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From: Dave Hansen <dave.hansen@intel.com>
To: Jarkko Sakkinen <jarkko@kernel.org>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	Jethro Beekman <jethro@fortanix.com>,
	Sean Christopherson <seanjc@google.com>
Cc: reinette.chatre@intel.com, tony.luck@intel.com,
	nathaniel@profian.com, stable@vger.kernel.org,
	Borislav Petkov <bp@suse.de>,
	linux-sgx@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/sgx: Free backing memory after faulting the enclave page
Date: Thu, 4 Nov 2021 15:38:55 -0700	[thread overview]
Message-ID: <7c122a82-e418-0bce-8f67-cbaa15abc9b9@intel.com> (raw)
In-Reply-To: <20211103232238.110557-1-jarkko@kernel.org>

On 11/3/21 4:22 PM, Jarkko Sakkinen wrote:
> --- a/arch/x86/kernel/cpu/sgx/encl.c
> +++ b/arch/x86/kernel/cpu/sgx/encl.c
> @@ -22,6 +22,7 @@ static int __sgx_encl_eldu(struct sgx_encl_page *encl_page,
>  {
>  	unsigned long va_offset = encl_page->desc & SGX_ENCL_PAGE_VA_OFFSET_MASK;
>  	struct sgx_encl *encl = encl_page->encl;
> +	struct inode *inode = file_inode(encl->backing);
>  	struct sgx_pageinfo pginfo;
>  	struct sgx_backing b;
>  	pgoff_t page_index;
> @@ -60,6 +61,9 @@ static int __sgx_encl_eldu(struct sgx_encl_page *encl_page,
>  
>  	sgx_encl_put_backing(&b, false);
>  
> +	/* Free the backing memory. */
> +	shmem_truncate_range(inode, PFN_PHYS(page_index), PFN_PHYS(page_index) + PAGE_SIZE - 1);
> +
>  	return ret;
>  }

This also misses tearing down the backing storage if it is in place at
sgx_encl_release().

Does a entry->epc_page==NULL page in there guarantee that it has backing
storage?

  parent reply	other threads:[~2021-11-04 22:39 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-03 23:22 [PATCH] x86/sgx: Free backing memory after faulting the enclave page Jarkko Sakkinen
2021-11-04 13:50 ` Dave Hansen
2021-11-04 15:04   ` Jarkko Sakkinen
2021-11-04 15:09     ` Jarkko Sakkinen
2021-11-04 15:13     ` Dave Hansen
2021-11-04 15:25       ` Jarkko Sakkinen
2021-11-04 15:29         ` Dave Hansen
2021-11-07 19:42           ` Jarkko Sakkinen
2021-11-07 19:51             ` Dave Hansen
2021-11-07 22:28               ` Jarkko Sakkinen
2021-11-08  6:34                 ` Dave Hansen
2021-11-08 20:07                   ` Jarkko Sakkinen
2021-11-04 22:38 ` Dave Hansen [this message]
2021-11-07 18:06   ` Jarkko Sakkinen
2021-11-07 19:06     ` Dave Hansen
2021-11-07 19:45       ` Jarkko Sakkinen
2021-11-07 19:58         ` Dave Hansen

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