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-rw-r--r--gdb/ChangeLog14
-rw-r--r--gdb/NEWS4
-rw-r--r--gdb/doc/ChangeLog5
-rw-r--r--gdb/doc/gdb.texinfo22
-rw-r--r--gdb/record-btrace.c88
-rw-r--r--gdb/testsuite/ChangeLog4
-rw-r--r--gdb/testsuite/gdb.btrace/data.exp10
7 files changed, 135 insertions, 12 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 2418b45..a605085 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,17 @@
+2014-05-23 Markus Metzger <markus.t.metzger@intel.com>
+
+ * record-btrace.c (record_btrace_allow_memory_access): Remove.
+ (replay_memory_access_read_only, replay_memory_access_read_write)
+ (replay_memory_access_types, replay_memory_access)
+ (set_record_btrace_cmdlist, show_record_btrace_cmdlist)
+ (cmd_set_record_btrace, cmd_show_record_btrace)
+ (cmd_show_replay_memory_access): New.
+ (record_btrace_xfer_partial, record_btrace_insert_breakpoint)
+ (record_btrace_remove_breakpoint): Replace
+ record_btrace_allow_memory_access with replay_memory_access.
+ (_initialize_record_btrace): Add commands.
+ * NEWS: Announce it.
+
2014-05-22 Ramana Radhakrishnan <ramana.radhakrishnan@arm.com>
* aarch64-linux-nat.c (asm/ptrace.h): Include.
diff --git a/gdb/NEWS b/gdb/NEWS
index 4663650..5a0a76e 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -67,6 +67,10 @@ set auto-connect-native-target
native target for the run, attach, etc. commands when not connected
to any target yet. See also "target native" below.
+set record btrace replay-memory-access (read-only|read-write)
+show record btrace replay-memory-access
+ Control what memory accesses are allowed during replay.
+
* New features in the GDB remote stub, GDBserver
** New option --debug-format=option1[,option2,...] allows one to add
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index 18588f6..25bdc32 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,8 @@
+2014-05-23 Markus Metzger <markus.t.metzger@intel.com>
+
+ * gdb.texinfo (Process Record and Replay): Document "set/show btrace
+ replay-memory-access".
+
2014-05-21 Pedro Alves <palves@redhat.com>
* gdb.texinfo (Starting): Document "set/show
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 47d4bb7..cc188ae 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -6451,6 +6451,28 @@ results.
@item show record full memory-query
Show the current setting of @code{memory-query}.
+@kindex set record btrace
+The @code{btrace} record target does not trace data. As a
+convenience, when replaying, @value{GDBN} reads read-only memory off
+the live program directly, assuming that the addresses of the
+read-only areas don't change. This for example makes it possible to
+disassemble code while replaying, but not to print variables.
+In some cases, being able to inspect variables might be useful.
+You can use the following command for that:
+
+@item set record btrace replay-memory-access
+Control the behavior of the @code{btrace} recording method when
+accessing memory during replay. If @code{read-only} (the default),
+@value{GDBN} will only allow accesses to read-only memory.
+If @code{read-write}, @value{GDBN} will allow accesses to read-only
+and to read-write memory. Beware that the accessed memory corresponds
+to the live target and not necessarily to the current replay
+position.
+
+@kindex show record btrace
+@item show record btrace replay-memory-access
+Show the current setting of @code{replay-memory-access}.
+
@kindex info record
@item info record
Show various statistics about the recording depending on the recording
diff --git a/gdb/record-btrace.c b/gdb/record-btrace.c
index 2304020..166e78e 100644
--- a/gdb/record-btrace.c
+++ b/gdb/record-btrace.c
@@ -43,8 +43,22 @@ static struct target_ops record_btrace_ops;
/* A new thread observer enabling branch tracing for the new thread. */
static struct observer *record_btrace_thread_observer;
-/* Temporarily allow memory accesses. */
-static int record_btrace_allow_memory_access;
+/* Memory access types used in set/show record btrace replay-memory-access. */
+static const char replay_memory_access_read_only[] = "read-only";
+static const char replay_memory_access_read_write[] = "read-write";
+static const char *const replay_memory_access_types[] =
+{
+ replay_memory_access_read_only,
+ replay_memory_access_read_write,
+ NULL
+};
+
+/* The currently allowed replay memory access type. */
+static const char *replay_memory_access = replay_memory_access_read_only;
+
+/* Command lists for "set/show record btrace". */
+static struct cmd_list_element *set_record_btrace_cmdlist;
+static struct cmd_list_element *show_record_btrace_cmdlist;
/* Print a record-btrace debug message. Use do ... while (0) to avoid
ambiguities when used in if statements. */
@@ -816,7 +830,8 @@ record_btrace_xfer_partial (struct target_ops *ops, enum target_object object,
struct target_ops *t;
