Fix compiler warnings.

Mostly harmless cases of warn_unused_result.

qrexec/qrexec-agent.c

@@ -533,7 +533,9 @@ void handle_new_passfd()
 		exit(1);
 	}
 	// let client know what fd has been allocated
-	write(fd, &fd, sizeof(fd));
+	if (write(fd, &fd, sizeof(fd)) != sizeof(fd)) {
+		perror("write to client");
+	}
 }
 
 

qrexec/qrexec-client-vm.c

@@ -80,10 +80,16 @@ int main(int argc, char **argv)
 
 	for (i = 0; i < 3; i++) {
 		local_fd[i] = connect_unix_socket();
-		read(local_fd[i], &remote_fd[i], sizeof(remote_fd[i]));
+		if (read(local_fd[i], &remote_fd[i], sizeof(remote_fd[i])) != sizeof(remote_fd[i])) {
+			perror("read client fd");
+			exit(1);
+		}
 		if (i != 2 || getenv("PASS_LOCAL_STDERR")) {
 			char *env;
-			asprintf(&env, "SAVED_FD_%d=%d", i, dup(i));
+			if (asprintf(&env, "SAVED_FD_%d=%d", i, dup(i)) < 0) {
+				perror("prepare SAVED_FD_");
+				exit(1);
+			}
 			putenv(env);
 			dup2(local_fd[i], i);
 			close(local_fd[i]);
@@ -98,7 +104,12 @@ int main(int argc, char **argv)
 		 sizeof(params.process_fds.ident), "%d %d %d",
 		 remote_fd[0], remote_fd[1], remote_fd[2]);
 
-	write(trigger_fd, &params, sizeof(params));
+	if (write(trigger_fd, &params, sizeof(params)) < 0) {
+		if (!getenv("PASS_LOCAL_STDERR"))
+			perror("write to agent");
+		exit(1);
+	}
+
 	close(trigger_fd);
 
 	abs_exec_path = strdup(argv[3]);

qubes-rpc/gui-fatal.c

@@ -18,8 +18,11 @@ static void produce_message(const char * type, const char *fmt, va_list args)
 	char *dialog_msg;
 	char buf[1024];
 	(void) vsnprintf(buf, sizeof(buf), fmt, args);
-	asprintf(&dialog_msg, "%s: %s: %s (error type: %s)",
-		 program_invocation_short_name, type, buf, strerror(errno));
+	if (asprintf(&dialog_msg, "%s: %s: %s (error type: %s)",
+		 program_invocation_short_name, type, buf, strerror(errno)) < 0) {
+		fprintf(stderr, "Failed to allocate memory for error message :(\n");
+		return;
+	}
 	fprintf(stderr, "%s\n", dialog_msg);
 	switch (fork()) {
 	case -1:

qubes-rpc/qfile-agent.c

@@ -5,8 +5,10 @@ char *get_abs_path(const char *cwd, const char *pathname)
 	char *ret;
 	if (pathname[0] == '/')
 		return strdup(pathname);
-	asprintf(&ret, "%s/%s", cwd, pathname);
-	return ret;
+	if (asprintf(&ret, "%s/%s", cwd, pathname) < 0)
+		return NULL;
+	else
+		return ret;
 }
 
 int do_fs_walk(const char *file)
@@ -28,9 +30,13 @@ int do_fs_walk(const char *file)
 		char *fname = ent->d_name;
 		if (!strcmp(fname, ".") || !strcmp(fname, ".."))
 			continue;
-		asprintf(&newfile, "%s/%s", file, fname);
-		do_fs_walk(newfile);
-		free(newfile);
+		if (asprintf(&newfile, "%s/%s", file, fname) >= 0) {
+			do_fs_walk(newfile);
+			free(newfile);
+		} else {
+			fprintf(stderr, "asprintf failed\n");
+			exit(1);
+		}
 	}
 	closedir(dir);
 	// directory metadata is resent; this makes the code simple,
@@ -68,9 +74,11 @@ int main(int argc, char **argv)
 				    ("Internal error: nonabsolute filenames not allowed");
 			*sep = 0;
 		} while (sep[1] == 0);
-		if (entry[0] == 0)
-			chdir("/");
-		else if (chdir(entry))
+		if (entry[0] == 0) {
+			if (chdir("/") < 0) {
+				gui_fatal("Internal error: chdir(\"/\") failed?!");
+			}
+		} else if (chdir(entry))
 			gui_fatal("chdir to %s", entry);
 		do_fs_walk(sep + 1);
 		free(entry);

