Commit: ec86fe6295f8f8c46e85dad08f76665001a366b8 - binutils_os216 (git)

GNU Binutils with patches for OS216

Commit MetaInfo

• Révision: ec86fe6295f8f8c46e85dad08f76665001a366b8 (tree)
• l'heure: 2020-06-16 21:58:32
• Auteur: Luis Machado <luis.machado@lina...>
• Commiter: Luis Machado

Message de Log

New mtag commands

Add new commands under the "mtag" prefix to allow users to inspect, modify and
check memory tags in different ways.

The available subcommands are the following:

- mtag showltag <address>: Shows the logical tag for a particular address.

- mtag setltag <address> <tag>: Prints the address tagged with the logical tag

<tag>

- mtag showatag <address>: Shows the allocation tag for a particular address.

- mtag setatag <address> <length> <tags>: Sets one or more allocation tags to

the specified tags.

- mtag check <address>: Check if the logical tag in <address> matches its

allocation tag.

These commands make use of the memory tagging gdbarch methods, and are still
available, but disabled, when memory tagging is not supported by the
architecture.

gdb/ChangeLog:

YYYY-MM-DD Luis Machado <[e-mail]>

* printcmd.c: Include gdbsupport/rsp-low.h.
(mtaglist): New static global.
(process_print_command_args): Factored out of
print_command_1.
(print_command_1): Use process_print_command_args.
(cast_non_lval_void_ptr, show_memtag_unsupported, mtag_command)
(mtag_showtag_command, mtag_showltag_command, mtag_showatag_command)
(parse_setltag_input, mtag_setltag_command, parse_setatag_input)
(mtag_setatag_command, mtag_check_command): New functions.
(_initialize_printcmd): Add "mtag" prefix and subcommands.

gdbsupport/ChangeLog:

YYYY-MM-DD Luis Machado <[e-mail]>

* rsp-low.cc (fromhex): Change error message text to not be
RSP-specific.

Change Summary

• modified: gdb/printcmd.c
• modified: gdbsupport/rsp-low.cc

Modification

--- a/gdb/printcmd.c
+++ b/gdb/printcmd.c
@@ -53,6 +53,11 @@
 #include "source.h"
 #include "gdbsupport/byte-vector.h"
 #include "gdbsupport/gdb_optional.h"
+#include "gdbsupport/rsp-low.h"
+
+/* Chain containing all defined mtag subcommands.  */
+
+struct cmd_list_element *mtaglist;
 
 /* Last specified output format.  */
 
@@ -1209,31 +1214,38 @@ print_value (value *val, const value_print_options &opts)
   annotate_value_history_end ();
 }
 
-/* Implementation of the "print" and "call" commands.  */
+/* Helper for parsing arguments for print_command_1.  */
 
-static void
-print_command_1 (const char *args, int voidprint)
+static struct value *
+process_print_command_args (const char *args, value_print_options *print_opts)
 {
-  struct value *val;
-  value_print_options print_opts;
-
-  get_user_print_options (&print_opts);
+  get_user_print_options (print_opts);
   /* Override global settings with explicit options, if any.  */
-  auto group = make_value_print_options_def_group (&print_opts);
+  auto group = make_value_print_options_def_group (print_opts);
   gdb::option::process_options
     (&args, gdb::option::PROCESS_OPTIONS_REQUIRE_DELIMITER, group);
 
-  print_command_parse_format (&args, "print", &print_opts);
+  print_command_parse_format (&args, "print", print_opts);
 
   const char *exp = args;
 
   if (exp != nullptr && *exp)
     {
       expression_up expr = parse_expression (exp);
-      val = evaluate_expression (expr.get ());
+      return evaluate_expression (expr.get ());
     }
-  else
-    val = access_value_history (0);
+
+  return access_value_history (0);
+}
+
+/* Implementation of the "print" and "call" commands.  */
+
+static void
+print_command_1 (const char *args, int voidprint)
+{
+  value_print_options print_opts;
+
+  struct value *val = process_print_command_args (args, &print_opts);
 
   if (voidprint || (val && value_type (val) &&
 		    value_type (val)->code () != TYPE_CODE_VOID))
@@ -2701,6 +2713,245 @@ eval_command (const char *arg, int from_tty)
   execute_command (expanded.c_str (), from_tty);
 }
 
