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h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZjVUbm1i0r7id0oXgnlEVsYHjjTTsjagynsDqwUq4JWQboX2Ta+P0jQIneVqXglDF Y0iOs637bqapD1xlzQM3YZPtUEaAwFrKBHTwUhWke7Ow02jmtEmAo0gbD34MtSDSHl bRQtizh+12rSoMMLXxrwY+KFMReQSmAN745ISqtk= Date: Mon, 13 Jul 2026 10:00:39 +0100 From: Catalin Marinas To: Breno Leitao Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: [PATCH] mm: kmemleak: confirm suspected leaks with a second scan Message-ID: References: <20260709173347.689607-1-catalin.marinas@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: BD65020007 X-Stat-Signature: zcdaaoy4uhw1ydarin7ndrajcge566zo X-Rspam-User: X-Rspamd-Server: rspam12 X-HE-Tag: 1783933253-284607 X-HE-Meta: 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 aZjJTCxm hrUTxhiRc3wT+qp62alEIysK8b/CFJofSu7ExLucgNyOe3eeH43LXWvLRKf/oHnVncnnophkGMJV4QqdKqSlQ8ulxuq3GNH6YAUCdXkey4qoj6DOOiSxLCZ26I3YZjBXpbdVG438pArGT2MbRdy/r0BD6CVEumcfil1VQJV/gYJmwoQiw9VEpL6KvMlLw/kg3/zyuXc4FC/N8jQB9RkbO5L5r4z/gGKaO/WsXMWr/fpauvM/xzU7c8eObH93FmXX4hkrz33AJF2bIMay9r2JVH6M4GaTTdedAQ8N1DsJASQy0umUvqHqh6eQbJvOdyBhEqIs6e2uxU2q9+YhjLZ/RxH5JxXYh5gJCse1Gp5MrJDcdZNkSPK84N5SS/Q== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Jul 10, 2026 at 01:51:40AM -0700, Breno Leitao wrote: > On Thu, Jul 09, 2026 at 06:24:47PM +0100, Catalin Marinas wrote: > > The kmemleak marking phase is not atomic. While the object graph is > > traversed, the kernel can modify pointers, free objects or allocate new > > ones. If a reference to an object is moved from one location to another, > > kmemleak scanning may miss it. We have explicit annotations like > > kmemleak_transient_leak() but identifying and maintaining them is not > > trivial. > > > > Given that such transient leaks are short-lived, rather than just > > reporting such objects as leaks, do another scan to confirm the > > suspected objects. If no new leaks are found during the first scan, skip > > the confirmation one. > > > > Signed-off-by: Catalin Marinas > > Assisted-by: Claude:claude-opus-4-8 > > Cc: Breno Leitao > > Cc: Andrew Morton > > Tested-by: Breno Leitao > Reviewed-by: Breno Leitao Thanks! > PS: This is now conflicting with commit 946935b07cc94 ("mm/kmemleak: > skip the remaining scan phases when interrupted"), which has just showed > up in linux-next. So, a respin might be required. > > > BTW, I'll be away from Saturday for three weeks. I may reply > > occasionally but won't be able to test anything. > > Let me know if you want me to respin it based on linux-next. Yes, please, you have time. Thank you! -- Catalin