2002-01-03 Michael Snyder <msnyder@redhat.com>

	Implement a "generate-core-file" command in gdb, save target state.
	* gcore.c: New file.  Implement new command 'generate-core-file'.
	Save a corefile image of the current state of the inferior.
	* linux-proc.c: Add linux-specific code for saving corefiles.
	* target.h (struct target_ops): Add new target vectors for saving
	corefiles; to_find_memory_regions and to_make_corefile_notes.
	(target_find_memory_regions): New macro.
	(target_make_corefile_notes): New macro.
	* target.c (update_current_target): Inherit new target methods.
	(dummy_find_memory_regions): New place-holder method.
	(dummy_make_corefile_notes): New place-holder method.
	(init_dummy_target): Initialize new dummy target vectors.
	* exec.c (exec_set_find_memory_regions): New function.
	Allow the exec_ops vector for memory regions to be taken over.
	(exec_make_note_section): New function, target vector method.
	* defs.h (exec_set_find_memory_regions): Export prototype.
	* procfs.c (proc_find_memory_regions): New function, corefile method.
	(procfs_make_note_section): New function, corefile method.
	(init_procfs_ops): Set new target vector pointers.
	(find_memory_regions_callback): New function.
	(procfs_do_thread_registers): New function.
	(procfs_corefile_thread_callback): New function.
	* sol-thread.c (sol_find_memory_regions): New function.
	(sol_make_note_section): New function.
	(init_sol_thread_ops): Initialize new target vectors.
	* inftarg.c (inftarg_set_find_memory_regions): New function.
	Allow to_find_memory_regions vector to be taken over.
	(inftarg_set_make_corefile_notes): New function.
	Allow to_make_corefile_notes vector to be taken over.
	* thread-db.c (thread_db_new_objfile): Don't activate thread-db
	interface layer if not target_has_execution (may be a corefile).
	* config/i386/linux.mh: Add gcore.o to NATDEPFILES.
	* config/sparc/sun4sol2.mh: Ditto.
	* config/alpha/alpha-linux.mh: Ditto.
	* config/arm/linux.mh: Ditto.
	* config/i386/x86-64linux.mh: Ditto.
	* config/ia64/linux.mh: Ditto.
	* config/m68k/linux.mh: Ditto.
	* config/mips/linux.mh: Ditto.
	* config/powerpc/linux.mh: Ditto.
	* config/sparc/linux.mh: Ditto.

1 files changed, 493 insertions, 0 deletions

diff --git a/gdb/gcore.c b/gdb/gcore.c
new file mode 100644
index 0000000..48ed6a3
--- /dev/null
+++ b/gdb/gcore.c
@@ -0,0 +1,493 @@
+/* Generate a core file for the inferior process.
+   Copyright 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 "command.h"
+#include "inferior.h"
+#include "gdbcore.h"
+#include "elf-bfd.h"
+#include <sys/procfs.h>
+#include "symfile.h"
+#include "objfiles.h"
+
+static char                  *default_gcore_target (void);
+static enum bfd_architecture  default_gcore_arch (void);
+static unsigned long          default_gcore_mach (void);
+static int                    gcore_memory_sections (bfd *);
+
+/* Function: gcore_command
+   Generate a core file from the inferior process.  */
+
+static void
+gcore_command (char *args, int from_tty)
+{
+  struct cleanup *old_chain;
+  char *corefilename, corefilename_buffer[40];
+  asection *note_sec;
+  bfd *obfd;
+  void *note_data = NULL;
+  int note_size = 0;
+
+  /* No use generating a corefile without a target process.  */
+  if (!(target_has_execution))
+    noprocess ();
+
+  if (args && *args)
+    corefilename = args;
+  else
+    {
+      /* Default corefile name is "core.PID".  */
+      sprintf (corefilename_buffer, "core.%d", PIDGET (inferior_ptid));
+      corefilename = corefilename_buffer;
+    }
+
+  if (info_verbose)
+    fprintf_filtered (gdb_stdout, 
+		      "Opening corefile '%s' for output.\n", corefilename);
+
+  /* Open the output file. */
+  if (!(obfd = bfd_openw (corefilename, NULL /*default_gcore_target ()*/)))
+    {
+      error ("Failed to open '%s' for output.", corefilename);
+    }
+
+  /* Need a cleanup that will close the file (FIXME: delete it?). */
+  old_chain = make_cleanup_bfd_close (obfd);
+
+  bfd_set_format (obfd, bfd_core);
+  bfd_set_arch_mach (obfd, default_gcore_arch (), default_gcore_mach ());
