gdb_server: fix memory leaks in users of get_reg_features_list()

v4:
- changed first line of commit message
v3:
- added extra LOG_ERROR() message
v2:
- Added missing "goto error"
- free also the on extra element of features[]

In contrast to target_get_gdb_reg_list(), the list returned by
get_reg_features_list() consists of items which are itself
malloc'ed.
--> Free the list items prior freeing the list itself.

Additionally:
- gdb_generate_target_description():
  o Do error handling similar as gdb_get_target_description_chunk() does.
- gdb_get_target_description_chunk()
  o **features must be initialised prior an "goto error" can happen

Change-Id: Iad07824618c51084e0aa0499ee6fc96198b320f0
Signed-off-by: Christian Eggers <ceggers@gmx.de>
Reviewed-on: http://openocd.zylin.com/1917
Tested-by: jenkins
Reviewed-by: Trevor Woerner <trevor.woerner@linaro.org>
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>

1 files changed, 25 insertions, 13 deletions

diff --git a/src/server/gdb_server.c b/src/server/gdb_server.c
index d4cc274..63c5f6b 100644
--- a/src/server/gdb_server.c
+++ b/src/server/gdb_server.c
@@ -2050,8 +2050,10 @@ static int get_reg_features_list(struct target *target, char **feature_list[], i
 static int gdb_generate_target_description(struct target *target, char **tdesc_out)
 {
 	int retval = ERROR_OK;
-	struct reg **reg_list;
+	struct reg **reg_list = NULL;
 	int reg_list_size;
+	char **features = NULL;
+	int feature_list_size = 0;
 	char *tdesc = NULL;
 	int pos = 0;
 	int size = 0;
@@ -2061,21 +2063,22 @@ static int gdb_generate_target_description(struct target *target, char **tdesc_o
 
 	if (retval != ERROR_OK) {
 		LOG_ERROR("get register list failed");
-		return ERROR_FAIL;
+		retval = ERROR_FAIL;
+		goto error;
 	}
 
 	if (reg_list_size <= 0) {
-		free(reg_list);
-		return ERROR_FAIL;
+		LOG_ERROR("get register list failed");
+		retval = ERROR_FAIL;
+		goto error;
 	}
 
-	char **features = NULL;
 	/* Get a list of available target registers features */
-	retval = get_reg_features_list(target, &features, NULL, reg_list, reg_list_size);
+	retval = get_reg_features_list(target, &features, &feature_list_size, reg_list, reg_list_size);
 	if (retval != ERROR_OK) {
 		LOG_ERROR("Can't get the registers feature list");
-		free(reg_list);
-		return ERROR_FAIL;
+		retval = ERROR_FAIL;
+		goto error;
 	}
 
 	/* If we found some features associated with registers, create sections */
@@ -2155,8 +2158,13 @@ static int gdb_generate_target_description(struct target *target, char **tdesc_o
 	xml_printf(&retval, &tdesc, &pos, &size,
 			"</target>\n");
 
-	free(reg_list);
+error:
+
+	/* note: features[] contains (feature_list_size + 1) elements */
+	for (int j = feature_list_size; j >= 0; j--)
+		free(features[j]);
 	free(features);
+	free(reg_list);
 
 	if (retval == ERROR_OK)
 		*tdesc_out = tdesc;
@@ -2225,6 +2233,7 @@ static int gdb_target_description_supported(struct target *target, int *supporte
 	int retval = ERROR_OK;
 	struct reg **reg_list = NULL;
 	int reg_list_size = 0;
+	char **features = NULL;
 	int feature_list_size = 0;
 	char **features = NULL;
 
@@ -2236,6 +2245,7 @@ static int gdb_target_description_supported(struct target *target, int *supporte
 	}
 
 	if (reg_list_size <= 0) {
+		LOG_ERROR("get register list failed");
 		retval = ERROR_FAIL;
 		goto error;
 	}
@@ -2255,11 +2265,13 @@ static int gdb_target_description_supported(struct target *target, int *supporte
 	}
 
 error:
-	if (reg_list != NULL)
-		free(reg_list);
 
-	if (features != NULL)
-		free(features);
+	/* note: features[] contains (feature_list_size + 1) elements */
+	for (int j = feature_list_size; j >= 0; j--)
+		free(features[j]);
+	free(features);
+
+	free(reg_list);
 
 	return retval;
 }