From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E1BEB22D4DC for ; Sun, 29 Mar 2026 07:18:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774768708; cv=none; b=ncWm1xZDR9GK7XF/nZHEZPV3IDZnyLb/VruTYBdQjf5e3MamaiDedyBoNSkhfEWr9uiZRR8t4mEibreOpZcjDtibNN0I95Fbf4+n/WJs78n+MRxDRwusxwQvq+4PTRNPw+gdGP9SgHr477rTjSwsqqMxsOprvOS8nBdF8VhGNKM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774768708; c=relaxed/simple; bh=XTJr/joAqHRuNIlq5VABLMOheW+feyBqER3SHd+r7NQ=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=h0U5wqspTEELv7qQu7PWBup74Vost1OeJGlMCip3Zu+Gcy7PqjvRsra3EnVme03eC6IbNnXAUGq1Jb4IftrTfbdxoa8FsXn+MxSkFuiExu685U9h/PVsUpyk5MDnD5bjszv2X2eIbaQ/w13jG8LZfqi1QehtwqKeD6AFcuWeCgI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dJ8HlnIA; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="dJ8HlnIA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9D25C116C6; Sun, 29 Mar 2026 07:18:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1774768707; bh=XTJr/joAqHRuNIlq5VABLMOheW+feyBqER3SHd+r7NQ=; h=Subject:To:Cc:From:Date:From; b=dJ8HlnIAVZlSRG+nwP0zErirXUOebnZd8n7woZffp6cQK2DSiXnjiPJeLMkAT/N3A aprXJdGEG0O30LuhQAyDcxvOL8lgb1qttthCt3oiItmz43L/Rs8P2I/9XtamGrTdpf 7EoRTc3tHieIrZ9LtINv6M0go3qwpyYNPjkGRvco= Subject: FAILED: patch "[PATCH] s390/entry: Scrub r12 register on kernel entry" failed to apply to 6.6-stable tree To: gor@linux.ibm.com,iii@linux.ibm.com Cc: From: Date: Sun, 29 Mar 2026 09:18:23 +0200 Message-ID: <2026032923-rerun-crouch-f0cc@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 0738d395aab8fae3b5a3ad3fc640630c91693c27 # git commit -s git send-email --to '' --in-reply-to '2026032923-rerun-crouch-f0cc@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 0738d395aab8fae3b5a3ad3fc640630c91693c27 Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Thu, 26 Mar 2026 19:50:14 +0100 Subject: [PATCH] s390/entry: Scrub r12 register on kernel entry Before commit f33f2d4c7c80 ("s390/bp: remove TIF_ISOLATE_BP"), all entry handlers loaded r12 with the current task pointer (lg %r12,__LC_CURRENT) for use by the BPENTER/BPEXIT macros. That commit removed TIF_ISOLATE_BP, dropping both the branch prediction macros and the r12 load, but did not add r12 to the register clearing sequence. Add the missing xgr %r12,%r12 to make the register scrub consistent across all entry points. Fixes: f33f2d4c7c80 ("s390/bp: remove TIF_ISOLATE_BP") Cc: stable@kernel.org Reviewed-by: Ilya Leoshkevich Signed-off-by: Vasily Gorbik diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 4873fe9d891b..689d253e1afc 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -271,6 +271,7 @@ SYM_CODE_START(system_call) xgr %r9,%r9 xgr %r10,%r10 xgr %r11,%r11 + xgr %r12,%r12 la %r2,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs mvc __PT_R8(64,%r2),__LC_SAVE_AREA(%r13) MBEAR %r2,%r13 @@ -407,6 +408,7 @@ SYM_CODE_START(\name) xgr %r6,%r6 xgr %r7,%r7 xgr %r10,%r10 + xgr %r12,%r12 xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11) mvc __PT_R8(64,%r11),__LC_SAVE_AREA(%r13) MBEAR %r11,%r13 @@ -496,6 +498,7 @@ SYM_CODE_START(mcck_int_handler) xgr %r6,%r6 xgr %r7,%r7 xgr %r10,%r10 + xgr %r12,%r12 stmg %r8,%r9,__PT_PSW(%r11) xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11) xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)