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Date:   Mon, 28 Sep 2020 04:32:26 +0300
From:   Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To:     x86@kernel.org, linux-sgx@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org,
        Sean Christopherson <sean.j.christopherson@intel.com>,
        Andy Lutomirski <luto@amacapital.net>,
        Jethro Beekman <jethro@fortanix.com>,
        Cedric Xing <cedric.xing@intel.com>, akpm@linux-foundation.org,
        andriy.shevchenko@linux.intel.com, asapek@google.com, bp@alien8.de,
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        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 v38 21/24] x86/vdso: Implement a vDSO for Intel SGX
 enclave call
Message-ID: <20200928013226.GA8561@linux.intel.com>
References: <20200915110522.893152-1-jarkko.sakkinen@linux.intel.com>
 <20200915110522.893152-22-jarkko.sakkinen@linux.intel.com>
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In-Reply-To: <20200915110522.893152-22-jarkko.sakkinen@linux.intel.com>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
Precedence: bulk

On Tue, Sep 15, 2020 at 02:05:19PM +0300, Jarkko Sakkinen wrote:
> +struct sgx_enclave_run {
> +	__u64 tcs;
> +	__u32 flags;
> +	__u32 exit_reason;
> +
> +	union {
> +		sgx_enclave_exit_handler_t user_handler;
> +		__u64 __user_handler;
> +	};

I will replace this with just:

	__u64 user_handler;

> +	__u64 user_data;
> +
> +	union {
> +		struct sgx_enclave_exception exception;
> +
> +		/* Pad the entire struct to 256 bytes. */
> +		__u8 pad[256 - 32];
> +	};
> +};

Resulting:


struct sgx_enclave_run {
	__u64 tcs;
	__u32 flags;
	__u32 exit_reason;
	__u64 user_handler;
	__u64 user_data;

	union {
		struct sgx_enclave_exception exception;

		/* Pad the entire struct to 256 bytes. */
		__u8 pad[256 - 32];
	};
};

BTW, why there is that padding?

/Jarkko