diff options
Diffstat (limited to 'arch/x86/kernel/cpu/sgx/driver.c')
| -rw-r--r-- | arch/x86/kernel/cpu/sgx/driver.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/driver.c new file mode 100644 index 000000000..aa9b8b868 --- /dev/null +++ b/arch/x86/kernel/cpu/sgx/driver.c @@ -0,0 +1,180 @@ +// 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)) + return -ENODEV; + + cpuid_count(SGX_CPUID, 0, &eax, &ebx, &ecx, &edx); + + if (!(eax & 1)) { + pr_err("SGX disabled: SGX1 instruction support not available.\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) + return ret; + + return 0; +} |