linux-kernel - Re: [PATCH 4/6] x86/cpu: Add platform ID to CPU info structure

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: <aW_pF5ulDUplHOy9@black.igk.intel.com>
Date: Tue, 20 Jan 2026 21:44:07 +0100
From: Andy Shevchenko <andriy.shevchenko@...el.com>
To: Dave Hansen <dave.hansen@...el.com>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>, linux-kernel@...r.kernel.org,
	sohil.mehta@...el.com, Borislav Petkov <bp@...en8.de>,
	"H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...hat.com>,
	Jon Kohler <jon@...anix.com>,
	Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>,
	"Peter Zijlstra (Intel)" <peterz@...radead.org>,
	Thomas Gleixner <tglx@...nel.org>, Tony Luck <tony.luck@...el.com>,
	x86@...nel.org
Subject: Re: [PATCH 4/6] x86/cpu: Add platform ID to CPU info structure

On Tue, Jan 20, 2026 at 07:06:56AM -0800, Dave Hansen wrote:
> On 1/20/26 00:27, Andy Shevchenko wrote:
> ...
> >> Note: This should not grow the size of 'struct cpuinfo_x86' in
> >> practice since the u8 fits next to another u8 in the structure.
> > 
> > Have you run `pahole` to confirm?
> 
> I have not. If you'd like to contribute to the series by compiling this
> and running pahole on it, I'd very much appreciate it!

Okay, here is the diff:

--- old	2026-01-20 21:40:39.170530703 +0100
+++ new	2026-01-20 21:37:42.717138133 +0100
@@ -19,8 +19,9 @@
 	};
 
 	__u8                       x86_stepping;         /*     4     1 */
+	__u8                       x86_platform_id;      /*     5     1 */
 
-	/* XXX 3 bytes hole, try to pack */
+	/* XXX 2 bytes hole, try to pack */
 
 	int                        x86_tlbsize;          /*     8     4 */
 	__u32                      vmx_capability[5];    /*    12    20 */
@@ -75,8 +76,8 @@
 
 	unsigned int               initialized:1;        /*   332: 8  4 */
 
-	/* size: 336, cachelines: 6, members: 27 */
-	/* sum members: 319, holes: 5, sum holes: 14 */
+	/* size: 336, cachelines: 6, members: 28 */
+	/* sum members: 320, holes: 5, sum holes: 13 */
 	/* sum bitfield members: 1 bits (0 bytes) */
 	/* bit_padding: 23 bits */
 	/* last cacheline: 16 bytes */

-- 
With Best Regards,
Andy Shevchenko