The following commit has been merged into the x86/sgx branch of tip: Commit-ID: 888d249117876239593fe3039b6ead8ad6849035 Gitweb: https://git.kernel.org/tip/888d249117876239593fe3039b6ead8ad6849035 Author: Jarkko Sakkinen <jarkko@xxxxxxxxxx> AuthorDate: Fri, 13 Nov 2020 00:01:23 +02:00 Committer: Borislav Petkov <bp@xxxxxxx> CommitterDate: Wed, 18 Nov 2020 18:02:49 +01:00 x86/sgx: Add SGX_IOC_ENCLAVE_CREATE Add an ioctl() that performs the ECREATE function of the ENCLS instruction, which creates an SGX Enclave Control Structure (SECS). Although the SECS is an in-memory data structure, it is present in enclave memory and is not directly accessible by software. Co-developed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Tested-by: Jethro Beekman <jethro@xxxxxxxxxxxx> Link: https://lkml.kernel.org/r/20201112220135.165028-13-jarkko@xxxxxxxxxx --- Documentation/userspace-api/ioctl/ioctl-number.rst | 1 +- arch/x86/include/uapi/asm/sgx.h | 25 ++- arch/x86/kernel/cpu/sgx/Makefile | 1 +- arch/x86/kernel/cpu/sgx/driver.c | 12 +- arch/x86/kernel/cpu/sgx/driver.h | 3 +- arch/x86/kernel/cpu/sgx/encl.c | 8 +- arch/x86/kernel/cpu/sgx/encl.h | 7 +- arch/x86/kernel/cpu/sgx/ioctl.c | 123 ++++++++++++- 8 files changed, 180 insertions(+) create mode 100644 arch/x86/include/uapi/asm/sgx.h create mode 100644 arch/x86/kernel/cpu/sgx/ioctl.c diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst index 55a2d9b..a4c75a2 100644 --- a/Documentation/userspace-api/ioctl/ioctl-number.rst +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst @@ -323,6 +323,7 @@ Code Seq# Include File Comments <mailto:tlewis@xxxxxxxxxxxxxx> 0xA3 90-9F linux/dtlk.h 0xA4 00-1F uapi/linux/tee.h Generic TEE subsystem +0xA4 00-1F uapi/asm/sgx.h <mailto:linux-sgx@xxxxxxxxxxxxxxx> 0xAA 00-3F linux/uapi/linux/userfaultfd.h 0xAB 00-1F linux/nbd.h 0xAC 00-1F linux/raw.h diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h new file mode 100644 index 0000000..f31bb17 --- /dev/null +++ b/arch/x86/include/uapi/asm/sgx.h @@ -0,0 +1,25 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* + * Copyright(c) 2016-20 Intel Corporation. + */ +#ifndef _UAPI_ASM_X86_SGX_H +#define _UAPI_ASM_X86_SGX_H + +#include <linux/types.h> +#include <linux/ioctl.h> + +#define SGX_MAGIC 0xA4 + +#define SGX_IOC_ENCLAVE_CREATE \ + _IOW(SGX_MAGIC, 0x00, struct sgx_enclave_create) + +/** + * struct sgx_enclave_create - parameter structure for the + * %SGX_IOC_ENCLAVE_CREATE ioctl + * @src: address for the SECS page data + */ +struct sgx_enclave_create { + __u64 src; +}; + +#endif /* _UAPI_ASM_X86_SGX_H */ diff --git a/arch/x86/kernel/cpu/sgx/Makefile b/arch/x86/kernel/cpu/sgx/Makefile index 3fc4511..91d3dc7 100644 --- a/arch/x86/kernel/cpu/sgx/Makefile +++ b/arch/x86/kernel/cpu/sgx/Makefile @@ -1,4 +1,5 @@ obj-y += \ driver.o \ encl.o \ + ioctl.o \ main.o diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/driver.c index c2810e1..ee947b7 100644 --- a/arch/x86/kernel/cpu/sgx/driver.c +++ b/arch/x86/kernel/cpu/sgx/driver.c @@ -88,10 +88,22 @@ static unsigned long sgx_get_unmapped_area(struct file *file, 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, }; diff --git a/arch/x86/kernel/cpu/sgx/driver.h b/arch/x86/kernel/cpu/sgx/driver.h index cda9c43..a728e8e 100644 --- a/arch/x86/kernel/cpu/sgx/driver.h +++ b/arch/x86/kernel/cpu/sgx/driver.h @@ -9,8 +9,11 @@ #include <linux/rwsem.h> #include <linux/sched.h> #include <linux/workqueue.h> +#include <uapi/asm/sgx.h> #include "sgx.h" +long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg); + int sgx_drv_init(void); #endif /* __ARCH_X86_SGX_DRIVER_H__ */ diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index