ppc-aix core file relocation.

The current code attempts to provide relocation support when debugging
core files via the rs6000_xfer_partial method of the rs6000-nat
target_ops vector. However, this target_ops vector does not get pushed
on the target stack at all when debugging core files, thus bypassing
completely that part of the code.

This patch fixes the problem by extending corelow's core_xfer_partial
into handling the TARGET_OBJECT_LIBRARIES_AIX object.

gdb/ChangeLog:

	* gdbarch.sh (core_xfer_shared_libraries_aix): New method.
	* gdbarch.h, gdbarch.c: Regenerate.
	* corelow.c (core_xfer_partial): Add TARGET_OBJECT_LIBRARIES_AIX
	handling.

	* rs6000-aix-tdep.h: New file.
	* Makefile.in (HFILES_NO_SRCDIR): Add rs6000-aix-tdep.h.
	* rs6000-aix-tdep.c: Include "rs6000-aix-tdep.h" and
	"xml-utils.h".
	(struct field_info, struct ld_info_desc): New types.
	(ld_info32_desc, ld_info64_desc): New static constants.
	(struct ld_info): New type.
	(rs6000_aix_extract_ld_info): New function.
	(rs6000_aix_shared_library_to_xml): Likewise.
	(rs6000_aix_ld_info_to_xml): Likewise.
	(rs6000_aix_core_xfer_shared_libraries_aix): Likewise.
	(rs6000_aix_init_osabi): Add call to
	set_gdbarch_core_xfer_shared_libraries_aix.
	* rs6000-nat.c: Add "rs6000-aix-tdep.h" include.
	Remove "xml-utils.h" include.
	(LdInfo): Delete typedef.
	(ARCH64_DECL, LDI_FIELD, LDI_NEXT, LDI_FD, LDI_FILENAME):
	Delete macros.
	(rs6000_ptrace_ldinfo): Change return type to gdb_byte *.
	Adjust code accordingly.
	(rs6000_core_ldinfo): Delete, folded into
	rs6000_aix_core_xfer_shared_libraries_aix.
	(rs6000_xfer_shared_library): Delete.
	(rs6000_xfer_shared_libraries): Reimplement.

1 files changed, 297 insertions, 0 deletions

diff --git a/gdb/rs6000-aix-tdep.c b/gdb/rs6000-aix-tdep.c
index 0d4fec5..9956eb3 100644
--- a/gdb/rs6000-aix-tdep.c
+++ b/gdb/rs6000-aix-tdep.c
@@ -34,10 +34,12 @@
 #include "breakpoint.h"
 #include "rs6000-tdep.h"
 #include "ppc-tdep.h"
+#include "rs6000-aix-tdep.h"
 #include "exceptions.h"
 #include "xcoffread.h"
 #include "solib.h"
 #include "solib-aix.h"
+#include "xml-utils.h"
 
 /* If the kernel has to deliver a signal, it pushes a sigcontext
    structure on the stack and then calls the signal handler, passing
@@ -747,6 +749,299 @@ rs6000_aix_osabi_sniffer (bfd *abfd)
   return GDB_OSABI_AIX;
 }
 
