From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org, linux-sgx@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org, linux-mm@kvack.org,
Andrew Morton <akpm@linux-foundation.org>,
Matthew Wilcox <willy@infradead.org>,
Jethro Beekman <jethro@fortanix.com>,
Haitao Huang <haitao.huang@linux.intel.com>,
Chunyang Hui <sanqian.hcy@antfin.com>,
Jordan Hand <jorhand@linux.microsoft.com>,
Nathaniel McCallum <npmccallum@redhat.com>,
Seth Moore <sethmo@google.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Suresh Siddha <suresh.b.siddha@intel.com>,
andriy.shevchenko@linux.intel.com, asapek@google.com,
cedric.xing@intel.com, chenalexchen@google.com,
conradparker@google.com, cyhanish@google.com,
dave.hansen@intel.com, haitao.huang@intel.com,
josh@joshtriplett.org, kai.huang@intel.com, kai.svahn@intel.com,
kmoy@google.com, ludloff@google.com, luto@kernel.org,
nhorman@redhat.com, puiterwijk@redhat.com, rientjes@google.com,
tglx@linutronix.de, yaozhangx@google.com
Subject: Re: [PATCH v36 11/24] x86/sgx: Add SGX enclave driver
Date: Wed, 26 Aug 2020 16:46:06 +0300 [thread overview]
Message-ID: <20200826134606.GC6532@linux.intel.com> (raw)
In-Reply-To: <20200825164412.GF12107@zn.tnic>
On Tue, Aug 25, 2020 at 06:44:12PM +0200, Borislav Petkov wrote:
> On Thu, Jul 16, 2020 at 04:52:50PM +0300, Jarkko Sakkinen wrote:
>
> Just minor things below - I'm not even going to pretend I fully
> understand what's going on but FWICT, it looks non-threateningly ok to
> me.
>
> > diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/driver.c
> > new file mode 100644
> > index 000000000000..b52520407f5b
> > --- /dev/null
> > +++ b/arch/x86/kernel/cpu/sgx/driver.c
> > @@ -0,0 +1,177 @@
> > +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
> > +// Copyright(c) 2016-18 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"
> > +
> > +MODULE_DESCRIPTION("Intel SGX Enclave Driver");
> > +MODULE_AUTHOR("Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>");
> > +MODULE_LICENSE("Dual BSD/GPL");
>
> That boilerplate stuff usually goes to the end of the file.
These all are cruft from the times when we still had a kernel module.
I.e. I'll just remove them.
>
> ...
>
> > +static struct sgx_encl_page *sgx_encl_load_page(struct sgx_encl *encl,
> > + unsigned long addr)
> > +{
> > + struct sgx_encl_page *entry;
> > + unsigned int flags;
> > +
> > + /* If process was forked, VMA is still there but vm_private_data is set
> > + * to NULL.
> > + */
> > + if (!encl)
> > + return ERR_PTR(-EFAULT);
> > +
> > + flags = atomic_read(&encl->flags);
> > +
>
> ^ Superfluous newline.
>
> > + if ((flags & SGX_ENCL_DEAD) || !(flags & SGX_ENCL_INITIALIZED))
> > + return ERR_PTR(-EFAULT);
> > +
> > + entry = xa_load(&encl->page_array, PFN_DOWN(addr));
> > + if (!entry)
> > + return ERR_PTR(-EFAULT);
> > +
> > + /* Page is already resident in the EPC. */
> > + if (entry->epc_page)
> > + return entry;
> > +
> > + return ERR_PTR(-EFAULT);
> > +}
> > +
> > +static void sgx_mmu_notifier_release(struct mmu_notifier *mn,
> > + struct mm_struct *mm)
> > +{
> > + struct sgx_encl_mm *encl_mm =
> > + container_of(mn, struct sgx_encl_mm, mmu_notifier);
>
> Just let it stick out.
>
> > + struct sgx_encl_mm *tmp = NULL;
> > +
> > + /*
> > + * The enclave itself can remove encl_mm. Note, objects can't be moved
> > + * off an RCU protected list, but deletion is ok.
> > + */
> > + spin_lock(&encl_mm->encl->mm_lock);
> > + list_for_each_entry(tmp, &encl_mm->encl->mm_list, list) {
> > + if (tmp == encl_mm) {
> > + list_del_rcu(&encl_mm->list);
> > + break;
> > + }
> > + }
> > + spin_unlock(&encl_mm->encl->mm_lock);
> > +
> > + if (tmp == encl_mm) {
> > + synchronize_srcu(&encl_mm->encl->srcu);
> > + mmu_notifier_put(mn);
> > + }
> > +}
> > +
> > +static void sgx_mmu_notifier_free(struct mmu_notifier *mn)
> > +{
> > + struct sgx_encl_mm *encl_mm =
> > + container_of(mn, struct sgx_encl_mm, mmu_notifier);
>
> Ditto.