b9d445d..57eff30 100644 --- a/arch/x86/kernel/cpu/sgx/encl.c +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -46,6 +46,7 @@ static vm_fault_t sgx_vma_fault(struct vm_fault *vmf) struct sgx_encl_page *entry; unsigned long phys_addr; struct sgx_encl *encl; + unsigned long pfn; vm_fault_t ret; encl = vma->vm_private_data; @@ -61,6 +62,13 @@ static vm_fault_t sgx_vma_fault(struct vm_fault *vmf) phys_addr = sgx_get_epc_phys_addr(entry->epc_page); + /* Check if another thread got here first to insert the PTE. */ + if (!follow_pfn(vma, addr, &pfn)) { + mutex_unlock(&encl->lock); + + return VM_FAULT_NOPAGE; + } + ret = vmf_insert_pfn(vma, addr, PFN_DOWN(phys_addr)); if (ret != VM_FAULT_NOPAGE) { mutex_unlock(&encl->lock); diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h index 1df8011..7cc1758 100644 --- a/arch/x86/kernel/cpu/sgx/encl.h +++ b/arch/x86/kernel/cpu/sgx/encl.h @@ -26,9 +26,16 @@ struct sgx_encl_page { struct sgx_encl *encl; }; +enum sgx_encl_flags { + SGX_ENCL_IOCTL = BIT(0), + SGX_ENCL_DEBUG = BIT(1), + SGX_ENCL_CREATED = BIT(2), +}; + struct sgx_encl { unsigned long base; unsigned long size; + unsigned long flags; unsigned int page_cnt; unsigned int secs_child_cnt; struct mutex lock; diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c new file mode 100644 index 0000000..1355490 --- /dev/null +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -0,0 +1,123 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2016-20 Intel Corporation. */ + +#include <asm/mman.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" + +static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs) +{ + struct sgx_epc_page *secs_epc; + struct sgx_pageinfo pginfo; + struct sgx_secinfo secinfo; + unsigned long encl_size; + long ret; + + /* The extra page goes to SECS. */ + encl_size = secs->size + PAGE_SIZE; + + secs_epc = __sgx_alloc_epc_page(); + if (IS_ERR(secs_epc)) + return PTR_ERR(secs_epc); + + 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_DEBUG) + set_bit(SGX_ENCL_DEBUG, &encl->flags); + + encl->secs.encl = encl; + encl->base = secs->base; + encl->size = secs->size; + + /* Set only after completion, as encl->lock has not been taken. */ + set_bit(SGX_ENCL_CREATED, &encl->flags); + + return 0; + +err_out: + sgx_free_epc_page(encl->secs.epc_page); + encl->secs.epc_page = NULL; + + return ret; +} + +/** + * sgx_ioc_enclave_create() - handler for %SGX_IOC_ENCLAVE_CREATE + * @encl: An enclave pointer. + * @arg: The ioctl argument. + * + * Allocate kernel data structures for the enclave and invoke ECREATE. + * + * Return: + * - 0: Success. + * - -EIO: ECREATE failed. + * - -errno: POSIX error. + */ +static long sgx_ioc_enclave_create(struct sgx_encl *encl, void __user *arg) +{ + struct sgx_enclave_create create_arg; + void *secs; + int ret; + + if (test_bit(SGX_ENCL_CREATED, &encl->flags)) + return -EINVAL; + + if (copy_from_user(&create_arg, arg, sizeof(create_arg))) + return -EFAULT; + + secs = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!secs) + return -ENOMEM; + + if (copy_from_user(secs, (void __user *)create_arg.src, PAGE_SIZE)) + ret = -EFAULT; + else + ret = sgx_encl_create(encl, secs); + + kfree(secs); + return ret; +} + +long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) +{ + struct sgx_encl *encl = filep->private_data; + int ret; + + if (test_and_set_bit(SGX_ENCL_IOCTL, &encl->flags)) + return -EBUSY; + + switch (cmd) { + case SGX_IOC_ENCLAVE_CREATE: + ret = sgx_ioc_enclave_create(encl, (void __user *)arg); + break; + default: + ret = -ENOIOCTLCMD; + break; + } + + clear_bit(SGX_ENCL_IOCTL, &encl->flags); + return ret; +}
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