linux-kernel - Re: [PATCH v11 1/3] x86/tdx: Add TDX Guest attestation interface driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <dcf53e6b-d60f-5d6b-029a-38df68d66302@intel.com>
Date:   Sun, 28 Aug 2022 13:14:24 -0700
From:   Dave Hansen <dave.hansen@...el.com>
To:     Kuppuswamy Sathyanarayanan 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
        Shuah Khan <shuah@...nel.org>
Cc:     "H . Peter Anvin" <hpa@...or.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>,
        Tony Luck <tony.luck@...el.com>,
        Andi Kleen <ak@...ux.intel.com>,
        Kai Huang <kai.huang@...el.com>,
        Wander Lairson Costa <wander@...hat.com>,
        Isaku Yamahata <isaku.yamahata@...il.com>,
        marcelo.cerri@...onical.com, tim.gardner@...onical.com,
        khalid.elmously@...onical.com, philip.cox@...onical.com,
        linux-kernel@...r.kernel.org, linux-kselftest@...r.kernel.org,
        linux-doc@...r.kernel.org
Subject: Re: [PATCH v11 1/3] x86/tdx: Add TDX Guest attestation interface
 driver

On 8/26/22 08:06, Kuppuswamy Sathyanarayanan wrote:
> +struct tdx_report_req {
> +	__u8  subtype;
> +	__u64 reportdata;
> +	__u32 rpd_len;
> +	__u64 tdreport;
> +	__u32 tdr_len;
> +};

Please do take a look at how the compiler ends up building that structure.

If you sized things to "save space", the way the compiler treats that
structure may surprise you.  You might also want to look at how a 32-bit
compile deals with it versus a 64-bit one.