+
+  /* An external target method must build the notes section. */
+  note_data = (char *) target_make_corefile_notes (obfd, &note_size);
+
+  /* Create the note section. */
+  if (note_data != NULL && note_size != 0)
+    {
+      if ((note_sec = bfd_make_section_anyway (obfd, "note0")) == NULL)
+	error ("Failed to create 'note' section for corefile: %s", 
+	       bfd_errmsg (bfd_get_error ()));
+
+      bfd_set_section_vma (obfd, note_sec, 0);
+      bfd_set_section_flags (obfd, note_sec, 
+			     SEC_HAS_CONTENTS | SEC_READONLY | SEC_ALLOC);
+      bfd_set_section_alignment (obfd, note_sec, 0);
+      bfd_set_section_size (obfd, note_sec, note_size);
+    }
+
+  /* Now create the memory/load sections. */
+  if (gcore_memory_sections (obfd) == 0)
+    error ("gcore: failed to get corefile memory sections from target.");
+
+  /* Write out the contents of the note section. */
+  if (note_data != NULL && note_size != 0)
+    {
+      if (!bfd_set_section_contents (obfd, note_sec, note_data, 0, note_size))
+	{
+	  warning ("writing note section (%s)", 
+		   bfd_errmsg (bfd_get_error ()));
+	}
+    }
+
+  /* Succeeded. */
+  fprintf_filtered (gdb_stdout, 
+		    "Saved corefile %s\n", corefilename);
+
+  /* Clean-ups will close the output file and free malloc memory. */
+  do_cleanups (old_chain);
+  return;
+}
+
+static unsigned long
+default_gcore_mach (void)
+{
+#ifdef TARGET_ARCHITECTURE
+  const struct bfd_arch_info * bfdarch = TARGET_ARCHITECTURE;
+
+  if (bfdarch != NULL)
+    return bfdarch->mach;
+#endif
+  if (exec_bfd == NULL)
+    error ("Can't find default bfd machine type (need execfile).");
+
+  return bfd_get_mach (exec_bfd);
+}
+
+static enum bfd_architecture
+default_gcore_arch (void)
+{
+#ifdef TARGET_ARCHITECTURE
+  const struct bfd_arch_info * bfdarch = TARGET_ARCHITECTURE;
+
+  if (bfdarch != NULL)
+    return bfdarch->arch;
+#endif
+  if (exec_bfd == NULL)
+    error ("Can't find bfd architecture for corefile (need execfile).");
+
+  return bfd_get_arch (exec_bfd);
+}
+
+static char *
+default_gcore_target (void)
+{
+  /* FIXME -- this may only work for ELF targets.  */
+  if (exec_bfd == NULL)
+    error ("Can't find default bfd target for corefile (need execfile).");
+
+  return bfd_get_target (exec_bfd);
+}
+
+/*
+ * Default method for stack segment (preemptable by target).
+ */
+
+static int (*override_derive_stack_segment) (bfd_vma *, bfd_vma *);
+
+extern void
+preempt_derive_stack_segment (int (*override_func) (bfd_vma *, bfd_vma *))
+{
+  override_derive_stack_segment = override_func;
+}
+
+/* Function: default_derive_stack_segment
+   Derive a reasonable stack segment by unwinding the target stack. 
+   
+   Returns 0 for failure, 1 for success.  */
+
+static int 
+default_derive_stack_segment (bfd_vma *bottom, bfd_vma *top)
+{
+  bfd_vma tmp_vma;
+  struct frame_info *fi, *tmp_fi;
+
+  if (bottom == NULL || top == NULL)
+    return 0;	/* Paranoia. */
+
+  if (!target_has_stack || !target_has_registers)
+    return 0;	/* Can't succeed without stack and registers. */
+
+  if ((fi = get_current_frame ()) == NULL)
+    return 0;	/* Can't succeed without current frame. */
+
+  /* Save frame pointer of TOS frame. */
+  *top = fi->frame;
+  /* If current stack pointer is more "inner", use that instead. */
+  if (INNER_THAN (read_sp (), *top))
+    *top = read_sp ();
+
+  /* Find prev-most frame. */
+  while ((tmp_fi = get_prev_frame (fi)) != NULL)
+    fi = tmp_fi;
+
+  /* Save frame pointer of prev-most frame. */
+  *bottom = fi->frame;
+
+  /* Now canonicalize their order, so that 'bottom' is a lower address
+   (as opposed to a lower stack frame). */
+  if (*bottom > *top)
+    {
+      tmp_vma = *top;
+      *top = *bottom;
+      *bottom = tmp_vma;
+    }
+
+  return 1;	/* success */
+}
+
+static int
+derive_stack_segment (bfd_vma *bottom, bfd_vma *top)
+{
+  if (override_derive_stack_segment)
+    return override_derive_stack_segment (bottom, top);
+  else
+    return default_derive_stack_segment (bottom, top);
+}
+
+/*
+ * Default method for heap segment (preemptable by target).
