno = 0;
+      *(int *) &registers[ regno * 4 + i] = ptrace (PTRACE_PEEKUSR, inferior_pid,
+				 (PTRACE_ARG3_TYPE) regaddr, 0);
+      regaddr += sizeof (int);
+      if (errno != 0)
+	{
+	  /* Warning, not error, in case we are attached; sometimes the
+	     kernel doesn't let us at the registers.  */
+	  char *err = strerror (errno);
+	  char *msg = alloca (strlen (err) + 128);
+	  sprintf (msg, "reading register %d: %s", regno, err);
+	  error (msg);
+	  goto error_exit;
+	}
+    }
+ error_exit:;
+}
+
+/* Fetch all registers, or just one, from the child process.  */
+
+void
+fetch_inferior_registers (regno)
+     int regno;
+{
+  if (regno == -1 || regno == 0)
+    for (regno = 0; regno < NUM_REGS-NUM_FREGS; regno++)
+      fetch_register (regno);
+  else
+    fetch_register (regno);
+}
+
+/* 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).  */
+
+void
+store_inferior_registers (regno)
+     int regno;
+{
+  register unsigned int regaddr;
+  register int i;
+  unsigned int offset = U_REGS_OFFSET;
+
+  if (regno >= 0)
+    {
+#if 0
+      if (CANNOT_STORE_REGISTER (regno))
+	return;
+#endif
+      regaddr = register_addr (regno, offset);
+      errno = 0;
+#if 0
+      if (regno == PCOQ_HEAD_REGNUM || regno == PCOQ_TAIL_REGNUM)
+        {
+          scratch = *(int *) &registers[REGISTER_BYTE (regno)] | 0x3;
+          ptrace (PT_WUREGS, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
+                  scratch, 0);
+          if (errno != 0)
+            {
+	      /* Error, even if attached.  Failing to write these two
+		 registers is pretty serious.  */
+              sprintf (buf, "writing register number %d", regno);
+              perror_with_name (buf);
+            }
+        }
+      else
+#endif
+	for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(int))
+	  {
+	    errno = 0;
+	    ptrace (PTRACE_POKEUSR, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
+		    *(int *) &registers[REGISTER_BYTE (regno) + i]);
+	    if (errno != 0)
+	      {
+		/* Warning, not error, in case we are attached; sometimes the
+		   kernel doesn't let us at the registers.  */
+		char *err = strerror (errno);
+		char *msg = alloca (strlen (err) + 128);
+		sprintf (msg, "writing register %d: %s",
+			 regno, err);
+		error (msg);
+		return;
+	      }
+	    regaddr += sizeof(int);
+	  }
+    }
+  else
+    for (regno = 0; regno < NUM_REGS-NUM_FREGS; regno++)
+      store_inferior_registers (regno);
+}
+
+/* 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 from inferior's memory starting at MEMADDR
+   to debugger memory starting at MYADDR.  */
+
+void
+read_inferior_memory (memaddr, myaddr, len)
+     CORE_ADDR memaddr;
+     char *myaddr;
+     int len;
+{
+  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));
+
+  /* Read all the longwords */
+  for (i = 0; i < count; i++, addr += sizeof (int))
+    {
+      buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid, addr, 0);
+    }
+
+  /* Copy appropriate bytes out of the buffer.  */
+  memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);
+}
+
+/* Copy LEN bytes of data from debugger memory at MYADDR
+   to inferior's memory at MEMADDR.
+   On failure (cannot write the inferior)
+   returns the value of errno.  */
+
+int
+write_inferior_memory (memaddr, myaddr, len)
+     CORE_ADDR memaddr;
+     char *myaddr;
+     int len;
+{
+  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));
+  extern int errno;
+
+  /* Fill start and end extra bytes of buffer with existing memory data.  */
+
+  buffer[0] = ptrace (PTRACE_PEEKTEXT, inferior_pid, addr, 0);
+
+  if (count > 1)
+    {
+      buffer[count - 1]
+	= ptrace (PTRACE_PEEKTEXT, inferior_pid,
+		  addr + (count - 1) * sizeof (int), 0);
+    }
+
+  /* Copy data to be written over corresponding part of buffer */
+
+  memcpy ((char *) buffer + (memaddr & (sizeof (int) - 1)), myaddr, len);
+
+  /* Write the entire buffer.  */
+
+  for (i = 0; i < count; i++, addr += sizeof (int))
+    {
+      errno = 0;
+      ptrace (PTRACE_POKETEXT, inferior_pid, addr, buffer[i]);
+      if (errno)
+	return errno;
+    }
+
+  return 0;
+}
+
+void
+initialize ()
+{
+  inferior_pid = 0;
+}
+
+int
+have_inferior_p ()
+{
+  return inferior_pid != 0;
+}