Merge "fs/proc: re-factor proc_pid_cmdline_read() a bit" (8a86f801) · Commits · e / devices / android_kernel_xiaomi_nabu

fs/proc/base.c

+39 −25

Original line number	Diff line number	Diff line
		@@ -208,11 +208,9 @@ static int proc_root_link(struct dentry dentry, struct path path)
		return result;
		}

		static ssize_t proc_pid_cmdline_read(struct file file, char __user buf,
		static ssize_t get_mm_cmdline(struct mm_struct mm, char __user buf,
		size_t _count, loff_t *pos)
		{
		struct task_struct *tsk;
		struct mm_struct *mm;
		char *page;
		unsigned long count = _count;
		unsigned long arg_start, arg_end, env_start, env_end;
		@@ -221,26 +219,13 @@ static ssize_t proc_pid_cmdline_read(struct file file, char __user buf,
		char c;
		ssize_t rv;

		BUG_ON(*pos < 0);

		tsk = get_proc_task(file_inode(file));
		if (!tsk)
		return -ESRCH;
		mm = get_task_mm(tsk);
		put_task_struct(tsk);
		if (!mm)
		return 0;
		/* Check if process spawned far enough to have cmdline. */
		if (!mm->env_end) {
		rv = 0;
		goto out_mmput;
		}
		if (!mm->env_end)
		return 0;

		page = (char *)__get_free_page(GFP_KERNEL);
		if (!page) {
		rv = -ENOMEM;
		goto out_mmput;
		}
		if (!page)
		return -ENOMEM;

		down_read(&mm->mmap_sem);
		arg_start = mm->arg_start;
		@@ -368,13 +353,42 @@ static ssize_t proc_pid_cmdline_read(struct file file, char __user buf,

		out_free_page:
		free_page((unsigned long)page);
		out_mmput:
		mmput(mm);
		if (rv > 0)
		*pos += rv;
		return rv;
		}

		static ssize_t get_task_cmdline(struct task_struct tsk, char __user buf,
		size_t count, loff_t *pos)
		{
		struct mm_struct *mm;
		ssize_t ret;

		mm = get_task_mm(tsk);
		if (!mm)
		return 0;

		ret = get_mm_cmdline(mm, buf, count, pos);
		mmput(mm);
		return ret;
		}

		static ssize_t proc_pid_cmdline_read(struct file file, char __user buf,
		size_t count, loff_t *pos)
		{
		struct task_struct *tsk;
		ssize_t ret;

		BUG_ON(*pos < 0);

		tsk = get_proc_task(file_inode(file));
		if (!tsk)
		return -ESRCH;
		ret = get_task_cmdline(tsk, buf, count, pos);
		put_task_struct(tsk);
		if (ret > 0)
		*pos += ret;
		return ret;
		}

		static const struct file_operations proc_pid_cmdline_ops = {
		.read = proc_pid_cmdline_read,
		.llseek = generic_file_llseek,