From FEDORA_PATCHES Mon Sep 17 00:00:00 2001

From: Keith Seitz <keiths@redhat.com>

Date: Mon, 27 Jul 2020 18:01:32 -0400

Subject: gdb-rhbz1842691-corefile-mem-access-7of15.patch

;; Add new gdbarch method, read_core_file_mappings

;; Kevin Buettner, RH BZ 1842961

   Author: Kevin Buettner <kevinb@redhat.com>

   Date:   Fri Jul 3 13:32:08 2020 -0700

    Add new gdbarch method, read_core_file_mappings

    The new gdbarch method, read_core_file_mappings, will be used for

    reading file-backed mappings from a core file.  It'll be used

    for two purposes: 1) to construct a table of file-backed mappings

    in corelow.c, and 2) for display of core file mappings.

    For Linux, I tried a different approach in which knowledge of the note

    format was placed directly in corelow.c.  This seemed okay at first;

    it was only one note format and the note format was fairly simple.

    After looking at FreeBSD's note/mapping reading code, I concluded

    that it's best to leave architecture specific details for decoding

    the note in (architecture specific) tdep files.

    With regard to display of core file mappings, I experimented with

    placing the mappings display code in corelow.c.  It has access to the

    file-backed mappings which were read in when the core file was loaded.

    And, better, still common code could be used for all architectures.

    But, again, the FreeBSD mapping code convinced me that this was not

    the best approach since it has even more mapping info than Linux.

    Display code which would work well for Linux will leave out mappings

    as well as protection info for mappings.

    So, for these reasons, I'm introducing a new gdbarch method for

    reading core file mappings.

    gdb/ChangeLog:

    	* arch-utils.c (default_read_core_file_mappings): New function.

    	* arch-utils.c (default_read_core_file_mappings): Declare.

    	* gdbarch.sh (read_core_file_mappings): New gdbarch method.

    	* gdbarch.h, gdbarch.c: Regenerate.

diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c

--- a/gdb/arch-utils.c

+++ b/gdb/arch-utils.c

@@ -1004,6 +1004,22 @@ default_get_pc_address_flags (frame_info *frame, CORE_ADDR pc)

   return "";

 }

+/* See arch-utils.h.  */

+void

+default_read_core_file_mappings (struct gdbarch *gdbarch,

+                                 struct bfd *cbfd,

+				 gdb::function_view<void (ULONGEST count)>

+				   pre_loop_cb,

+				 gdb::function_view

+				                          ULONGEST start,

+							  ULONGEST end,

+							  ULONGEST file_ofs,

+							  const char *filename,

+							  const void *other)>

+				   loop_cb)

+{

+}

+

 void

 _initialize_gdbarch_utils (void)

 {

diff --git a/gdb/arch-utils.h b/gdb/arch-utils.h

--- a/gdb/arch-utils.h

+++ b/gdb/arch-utils.h

@@ -276,4 +276,16 @@ extern ULONGEST default_type_align (struct gdbarch *gdbarch,

 extern std::string default_get_pc_address_flags (frame_info *frame,

 						 CORE_ADDR pc);

+/* Default implementation of gdbarch read_core_file_mappings method.  */

+extern void default_read_core_file_mappings (struct gdbarch *gdbarch,

+					     struct bfd *cbfd,

+					     gdb::function_view<void (ULONGEST count)>

+					       pre_loop_cb,

+					     gdb::function_view

+								      ULONGEST start,

+								      ULONGEST end,

+								      ULONGEST file_ofs,

+								      const char *filename,

+								      const void *other)>

+					       loop_cb);

 #endif /* ARCH_UTILS_H */

diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c

--- a/gdb/gdbarch.c

+++ b/gdb/gdbarch.c

@@ -358,6 +358,7 @@ struct gdbarch

   const disasm_options_and_args_t * valid_disassembler_options;

   gdbarch_type_align_ftype *type_align;

   gdbarch_get_pc_address_flags_ftype *get_pc_address_flags;

+  gdbarch_read_core_file_mappings_ftype *read_core_file_mappings;

 };

 /* Create a new ``struct gdbarch'' based on information provided by

@@ -473,6 +474,7 @@ gdbarch_alloc (const struct gdbarch_info *info,

   gdbarch->addressable_memory_unit_size = default_addressable_memory_unit_size;

   gdbarch->type_align = default_type_align;

   gdbarch->get_pc_address_flags = default_get_pc_address_flags;

+  gdbarch->read_core_file_mappings = default_read_core_file_mappings;

   /* gdbarch_alloc() */

   return gdbarch;

@@ -721,6 +723,7 @@ verify_gdbarch (struct gdbarch *gdbarch)

