From nobody Wed Feb 11 04:19:08 2026 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 C423D28373; Sat, 18 May 2024 09:44:54 +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=1716025496; cv=none; b=GgQqua7oU8ZPZvftnyGdPDOjQQkyOCq6lTLDIbViYmxEDTdYxkzkIKb1BCQVvLT30Pr0IPGXz70jXPS0G4te/hysW5X4wzkz4xYWEYKtHW36Sc1bptigXp5DQYSZYM6YNLT/r4R78CSW5FjsyuACuxldG2BnSePF+Twf6+Yr8HQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716025496; c=relaxed/simple; bh=ehmUU5DrSg7e7UVvhbwUWBH+UYuQcSC511rfaxLNOpM=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=FLJbMQ3Mw9J81cLW13eY91wSFmpHjaZG94Zcg6O8SYCQJbHH9SKseJhwriOCPVEAxyAFTdZg7pjLc9fXJUhyWzygtRnmG7+qapCJ6v9hppYs7/6X6hCfIEfHq7Fb6ZDxcqM6rM1CaLLob1Kc9i/uy/QexerwIggQ25Je5UQB410= 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=hF3U/sM9; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=alx1B85r; 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="hF3U/sM9"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="alx1B85r" Date: Sat, 18 May 2024 09:44:52 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1716025493; 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=CXb2zhViL9/cb+MGhd87dpFhnyoKIP/1oxdzA10sf5A=; b=hF3U/sM9i1IGebuLUgOQufKQ0iew+WjjHxUKdKCe/q6M+oSoz9lQnGQtDom9L8bzQfX6O1 AybTgunqXp44LFrSCE1k99bD9KI0F/QtD2ULxxS8tOUmOrMp4CtHOF+3AtvsRwzGADQCIa rBcBrfo6lHlzq5tHR7OYshuJ0AVEiqIeF6ViARwVCKffGFXGej4t2rFantOlPEqU5XiAuS eeJEqWhX27FLR9iDdMspj3LuEjqM1YfUQMp5yEKvuZZUyB/EdFf2nZV/OzLwv1vhE0cyCc p6UcwSVvfMwTDGQnmrO86gq0XMRjcLhDTe+H/muEH0Uk/VHvyDUE9c2J0IqQrw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1716025493; 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=CXb2zhViL9/cb+MGhd87dpFhnyoKIP/1oxdzA10sf5A=; b=alx1B85r5oQaMe2E5I/IYYKar4fcF0c15E3jAcoDxYw/EHAtiZqXyVkWcF6+nf/B3FOJb0 swPARmw5yBmmuMAQ== From: "tip-bot2 for Uros Bizjak" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/percpu] x86/percpu: Fix operand constraint modifier in __raw_cpu_write() Cc: Uros Bizjak , Ingo Molnar , Andy Lutomirski , Josh Poimboeuf , Linus Torvalds , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20240430091833.196482-5-ubizjak@gmail.com> References: <20240430091833.196482-5-ubizjak@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <171602549262.10875.7562387052692287292.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 x86/percpu branch of tip: Commit-ID: 1fe67aee8ab3fdab4357afc983a9e9ff3892d694 Gitweb: https://git.kernel.org/tip/1fe67aee8ab3fdab4357afc983a9e9ff3= 892d694 Author: Uros Bizjak AuthorDate: Tue, 30 Apr 2024 11:17:24 +02:00 Committer: Ingo Molnar CommitterDate: Sat, 18 May 2024 11:18:42 +02:00 x86/percpu: Fix operand constraint modifier in __raw_cpu_write() __raw_cpu_write() with !USE_X86_SEG_SUPPORT config uses read/write operand constraint modifier "+" for its memory location. This signals the compiler that the location is both read and written by the asm. This is not true, because MOV insn only writes to the output. Correct the modifier to "=3D" to inform the compiler that the memory location is only written to. This also prevents the compiler from value tracking the undefined value from the uninitialized memory. Signed-off-by: Uros Bizjak Signed-off-by: Ingo Molnar Cc: Andy Lutomirski Cc: Josh Poimboeuf Cc: Linus Torvalds Link: https://lore.kernel.org/r/20240430091833.196482-5-ubizjak@gmail.com --- arch/x86/include/asm/percpu.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index d202551..c77393c 100644 --- a/arch/x86/include/asm/percpu.h +++ b/arch/x86/include/asm/percpu.h @@ -178,7 +178,7 @@ do { \ (void)pto_tmp__; \ } \ asm qual(__pcpu_op2_##size("mov", "%[val]", __percpu_arg([var])) \ - : [var] "+m" (__my_cpu_var(_var)) \ + : [var] "=3Dm" (__my_cpu_var(_var)) \ : [val] __pcpu_reg_imm_##size(pto_val__)); \ } while (0)