+/* A structure encoding the offset and size of a field within
+   a struct.  */
+
+struct field_info
+{
+  int offset;
+  int size;
+};
+
+/* A structure describing the layout of all the fields of interest
+   in AIX's struct ld_info.  Each field in this struct corresponds
+   to the field of the same name in struct ld_info.  */
+
+struct ld_info_desc
+{
+  struct field_info ldinfo_next;
+  struct field_info ldinfo_fd;
+  struct field_info ldinfo_textorg;
+  struct field_info ldinfo_textsize;
+  struct field_info ldinfo_dataorg;
+  struct field_info ldinfo_datasize;
+  struct field_info ldinfo_filename;
+};
+
+/* The following data has been generated by compiling and running
+   the following program on AIX 5.3.  */
+
+#if 0
+    #include <stddef.h>
+    #include <stdio.h>
+    #define __LDINFO_PTRACE32__
+    #define __LDINFO_PTRACE64__
+    #include <sys/ldr.h>
+
+    #define pinfo(type,member)              \
+      {                                         \
+        struct type ldi = {0};                  \
+                                                \
+        printf ("  {%d, %d},\t/* %s */\n",      \
+                offsetof (struct type, member), \
+                sizeof (ldi.member),            \
+                #member);                       \
+      }                                         \
+      while (0)
+
+    int
+    main (void)
+    {
+      printf ("static const struct ld_info_desc ld_info32_desc =\n{\n");
+      pinfo (__ld_info32, ldinfo_next);
+      pinfo (__ld_info32, ldinfo_fd);
+      pinfo (__ld_info32, ldinfo_textorg);
+      pinfo (__ld_info32, ldinfo_textsize);
+      pinfo (__ld_info32, ldinfo_dataorg);
+      pinfo (__ld_info32, ldinfo_datasize);
+      pinfo (__ld_info32, ldinfo_filename);
+      printf ("};\n");
+
+      printf ("\n");
+
+      printf ("static const struct ld_info_desc ld_info64_desc =\n{\n");
+      pinfo (__ld_info64, ldinfo_next);
+      pinfo (__ld_info64, ldinfo_fd);
+      pinfo (__ld_info64, ldinfo_textorg);
+      pinfo (__ld_info64, ldinfo_textsize);
+      pinfo (__ld_info64, ldinfo_dataorg);
+      pinfo (__ld_info64, ldinfo_datasize);
+      pinfo (__ld_info64, ldinfo_filename);
+      printf ("};\n");
+
+      return 0;
+    }
+#endif /* 0 */
+
+/* Layout of the 32bit version of struct ld_info.  */
+
+static const struct ld_info_desc ld_info32_desc =
+{
+  {0, 4},       /* ldinfo_next */
+  {4, 4},       /* ldinfo_fd */
+  {8, 4},       /* ldinfo_textorg */
+  {12, 4},      /* ldinfo_textsize */
+  {16, 4},      /* ldinfo_dataorg */
+  {20, 4},      /* ldinfo_datasize */
+  {24, 2},      /* ldinfo_filename */
+};
+
+/* Layout of the 64bit version of struct ld_info.  */
+
+static const struct ld_info_desc ld_info64_desc =
+{
+  {0, 4},       /* ldinfo_next */
+  {8, 4},       /* ldinfo_fd */
+  {16, 8},      /* ldinfo_textorg */
+  {24, 8},      /* ldinfo_textsize */
+  {32, 8},      /* ldinfo_dataorg */
+  {40, 8},      /* ldinfo_datasize */
+  {48, 2},      /* ldinfo_filename */
+};
+
+/* A structured representation of one entry read from the ld_info
+   binary data provided by the AIX loader.  */
+
+struct ld_info
+{
+  ULONGEST next;
+  int fd;
+  CORE_ADDR textorg;
+  ULONGEST textsize;
+  CORE_ADDR dataorg;
+  ULONGEST datasize;
+  char *filename;
+  char *member_name;
+};
+
+/* Return a struct ld_info object corresponding to the entry at
+   LDI_BUF.
+
+   Note that the filename and member_name strings still point
+   to the data in LDI_BUF.  So LDI_BUF must not be deallocated
+   while the struct ld_info object returned is in use.  */
+
+static struct ld_info
+rs6000_aix_extract_ld_info (struct gdbarch *gdbarch,
+			    const gdb_byte *ldi_buf)
+{
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+  struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
+  const struct ld_info_desc desc
+    = tdep->wordsize == 8 ? ld_info64_desc : ld_info32_desc;
+  struct ld_info info;
+
+  info.next = extract_unsigned_integer (ldi_buf + desc.ldinfo_next.offset,
+					desc.ldinfo_next.size,
+					byte_order);
+  info.fd = extract_signed_integer (ldi_buf + desc.ldinfo_fd.offset,
+				    desc.ldinfo_fd.size,
+				    byte_order);
+  info.textorg = extract_typed_address (ldi_buf + desc.ldinfo_textorg.offset,
+					ptr_type);
+  info.textsize
+    = extract_unsigned_integer (ldi_buf + desc.ldinfo_textsize.offset,
+				desc.ldinfo_textsize.size,
+				byte_order);
+  info.dataorg = extract_typed_address (ldi_buf + desc.ldinfo_dataorg.offset,
+					ptr_type);
+  info.datasize
+    = extract_unsigned_integer (ldi_buf + desc.ldinfo_datasize.offset,
+				desc.ldinfo_datasize.size,
+				byte_order);
