On Thursday, 2020-07-16 at 16:52:51 +03, Jarkko Sakkinen wrote: > Add an ioctl that performs ENCLS[ECREATE], which creates SGX Enclave > Control Structure for the enclave. SECS contains attributes about the > enclave that are used by the hardware and cannot be directly accessed by > software, as SECS resides in the EPC. > > One essential field in SECS is a field that stores the SHA256 of the > measured enclave pages. This field, MRENCLAVE, is initialized by the > ECREATE instruction and updated by every EADD and EEXTEND operation. > Finally, EINIT locks down the value. > > Acked-by: Jethro Beekman <[email protected]> > Tested-by: Jethro Beekman <[email protected]> > Tested-by: Haitao Huang <[email protected]> > Tested-by: Chunyang Hui <[email protected]> > Tested-by: Jordan Hand <[email protected]> > Tested-by: Nathaniel McCallum <[email protected]> > Tested-by: Seth Moore <[email protected]>
Tested-by: Darren Kenny <[email protected]> Reviewed-by: Darren Kenny <[email protected]> > Co-developed-by: Sean Christopherson <[email protected]> > Signed-off-by: Sean Christopherson <[email protected]> > Co-developed-by: Suresh Siddha <[email protected]> > Signed-off-by: Suresh Siddha <[email protected]> > Signed-off-by: Jarkko Sakkinen <[email protected]> > --- > .../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 | 1 + > arch/x86/kernel/cpu/sgx/ioctl.c | 226 ++++++++++++++++++ > 6 files changed, 266 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 59472cd6a11d..35f713e3a267 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:[email protected]> > 0xA3 90-9F linux/dtlk.h > 0xA4 00-1F uapi/linux/tee.h Generic > TEE subsystem > +0xA4 00-1F uapi/asm/sgx.h Intel > SGX subsystem (a legit conflict as TEE and SGX do not co-exist) > 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 000000000000..3787d278e84b > --- /dev/null > +++ b/arch/x86/include/uapi/asm/sgx.h > @@ -0,0 +1,25 @@ > +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) WITH > Linux-syscall-note */ > +/* > + * Copyright(c) 2016-19 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 3fc451120735..91d3dc784a29 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 b52520407f5b..5559bc18de41 100644 > --- a/arch/x86/kernel/cpu/sgx/driver.c > +++ b/arch/x86/kernel/cpu/sgx/driver.c > @@ -118,10 +118,22 @@ 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 f7ce40dedc91..e4063923115b 100644 > --- a/arch/x86/kernel/cpu/sgx/driver.h > +++ b/arch/x86/kernel/cpu/sgx/driver.h > @@ -9,6 +9,7 @@ > #include <linux/rwsem.h> > #include <linux/sched.h> > #include <linux/workqueue.h> > +#include <uapi/asm/sgx.h> > #include "sgx.h" > > #define SGX_EINIT_SPIN_COUNT 20 > diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c > new file mode 100644 > index 000000000000..7981c411b05a > --- /dev/null > +++ b/arch/x86/kernel/cpu/sgx/ioctl.c > @@ -0,0 +1,226 @@ > +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) > +// Copyright(c) 2016-19 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 u32 sgx_calc_ssa_frame_size(u32 miscselect, u64 xfrm) > +{ > + u32 size_max = PAGE_SIZE; > + u32 size; > + int i; > + > + for (i = 2; i < 64; i++) { > + if (!((1 << i) & xfrm)) > + continue; > + > + size = SGX_SSA_GPRS_SIZE + sgx_xsave_size_tbl[i]; > + > + if (miscselect & SGX_MISC_EXINFO) > + size += SGX_SSA_MISC_EXINFO_SIZE; > + > + if (size > size_max) > + size_max = size; > + } > + > + return PFN_UP(size_max); > +} > + > +static int sgx_validate_secs(const struct sgx_secs *secs) > +{ > + u64 max_size = (secs->attributes & SGX_ATTR_MODE64BIT) ? > + sgx_encl_size_max_64 : sgx_encl_size_max_32; > + > + if (secs->size < (2 * PAGE_SIZE) || !is_power_of_2(secs->size)) > + return -EINVAL; > + > + if (secs->base & (secs->size - 1)) > + return -EINVAL; > + > + if (secs->miscselect & sgx_misc_reserved_mask || > + secs->attributes & sgx_attributes_reserved_mask || > + secs->xfrm & sgx_xfrm_reserved_mask) > + return -EINVAL; > + > + if (secs->size >= max_size) > + return -EINVAL; > + > + if (!(secs->xfrm & XFEATURE_MASK_FP) || > + !