+ */
+
+static int (*override_derive_heap_segment) (bfd *, bfd_vma *, bfd_vma *);
+
+extern void
+preempt_derive_heap_segment (int (*override_func) (bfd *, 
+						   bfd_vma *, bfd_vma *))
+{
+  override_derive_heap_segment = override_func;
+}
+
+/* Function: default_derive_heap_segment
+   Derive a reasonable heap segment by looking at sbrk and
+   the static data sections.
+   
+   Returns 0 for failure, 1 for success.  */
+
+static int 
+default_derive_heap_segment (bfd *abfd, bfd_vma *bottom, bfd_vma *top)
+{
+  bfd_vma top_of_data_memory = 0;
+  bfd_vma top_of_heap = 0;
+  bfd_size_type sec_size;
+  struct value *zero, *sbrk;
+  bfd_vma sec_vaddr;
+  asection *sec;
+
+  if (bottom == NULL || top == NULL)
+    return 0;		/* Paranoia. */
+
+  if (!target_has_execution)
+    return 0;		/* This function depends on being able
+			   to call a function in the inferior.  */
+
+  /* Assumption: link map is arranged as follows (low to high addresses):
+     text sections
+     data sections (including bss)
+     heap
+  */
+
+  for (sec = abfd->sections; sec; sec = sec->next)
+    {
+      if (bfd_get_section_flags (abfd, sec) & SEC_DATA ||
+	  strcmp (".bss", bfd_get_section_name (abfd, sec)) == 0)
+	{
+	  sec_vaddr = bfd_get_section_vma (abfd, sec);
+	  sec_size = bfd_get_section_size_before_reloc (sec);
+	  if (sec_vaddr + sec_size > top_of_data_memory)
+	    top_of_data_memory = sec_vaddr + sec_size;
+	}
+    }
+  /* Now get the top-of-heap by calling sbrk in the inferior.  */
+  if ((sbrk = find_function_in_inferior ("sbrk")) == NULL)
+    return 0;
+  if ((zero = value_from_longest (builtin_type_int, (LONGEST) 0)) == NULL)
+    return 0;
+  if ((sbrk = call_function_by_hand (sbrk, 1, &zero)) == NULL)
+    return 0;
+  top_of_heap = value_as_long (sbrk);
+
+  /* Return results. */
+  if (top_of_heap > top_of_data_memory)
+    {
+      *bottom = top_of_data_memory;
+      *top = top_of_heap;
+      return 1;	/* success */
+    }
+  else
+    return 0;	/* No additional heap space needs to be saved. */
+}
+
+static int
+derive_heap_segment (bfd *abfd, bfd_vma *bottom, bfd_vma *top)
+{
+  if (override_derive_heap_segment)
+    return override_derive_heap_segment (abfd, bottom, top);
+  else
+    return default_derive_heap_segment (abfd, bottom, top);
+}
+
+/* ARGSUSED */
+static void
+make_output_phdrs (bfd *obfd, asection *osec, void *ignored)
+{
+  int p_flags = 0;
+  int p_type;
+
+  /* FIXME: these constants may only be applicable for ELF.  */
+  if (strncmp (osec->name, "load", 4) == 0)
+    p_type = PT_LOAD;
+  else
+    p_type = PT_NOTE;
+
+  p_flags |= PF_R;	/* Segment is readable.  */
+  if (!(bfd_get_section_flags (obfd, osec) & SEC_READONLY))
+    p_flags |= PF_W;	/* Segment is writable.  */
+  if (bfd_get_section_flags (obfd, osec) & SEC_CODE)
+    p_flags |= PF_X;	/* Segment is executable.  */
+
+  bfd_record_phdr (obfd, p_type, 1, p_flags, 0, 0, 
+		   0, 0, 1, &osec);
+}
+
+static asection *
+make_mem_sec (bfd *obfd, 
+	      bfd_vma addr, 
+	      bfd_size_type size, 
+	      unsigned int flags, 
+	      unsigned int alignment)
+{
+  asection *osec;
+
+  if ((osec = bfd_make_section_anyway (obfd, "load")) == NULL)
+    {
+      warning ("Couldn't make gcore segment: %s",
+	       bfd_errmsg (bfd_get_error ()));
+      return NULL;
+    }
+
+  if (info_verbose)
+    {
+      fprintf_filtered (gdb_stdout, 
+			"Save segment, %ld bytes at 0x%s\n",
+			size, paddr_nz (addr));
+    }
+
+  bfd_set_section_size (obfd, osec, size);
+  bfd_set_section_vma (obfd, osec, addr);
+  osec->lma = 0;	/* FIXME: there should be a macro for this! */
+  bfd_set_section_alignment (obfd, osec, alignment);
+  bfd_set_section_flags (obfd, osec, 
+			 flags | SEC_LOAD | SEC_ALLOC | SEC_HAS_CONTENTS);
+  return osec;
+}
+
+static int
+gcore_create_callback (CORE_ADDR vaddr, 
+		       unsigned long size,