/* Filter out requests that don't make sense during replay. */
- if (!record_btrace_allow_memory_access && record_btrace_is_replaying (ops))
+ if (replay_memory_access == replay_memory_access_read_only
+ && record_btrace_is_replaying (ops))
{
switch (object)
{
@@ -870,18 +885,19 @@ record_btrace_insert_breakpoint (struct target_ops *ops,
struct bp_target_info *bp_tgt)
{
volatile struct gdb_exception except;
- int old, ret;
+ const char *old;
+ int ret;
/* Inserting breakpoints requires accessing memory. Allow it for the
duration of this function. */
- old = record_btrace_allow_memory_access;
- record_btrace_allow_memory_access = 1;
+ old = replay_memory_access;
+ replay_memory_access = replay_memory_access_read_write;
ret = 0;
TRY_CATCH (except, RETURN_MASK_ALL)
ret = ops->beneath->to_insert_breakpoint (ops->beneath, gdbarch, bp_tgt);
- record_btrace_allow_memory_access = old;
+ replay_memory_access = old;
if (except.reason < 0)
throw_exception (except);
@@ -897,18 +913,19 @@ record_btrace_remove_breakpoint (struct target_ops *ops,
struct bp_target_info *bp_tgt)
{
volatile struct gdb_exception except;
- int old, ret;
+ const char *old;
+ int ret;
/* Removing breakpoints requires accessing memory. Allow it for the
duration of this function. */
- old = record_btrace_allow_memory_access;
- record_btrace_allow_memory_access = 1;
+ old = replay_memory_access;
+ replay_memory_access = replay_memory_access_read_write;
ret = 0;
TRY_CATCH (except, RETURN_MASK_ALL)
ret = ops->beneath->to_remove_breakpoint (ops->beneath, gdbarch, bp_tgt);
- record_btrace_allow_memory_access = old;
+ replay_memory_access = old;
if (except.reason < 0)
throw_exception (except);
@@ -1939,6 +1956,32 @@ cmd_record_btrace_start (char *args, int from_tty)
execute_command ("target record-btrace", from_tty);
}
+/* The "set record btrace" command. */
+
+static void
+cmd_set_record_btrace (char *args, int from_tty)
+{
+ cmd_show_list (set_record_btrace_cmdlist, from_tty, "");
+}
+
+/* The "show record btrace" command. */
+
+static void
+cmd_show_record_btrace (char *args, int from_tty)
+{
+ cmd_show_list (show_record_btrace_cmdlist, from_tty, "");
+}
+
+/* The "show record btrace replay-memory-access" command. */
+
+static void
+cmd_show_replay_memory_access (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (gdb_stdout, _("Replay memory access is %s.\n"),
+ replay_memory_access);
+}
+
void _initialize_record_btrace (void);
/* Initialize btrace commands. */
@@ -1951,6 +1994,29 @@ _initialize_record_btrace (void)
&record_cmdlist);
add_alias_cmd ("b", "btrace", class_obscure, 1, &record_cmdlist);
+ add_prefix_cmd ("btrace", class_support, cmd_set_record_btrace,
+ _("Set record options"), &set_record_btrace_cmdlist,
+ "set record btrace ", 0, &set_record_cmdlist);
+
+ add_prefix_cmd ("btrace", class_support, cmd_show_record_btrace,
+ _("Show record options"), &show_record_btrace_cmdlist,
+ "show record btrace ", 0, &show_record_cmdlist);
+
+ add_setshow_enum_cmd ("replay-memory-access", no_class,
+ replay_memory_access_types, &replay_memory_access, _("\
+Set what memory accesses are allowed during replay."), _("\
+Show what memory accesses are allowed during replay."),
+ _("Default is READ-ONLY.\n\n\
+The btrace record target does not trace data.\n\
+The memory therefore corresponds to the live target and not \
+to the current replay position.\n\n\
+When READ-ONLY, allow accesses to read-only memory during replay.\n\
+When READ-WRITE, allow accesses to read-only and read-write memory during \
+replay."),
+ NULL, cmd_show_replay_memory_access,
+ &set_record_btrace_cmdlist,
+ &show_record_btrace_cmdlist);
+
init_record_btrace_ops ();
add_target (&record_btrace_ops);
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 1473d96..fdbae25 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2014-05-23 Markus Metzger <markus.t.metzger@intel.com>
+
+ * gdb.btrace/data.exp: Test memory access during btrace replay.
+
2014-05-22 Simon Marchi <simon.marchi@ericsson.com>
* lib/mi-support.exp (mi_run_cmd_full): Add comments.
diff --git a/gdb/testsuite/gdb.btrace/data.exp b/gdb/testsuite/gdb.btrace/data.exp
index 64c5443..91d8d8b 100644
--- a/gdb/testsuite/gdb.btrace/data.exp
+++ b/gdb/testsuite/gdb.btrace/data.exp
@@ -40,6 +40,14 @@ gdb_test "reverse-step" ".*test\.4.*"
gdb_test "print glob" "unavailable\[^\\\r\\\n\]*"
gdb_test "print loc" "unavailable\[^\\\r\\\n\]*"
+# we can read memory if we explicitly allow it.
+gdb_test_no_output "set record btrace replay-memory-access read-write"
+gdb_test "print glob" "1"
+
+# we can't if we don't explicitly allow it.
+gdb_test_no_output "set record btrace replay-memory-access read-only"
+gdb_test "print glob" "unavailable\[^\\\r\\\n\]*"
+
# stop replaying and try again
-gdb_test "record goto end"
+gdb_test "record goto end" ".*main\.3.*"
gdb_test "print glob" "1"