xen: add "capabilities" file (818fd206) · Commits · 戴 / test

The xenfs capabilities file allows usermode to determine what capabilities the domain has. The only one at present is "control_d" in a privileged domain. Signed-off-by:

Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

drivers/xen/xenfs/super.c

+18 −1

Original line number	Diff line number	Diff line
		@@ -20,10 +20,27 @@
		MODULE_DESCRIPTION("Xen filesystem");
		MODULE_LICENSE("GPL");

		static ssize_t capabilities_read(struct file file, char __user buf,
		size_t size, loff_t *off)
		{
		char *tmp = "";

		if (xen_initial_domain())
		tmp = "control_d\n";

		return simple_read_from_buffer(buf, size, off, tmp, strlen(tmp));
		}

		static const struct file_operations capabilities_file_ops = {
		.read = capabilities_read,
		};

		static int xenfs_fill_super(struct super_block sb, void data, int silent)
		{
		static struct tree_descr xenfs_files[] = {
		[2] = {"xenbus", &xenbus_file_ops, S_IRUSR\|S_IWUSR},
		[1] = {},
		{ "xenbus", &xenbus_file_ops, S_IRUSR\|S_IWUSR },
		{ "capabilities", &capabilities_file_ops, S_IRUGO },
		{""},
		};

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