+		       int read, int write, int exec, 
+		       void *data)
+{
+  flagword flags = 0;
+
+  if (write == 0)
+    {
+      flags |= SEC_READONLY;
+      /* Set size == zero for readonly sections. */
+      size = 0;
+    }
+  if (exec)
+    {
+      flags |= SEC_CODE;
+    }
+  else
+    {
+      flags |= SEC_DATA;
+    }
+
+  return ((make_mem_sec ((bfd *) data, vaddr, size, flags, 0)) == NULL);
+}
+
+static int
+objfile_find_memory_regions (int (*func) (CORE_ADDR, 
+					  unsigned long,
+					  int, int, int,
+					   void *), 
+			     void *obfd)
+{
+  /* Use objfile data to create memory sections. */
+  struct objfile *objfile;
+  struct obj_section *objsec;
+  bfd_vma temp_bottom, temp_top;
+
+  /* Call callback function for each objfile section. */
+  ALL_OBJSECTIONS (objfile, objsec)
+    {
+      bfd *ibfd = objfile->obfd;
+      asection *isec = objsec->the_bfd_section;
+      flagword flags = bfd_get_section_flags (ibfd, isec);
+      int ret;
+
+      if ((flags & SEC_ALLOC) || (flags & SEC_LOAD))
+	{
+	  int size = bfd_section_size (ibfd, isec);
+	  int ret;
+
+	  if ((ret = (*func) (objsec->addr, 
+			      bfd_section_size (ibfd, isec), 
+			      1, /* All sections will be readable.  */
+			      (flags & SEC_READONLY) == 0, /* writable */
+			      (flags & SEC_CODE) != 0, /* executable */
+			      obfd)) != 0)
+	    return ret;
+	}
+    }
+
+  /* Make a stack segment. */
+  if (derive_stack_segment (&temp_bottom, &temp_top))
+    (*func) (temp_bottom, 
+	     temp_top - temp_bottom, 
+	     1, /* Stack section will be readable */
+	     1, /* Stack section will be writable */
+	     0, /* Stack section will not be executable */
+	     obfd);
+
+  /* Make a heap segment. */
+  if (derive_heap_segment (exec_bfd, &temp_bottom, &temp_top))
+    (*func) (temp_bottom, 
+	     temp_top - temp_bottom, 
+	     1, /* Heap section will be readable */
+	     1, /* Heap section will be writable */
+	     0, /* Heap section will not be executable */
+	     obfd);
+  return 0;
+}
+
+static void
+gcore_copy_callback (bfd *obfd, asection *osec, void *ignored)
+{
+  bfd_size_type size = bfd_section_size (obfd, osec);
+  struct cleanup *old_chain = NULL;
+  void *memhunk;
+
+  if (size == 0)
+    return;	/* Read-only sections are marked as zero-size.
+		   We don't have to copy their contents. */
+  if (strncmp ("load", bfd_get_section_name (obfd, osec), 4) != 0)
+    return;	/* Only interested in "load" sections. */
+
+  if ((memhunk = xmalloc (size)) == NULL)
+    error ("Not enough memory to create corefile.");
+  old_chain = make_cleanup (xfree, memhunk);
+
+  if (target_read_memory (bfd_section_vma (obfd, osec), 
+			  memhunk, size) != 0)
+    warning ("Memory read failed for corefile section, %ld bytes at 0x%s\n",
+	     (long) size, paddr (bfd_section_vma (obfd, osec)));
+  if (!bfd_set_section_contents (obfd, osec, memhunk, 0, size))
+    warning ("Failed to write corefile contents (%s).", 
+	     bfd_errmsg (bfd_get_error ()));
+
+  do_cleanups (old_chain);	/* frees the xmalloc buffer */
+}
+
+static int
+gcore_memory_sections (bfd *obfd)
+{
+  if (target_find_memory_regions (gcore_create_callback, obfd) != 0)
+    return 0;	/* FIXME error return/msg? */
+
+  /* Record phdrs for section-to-segment mapping. */
+  bfd_map_over_sections (obfd, make_output_phdrs, NULL);
+
+  /* Copy memory region contents. */
+  bfd_map_over_sections (obfd, gcore_copy_callback, NULL);
+
+  return 1;	/* success */
+}
+
+void
+_initialize_gcore (void)
+{
+  add_com ("generate-core-file", class_files, gcore_command,
+	   "Save a core file with the current state of the debugged process.\n\
+Argument is optional filename.  Default filename is 'core.<process_id>'.");
+
+  add_com_alias ("gcore", "generate-core-file", class_files, 1);
+  exec_set_find_memory_regions (objfile_find_memory_regions);
+}