(secs->xfrm & XFEATURE_MASK_SSE) || > + (((secs->xfrm >> XFEATURE_BNDREGS) & 1) != > + ((secs->xfrm >> XFEATURE_BNDCSR) & 1))) > + return -EINVAL; > + > + if (!secs->ssa_frame_size) > + return -EINVAL; > + > + if (sgx_calc_ssa_frame_size(secs->miscselect, secs->xfrm) > > + secs->ssa_frame_size) > + return -EINVAL; > + > + if (memchr_inv(secs->reserved1, 0, sizeof(secs->reserved1)) || > + memchr_inv(secs->reserved2, 0, sizeof(secs->reserved2)) || > + memchr_inv(secs->reserved3, 0, sizeof(secs->reserved3)) || > + memchr_inv(secs->reserved4, 0, sizeof(secs->reserved4))) > + return -EINVAL; > + > + return 0; > +} > + > +static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs) > +{ > + unsigned long encl_size = secs->size + PAGE_SIZE; > + struct sgx_epc_page *secs_epc; > + struct sgx_pageinfo pginfo; > + struct sgx_secinfo secinfo; > + struct file *backing; > + long ret; > + > + if (sgx_validate_secs(secs)) { > + pr_debug("invalid SECS\n"); > + return -EINVAL; > + } > + > + backing = shmem_file_setup("SGX backing", encl_size + (encl_size >> 5), > + VM_NORESERVE); > + if (IS_ERR(backing)) > + return PTR_ERR(backing); > + > + encl->backing = backing; > + > + secs_epc = __sgx_alloc_epc_page(); > + 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_addr(secs_epc)); > + if (ret) { > + pr_debug("ECREATE returned %ld\n", ret); > + goto err_out; > + } > + > + if (secs->attributes & SGX_ATTR_DEBUG) > + atomic_or(SGX_ENCL_DEBUG, &encl->flags); > + > + encl->secs.encl = encl; > + encl->secs_attributes = secs->attributes; > + encl->allowed_attributes |= SGX_ATTR_ALLOWED_MASK; > + encl->base = secs->base; > + encl->size = secs->size; > + encl->ssaframesize = secs->ssa_frame_size; > + > + /* > + * Set SGX_ENCL_CREATED only after the enclave is fully prepped. This > + * allows setting and checking enclave creation without having to take > + * encl->lock. > + */ > + atomic_or(SGX_ENCL_CREATED, &encl->flags); > + > + return 0; > + > +err_out: > + sgx_free_epc_page(encl->secs.epc_page); > + encl->secs.epc_page = NULL; > + > +err_out_backing: > + fput(encl->backing); > + encl->backing = NULL; > + > + return ret; > +} > + > +/** > + * sgx_ioc_enclave_create - handler for %SGX_IOC_ENCLAVE_CREATE > + * @filep: open file to /dev/sgx > + * @arg: userspace pointer to a struct sgx_enclave_create instance > + * > + * Allocate kernel data structures for a new enclave and execute ECREATE > after > + * verifying the correctness of the provided SECS. > + * > + * Note, enforcement of restricted and disallowed attributes is deferred > until > + * sgx_ioc_enclave_init(), only the architectural correctness of the SECS is > + * checked by sgx_ioc_enclave_create(). > + * > + * Return: > + * 0 on success, > + * -errno otherwise > + */ > +static long sgx_ioc_enclave_create(struct sgx_encl *encl, void __user *arg) > +{ > + struct sgx_enclave_create ecreate; > + struct page *secs_page; > + struct sgx_secs *secs; > + int ret; > + > + if (atomic_read(&encl->flags) & SGX_ENCL_CREATED) > + return -EINVAL; > + > + if (copy_from_user(&ecreate, arg, sizeof(ecreate))) > + return -EFAULT; > + > + secs_page = alloc_page(GFP_KERNEL); > + if (!secs_page) > + return -ENOMEM; > + > + secs = kmap(secs_page); > + if (copy_from_user(secs, (void __user *)ecreate.src, sizeof(*secs))) { > + ret = -EFAULT; > + goto out; > + } > + > + ret = sgx_encl_create(encl, secs); > + > +out: > + kunmap(secs_page); > + __free_page(secs_page); > + return ret; > +} > + > +long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) > +{ > + struct sgx_encl *encl = filep->private_data; > + int ret, encl_flags; > + > + encl_flags = atomic_fetch_or(SGX_ENCL_IOCTL, &encl->flags); > + if (encl_flags & SGX_ENCL_IOCTL) > + return -EBUSY; > + > + if (encl_flags & SGX_ENCL_DEAD) { > + ret = -EFAULT; > + goto out; > + } > + > + switch (cmd) { > + case SGX_IOC_ENCLAVE_CREATE: > + ret = sgx_ioc_enclave_create(encl, (void __user *)arg); > + break; > + default: > + ret = -ENOIOCTLCMD; > + break; > + } > + > +out: > + atomic_andnot(SGX_ENCL_IOCTL, &encl->flags); > + return ret; > +} > -- > 2.25.1
