path: root/arch/x86/kernel/cpu/sgx/ioctl.c

// SPDX-License-Identifier: GPL-2.0
/*  Copyright(c) 2016-20 Intel Corporation. */

#include <asm/mman.h>
#include <asm/sgx.h>
#include <linux/mman.h>
#include <linux/delay.h>
#include <linux/file.h>
#include <linux/hashtable.h>
#include <linux/highmem.h>
#include <linux/ratelimit.h>
#include <linux/sched/signal.h>
#include <linux/shmem_fs.h>
#include <linux/slab.h>
#include <linux/suspend.h>
#include "driver.h"
#include "encl.h"
#include "encls.h"

struct sgx_va_page *sgx_encl_grow(struct sgx_encl *encl, bool reclaim)
{
	struct sgx_va_page *va_page = NULL;
	void *err;

	BUILD_BUG_ON(SGX_VA_SLOT_COUNT !=
		(SGX_ENCL_PAGE_VA_OFFSET_MASK >> 3) + 1);

	if (!(encl->page_cnt % SGX_VA_SLOT_COUNT)) {
		va_page = kzalloc(sizeof(*va_page), GFP_KERNEL);
		if (!va_page)
			return ERR_PTR(-ENOMEM);

		va_page->epc_page = sgx_alloc_va_page(reclaim);
		if (IS_ERR(va_page->epc_page)) {
			err = ERR_CAST(va_page->epc_page);
			kfree(va_page);
			return err;
		}

		WARN_ON_ONCE(encl->page_cnt % SGX_VA_SLOT_COUNT);
	}
	encl->page_cnt++;
	return va_page;
}

void sgx_encl_shrink(struct sgx_encl *encl, struct sgx_va_page *va_page)
{
	encl->page_cnt--;

	if (va_page) {
		sgx_encl_free_epc_page(va_page->epc_page);
		list_del(&va_page->list);
		kfree(va_page);
	}
}

static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs)
{
	struct sgx_epc_page *secs_epc;
	struct sgx_va_page *va_page;
	struct sgx_pageinfo pginfo;
	struct sgx_secinfo secinfo;
	unsigned long encl_size;
	struct file *backing;
	long ret;

	va_page = sgx_encl_grow(encl, true);
	if (IS_ERR(va_page))
		return PTR_ERR(va_page);
	else if (va_page)
		list_add(&va_page->list, &encl->va_pages);
	/* else the tail page of the VA page list had free slots. */

	/* The extra page goes to SECS. */
	encl_size = secs->size + PAGE_SIZE;

	backing = shmem_file_setup("SGX backing", encl_size + (encl_size >> 5),
				   VM_NORESERVE);
	if (IS_ERR(backing)) {
		ret = PTR_ERR(backing);
		goto err_out_shrink;
	}

	encl->backing = backing;

	secs_epc = sgx_alloc_epc_page(&encl->secs, true);
	if (IS_ERR(secs_epc)) {
		ret = PTR_ERR(secs_epc);
		goto err_out_backing;
	}

	encl->secs.epc_page = secs_epc;

	pginfo.addr = 0;
	pginfo.contents = (unsigned long)secs;
	pginfo.metadata = (unsigned long)&secinfo;
	pginfo.secs = 0;
	memset(&secinfo, 0, sizeof(secinfo));

	ret = __ecreate((void *)&pginfo, sgx_get_epc_virt_addr(secs_epc));
	if (ret) {
		ret = -EIO;
		goto err_out;
	}

	if (secs->attributes & SGX_ATTR_DEB