>
> ...
>
> > +/**
> > + * sgx_encl_may_map() - Check if a requested VMA mapping is allowed
> > + * @encl: an enclave
> > + * @start: lower bound of the address range, inclusive
> > + * @end: upper bound of the address range, exclusive
> > + * @vm_prot_bits: requested protections of the address range
> > + *
> > + * Iterate through the enclave pages contained within [@start, @end) to verify
> > + * the permissions requested by @vm_prot_bits do not exceed that of any enclave
> > + * page to be mapped.
> > + *
> > + * Return:
> > + * 0 on success,
> > + * -EACCES if VMA permissions exceed enclave page permissions
> > + */
> > +int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,
> > + unsigned long end, unsigned long vm_flags)
> > +{
> > + unsigned long vm_prot_bits = vm_flags & (VM_READ | VM_WRITE | VM_EXEC);
> > + unsigned long idx_start = PFN_DOWN(start);
> > + unsigned long idx_end = PFN_DOWN(end - 1);
> > + struct sgx_encl_page *page;
> > + XA_STATE(xas, &encl->page_array, idx_start);
> > +
> > + /*
> > + * Disallow RIE tasks as their VMA permissions might conflict with the
>
> "RIE", hmm what is that?
>
> /me looks at the test
>
> Aaah, READ_IMPLIES_EXEC. Is "RIE" some widely accepted acronym I'm not
> aware of?
I think it was used in some email discussions related to this piece of
code but I'm happy to write it as READ_IMPLIES_EXEC :-)
>
> > + * enclave page permissions.
> > + */
> > + if (!!(current->personality & READ_IMPLIES_EXEC))
>
> The "!!" is not really needed - you're in boolean context.
>
> ...
>
> --
> Regards/Gruss,
> Boris.
>
> https://people.kernel.org/tglx/notes-about-netiquette
Thanks for the remarks.
/Jarkko
next prev parent reply other threads:[~2020-08-26 13:46 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-16 13:52 [PATCH v36 00/24] Intel SGX foundations Jarkko Sakkinen
2020-07-16 13:52 ` [PATCH v36 01/24] x86/cpufeatures: x86/msr: Add Intel SGX hardware bits Jarkko Sakkinen
2020-08-06 13:13 ` Darren Kenny
2020-07-16 13:52 ` [PATCH v36 02/24] x86/cpufeatures: x86/msr: Add Intel SGX Launch Control " Jarkko Sakkinen
2020-08-06 13:14 ` Darren Kenny
2020-07-16 13:52 ` [PATCH v36 03/24] x86/mm: x86/sgx: Signal SIGSEGV with PF_SGX Jarkko Sakkinen
2020-08-06 13:16 ` Darren Kenny
2020-08-20 15:31 ` Borislav Petkov
2020-08-21 17:35 ` Jarkko Sakkinen
2020-07-16 13:52 ` [PATCH v36 04/24] x86/sgx: Add SGX microarchitectural data structures Jarkko Sakkinen
2020-08-06 13:14 ` Darren Kenny
2020-07-16 13:52 ` [PATCH v36 05/24] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen
2020-08-07 9:37 ` Darren Kenny
2020-07-16 13:52 ` [PATCH v36 06/24] x86/cpu/intel: Detect SGX support Jarkko Sakkinen
2020-08-06 13:17 ` Darren Kenny
2020-07-16 13:52 ` [PATCH v36 07/24] x86/cpu/intel: Add nosgx kernel parameter Jarkko Sakkinen
2020-08-06 13:18 ` Darren Kenny
2020-07-16 13:52 ` [PATCH v36 08/24] x86/sgx: Initialize metadata for Enclave Page Cache (EPC) sections Jarkko Sakkinen
2020-08-06 13:27 ` Darren Kenny
2020-07-16 13:52 ` [PATCH v36 09/24] x86/sgx: Add __sgx_alloc_epc_page() and sgx_free_epc_page() Jarkko Sakkinen
