[pushed] Plug target side conditions and commands leaks (was: Re: [PATCH] Let gdbserver doesn't tell GDB it support target-side breakpoint conditions and commands if it doesn't support 'Z' packet)

[Pedro Alves <palves at redhat dot com>]

On 11/28/2013 09:07 AM, Hui Zhu wrote:
> --- a/gdb/remote.c
> +++ b/gdb/remote.c
> @@ -8187,6 +8187,14 @@ static int
>   remote_insert_breakpoint (struct gdbarch *gdbarch,
>   			  struct bp_target_info *bp_tgt)
>   {
> +  int have_target_target_side_commands = 0;
> +
> +  /* Check bp_tgt->tcommands in this place because
> +     remote_add_target_side_commands will release bp_tgt->tcommands.  */

Well, that's quite fragile, isn't it.  If Z packets have been found
to not be supported, then nothing is releasing bp_tgt->tcommands
(and bp_tgt->conditions).

> +
> +  if (!VEC_empty (agent_expr_p, bp_tgt->tcommands))
> +    have_target_target_side_commands = 1;
> +

I've pushed this patch below.

----------
Plug target side conditions and commands leaks.

The memory management of bp_location->target_info.conditions|tcommands
is currently a little fragile.  If the target reports support for
target conditions or commands, and then target side breakpoint support
is disabled, or some error is thrown before remote_add_target_side_XXX
is called, we'll leak these lists.  This patch makes us free these
lists when the locations are deleted, and also, just before recreating
the commands|conditions lists.

Tested on x86_64 Fedora 17, native and gdbserver.

gdb/
2013-11-29  Pedro Alves  <palves@redhat.com>

	* breakpoint.c (build_target_condition_list): Release previous
	conditions.
	(build_target_command_list): Release previous commands.
	(bp_location_dtor): Release target conditions and commands.
	* remote.c (remote_add_target_side_condition): Don't release
	conditions.
	(remote_add_target_side_commands): Don't release commands.
---

 gdb/ChangeLog    |   10 ++++++++++
 gdb/breakpoint.c |    9 +++++++++
 gdb/remote.c     |    4 ----
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index e86f5c3..5f0626c 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,13 @@
+2013-11-29  Pedro Alves  <palves@redhat.com>
+
+	* breakpoint.c (build_target_condition_list): Release previous
+	conditions.
+	(build_target_command_list): Release previous commands.
+	(bp_location_dtor): Release target conditions and commands.
+	* remote.c (remote_add_target_side_condition): Don't release
+	conditions.
+	(remote_add_target_side_commands): Don't release commands.
+
 2013-11-29  Yao Qi  <yao@codesourcery.com>
 	    Pedro Alves  <palves@redhat.com>

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 897b664..111660f 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -2096,6 +2096,9 @@ build_target_condition_list (struct bp_location *bl)
   int modified = bl->needs_update;
   struct bp_location *loc;

+  /* Release conditions left over from a previous insert.  */
+  VEC_free (agent_expr_p, bl->target_info.conditions);
+
   /* This is only meaningful if the target is
      evaluating conditions and if the user has
      opted for condition evaluation on the target's
@@ -2287,6 +2290,9 @@ build_target_command_list (struct bp_location *bl)
   int modified = bl->needs_update;
   struct bp_location *loc;

+  /* Release commands left over from a previous insert.  */
+  VEC_free (agent_expr_p, bl->target_info.tcommands);
+
   /* For now, limit to agent-style dprintf breakpoints.  */
   if (bl->owner->type != bp_dprintf
       || strcmp (dprintf_style, dprintf_style_agent) != 0)
@@ -12734,6 +12740,9 @@ bp_location_dtor (struct bp_location *self)
   if (self->cond_bytecode)
     free_agent_expr (self->cond_bytecode);
   xfree (self->function_name);
+
+  VEC_free (agent_expr_p, self->target_info.conditions);
+  VEC_free (agent_expr_p, self->target_info.tcommands);
 }

 static const struct bp_location_ops bp_location_ops =
diff --git a/gdb/remote.c b/gdb/remote.c
index 186c058..be54450 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -8151,8 +8151,6 @@ remote_add_target_side_condition (struct gdbarch *gdbarch,
 	buf = pack_hex_byte (buf, aexpr->buf[i]);
       *buf = '\0';
     }
-
-  VEC_free (agent_expr_p, bp_tgt->conditions);
   return 0;
 }

@@ -8183,8 +8181,6 @@ remote_add_target_side_commands (struct gdbarch *gdbarch,
 	buf = pack_hex_byte (buf, aexpr->buf[i]);
       *buf = '\0';
     }
-
-  VEC_free (agent_expr_p, bp_tgt->tcommands);
 }

 /* Insert a breakpoint.  On targets that have software breakpoint