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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A77AEC3ABCB for ; Mon, 12 May 2025 14:15:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:Message-ID:In-Reply-To:Date:From:Cc:To:Subject: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:References:List-Owner; bh=WEajEjroG3KrJXm5xDlUPSI4uEwR8mvzm5iXEs8Yd8g=; b=HdyX/cIjGsVTBvJNUOr7vxFszx 0dRAAVMOXECNeb4yk79k7wxbpGyy7sl2l4US+sEaSU/ZEhFLAF6oNCMGGEeNKFNPgQ8Qc2WNlk6OE o5VIDommf7+WpCzchooIAO8jJ63BlA3xwJjn3zSQxomhK9umvEpMAgkuap3oTMPVNBjoN6lqDkmDv r6/G13XHNYRrQK79wto7q1vFIfSDz4paBqVrwh7avSlQRB8dk/di3WnvUaczzGyj9+RWaW8JWdYxs Ft6PlbjYnJdHN9W2iNIkbV4zC/SaFRLOw6nSX4HJF/chIuPLu6u1ZhUkShFEefRFMyZHBQqXIsbwn DUT26uww==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uETwO-00000009goZ-3pUI; Mon, 12 May 2025 14:15:36 +0000 Received: from nyc.source.kernel.org ([147.75.193.91]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uETFH-00000009Z26-0B8A for linux-um@lists.infradead.org; Mon, 12 May 2025 13:31:05 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id DA3F2A4AAF6; Mon, 12 May 2025 13:31:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0D3FAC4CEE7; Mon, 12 May 2025 13:31:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1747056661; bh=I3w0yqK/Esga4Z5BS0l+X/WliYjn3vuYn8g72dxaGVA=; h=Subject:To:Cc:From:Date:In-Reply-To:From; b=tY3XETxa1QhmOeo7qbnZUePHMz0RoOO8OEBS0VGOXRI4xtSqM20Vo0N1Wz9pudXNU iDo4Cf4iK9S0uaaz7D8hLj878cA5xFoPoygBao9m5VNcWWmq+Gw64PI06bGxMmQzzC rB0a29lJ5tyuUgOz4enGPJKNH7jajFsN1JP5MDqM= Subject: Patch "[PATCH 6.12] Revert "um: work around sched_yield not yielding in time-travel mode"" has been added to the 6.12-stable tree To: benjamin.berg@intel.com,chunkeey@gmail.com,gregkh@linuxfoundation.org,johannes@sipsolutions.net,linux-um@lists.infradead.org,richard@nod.at,sashal@kernel.org Cc: From: Date: Mon, 12 May 2025 15:30:58 +0200 In-Reply-To: <20250509095040.33355-1-chunkeey@gmail.com> Message-ID: <2025051258-silenced-resend-bc87@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit X-stable: commit X-Patchwork-Hint: ignore X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250512_063103_308366_119DCE5B X-CRM114-Status: GOOD ( 17.79 ) X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org This is a note to let you know that I've just added the patch titled [PATCH 6.12] Revert "um: work around sched_yield not yielding in time-travel mode" to the 6.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: revert-um-work-around-sched_yield-not-yielding-in-time-travel-mode.patch and it can be found in the queue-6.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From chunkeey@gmail.com Mon May 12 13:25:04 2025 From: Christian Lamparter Date: Fri, 9 May 2025 11:50:39 +0200 Subject: [PATCH 6.12] Revert "um: work around sched_yield not yielding in time-travel mode" To: linux-kernel@vger.kernel.org, linux-um@lists.infradead.org Cc: benjamin.berg@intel.com, sashal@kernel.org, johannes@sipsolutions.net, richard@nod.at, stable@vger.kernel.org Message-ID: <20250509095040.33355-1-chunkeey@gmail.com> From: Christian Lamparter This reverts commit da780c4a075ba2deb05ae29f0af4a990578c7901 which is commit 887c5c12e80c8424bd471122d2e8b6b462e12874 upstream. Reason being that the patch depends on at least commit 0b8b2668f998 ("um: insert scheduler ticks when userspace does not yield") in order to build. Otherwise it fails with: | /usr/bin/ld: arch/um/kernel/skas/syscall.o: in function `handle_syscall': | linux-6.12.27/arch/um/kernel/skas/syscall.c:43:(.text+0xa2): undefined | reference to `tt_extra_sched_jiffies' | collect2: error: ld returned 1 exit status The author Benjamin Berg commented: "I think it is better to just not backport commit 0b8b2668f998 ("um: insert scheduler ticks when userspace does not yield")" Link: https://lore.kernel.org/linux-um/8ce0b6056a9726e540f61bce77311278654219eb.camel@sipsolutions.net/ Cc: # 6.12.y Cc: Benjamin Berg Signed-off-by: Christian Lamparter Signed-off-by: Greg Kroah-Hartman --- arch/um/include/linux/time-internal.h | 2 -- arch/um/kernel/skas/syscall.c | 11 ----------- 2 files changed, 13 deletions(-) --- a/arch/um/include/linux/time-internal.h +++ b/arch/um/include/linux/time-internal.h @@ -83,8 +83,6 @@ extern void time_travel_not_configured(v #define time_travel_del_event(...) time_travel_not_configured() #endif /* CONFIG_UML_TIME_TRAVEL_SUPPORT */ -extern unsigned long tt_extra_sched_jiffies; - /* * Without CONFIG_UML_TIME_TRAVEL_SUPPORT this is a linker error if used, * which is intentional since we really shouldn't link it in that case. --- a/arch/um/kernel/skas/syscall.c +++ b/arch/um/kernel/skas/syscall.c @@ -31,17 +31,6 @@ void handle_syscall(struct uml_pt_regs * goto out; syscall = UPT_SYSCALL_NR(r); - - /* - * If no time passes, then sched_yield may not actually yield, causing - * broken spinlock implementations in userspace (ASAN) to hang for long - * periods of time. - */ - if ((time_travel_mode == TT_MODE_INFCPU || - time_travel_mode == TT_MODE_EXTERNAL) && - syscall == __NR_sched_yield) - tt_extra_sched_jiffies += 1; - if (syscall >= 0 && syscall < __NR_syscalls) { unsigned long ret = EXECUTE_SYSCALL(syscall, regs); Patches currently in stable-queue which might be from chunkeey@gmail.com are queue-6.12/revert-um-work-around-sched_yield-not-yielding-in-time-travel-mode.patch