From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 706361094478 for ; Sat, 21 Mar 2026 14:40:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 722886B00BD; Sat, 21 Mar 2026 10:40:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6FA406B00BF; Sat, 21 Mar 2026 10:40:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6375B6B00C0; Sat, 21 Mar 2026 10:40:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 526306B00BD for ; Sat, 21 Mar 2026 10:40:05 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id F219913B2BE for ; Sat, 21 Mar 2026 14:40:04 +0000 (UTC) X-FDA: 84570329928.13.1375C1D Received: from hillsboro-edge.smtp.mymangomail.com (hillsboro-edge.smtp.mymangomail.com [5.78.130.219]) by imf24.hostedemail.com (Postfix) with ESMTP id C5716180005 for ; Sat, 21 Mar 2026 14:40:02 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=gerlicz.space header.s=mango-1 header.b=JVqdmvMK; dmarc=pass (policy=quarantine) header.from=gerlicz.space; spf=pass (imf24.hostedemail.com: domain of oskar@gerlicz.space designates 5.78.130.219 as permitted sender) smtp.mailfrom=oskar@gerlicz.space ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1774104003; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=bRI3gi1rj7sgjUnDtTTIzUk4ldjLipnVZsAhyw+Xi5g=; b=SMMaaqj9qwabRVI0+d0AQeh6D84xohIR8BeGxUBV+t0UOMYm3AS3zG/tGI2PZKJbekZDCs gk8vyXvzqn5VE7whJsl0imBUTzta4dGTETT8ZtY1Q3PkMWUdXZtsfedjecPUJ/riwl/KkO NS+8Siom4nDs+7P62lRj0lxxM7p5eiQ= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1774104003; a=rsa-sha256; cv=none; b=i5oWvQ4gXFzrFHo8S6pU0e1BsZr8ebIk3b1gbBpsj9AdwARYbJcBPc0VbJwTry7uLWnqsV etK+/E+MC1vb6cm/Db7tekonnju3AOtf84XqJt6rqk7KnknDyxZmEARXqNYSpOt6mXYiBU yF+kl0t/wYd9gU28I+aHkg/T1c5JEHA= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=gerlicz.space header.s=mango-1 header.b=JVqdmvMK; dmarc=pass (policy=quarantine) header.from=gerlicz.space; spf=pass (imf24.hostedemail.com: domain of oskar@gerlicz.space designates 5.78.130.219 as permitted sender) smtp.mailfrom=oskar@gerlicz.space Received: from smtp.mymangomail.com (localhost [127.0.0.1]) by smtp.mymangomail.com (Mango Mail) with ESMTP id 38265408C6; Sat, 21 Mar 2026 10:39:37 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gerlicz.space; s=mango-1; t=1774103977; bh=jz9Jb4ua+BZoDIIioX5BJmmKHIi5gc9v+wumLKcLorw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JVqdmvMKUvq7LkIocLlE+laSboKDD8eUR7gtgbTJNfrEUqkWY7oww1mbKyjxe15ZH +B46IAuq0t89QKyh2cxDSV/TKkLdndJ0H2bh7Y4CajAdagVA5N9j1wwXjFrbgDafcT jExo16mpKfZI0hj7IJrVuaBXiN3EI6DRSKsOOehY= X-Mango-Origin: 1 X-Mango-Origin: 1 X-Mango-Origin: 1 X-Mango-Origin: 1 X-Mango-Origin: 1 X-Mango-Origin: 1 X-Mango-Origin: 1 X-Mango-Origin: 1 X-Mango-Origin: 1 Received: from authenticated-user (smtp.mymangomail.com [205.185.121.143]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp.mymangomail.com (Mango Mail) with ESMTPSA id 2255641648; Sat, 21 Mar 2026 10:38:15 -0400 (EDT) From: Oskar Gerlicz Kowalczuk To: Pasha Tatashin , Mike Rapoport , Baoquan He Cc: Pratyush Yadav , Andrew Morton , linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-mm@kvack.org, Oskar Gerlicz Kowalczuk Subject: [PATCH v3 2/5] kexec: abort liveupdate handover on kernel_kexec() unwind Date: Sat, 21 Mar 2026 15:36:39 +0100 Message-ID: <20260321143642.166313-2-oskar@gerlicz.space> In-Reply-To: <20260321143642.166313-1-oskar@gerlicz.space> References: <20260321143642.166313-1-oskar@gerlicz.space> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: C5716180005 X-Stat-Signature: 1b49t3q1d8de7d7ty7jwrjubgyju9gss X-Rspam-User: X-HE-Tag: 1774104002-496313 X-HE-Meta: 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 R3Zh6B6L kwGzjVVyPR5EcydQag2f6+BpxahUKvg4rkNpgRj5D37ayR3xz+mhqZfsIO2/qDJ/eqjv4tOVSiDCvVW953ZbNx1UmvgOZqiaAzfTHyjexIX+7EW7dEzDQ8X2gc9FjudW0ba35ZnlRpLhK/fX/UwX48XI60ylM/JATwwOZGi0h0pYY8ZZpOU3KP/bS2Fp6PT1JklIr9zAI1qud94qIk4kzGtYutxupejsNLGtFSr9k68sYc7PAqA7/fwcufnTsNiEUX1oWLxj2uSvN9F/sXIZkeGrEL3uBisDT96XaSinvDSH0ykVr8fhIeT9K++/85Ij0mUfIUOix6UjIl1GPiq5gGSQyRNMsl7wJd9Z2hTLfNtuabOfRPSkoTS2Efsq9m9hnYceHaNXKY5fODgL/uXFtzqPFbCX6q9E4uLkLl1qKRB4vaNUQ6agGrVB4plcF1fiah9obIs+IJ4aoPASvjWJPQaVOKayrtl/aNvbB Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: liveupdate_reboot() can freeze outgoing session state before the kexec transition completes. v2 only unwound that state when kernel_kexec() returned a non-zero