From nobody Sun Dec 14 18:12:29 2025 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 3D24D31E102; Tue, 4 Nov 2025 08:17:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762244263; cv=none; b=Pz0MFHVPich08eQUHe4PNU4iQeQY+8H+1kedeFDfkAhZug71LcXqKldhPi0rV8q/14s6Odn7t4CM/z3Xcdh7CU4RCkLEdF90BXa7O6f1ZS4KoQu7mUEoUSbk7SBPN33MBIyGTKd0EIDGbp+ykhsympFMdQgXTUbTOEH5Z/xmZSc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762244263; c=relaxed/simple; bh=snvxwxZ2Z6WOOwjfWyAx76X6+Hzle9Kg6w6J9UaFdYk=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=CgF8ZSPAANWuL+yUdXHWXaqG5uNimMN+yG9sB06jx0pIFGIXlTMAPNROGKPWO3s9xDW9KaCQCmGRNyaGwi7rp39fOI+ZVrBpdgLZ8s3VNfSahQ0gxqxeyBRceHoG0qLCRUbefPRut7FJUyAnTO4hbdNCjNL3urs5yQo+0EArQ6Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=ProrDHzb; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=DzkRpmSO; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="ProrDHzb"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="DzkRpmSO" Date: Tue, 04 Nov 2025 08:17:38 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1762244259; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=YKvfJbzEAfhsdi3HPRkVfSJB5hu0oh0G7vmOIME3Z7g=; b=ProrDHzbCypQnJFVGaQlxQmyk+hfTu1lp4X9sjKy/wOBppK+kKDnYlLY5IvTiBoeMZt8zy 4CeNS7uzlj7fjYlV8EpPNejiF458WgNdx913dVlR/G6sQTKp0hPcPVCn00TOAjQpEcdz9X oYsqZyXx0jMIoPc+ptOXv1NriGGTN26deknEzDLEv7y/qsCWocXpFWl9R1sX+IA5uWD61N /zM43x80cNF4aBF1SVNmcnPofcaMzyzwtl41J5QDgOcuzeVQyAZXS//VNNX59FLB1S7OIi G+ESafmEa/S9f+C+GcDqMxuEHAlgGe9wsPjdcjAydfRUGDieVEzj8lWc4XTK+Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1762244259; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=YKvfJbzEAfhsdi3HPRkVfSJB5hu0oh0G7vmOIME3Z7g=; b=DzkRpmSOtVWPr2VjHC40vJqPPVoonQvpWUfbcC1bL+NEn9VvSOOClr8Sm5YYk3575DQA/7 F4Iaut5iBY8tKODw== From: "tip-bot2 for Thomas Gleixner" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: core/rseq] rseq: Simplify registration Cc: Thomas Gleixner , "Peter Zijlstra (Intel)" , Ingo Molnar , Mathieu Desnoyers , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20251027084306.274661227@linutronix.de> References: <20251027084306.274661227@linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <176224425825.2601451.15206634611280288656.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the core/rseq branch of tip: Commit-ID: 067b3b41b4dd5bf51d6874206f5c1f72e0684eeb Gitweb: https://git.kernel.org/tip/067b3b41b4dd5bf51d6874206f5c1f72e= 0684eeb Author: Thomas Gleixner AuthorDate: Mon, 27 Oct 2025 09:44:24 +01:00 Committer: Ingo Molnar CommitterDate: Tue, 04 Nov 2025 08:30:05 +01:00 rseq: Simplify registration There is no point to read the critical section element in the newly registered user space RSEQ struct first in order to clear it. Just clear it and be done with it. Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Reviewed-by: Mathieu Desnoyers Link: https://patch.msgid.link/20251027084306.274661227@linutronix.de --- kernel/rseq.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/kernel/rseq.c b/kernel/rseq.c index 51fafc4..80af48a 100644 --- a/kernel/rseq.c +++ b/kernel/rseq.c @@ -492,11 +492,9 @@ void rseq_syscall(struct pt_regs *regs) /* * sys_rseq - setup restartable sequences for caller thread. */ -SYSCALL_DEFINE4(rseq, struct rseq __user *, rseq, u32, rseq_len, - int, flags, u32, sig) +SYSCALL_DEFINE4(rseq, struct rseq __user *, rseq, u32, rseq_len, int, flag= s, u32, sig) { int ret; - u64 rseq_cs; =20 if (flags & RSEQ_FLAG_UNREGISTER) { if (flags & ~RSEQ_FLAG_UNREGISTER) @@ -557,11 +555,9 @@ SYSCALL_DEFINE4(rseq, struct rseq __user *, rseq, u32,= rseq_len, * avoid a potential segfault on return to user-space. The proper thing * to do would have been to fail the registration but this would break * older libcs that reuse the rseq area for new threads without - * clearing the fields. + * clearing the fields. Don't bother reading it, just reset it. */ - if (rseq_get_rseq_cs_ptr_val(rseq, &rseq_cs)) - return -EFAULT; - if (rseq_cs && clear_rseq_cs(rseq)) + if (put_user(0UL, &rseq->rseq_cs)) return -EFAULT; =20 #ifdef CONFIG_DEBUG_RSEQ