qubes-rpc/qfile-utils.c

@@ -27,21 +27,25 @@ void do_notify_progress(long long total, int flag)
 	const char *du_size_env = getenv("FILECOPY_TOTAL_SIZE");
 	const char *progress_type_env = getenv("PROGRESS_TYPE");
 	const char *saved_stdout_env = getenv("SAVED_FD_1");
+	int ignore;
 	if (!progress_type_env)
 		return;
 	if (!strcmp(progress_type_env, "console") && du_size_env) {
 		char msg[256];
 		snprintf(msg, sizeof(msg), "sent %lld/%lld KB\r",
 			 total / 1024, strtoull(du_size_env, NULL, 0));
-		write(2, msg, strlen(msg));
+		ignore = write(2, msg, strlen(msg));
 		if (flag == PROGRESS_FLAG_DONE)
-			write(2, "\n", 1);
+			ignore = write(2, "\n", 1);
 	}
 	if (!strcmp(progress_type_env, "gui") && saved_stdout_env) {
 		char msg[256];
 		snprintf(msg, sizeof(msg), "%lld\n", total);
-		write(strtoul(saved_stdout_env, NULL, 0), msg,
-		      strlen(msg));
+		ignore = write(strtoul(saved_stdout_env, NULL, 0), msg,
+				strlen(msg));
+	}
+	if (ignore < 0) {
+		/* silence gcc warning */
 	}
 }
 

qubes-rpc/qopen-in-vm.c

@@ -51,21 +51,21 @@ void recv_file_nowrite(const char *fname)
 {
 	char *tempfile;
 	char *errmsg;
-	int tmpfd;
+	int tmpfd = -1;
 
-	asprintf(&tempfile, "/tmp/file_edited_in_dvm.XXXXXX");
-	tmpfd = mkstemp(tempfile);
+	if (asprintf(&tempfile, "/tmp/file_edited_in_dvm.XXXXXX") != -1)
+		tmpfd = mkstemp(tempfile);
 	if (tmpfd < 0)
 		gui_fatal("unable to create any temporary file, aborting");
 	if (!copy_and_return_nonemptiness(tmpfd)) {
 		unlink(tempfile);
 		return;
 	}
-	asprintf(&errmsg,
+	if (asprintf(&errmsg,
 		 "The file %s has been edited in Disposable VM and the modified content has been received, "
 		 "but this file is in nonwritable directory and thus cannot be modified safely. The edited file has been "
-		 "saved to %s", fname, tempfile);
-	gui_nonfatal(errmsg);
+		 "saved to %s", fname, tempfile) != -1)
+        gui_nonfatal(errmsg);
 }
 
 void actually_recv_file(const char *fname, const char *tempfile, int tmpfd)
@@ -80,10 +80,11 @@ void actually_recv_file(const char *fname, const char *tempfile, int tmpfd)
 
 void recv_file(const char *fname)
 {
-	int tmpfd;
+	int tmpfd = -1;
 	char *tempfile;
-	asprintf(&tempfile, "%s.XXXXXX", fname);
-	tmpfd = mkstemp(tempfile);
+	if (asprintf(&tempfile, "%s.XXXXXX", fname) != -1) {
+		tmpfd = mkstemp(tempfile);
+	}
 	if (tmpfd < 0)
 		recv_file_nowrite(fname);
 	else

qubes-rpc/tar2qfile.c

@@ -956,7 +956,7 @@ int main(int argc, char **argv)
 {
 	int i;
 	char *entry;
-	int fd;
+	int fd = -1;
 	int use_stdin = 1;
 	struct filters filters;
 
@@ -1013,6 +1013,10 @@ int main(int argc, char **argv)
 		set_block(0);
 		fd = 0;
 	}
+	if (fd < 0) {
+		fprintf(stderr, "No input file provided\n");
+		exit(1);
+	}
 	tar_file_processor(fd, &filters);
 
 

qubes-rpc/vm-file-editor.c

@@ -214,7 +214,7 @@ main()
 				snprintf(cmd, sizeof(cmd),
 						"HOME=/home/user DISPLAY=:0 /usr/bin/zenity --error --text 'Unable to handle mimetype of the requested file (exit status: %d)!' > /tmp/kdialog.log 2>&1 </dev/null", status);
 #endif
-				system(cmd);
+				status = system(cmd);
 			}
 	}