error, which misses the preserve_context path where machine_kexec() can return to the old kernel with error == 0. If that return path skips the abort, outgoing sessions remain stuck in the reboot state and later user space operations cannot make progress. Treat every return to the original kernel after a prepared liveupdate handover as an unwind point and call liveupdate_reboot_abort() there as well. Fixes: 8b32d3ced269 ("kexec: abort liveupdate handover on kernel_kexec() unwind") Signed-off-by: Oskar Gerlicz Kowalczuk --- include/linux/liveupdate.h | 5 +++++ kernel/kexec_core.c | 6 +++++- kernel/liveupdate/luo_core.c | 11 ++++++++++- kernel/liveupdate/luo_internal.h | 1 + kernel/liveupdate/luo_session.c | 23 +++++++++++++++++++++++ 5 files changed, 44 insertions(+), 2 deletions(-) diff --git a/include/linux/liveupdate.h b/include/linux/liveupdate.h index dd11fdc76a5f..d93b043a0421 100644 --- a/include/linux/liveupdate.h +++ b/include/linux/liveupdate.h @@ -226,6 +226,7 @@ bool liveupdate_enabled(void); /* Called during kexec to tell LUO that entered into reboot */ int liveupdate_reboot(void); +void liveupdate_reboot_abort(void); int liveupdate_register_file_handler(struct liveupdate_file_handler *fh); int liveupdate_unregister_file_handler(struct liveupdate_file_handler *fh); @@ -250,6 +251,10 @@ static inline int liveupdate_reboot(void) return 0; } +static inline void liveupdate_reboot_abort(void) +{ +} + static inline int liveupdate_register_file_handler(struct liveupdate_file_handler *fh) { return -EOPNOTSUPP; diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 2fea396d29b9..95710a7d5e56 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -1139,6 +1139,7 @@ bool kexec_load_permitted(int kexec_image_type) int kernel_kexec(void) { int error = 0; + bool liveupdate_prepared = false; if (!kexec_trylock()) return -EBUSY; @@ -1147,6 +1148,7 @@ int kernel_kexec(void) goto Unlock; } + liveupdate_prepared = true; error = liveupdate_reboot(); if (error) goto Unlock; @@ -1230,7 +1232,9 @@ int kernel_kexec(void) } #endif - Unlock: +Unlock: + if (liveupdate_prepared) + liveupdate_reboot_abort(); kexec_unlock(); return error; } diff --git a/kernel/liveupdate/luo_core.c b/kernel/liveupdate/luo_core.c index dda7bb57d421..95a0b81ce60d 100644 --- a/kernel/liveupdate/luo_core.c +++ b/kernel/liveupdate/luo_core.c @@ -233,8 +233,9 @@ int liveupdate_reboot(void) err = kho_finalize(); if (err) { pr_err("kho_finalize failed %d\n", err); + liveupdate_reboot_abort(); /* - * kho_finalize() may return libfdt errors, to aboid passing to + * kho_finalize() may return libfdt errors, to avoid passing to * userspace unknown errors, change this to EAGAIN. */ err = -EAGAIN; @@ -243,6 +244,14 @@ int liveupdate_reboot(void) return err; } +void liveupdate_reboot_abort(void) +{ + if (!liveupdate_enabled()) + return; + + luo_session_abort_reboot(); +} + /** * liveupdate_enabled - Check if the live update feature is enabled. * diff --git a/kernel/liveupdate/luo_internal.h b/kernel/liveupdate/luo_internal.h index 0cfc0269d746..8a6b1f6c9b4f 100644 --- a/kernel/liveupdate/luo_internal.h +++ b/kernel/liveupdate/luo_internal.h @@ -88,6 +88,7 @@ int luo_session_retrieve(const char *name, struct file **filep); int __init luo_session_setup_outgoing(void *fdt); int __init luo_session_setup_incoming(void *fdt); int luo_session_serialize(void); +void luo_session_abort_reboot(void); int luo_session_deserialize(void); bool luo_session_quiesce(void); void luo_session_resume(void); diff --git a/kernel/liveupdate/luo_session.c b/kernel/liveupdate/luo_session.c index d97ec91e1118..200dd3b8229c 100644 --- a/kernel/liveupdate/luo_session.c +++ b/kernel/liveupdate/luo_session.c @@ -788,6 +788,29 @@ int luo_session_serialize(void) return err; } +void luo_session_abort_reboot(void) +{ + struct luo_session_header *sh = &luo_session_global.outgoing; + struct luo_session *session; + int i = 0; + + guard(rwsem_write)(&sh->rwsem); + if (!READ_ONCE(sh->rebooting)) + return; + + list_for_each_entry(session, &sh->list, list) { + if (i >= sh->header_ser->count) + break; + + luo_session_unfreeze_one(session, &sh->ser[i]); + memset(&sh->ser[i], 0, sizeof(sh->ser[i])); + i++; + } + + sh->header_ser->count = 0; + luo_session_reboot_done(sh); +} + /** * luo_session_quiesce - Ensure no active sessions exist and lock session lists. * -- 2.53.0