2020-08-06 13:29 ` Darren Kenny
2020-07-16 13:52 ` [PATCH v36 10/24] mm: Add vm_ops->mprotect() Jarkko Sakkinen
2020-08-06 13:35 ` Darren Kenny
2020-07-16 13:52 ` [PATCH v36 11/24] x86/sgx: Add SGX enclave driver Jarkko Sakkinen
2020-08-06 13:59 ` Darren Kenny
2020-08-25 16:44 ` Borislav Petkov
2020-08-26 13:46 ` Jarkko Sakkinen [this message]
2020-07-16 13:52 ` [PATCH v36 12/24] x86/sgx: Add SGX_IOC_ENCLAVE_CREATE Jarkko Sakkinen
2020-08-06 15:40 ` Darren Kenny
2020-08-26 14:52 ` Borislav Petkov
2020-08-27 13:24 ` Jarkko Sakkinen
2020-08-27 16:15 ` Borislav Petkov
2020-08-28 23:39 ` Jarkko Sakkinen
2020-08-29 0:21 ` Jarkko Sakkinen
2020-09-01 16:41 ` Haitao Huang
2020-09-04 11:55 ` Jarkko Sakkinen
2020-07-16 13:52 ` [PATCH v36 13/24] x86/sgx: Add SGX_IOC_ENCLAVE_ADD_PAGES Jarkko Sakkinen
2020-08-06 16:29 ` Darren Kenny
2020-07-16 13:52 ` [PATCH v36 14/24] x86/sgx: Add SGX_IOC_ENCLAVE_INIT Jarkko Sakkinen
2020-08-06 16:40 ` Darren Kenny
2020-07-16 13:52 ` [PATCH v36 15/24] x86/sgx: Allow a limited use of ATTRIBUTE.PROVISIONKEY for attestation Jarkko Sakkinen
2020-08-06 17:00 ` Darren Kenny
2020-08-18 13:30 ` Jarkko Sakkinen
2020-07-16 13:52 ` [PATCH v36 16/24] x86/sgx: Add a page reclaimer Jarkko Sakkinen
2020-07-16 13:52 ` [PATCH v36 17/24] x86/sgx: ptrace() support for the SGX driver Jarkko Sakkinen
2020-07-16 13:52 ` [PATCH v36 18/24] x86/vdso: Add support for exception fixup in vDSO functions Jarkko Sakkinen
2020-07-16 13:52 ` [PATCH v36 19/24] x86/fault: Add helper function to sanitize error code Jarkko Sakkinen
2020-07-16 13:52 ` [PATCH v36 20/24] x86/traps: Attempt to fixup exceptions in vDSO before signaling Jarkko Sakkinen
2020-07-16 13:53 ` [PATCH v36 21/24] x86/vdso: Implement a vDSO for Intel SGX enclave call Jarkko Sakkinen
2020-08-06 14:55 ` Nathaniel McCallum
2020-08-10 22:23 ` Sean Christopherson
2020-08-11 7:16 ` Jethro Beekman
2020-08-11 14:54 ` Sean Christopherson
2020-08-18 14:52 ` Jarkko Sakkinen
2020-08-18 15:06 ` Jarkko Sakkinen
2020-08-18 15:15 ` Nathaniel McCallum
2020-08-18 16:43 ` Jarkko Sakkinen
2020-08-19 13:33 ` Nathaniel McCallum
2020-08-19 14:00 ` Jethro Beekman
2020-08-19 21:23 ` Jarkko Sakkinen
2020-08-10 23:08 ` Andy Lutomirski
2020-08-10 23:48 ` Sean Christopherson
2020-08-11 0:52 ` Andy Lutomirski
2020-08-11 15:16 ` Andy Lutomirski
2020-08-13 19:38 ` Sean Christopherson
2020-08-17 13:12 ` Nathaniel McCallum
2020-08-17 15:01 ` Andy Lutomirski
2020-08-18 15:15 ` Jarkko Sakkinen
2020-08-20 0:19 ` Andy Lutomirski
2020-08-18 14:26 ` Jarkko Sakkinen
2020-07-16 13:53 ` [PATCH v36 22/24] selftests/x86: Add a selftest for SGX Jarkko Sakkinen
2020-08-27 4:47 ` Nathaniel McCallum
2020-08-27 15:20 ` Sean Christopherson
2020-08-28 23:27 ` Jarkko Sakkinen
2020-07-16 13:53 ` [PATCH v36 23/24] docs: x86/sgx: Document SGX micro architecture and kernel internals Jarkko Sakkinen
2020-07-28 21:35 ` Pavel Machek
2020-08-06 10:21 ` Dr. Greg
2020-08-08 22:18 ` Pavel Machek
2020-08-19 20:55 ` Jarkko Sakkinen
2020-07-16 13:53 ` [PATCH v36 24/24] x86/sgx: Update MAINTAINERS Jarkko Sakkinen
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