parser: Fix parser failing to handle errors when setting up work

The parser is not correctly handling some error conditions when
dealing with work units. Failure to spawn work, access files, etc
should be returned where appropriate, and be able to abort processing
if abort_on_error is set.

In addition some errors are leading to a direct exit without checking
for abort_on_error.

BugLink: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=921866
BugLink: http://bugs.launchpad.net/bugs/1815294

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Eric Chiang <ericchiang@google.com>

parser/parser.h

@@ -171,13 +171,23 @@ extern int preprocess_only;
 
 
 #ifdef DEBUG
-#define PDEBUG(fmt, args...) fprintf(stderr, "parser: " fmt, ## args)
+#define PDEBUG(fmt, args...)				\
+do {							\
+	int pdebug_error = errno;			\
+	fprintf(stderr, "parser: " fmt, ## args);	\
+	errno = pdebug_error;				\
+} while (0)
 #else
 #define PDEBUG(fmt, args...)	/* Do nothing */
 #endif
 #define NPDEBUG(fmt, args...)	/* Do nothing */
 
-#define PERROR(fmt, args...) fprintf(stderr, fmt, ## args)
+#define PERROR(fmt, args...)			\
+do {						\
+	int perror_error = errno;		\
+	fprintf(stderr, fmt, ## args);		\
+	errno = perror_error;			\
+} while (0)
 
 #ifndef TRUE
 #define TRUE	(1)

parser/parser_main.c

@@ -1090,8 +1090,11 @@ do {									\
 		work_sync_one(RESULT);					\
 } while (0)
 
+/* returns -1 if work_spawn fails, not a return value of any unit of work */
 #define work_spawn(WORK, RESULT)					\
-do {									\
+({									\
+	int localrc = 0;						\
+	do {								\
 	if (jobs == 0) {						\
 		/* no parallel work so avoid fork() overhead */		\
 		RESULT(WORK);						\
@@ -1127,11 +1130,17 @@ do {									\
 			fprintf(stderr, "    JOBS SPAWN: created %ld ...\n", njobs);									\
 	} else {							\
 		/* error */						\
-		if (debug_jobs)						\
+		if (debug_jobs)	{					\
-			fprintf(stderr, "    JOBS SPAWN: failed error: %d) ...\n", errno);								\
+			int error = errno;				\
+			fprintf(stderr, "    JOBS SPAWN: failed error: %d) ...\n", errno);	\
+			errno = error;					\
+		}							\
 		RESULT(errno);						\
+		localrc = -1;						\
 	}								\
-} while (0)
+	} while (0);							\
+	localrc;							\
+})
 
 
 /* sadly C forces us to do this with exit, long_jump or returning error
@@ -1208,11 +1217,15 @@ static int profile_dir_cb(int dirfd unused, const char *name, struct stat *st,
 	if (!S_ISDIR(st->st_mode) && !is_blacklisted(name, NULL)) {
 		struct dir_cb_data *cb_data = (struct dir_cb_data *)data;
 		autofree char *path = NULL;
-		if (asprintf(&path, "%s/%s", cb_data->dirname, name) < 0)
+		if (asprintf(&path, "%s/%s", cb_data->dirname, name) < 0) {
 			PERROR(_("Out of memory"));
-		work_spawn(process_profile(option, cb_data->kernel_interface,
+			handle_work_result(errno);
-					   path, cb_data->policy_cache),
+			return -1;
-			   handle_work_result);
+		}
+		rc = work_spawn(process_profile(option,
+						cb_data->kernel_interface,
+						path, cb_data->policy_cache),
+				handle_work_result);
 	}
 	return rc;
 }
@@ -1226,11 +1239,15 @@ static int binary_dir_cb(int dirfd unused, const char *name, struct stat *st,
 	if (!S_ISDIR(st->st_mode) && !is_blacklisted(name, NULL)) {
 		struct dir_cb_data *cb_data = (struct dir_cb_data *)data;
 		autofree char *path = NULL;
-		if (asprintf(&path, "%s/%s", cb_data->dirname, name) < 0)
+		if (asprintf(&path, "%s/%s", cb_data->dirname, name) < 0) {
 			PERROR(_("Out of memory"));
-		work_spawn(process_binary(option, cb_data->kernel_interface,
+			handle_work_result(errno);
-					   path),
+			return -1;
-			    handle_work_result);
+		}
+		rc = work_spawn(process_binary(option,
+					       cb_data->kernel_interface,
+					       path),
+				handle_work_result);
 	}
 	return rc;
 }
@@ -1360,11 +1377,14 @@ int main(int argc, char *argv[])
 		}
 		/* skip stdin if we've seen other command line arguments */
 		if (i == argc && optind != argc)
-			continue;
+			goto cleanup;
 
 		if (profilename && stat(profilename, &stat_file) == -1) {
+			last_error = errno;
 			PERROR("File %s not found, skipping...\n", profilename);
-			continue;
+			if (abort_on_error)
+				break;
+			goto cleanup;
 		}
 
 		if (profilename && S_ISDIR(stat_file.st_mode)) {
@@ -1379,20 +1399,27 @@ int main(int argc, char *argv[])
 			cb = binary_input ? binary_dir_cb : profile_dir_cb;
 			if ((retval = dirat_for_each(AT_FDCWD, profilename,
 						     &cb_data, cb))) {
+				last_error = errno;
 				PDEBUG("Failed loading profiles from %s\n",
 				       profilename);
+				if (abort_on_error)
+					break;
 			}
 		} else if (binary_input) {
+			/* ignore return as error is handled in work_spawn */
 			work_spawn(process_binary(option, kernel_interface,
 						  profilename),
 				   handle_work_result);
 		} else {
+			/* ignore return as error is handled in work_spawn */
 			work_spawn(process_profile(option, kernel_interface,
 						   profilename, policy_cache),
 				   handle_work_result);
 		}
 
-		if (profilename) free(profilename);
+	cleanup:
+		if (profilename)
+			free(profilename);
 		profilename = NULL;
 	}
 	work_sync(handle_work_result);