From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
x86@kernel.org, linux-sgx@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Andrew Morton <akpm@linux-foundation.org>,
Jethro Beekman <jethro@fortanix.com>,
andriy.shevchenko@linux.intel.com, asapek@google.com,
bp@alien8.de, 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, npmccallum@redhat.com, puiterwijk@redhat.com,
rientjes@google.com, tglx@linutronix.de, yaozhangx@google.com
Subject: Re: [PATCH v34 10/24] mm: Add vm_ops->mprotect()
Date: Mon, 6 Jul 2020 20:22:54 -0700 [thread overview]
Message-ID: <20200707032254.GB5208@linux.intel.com> (raw)
In-Reply-To: <20200707031424.GD25523@casper.infradead.org>
On Tue, Jul 07, 2020 at 04:14:24AM +0100, Matthew Wilcox wrote:
> On Tue, Jul 07, 2020 at 06:01:50AM +0300, Jarkko Sakkinen wrote:
> > +++ b/mm/mprotect.c
> > @@ -603,13 +603,20 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
> > goto out;
> > }
> >
> > + tmp = vma->vm_end;
> > + if (tmp > end)
> > + tmp = end;
> > +
> > error = security_file_mprotect(vma, reqprot, prot);
> > if (error)
> > goto out;
> >
> > - tmp = vma->vm_end;
> > - if (tmp > end)
> > - tmp = end;
>
> You don't need to move this any more, right?
Ya, I was typing up a longer version, you beat me to the punch...
The calculation of 'tmp' doesn't need to be moved. The previous incarnation
only moved it so that that 'tmp would be available for .may_mprotect().
The only reason .may_mprotect() was placed before security_file_mprotect()
was to avoid triggering LSM errors that would have been blocked by
.may_mprotect(), but that justification is no longer relevant as the
proposed SGX LSM hooks obviously didn't worm their way into this series.
> > + if (vma->vm_ops && vma->vm_ops->mprotect) {
> > + error = vma->vm_ops->mprotect(vma, nstart, tmp, prot);
> > + if (error)
> > + goto out;
> > + }
Based on "... and then the vma owner can do whatever it needs to before
calling mprotect_fixup(), which is already not static", my interpretation
is that Matthew's intent was to do:
if (vma->vm_ops && vma->vm_ops->mprotect)
error = = vma->vm_ops->mprotect(vma, nstart, tmp, prot);
else
error = mprotect_fixup(vma, &prev, nstart, tmp, newflags);
if (error)
goto out;
i.e. make .mprotect() a full replacement as opposed to a prereq hook.
> > +
> > error = mprotect_fixup(vma, &prev, nstart, tmp, newflags);
> > if (error)
> > goto out;
> > --
> > 2.25.1
> >
next prev parent reply other threads:[~2020-07-07 3:22 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-07 3:01 [PATCH v34 00/24] Intel SGX foundations Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 01/24] x86/cpufeatures: x86/msr: Add Intel SGX hardware bits Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 02/24] x86/cpufeatures: x86/msr: Add Intel SGX Launch Control " Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 03/24] x86/mm: x86/sgx: Signal SIGSEGV with PF_SGX Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 04/24] x86/sgx: Add SGX microarchitectural data structures Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 05/24] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 06/24] x86/cpu/intel: Detect SGX support Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 07/24] x86/cpu/intel: Add nosgx kernel parameter Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 08/24] x86/sgx: Initialize metadata for Enclave Page Cache (EPC) sections Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 09/24] x86/sgx: Add __sgx_alloc_epc_page() and sgx_free_epc_page() Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 10/24] mm: Add vm_ops->mprotect() Jarkko Sakkinen
2020-07-07 3:14 ` Matthew Wilcox
2020-07-07 3:22 ` Sean Christopherson [this message]
2020-07-07 3:24 ` Matthew Wilcox
2020-07-07 4:01 ` Jarkko Sakkinen
2020-07-07 4:10 ` Matthew Wilcox
2020-07-08 14:33 ` Jarkko Sakkinen
2020-07-08 14:37 ` Matthew Wilcox
2020-07-08 16:10 ` Jarkko Sakkinen
2020-07-08 22:56 ` Jarkko Sakkinen
2020-07-07 4:03 ` Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 11/24] x86/sgx: Add SGX enclave driver Jarkko Sakkinen
2020-07-07 3:36 ` Matthew Wilcox
2020-07-07 4:11 ` Jarkko Sakkinen
2020-07-07 4:29 ` Sean Christopherson
2020-07-07 4:39 ` Matthew Wilcox
2020-07-07 4:46 ` Sean Christopherson
2020-07-07 3:01 ` [PATCH v34 12/24] x86/sgx: Add SGX_IOC_ENCLAVE_CREATE Jarkko Sakkinen
2020-07-07 3:29 ` Sean Christopherson
2020-07-07 4:04 ` Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 13/24] x86/sgx: Add SGX_IOC_ENCLAVE_ADD_PAGES Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 14/24] x86/sgx: Add SGX_IOC_ENCLAVE_INIT Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 15/24] x86/sgx: Allow a limited use of ATTRIBUTE.PROVISIONKEY for attestation Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 16/24] x86/sgx: Add a page reclaimer Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 17/24] x86/sgx: ptrace() support for the SGX driver Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 18/24] x86/vdso: Add support for exception fixup in vDSO functions Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 19/24] x86/fault: Add helper function to sanitize error code Jarkko Sakkinen
2020-07-07 3:02 ` [PATCH v34 20/24] x86/traps: Attempt to fixup exceptions in vDSO before signaling Jarkko Sakkinen
2020-07-07 3:02 ` [PATCH v34 21/24] x86/vdso: Implement a vDSO for Intel SGX enclave call Jarkko Sakkinen
2020-07-07 3:02 ` [PATCH v34 22/24] selftests/x86: Add a selftest for SGX Jarkko Sakkinen
2020-07-07 3:02 ` [PATCH v34 23/24] docs: x86/sgx: Document SGX micro architecture and kernel internals Jarkko Sakkinen
2020-07-07 3:02 ` [PATCH v34 24/24] x86/sgx: Update MAINTAINERS Jarkko Sakkinen
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