+  info.filename = (char *) ldi_buf + desc.ldinfo_filename.offset;
+  info.member_name = info.filename + strlen (info.filename) + 1;
+
+  return info;
+}
+
+/* Append to OBJSTACK an XML string description of the shared library
+   corresponding to LDI, following the TARGET_OBJECT_LIBRARIES_AIX
+   format.  */
+
+static void
+rs6000_aix_shared_library_to_xml (struct ld_info *ldi,
+				  struct obstack *obstack)
+{
+  char *p;
+
+  obstack_grow_str (obstack, "<library name=\"");
+  p = xml_escape_text (ldi->filename);
+  obstack_grow_str (obstack, p);
+  xfree (p);
+  obstack_grow_str (obstack, "\"");
+
+  if (ldi->member_name[0] != '\0')
+    {
+      obstack_grow_str (obstack, " member=\"");
+      p = xml_escape_text (ldi->member_name);
+      obstack_grow_str (obstack, p);
+      xfree (p);
+      obstack_grow_str (obstack, "\"");
+    }
+
+  obstack_grow_str (obstack, " text_addr=\"");
+  obstack_grow_str (obstack, core_addr_to_string (ldi->textorg));
+  obstack_grow_str (obstack, "\"");
+
+  obstack_grow_str (obstack, " text_size=\"");
+  obstack_grow_str (obstack, pulongest (ldi->textsize));
+  obstack_grow_str (obstack, "\"");
+
+  obstack_grow_str (obstack, " data_addr=\"");
+  obstack_grow_str (obstack, core_addr_to_string (ldi->dataorg));
+  obstack_grow_str (obstack, "\"");
+
+  obstack_grow_str (obstack, " data_size=\"");
+  obstack_grow_str (obstack, pulongest (ldi->datasize));
+  obstack_grow_str (obstack, "\"");
+
+  obstack_grow_str (obstack, "></library>");
+}
+
+/* Convert the ld_info binary data provided by the AIX loader into
+   an XML representation following the TARGET_OBJECT_LIBRARIES_AIX
+   format.
+
+   LDI_BUF is a buffer containing the ld_info data.
+   READBUF, OFFSET and LEN follow the same semantics as target_ops'
+   to_xfer_partial target_ops method.
+
+   If CLOSE_LDINFO_FD is nonzero, then this routine also closes
+   the ldinfo_fd file descriptor.  This is useful when the ldinfo
+   data is obtained via ptrace, as ptrace opens a file descriptor
+   for each and every entry; but we cannot use this descriptor
+   as the consumer of the XML library list might live in a different
+   process.  */
+
+LONGEST
+rs6000_aix_ld_info_to_xml (struct gdbarch *gdbarch, const gdb_byte *ldi_buf,
+			   gdb_byte *readbuf, ULONGEST offset, LONGEST len,
+			   int close_ldinfo_fd)
+{
+  struct obstack obstack;
+  const char *buf;
+  LONGEST len_avail;
+
+  obstack_init (&obstack);
+  obstack_grow_str (&obstack, "<library-list-aix version=\"1.0\">\n");
+
+  while (1)
+    {
+      struct ld_info ldi = rs6000_aix_extract_ld_info (gdbarch, ldi_buf);
+
+      rs6000_aix_shared_library_to_xml (&ldi, &obstack);
+      if (close_ldinfo_fd)
+	close (ldi.fd);
+
+      if (!ldi.next)
+	break;
+      ldi_buf = ldi_buf + ldi.next;
+    }
+
+  obstack_grow_str0 (&obstack, "</library-list-aix>\n");
+
+  buf = obstack_finish (&obstack);
+  len_avail = strlen (buf);
+  if (offset >= len_avail)
+    len= 0;
+  else
+    {
+      if (len > len_avail - offset)
+        len = len_avail - offset;
+      memcpy (readbuf, buf + offset, len);
+    }
+
+  obstack_free (&obstack, NULL);
+  return len;
+}
+
+/* Implement the core_xfer_shared_libraries_aix gdbarch method.  */
+
+static LONGEST
+rs6000_aix_core_xfer_shared_libraries_aix (struct gdbarch *gdbarch,
+					   gdb_byte *readbuf,
+					   ULONGEST offset,
+					   LONGEST len)
+{
+  struct bfd_section *ldinfo_sec;
+  int ldinfo_size;
+  gdb_byte *ldinfo_buf;
+  struct cleanup *cleanup;
+  LONGEST result;
+
+  ldinfo_sec = bfd_get_section_by_name (core_bfd, ".ldinfo");
+  if (ldinfo_sec == NULL)
+    error (_("cannot find .ldinfo section from core file: %s"),
+	   bfd_errmsg (bfd_get_error ()));
+  ldinfo_size = bfd_get_section_size (ldinfo_sec);
+
+  ldinfo_buf = xmalloc (ldinfo_size);
+  cleanup = make_cleanup (xfree, ldinfo_buf);
+
+  if (! bfd_get_section_contents (core_bfd, ldinfo_sec,
+				  ldinfo_buf, 0, ldinfo_size))
+    error (_("unable to read .ldinfo section from core file: %s"),
+	  bfd_errmsg (bfd_get_error ()));
+
+  result = rs6000_aix_ld_info_to_xml (gdbarch, ldinfo_buf, readbuf,
+				      offset, len, 0);
+
+  do_cleanups (cleanup);
+  return result;
+}
+
 static void
 rs6000_aix_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
 {
@@ -774,6 +1069,8 @@ rs6000_aix_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
   /* Core file support.  */
   set_gdbarch_regset_from_core_section
     (gdbarch, rs6000_aix_regset_from_core_section);
+  set_gdbarch_core_xfer_shared_libraries_aix
+    (gdbarch, rs6000_aix_core_xfer_shared_libraries_aix);
 
   if (tdep->wordsize == 8)
     tdep->lr_frame_offset = 16;