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// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2016-20 Intel Corporation. */
#include <linux/acpi.h>
#include <linux/miscdevice.h>
#include <linux/mman.h>
#include <linux/security.h>
#include <linux/suspend.h>
#include <asm/traps.h>
#include "driver.h"
#include "encl.h"
u64 sgx_attributes_reserved_mask;
u64 sgx_xfrm_reserved_mask = ~0x3;
u32 sgx_misc_reserved_mask;
static int sgx_open(struct inode *inode, struct file *file)
{
struct sgx_encl *encl;
int ret;
encl = kzalloc(sizeof(*encl), GFP_KERNEL);
if (!encl)
return -ENOMEM;
kref_init(&encl->refcount);
xa_init(&encl->page_array);
mutex_init(&encl->lock);
INIT_LIST_HEAD(&encl->va_pages);
INIT_LIST_HEAD(&encl->mm_list);
spin_lock_init(&encl->mm_lock);
ret = init_srcu_struct(&encl->srcu);
if (ret) {
kfree(encl);
return ret;
}
file->private_data = encl;
return 0;
}
static int sgx_release(struct inode *inode, struct file *file)
{
struct sgx_encl *encl = file->private_data;
struct sgx_encl_mm *encl_mm;
/*
* Drain the remaining mm_list entries. At this point the list contains
* entries for processes, which have closed the enclave file but have
* not exited yet. The processes, which have exited, are gone from the
* list by sgx_mmu_notifier_release().
*/
for ( ; ; ) {
spin_lock(&encl->mm_lock);
if (list_empty(&encl->mm_list)) {
encl_mm = NULL;
} else {
encl_mm = list_first_entry(&encl->mm_list,
struct sgx_encl_mm, list);
list_del_rcu(&encl_mm->list);
}
spin_unlock(&encl->mm_lock);
/* The enclave is no longer mapped by any mm. */
if (!encl_mm)
break;
synchronize_srcu(&encl->srcu);
mmu_notifier_unregister(&encl_mm->mmu_notifier, encl_mm->mm);
kfree(encl_mm);
/* 'encl_mm' is gone, put encl_mm->encl reference: */
kref_put(&encl->refcount, sgx_encl_release);
}
kref_put(&encl->refcount, sgx_encl_release);
return 0;
}
static int sgx_mmap(struct file *file, struct vm_area_struct *vma)
{
struct sgx_encl *encl = file->private_data;
int ret;
ret = sgx_encl_may_map(encl, vma->vm_start, vma->vm_end, vma->vm_flags);
if (ret)
return ret;
ret = sgx_encl_mm_add(encl, vma->vm_mm);
if (ret)
return ret;
vma->vm_ops = &sgx_vm_ops;
vma->vm_flags |= VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP | VM_IO;
vma->vm_private_data = encl;
return 0;
}
static unsigned long sgx_get_unmapped_area(struct file *file,
unsigned long addr,
unsigned long len,
unsigned long pgoff,
unsigned long flags)
{
if ((flags & MAP_TYPE) == MAP_PRIVATE)
return -EINVAL;
if (flags & MAP_FIXED)
return addr;
return current->mm->get_unmapped_area(file, addr, len, pgoff, flags);
}
#ifdef CONFIG_COMPAT
static long sgx_compat_ioctl(struct file *filep, unsigned int cmd,
unsigned long arg)
{
return sgx_ioctl(filep, cmd, arg);
}
#endif
static const struct file_operations sgx_encl_fops = {
.owner = THIS_MODULE,
.open = sgx_open,
.release = sgx_release,
.unlocked_ioctl = sgx_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = sgx_compat_ioctl,
#endif
.mmap = sgx_mmap,
.get_unmapped_area = sgx_get_unmapped_area,
};
static struct miscdevice sgx_dev_enclave = {
.minor = MISC_DYNAMIC_MINOR,
.name = "sgx_enclave",
.nodename = "sgx_enclave",
.fops = &sgx_encl_fops,
};
int __init sgx_drv_init(void)
{
unsigned int eax, ebx, ecx, edx;
u64 attr_mask;
u64 xfrm_mask;
int ret;
if (!cpu_feature_enabled(X86_FEATURE_SGX_LC)) {
pr_info("SGX disabled: SGX launch control CPU feature is not available, /dev/sgx_enclave disabled.\n");
return -ENODEV;
}
cpuid_count(SGX_CPUID, 0, &eax, &ebx, &ecx, &edx);
if (!(eax & 1)) {
pr_info("SGX disabled: SGX1 instruction support not available, /dev/sgx_enclave disabled.\n");
return -ENODEV;
}
sgx_misc_reserved_mask = ~ebx | SGX_MISC_RESERVED_MASK;
cpuid_count(SGX_CPUID, 1, &eax, &ebx, &ecx, &edx);
attr_mask = (((u64)ebx) << 32) + (u64)eax;
sgx_attributes_reserved_mask = ~attr_mask | SGX_ATTR_RESERVED_MASK;
if (cpu_feature_enabled(X86_FEATURE_OSXSAVE)) {
xfrm_mask = (((u64)edx) << 32) + (u64)ecx;
sgx_xfrm_reserved_mask = ~xfrm_mask;
}
ret = misc_register(&sgx_dev_enclave);
if (ret) {
pr_info("SGX disabled: Unable to register the /dev/sgx_enclave driver (%d).\n", ret);
return ret;
}
return 0;
}
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