+/* Helper function for mtag commands.  Cast VALUE to a non-lval
+   (void *) pointer.  */
+
+static struct value *cast_non_lval_void_ptr (struct value *value)
+{
+  if (value == nullptr)
+    return nullptr;
+
+  struct value *val;
+
+  /* Turn into a non_lval.  */
+  val = value_non_lval (value);
+
+  struct gdbarch *gdbarch = get_type_arch (value_type (val));
+  const struct builtin_type *builtin = builtin_type (gdbarch);
+
+  /* Cast to (void *).  */
+  val = value_cast (builtin->builtin_data_ptr, val);
+
+  return val;
+}
+
+/* Convenience function for mtag commands.  */
+
+static void
+show_memtag_unsupported (void)
+{
+  error (_("Memory tagging not supported or disabled by the current"
+	   " architecture."));
+}
+
+/* Implement the "mtag" prefix command.  */
+
+static void
+mtag_command (const char *arg, int from_tty)
+{
+  help_list (mtaglist, "mtag ", all_commands, gdb_stdout);
+}
+
+/* Helper for showltag and showatag.  */
+
+static void
+mtag_showtag_command (const char *args, enum memtag_type tag_type)
+{
+  if (args == nullptr)
+    error_no_arg (_("address or pointer"));
+
+  /* Parse args into a value.  If the value is a pointer or an address,
+     then fetch the logical or allocation tag.  */
+  value_print_options print_opts;
+
+  struct value *val = process_print_command_args (args, &print_opts);
+
+  val = cast_non_lval_void_ptr (val);
+
+  std::string tag = gdbarch_memtag_to_string (target_gdbarch (),
+					      val, tag_type);
+  if (tag.empty ())
+    printf_filtered (_("%s tag unavailable.\n"),
+		     tag_type == tag_logical? "Logical" : "Allocation");
+
+  struct value *v_tag = process_print_command_args (tag.c_str (),
+						    &print_opts);
+  print_opts.output_format = 'x';
+  print_value (v_tag, print_opts);
+}
+
+/* Implement the "mtag showltag" command.  */
+
+static void
+mtag_showltag_command (const char *args, int from_tty)
+{
+  if (!memtag || !target_supports_memory_tagging ())
+    show_memtag_unsupported ();
+
+  mtag_showtag_command (args, tag_logical);
+}
+
+/* Implement the "mtag showatag" command.  */
+
+static void
+mtag_showatag_command (const char *args, int from_tty)
+{
+  if (!memtag || !target_supports_memory_tagging ())
+    show_memtag_unsupported ();
+
+  mtag_showtag_command (args, tag_allocation);
+}
+
+/* Parse ARGS and extract ADDR and TAG.
+   ARGS should have format <expression> <tag bytes>.  */
+
+static void
+parse_setltag_input (const char *args, struct value **val,
+		     gdb::byte_vector &tags, value_print_options *print_opts)
+{
+  /* Given <expression> can be reasonably complex, we parse things backwards
+     so we can isolate the <tag bytes> portion.  */
+
+  /* Fetch the address.  */
+  std::string s_address = extract_string_maybe_quoted (&args);
+
+  /* Parse the address into a value.  */
+  *val = process_print_command_args (s_address.c_str (), print_opts);
+
+  /* Fetch the tag bytes.  */
+  std::string s_tags = extract_string_maybe_quoted (&args);
+
+  /* Validate the input.  */
+  if (s_address.empty () || s_tags.empty ())
+    error (_("Missing arguments."));
+
+  tags = hex2bin (s_tags.c_str ());
+}
+
+/* Implement the "mtag setltag" command.  */
+
+static void
+mtag_setltag_command (const char *args, int from_tty)
+{
+  if (!memtag || !target_supports_memory_tagging ())
+    show_memtag_unsupported ();
+
+  if (args == nullptr)
+    error_no_arg (_("<address> <tag>"));