   /* Skip verify of valid_disassembler_options, invalid_p == 0 */

   /* Skip verify of type_align, invalid_p == 0 */

   /* Skip verify of get_pc_address_flags, invalid_p == 0 */

+  /* Skip verify of read_core_file_mappings, invalid_p == 0 */

   if (!log.empty ())

     internal_error (__FILE__, __LINE__,

                     _("verify_gdbarch: the following are invalid ...%s"),

@@ -1287,6 +1290,9 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)

   fprintf_unfiltered (file,

                       "gdbarch_dump: ravenscar_ops = %s\n",

                       host_address_to_string (gdbarch->ravenscar_ops));

+  fprintf_unfiltered (file,

+                      "gdbarch_dump: read_core_file_mappings = <%s>\n",

+                      host_address_to_string (gdbarch->read_core_file_mappings));

   fprintf_unfiltered (file,

                       "gdbarch_dump: gdbarch_read_pc_p() = %d\n",

                       gdbarch_read_pc_p (gdbarch));

@@ -5156,6 +5162,23 @@ set_gdbarch_get_pc_address_flags (struct gdbarch *gdbarch,

   gdbarch->get_pc_address_flags = get_pc_address_flags;

 }

+void

+gdbarch_read_core_file_mappings (struct gdbarch *gdbarch, struct bfd *cbfd,gdb::function_view<void (ULONGEST count)> pre_loop_cb,gdb::function_view<void (int num, ULONGEST start, ULONGEST end, ULONGEST file_ofs, const char *filename, const void *other)> loop_cb)

+{

+  gdb_assert (gdbarch != NULL);

+  gdb_assert (gdbarch->read_core_file_mappings != NULL);

+  if (gdbarch_debug >= 2)

+    fprintf_unfiltered (gdb_stdlog, "gdbarch_read_core_file_mappings called\n");

+  gdbarch->read_core_file_mappings (gdbarch, cbfd, pre_loop_cb, loop_cb);

+}

+

+void

+set_gdbarch_read_core_file_mappings (struct gdbarch *gdbarch,

+                                     gdbarch_read_core_file_mappings_ftype read_core_file_mappings)

+{

+  gdbarch->read_core_file_mappings = read_core_file_mappings;

+}

+

 /* Keep a registry of per-architecture data-pointers required by GDB

    modules.  */

diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h

--- a/gdb/gdbarch.h

+++ b/gdb/gdbarch.h

@@ -1640,6 +1640,12 @@ typedef std::string (gdbarch_get_pc_address_flags_ftype) (frame_info *frame, COR

 extern std::string gdbarch_get_pc_address_flags (struct gdbarch *gdbarch, frame_info *frame, CORE_ADDR pc);

 extern void set_gdbarch_get_pc_address_flags (struct gdbarch *gdbarch, gdbarch_get_pc_address_flags_ftype *get_pc_address_flags);

+/* Read core file mappings */

+

+typedef void (gdbarch_read_core_file_mappings_ftype) (struct gdbarch *gdbarch, struct bfd *cbfd,gdb::function_view<void (ULONGEST count)> pre_loop_cb,gdb::function_view<void (int num, ULONGEST start, ULONGEST end, ULONGEST file_ofs, const char *filename, const void *other)> loop_cb);

+extern void gdbarch_read_core_file_mappings (struct gdbarch *gdbarch, struct bfd *cbfd,gdb::function_view<void (ULONGEST count)> pre_loop_cb,gdb::function_view<void (int num, ULONGEST start, ULONGEST end, ULONGEST file_ofs, const char *filename, const void *other)> loop_cb);

+extern void set_gdbarch_read_core_file_mappings (struct gdbarch *gdbarch, gdbarch_read_core_file_mappings_ftype *read_core_file_mappings);

+

 extern struct gdbarch_tdep *gdbarch_tdep (struct gdbarch *gdbarch);

diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh

--- a/gdb/gdbarch.sh

+++ b/gdb/gdbarch.sh

@@ -1209,6 +1209,9 @@ m;ULONGEST;type_align;struct type *type;type;;default_type_align;;0

 # Return a string containing any flags for the given PC in the given FRAME.

 f;std::string;get_pc_address_flags;frame_info *frame, CORE_ADDR pc;frame, pc;;default_get_pc_address_flags;;0

+# Read core file mappings

+m;void;read_core_file_mappings;struct bfd *cbfd,gdb::function_view<void (ULONGEST count)> pre_loop_cb,gdb::function_view<void (int num, ULONGEST start, ULONGEST end, ULONGEST file_ofs, const char *filename, const void *other)> loop_cb;cbfd, pre_loop_cb, loop_cb;;default_read_core_file_mappings;;0

+

 EOF

 }