nuttx/tasks.cpp: Add px4_exec to tasks.cpp (move it from cdcacm check)

Add a generic px4 exec function to spawn processes either via:
- builtin list if configuration does not use file apps
- posix_spawn if configuration uses file apps

platforms/common/include/px4_platform_common/tasks.h

@@ -187,4 +187,10 @@ __EXPORT int px4_prctl(int option, const char *arg2, px4_task_t pid);
 /** return the name of the current task */
 __EXPORT const char *px4_get_taskname(void);
 
+/** Execute a named task from filesystem */
+__EXPORT int px4_exec(const char *appname,
+		      char *const *argv,
+		      const char *redirfile,
+		      int oflags);
+
 __END_DECLS

platforms/nuttx/src/px4/common/cdc_acm_check.cpp

@@ -40,20 +40,16 @@ __BEGIN_DECLS
 #include <syslog.h>
 #include <nuttx/config.h>
 #include <nuttx/wqueue.h>
-#include <builtin/builtin.h>
 
 #include <termios.h>
 #include <sys/ioctl.h>
 #include <sys/boardctl.h>
 #include <fcntl.h>
-#include <libgen.h>
-#include <spawn.h>
-
-#include <stdio.h>
 
 __END_DECLS
 
 #include <px4_platform_common/shutdown.h>
+#include <px4_platform_common/tasks.h>
 
 #include <uORB/Subscription.hpp>
 #include <uORB/topics/actuator_armed.h>
@@ -118,49 +114,6 @@ static int serial_disconnect(void)
 	return 0;
 }
 
-static int exec_wrap(const char *appname, char *const *argv, const char *redirfile, int oflags)
-{
-#ifdef CONFIG_BUILTIN
-	return exec_builtin(appname, argv, redirfile, oflags);
-#else
-	char path[CONFIG_PATH_MAX];
-	posix_spawn_file_actions_t file_actions;
-	posix_spawnattr_t attr;
-	pid_t pid;
-	int ret;
-
-	/* We launch processes from the /bin/ folder only */
-
-	sprintf(path, "/bin/");
-	strcat(path, basename((char *)appname));
-
-	/* Return ERROR if spawn fails */
-
-	pid = (pid_t)ERROR;
-
-	/* Initialize the attributes file actions structure */
-
-	ret = posix_spawn_file_actions_init(&file_actions);
-
-	if (ret != 0) {
-		goto errout;
-	}
-
-	ret = posix_spawnattr_init(&attr);
-
-	if (ret != 0) {
-		goto errout;
-	}
-
-	ret = posix_spawnp(&pid, path, &file_actions, &attr, argv, environ);
-
-errout:
-	posix_spawn_file_actions_destroy(&file_actions);
-	posix_spawnattr_destroy(&attr);
-
-	return (int)pid;
-#endif
-}
 
 static void mavlink_usb_check(void *arg)
 {
@@ -381,7 +334,7 @@ static void mavlink_usb_check(void *arg)
 								else if (launch_passthru) {
 									sched_lock();
 									exec_argv = (char **)gps_argv;
-									exec_wrap(exec_argv[0], exec_argv, nullptr, 0);
+									px4_exec(exec_argv[0], exec_argv, nullptr, 0);
 									sched_unlock();
 									exec_argv = (char **)passthru_argv;
 								}
@@ -390,7 +343,7 @@ static void mavlink_usb_check(void *arg)
 
 								sched_lock();
 
-								if (exec_wrap(exec_argv[0], exec_argv, nullptr, 0) > 0) {
+								if (px4_exec(exec_argv[0], exec_argv, nullptr, 0) > 0) {
 									usb_auto_start_state = UsbAutoStartState::connected;
 
 								} else {
@@ -419,7 +372,7 @@ static void mavlink_usb_check(void *arg)
 			if (!vbus_present && !vbus_present_prev) {
 				sched_lock();
 				static const char *stop_argv[] {"mavlink", "stop", "-d", USB_DEVICE_PATH, NULL};
-				exec_wrap(stop_argv[0], (char **)stop_argv, NULL, 0);
+				px4_exec(stop_argv[0], (char **)stop_argv, NULL, 0);
 				sched_unlock();
 
 				usb_auto_start_state = UsbAutoStartState::disconnecting;
@@ -442,7 +395,6 @@ static void mavlink_usb_check(void *arg)
 	}
 }
 
-
 void cdcacm_init(void)
 {
 #ifdef CONFIG_BUILD_KERNEL

platforms/nuttx/src/px4/common/tasks.cpp

@@ -43,6 +43,7 @@
 
 #include <px4_platform/task.h>
 
+#include <nuttx/config.h>
 #include <nuttx/board.h>
 #include <nuttx/kthread.h>
 
@@ -56,6 +57,10 @@
 #include <sched.h>
 #include <errno.h>
 #include <stdbool.h>
+#include <spawn.h>
+#include <libgen.h>
+
+#include <builtin/builtin.h>
 
 int px4_task_spawn_cmd(const char *name, int scheduler, int priority, int stack_size, main_t entry, char *const argv[])
 {
@@ -101,3 +106,68 @@ const char *px4_get_taskname(void)
 {
 	return getprogname();
 }
+
+int px4_exec(const char *appname, char *const *argv, const char *redirfile, int oflags)
+{
+#ifdef CONFIG_BUILTIN
+	return exec_builtin(appname, argv, redirfile, oflags);
+#else
+	char path[CONFIG_PATH_MAX];
+	posix_spawn_file_actions_t file_actions;
+	posix_spawnattr_t attr;
+	pid_t pid;
+	int ret;
+
+	/* We launch processes from the /bin/ folder only */
+
+	sprintf(path, "/bin/");
+	strcat(path, basename((char *)appname));
+
+	/* Initialize the attributes */
+
+	ret = posix_spawnattr_init(&attr);
+
+	if (ret != 0) {
+		goto errout;
+	}
+
+	/* Initialize the file actions structure */
+
+	ret = posix_spawn_file_actions_init(&file_actions);
+
+	if (ret != 0) {
+		goto errout_with_attrs;
+	}
+
+	/* Redirect output if instructed to do so */
+
+	if (redirfile) {
+		ret = posix_spawn_file_actions_addopen(&file_actions, 1, redirfile, oflags, 0644);
+
+		if (ret != 0) {
+			goto errout_with_actions;
+		}
+	}
+
+	/* Attempt to load the executable */
+
+	ret = posix_spawnp(&pid, path, &file_actions, &attr, argv, environ);
+
+	if (ret != 0) {
+		goto errout_with_actions;
+	}
+
+	posix_spawn_file_actions_destroy(&file_actions);
+	posix_spawnattr_destroy(&attr);
+	return pid;
+
+errout_with_actions:
+	posix_spawn_file_actions_destroy(&file_actions);
+
+errout_with_attrs:
+	posix_spawnattr_destroy(&attr);
+
+errout:
+	return ERROR;
+#endif
+}