+
+  gdb::byte_vector tags;
+  struct value *val;
+  value_print_options print_opts;
+
+  /* Parse the input.  */
+  parse_setltag_input (args, &val, tags, &print_opts);
+
+  val = cast_non_lval_void_ptr (val);
+
+  if (gdbarch_set_memtags (target_gdbarch (), val, 0, tags,
+			   tag_logical) != 0)
+    printf_filtered (_("Could not update the logical tag data.\n"));
+  else
+    {
+      /* Always print it in hex format.  */
+      print_opts.output_format = 'x';
+      print_value (val, print_opts);
+    }
+}
+
+/* Parse ARGS and extract ADDR, LENGTH and TAGS.  */
+
+static void
+parse_setatag_input (const char *args, struct value **val, size_t *length,
+		     gdb::byte_vector &tags)
+{
+  /* Fetch the address.  */
+  std::string s_address = extract_string_maybe_quoted (&args);
+
+  /* Parse the address into a value.  */
+  value_print_options print_opts;
+  *val = process_print_command_args (s_address.c_str (), &print_opts);
+
+  /* Fetch the length.  */
+  std::string s_length = extract_string_maybe_quoted (&args);
+
+  /* Fetch the tag bytes.  */
+  std::string s_tags = extract_string_maybe_quoted (&args);
+
+  /* Validate the input.  */
+  if (s_address.empty () || s_length.empty () || s_tags.empty ())
+    error (_("Missing arguments."));
+
+  errno = 0;
+  *length = strtoulst (s_length.c_str (), NULL, 10);
+  if (errno != 0)
+    error (_("Error parsing length argument."));
+
+  tags = hex2bin (s_tags.c_str ());
+}
+
+/* Implement the "mtag setatag" command.
+   ARGS should be in the format <address> <length> <tags>.  */
+
+static void
+mtag_setatag_command (const char *args, int from_tty)
+{
+  if (!memtag || !target_supports_memory_tagging ())
+    show_memtag_unsupported ();
+
+  if (args == nullptr)
+    error_no_arg (_("<starting address> <length> <tag bytes>"));
+
+  gdb::byte_vector tags;
+  size_t length = 0;
+  struct value *val;
+
+  /* Parse the input.  */
+  parse_setatag_input (args, &val, &length, tags);
+
+  val = cast_non_lval_void_ptr (val);
+
+  if (gdbarch_set_memtags (target_gdbarch (), val, length, tags,
+			   tag_allocation) != 0)
+    printf_filtered (_("Could not update the allocation tag(s).\n"));
+  else
+    printf_filtered (_("Allocation tag(s) updated successfully.\n"));
+}
+
+/* Implement the "mtag check" command.  */
+
+static void
+mtag_check_command (const char *args, int from_tty)
+{
+  if (!memtag || !target_supports_memory_tagging ())
+    show_memtag_unsupported ();
+
+  if (args == nullptr)
+    error (_("Argument required (address or pointer)"));
+
+  /* Parse the expression into a value.  If the value is an address or
+     pointer, then check its logical tag against the allocation tag.  */
+  value_print_options print_opts;
+
+  struct value *val = process_print_command_args (args, &print_opts);
+
+  val = cast_non_lval_void_ptr (val);
+
+  /* If memory tagging validation is on, check if the tag is valid.  */
+    if (gdbarch_memtag_mismatch_p (target_gdbarch (), val))
+	{
+	  std::string ltag = gdbarch_memtag_to_string (target_gdbarch (),
+						       val, tag_logical);
+	  std::string atag = gdbarch_memtag_to_string (target_gdbarch (),
+						       val, tag_allocation);
+	  printf_filtered (_("Logical tag (%s) does not match"
+			     " the allocation tag (%s).\n"),
+			   ltag.c_str (), atag.c_str ());
+	}
+    else
+      printf_filtered (_("Memory tags match.\n"));
