From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout.efficios.com (smtpout.efficios.com [158.69.130.18]) (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 A8ED0342160 for ; Wed, 18 Feb 2026 20:14:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=158.69.130.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771445660; cv=none; b=kalWs680m1bfLDOZ1+8+8dw49Oh2P0y0Q0mYRhvf8+rG5Ay1vgr6Hqj+MkZlDU5Jq2EWPE0fFzJocn3swHoZQ7dFIy945tqsDB2ejx/isk7P8o6NS4qY77zCnKL49p0F72Wal6IhunxszNjzdx6AKkJqEMvjZbfaJYv9Kng7/mY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771445660; c=relaxed/simple; bh=6b1Qrkz54Q/tkiF8LDraFZfcxkZlTcPMb2QRLUkK1O0=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=M/B6IOfC2uclM4B9nR3IdqfFLILF4X9T5mUUyYF8OO1NgDwi7gjmR4cwSDPfQF2KXyKQb/NXBTjGPvZ64yMMBMjAxikicG3AO++qRFeCqvpFj59om/49y93NBOU0ywqVGY45HnWpwBFZJ2EBkEpP+dzxo0MCLwbsUxS1BG9nMsY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com; spf=pass smtp.mailfrom=efficios.com; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b=mpDoou3m; arc=none smtp.client-ip=158.69.130.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=efficios.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b="mpDoou3m" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=efficios.com; s=smtpout1; t=1771445656; bh=c0QWY4WydQCvsXqsZtBINbTWu3X7OWD73NyP9tvw8xg=; h=From:To:Cc:Subject:Date:From; b=mpDoou3mNjEU3G890VQ/16/9rmQxURmkpK2oObnfQbpARdRA9YyMvxzdzHXqW2VZ4 BYQoZSL1t3nXNxcGl18jStTcoNTJYurwDwVrBtNnkqTplnj4JtxT8qCY03eStrh6tB ZSbXenw7aXWGujTa16bShwl9hIsIVHYeZySx9H32fn7K/7Y6cTYCM/e8BQkXHa8RHv FjqCAUTg8cLTnhaEtZETUfQRUMi7FlYsuk0C4N6NAwM8KKvsaO8lSuhfEb0Qd4x5cV nwPas/R+Ly2/f65NLl/qQ5kDeJVTzYMKWJ8qCviNoPhFcEN/deKZ2S/ckYpfYmX+ID GiPPAQA25u1LQ== Received: from thinkos.internal.efficios.com (mtl.efficios.com [216.120.195.104]) by smtpout.efficios.com (Postfix) with ESMTPSA id 4fGSQc4ZJFzG44; Wed, 18 Feb 2026 15:14:16 -0500 (EST) From: Mathieu Desnoyers To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, Mathieu Desnoyers , Ingo Molnar , Thomas Gleixner , Carlos O'Donell , Florian Weimer , Michael Jeanson Subject: [PATCH v2 0/2] Last minute rseq fixes for 7.0 Date: Wed, 18 Feb 2026 15:14:11 -0500 Message-Id: <20260218201413.1187745-1-mathieu.desnoyers@efficios.com> X-Mailer: git-send-email 2.39.5 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hi, Here are two last minute rseq fixes aiming at 7.0. The first is a clarification of a rseq registration comment to match the rseq_size range checks. The second ensures that the new scheduler slice extension field don't end up exposing a rseq feature size equal to the original rseq size, which would make life harder than it needs to be for userspace. Updates since v1: - Don't change the alignment of struct rseq, because the kernel needs to keep backward compatibility and access 32-byte aligned rseq structures. Instead, change the value returned by getauxval(AT_RSEQ_ALIGN) to return the value of the active rseq area size rounded up to next power of 2, which guarantees that the rseq structure will always be aligned on the nearest power of two large enough to contain it, even as it grows. Change the alignment check in the rseq registration accordingly. Thanks, Mathieu CC: Peter Zijlstra (Intel) CC: Ingo Molnar CC: Thomas Gleixner CC: Carlos O'Donell CC: Florian Weimer CC: Michael Jeanson Mathieu Desnoyers (2): rseq: Clarify rseq registration rseq_size bound check comment rseq: slice ext: Ensure rseq feature size differs from original rseq size fs/binfmt_elf.c | 3 ++- include/linux/rseq.h | 12 ++++++++++++ include/uapi/linux/rseq.h | 19 ++++++++++++++++--- kernel/rseq.c | 8 +++++--- 4 files changed, 35 insertions(+), 7 deletions(-) -- 2.39.5