[PATCH] Create call_usermodehelper_pipe() (e239ca54) · Commits · 戴 / test

include/linux/kmod.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -47,4 +47,8 @@ call_usermodehelper(char path, char argv, char *envp, int wait)

		extern void usermodehelper_init(void);

		struct file;
		extern int call_usermodehelper_pipe(char path, char argv[], char *envp[],
		struct file **filp);

		#endif /* __LINUX_KMOD_H__ */

kernel/kmod.c

+54 −1

Original line number	Diff line number	Diff line
		@@ -122,6 +122,7 @@ struct subprocess_info {
		struct key *ring;
		int wait;
		int retval;
		struct file *stdin;
		};

		/*
		@@ -145,6 +146,20 @@ static int ____call_usermodehelper(void *data)

		key_put(old_session);

		/* Install input pipe when needed */
		if (sub_info->stdin) {
		struct files_struct *f = current->files;
		struct fdtable *fdt;
		/* no races because files should be private here */
		sys_close(0);
		fd_install(0, sub_info->stdin);
		spin_lock(&f->file_lock);
		fdt = files_fdtable(f);
		FD_SET(0, fdt->open_fds);
		FD_CLR(0, fdt->close_on_exec);
		spin_unlock(&f->file_lock);
		}

		/* We can run anywhere, unlike our parent keventd(). */
		set_cpus_allowed(current, CPU_MASK_ALL);

		@@ -268,6 +283,44 @@ int call_usermodehelper_keys(char path, char argv, char *envp,
		}
		EXPORT_SYMBOL(call_usermodehelper_keys);

		int call_usermodehelper_pipe(char path, char argv, char *envp,
		struct file **filp)
		{
		DECLARE_COMPLETION(done);
		struct subprocess_info sub_info = {
		.complete = &done,
		.path = path,
		.argv = argv,
		.envp = envp,
		.retval = 0,
		};
		struct file *f;
		DECLARE_WORK(work, __call_usermodehelper, &sub_info);

		if (!khelper_wq)
		return -EBUSY;

		if (path[0] == '\0')
		return 0;

		f = create_write_pipe();
		if (!f)
		return -ENOMEM;
		*filp = f;

		f = create_read_pipe(f);
		if (!f) {
		free_write_pipe(*filp);
		return -ENOMEM;
		}
		sub_info.stdin = f;

		queue_work(khelper_wq, &work);
		wait_for_completion(&done);
		return sub_info.retval;
		}
		EXPORT_SYMBOL(call_usermodehelper_pipe);

		void __init usermodehelper_init(void)
		{
		khelper_wq = create_singlethread_workqueue("khelper");

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