From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay7-d.mail.gandi.net (relay7-d.mail.gandi.net [217.70.183.200]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8F9A61A5B92 for ; Sat, 11 Oct 2025 17:15:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.200 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760202938; cv=none; b=cWLrzRJZFjb80ixMX+BGfLqRmdnORVSa5xhBxe8bFTx2/xzxXCkezvkc0A1/d0kYmM0wwFk5q3HzKUHICE6JZpacBa/GKiar3WtmEJO8uctfPmfigZXjoXsWW08ZAq7YBDMHJsq+UsUkLSpXiumoCwdgL7zQD0E69AjRPAWQ7GI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760202938; c=relaxed/simple; bh=kiaram+8UojpifFoizXdF9Yn4tlvShlhOOTFmOY5nAo=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=UmgmH6l5zISe+VX2VOWGAag/5zKbs6vSSlEiXAzTgxm+ohzBZ3gXvJJcHepsAeyiVK7jgpxJN/+avRlf+G8IzpRpdKT1odwT+uFU0gFa2yvLLv+Lhnyz02O5/YLQF8M6icxL9aFNDU195BGy7zBT/DXxCjET7s7OziwhNfw7Pw4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=xenomai.org; spf=pass smtp.mailfrom=xenomai.org; dkim=pass (2048-bit key) header.d=xenomai.org header.i=@xenomai.org header.b=ccedfPYO; arc=none smtp.client-ip=217.70.183.200 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=xenomai.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=xenomai.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=xenomai.org header.i=@xenomai.org header.b="ccedfPYO" Received: by mail.gandi.net (Postfix) with ESMTPSA id 037974435D; Sat, 11 Oct 2025 17:15:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=xenomai.org; s=gm1; t=1760202928; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=sW85Sqx2vIodAyVVCsK4vrYsKXwbcdOsFq+FT4KT4Gg=; b=ccedfPYOOsDdqt3AY4ztV1TwEh05kr4KWyS3o24E2PYmXti7CjBnvrtAVqSRmcK7fKMKHY kreiEepwiLx99CJylvInwNgq/B+JpqgGaCjGPHaWIuWZblpvr4aDkKtNVt994ZoCvXR0oy OIjSdeKmpR1Lbwapj0iKt4k14Z90HzaH0YsUPK9delixvcYwFLMrQ8TX6w+nOB3eZRCI1V 2Y8AxBnLlgYZOOqKRf+8D6dG1eWBSDLiEYmoiu9dWqE1L+SYfd5mcmgl9OkB/NFMsqe9Tz MfZBwjqopOPJa8iu11VwYBsnn2SCjb0a4QJDx3/T275AkjBie70MTzbPytF7qA== From: Philippe Gerum To: Giulio Moro Cc: =?utf-8?Q?=C5=81ukasz?= Majewski , Xenomai Subject: Re: Unexpected switches to in-band In-Reply-To: (Giulio Moro's message of "Sat, 11 Oct 2025 11:47:29 -0500") References: <20251009151737.0d03b211@wsk> <20676160-4572-d92d-4b33-ff4255946345@bela.io> <87qzv9sa9c.fsf@xenomai.org> <87ikgls9kh.fsf@xenomai.org> User-Agent: mu4e 1.12.12; emacs 30.2 Date: Sat, 11 Oct 2025 19:15:27 +0200 Message-ID: <874is5s6kw.fsf@xenomai.org> Precedence: bulk X-Mailing-List: xenomai@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-GND-Sasl: rpm@xenomai.org Giulio Moro writes: > I realised that gitlab's v6.12.y-evl-rebase and v6.1.y-cip-evl-rebase can boot as-is on the PocketBeagle 2 and so I'll keep using those for tests going forward, without any third-party patches. > >>> Ok, so it looks like both of you observe the same issue, which seems to >>> be arch-independent. Checking the code which takes care of preventing >>> COW for oob-enabled processes (a behavior which may cause unwanted minor >>> faults in a tricky way), I stumbled upon a really bad bug. Could you >>> check whether the patch below helps? >>> >>> diff --git a/include/linux/sched/coredump.h b/include/linux/sched/coredump.h >>> index 73de18353e79..c6b1efcbd833 100644 >>> --- a/include/linux/sched/coredump.h >>> +++ b/include/linux/sched/coredump.h >>> @@ -91,7 +91,7 @@ static inline int get_dumpable(struct mm_struct *mm) >>> #define MMF_VM_MERGE_ANY 30 >>> #define MMF_VM_MERGE_ANY_MASK (1 << MMF_VM_MERGE_ANY) >>> -#define MMF_DOVETAILED 31 /* mm belongs to a dovetailed process */ >>> +#define MMF_DOVETAILED 18 /* mm belongs to a dovetailed process */ >>> #define MMF_TOPDOWN 31 /* mm searches top >>> down by default */ >>> #define MMF_TOPDOWN_MASK (1 << MMF_TOPDOWN) > > Tried that on top of v6.12.y-evl-rebase , it doesn't seem to fix the problem, neither for latmus nor for our application. > >> Note: this issue only affects kernels from v6.10 and on > > I can confirm that on v6.1.y-cip-evl-rebase I don't see that issue, even though MMF_DOVETAILED is 31 also there. Quick check: does "evl check" run without any output (as expected)? -- Philippe.