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From: David Binderman <dcb314@hotmail.com>
To: "graf@amazon.com" <graf@amazon.com>,
	"rppt@kernel.org" <rppt@kernel.org>,
	"pasha.tatashin@soleen.com" <pasha.tatashin@soleen.com>,
	"pratyush@kernel.org" <pratyush@kernel.org>,
	"kexec@lists.infradead.org" <kexec@lists.infradead.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: linux-6.19-rc8/kernel/liveupdate/kexec_handover.c:1089: Possible 32/64 bit mixup ?
Date: Thu, 5 Feb 2026 09:21:17 +0000	[thread overview]
Message-ID: <VI1PR02MB3952964EF347629B2686A36E9C99A@VI1PR02MB3952.eurprd02.prod.outlook.com> (raw)

Hello there,

Source code analyser cppcheck says:

linux-6.19-rc8/kernel/liveupdate/kexec_handover.c:1089:15: style: int result is assigned to long variable. If the variable is long to avoid loss of information, then you have loss of information. [truncLongCastAssignment]

Source code is

    contig_pages = (1 << order);

I admit the error message is hard to understand, but AFAIK
if local variable order remains under 30 or so, then there is no problem.

However, if it goes above 32, then there will be loss of data. 
Expression 1 << order is type int.

Suggest add some code or comment to document the expected range
of local variable order. If it ever goes above 32, suggest new code

    contig_pages = 1UL << order;

Regards

David Binderman

             reply	other threads:[~2026-02-05  9:21 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-02-05  9:21 David Binderman [this message]
2026-02-10 13:41 ` Pratyush Yadav

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