+}
+
 void _initialize_printcmd ();
 void
 _initialize_printcmd ()
@@ -2911,4 +3162,60 @@ certain operations have illegal tags."),
 			    NULL,
 			    show_memtag,
 			    &setlist, &showlist);
+
+  /* Memory tagging commands.  */
+  add_prefix_cmd ("mtag", class_vars, mtag_command, _("\
+Generic command for showing and manipulating memory tag properties."),
+		  &mtaglist, "mtag ", 0, &cmdlist);
+  add_cmd ("showltag", class_vars, mtag_showltag_command,
+	   ("Show the logical tag for an address.\n\
+Usage: mtag showltag <address>.\n\
+<address> is an expression that evaluates to a pointer or memory address.\n\
+GDB will show the logical tag associated with <address>.  The tag\n\
+interpretation is architecture-specific."),
+	   &mtaglist);
+  add_cmd ("showatag", class_vars, mtag_showatag_command,
+	   _("Show the allocation tag for an address.\n\
+Usage: mtag showatag <address>.\n\
+<address> is an expression that evaluates to a pointer or memory address.\n\
+GDB will show the allocation tag associated with <address>.  The tag\n\
+interpretation is architecture-specific."),
+	   &mtaglist);
+  add_cmd ("setltag", class_vars, mtag_setltag_command,
+	   _("Set the logical tag for an address.\n\
+Usage: mtag setltag <address> <tag>\n\
+<address> is an expression that evaluates to a pointer or memory address.\n\
+<tag> is a sequence of hex bytes that will be interpreted by the\n\
+architecture as a single memory tag.\n\
+GDB will set the logical tag for <address> to <tag>, and will show the\n\
+resulting address with the updated tag."),
+	   &mtaglist);
+  add_cmd ("setatag", class_vars, mtag_setatag_command,
+	   _("Set the allocation tag for an address.\n\
+Usage: mtag setatag <address> <length> <tag_bytes>\n\
+<address> is an expression that evaluates to a pointer or memory address\n\
+<length> is the number of bytes that will get added to <address> to calculate\n\
+the memory range.\n\
+<tag bytes> is a sequence of hex bytes that will be interpreted by the\n\
+architecture as one or more memory tags.\n\
+Sets the tags of the memory range [<address>, <address> + <length>)\n\
+to the specified tag bytes.\n\
+\n\
+If the number of tags is greater than or equal to the number of tag granules\n\
+in the [<address>, <address> + <length) range, only the tags up to the\n\
+number of tag granules will be stored.\n\
+\n\
+If the number of tags is less than the number of tag granules, then the\n\
+command is a fill operation.  The tag bytes are interpreted as a pattern\n\
+that will get repeated until the number of tag granules in the memory range\n\
+[<address>, <address> + <length>] is stored to."),
+	   &mtaglist);
+  add_cmd ("check", class_vars, mtag_check_command,
+	   _("Validate the logical tag against the allocation tag.\n\
+Usage: mtag check <address>\n\
+<address> is an expression that evaluates to a pointer or memory address\n\
+GDB will fetch the logical and allocation tags for <address> and will\n\
+compare them for equality.  If the tags do not match, GDB will show\n\
+additional information about the mismatch."),
+	   &mtaglist);
 }

--- a/gdbsupport/rsp-low.cc
+++ b/gdbsupport/rsp-low.cc
@@ -32,7 +32,7 @@ fromhex (int a)
   else if (a >= 'A' && a <= 'F')
     return a - 'A' + 10;
   else
-    error (_("Reply contains invalid hex digit %d"), a);
+    error (_("Invalid hex digit %d"), a);
 }
 
 /* See rsp-low.h.  */