From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=217.140.110.172 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794240072; b=aLH7+I4UywEkZf0/4R9sQNKLKA359yAxG0upypWgVWBFSP7pzKjUr1Av/0Iyd6g7yrvo 5/lHqITcQJpL8xoKA4sBs7j0o8PxDXTU13m2NS0xrKr8X69VoqI6JK+FotP2ToWjTwcoE m+8Vr63QQxlHFbzYaPoBNUGHJFu9sXaJBqDLY8KFX8pHOr+Ofacrev1jFvoxy3mhU9B6M B5eSi9IzfAAxxMAtz70Hf4/wtq8sAiWVm35TQmrEg/DGhyZ5e7F3JMZCV8pvBRsHiTK1n ESOnMUAGIbGYXQPp+AHIlYvZ58EsDLvKxwaKo4LzZSV981tDUjNcX/A7mg+8IH1bXfw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794240072; h=DMARC-Filter:Received:Received:DKIM-Signature:From:Date:Subject: MIME-Version:Content-Type:Content-Transfer-Encoding:Message-Id: References:In-Reply-To:To:Cc:X-Mailer:X-Developer-Signature: X-Developer-Key; bh=btt91I3qkVKycKN2iTEdAlTvCKoqHGuYdHT3imsqzq4=; b=HaZVpATmI2MBcP15D7acgwh1QgI3PHFjQRf+O8TznHTlp0groTX0eOMwu/lgdMVmYUTo F7gBbA7MFtmmEFzxw4x9RcY5d9bqkUIR3b16OWyjyGVmQOS2Rz8UJeIXQWMe8/POfMV4U sOVWg/iZvbm1+BmzCZtg4hqhKLRe2h7rNCLL3Xm70pxDrbSCXH3ku7n9OqFIexSwc8ZJQ 6DZrxhwmT4NdozGpKFGStQHScIbPtVLKg9YmBJ4w0qBu+UD2d52BODml5mO4fchvWD3sc d9Tofw9RvIHoCQavUV9MhsJF6WmbD4pxOj1iwJ6zTj0DBnLmTTu5nsrRAkdzi2puhuQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=TlZPPpIu; arc=none smtp.remote-ip=217.140.110.172 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1C7F1606EEB3; Mon, 9 Nov 2026 16:01:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 1C7F1606EEB3 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=TlZPPpIu Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6469014BF; Mon, 9 Nov 2026 08:01:08 -0800 (PST) Received: from localhost.localdomain (e123572-lin.cambridge.arm.com [10.2.208.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 834683F882; Mon, 9 Nov 2026 08:01:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1794240071; bh=mOcsxuhd+SBVwiebOzIYBEP81ioeefXUqmJIoRAwM7k=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=TlZPPpIuSAP4I+z+O/V0g8YhQgOIXJl6Swij87O2nM0jC0yFMqzP4RnfBDhA0K2Np zmenIGRDNNxgb7EkMlF/p+DzoptibtBufaC0+Z5nwO7L9q+HCuGpXOjPZRSyhynVh1 hhvLy4QHJR7+kuEIs/mMW0IpVln0Rc0+cAtMCVYk= From: Kevin Brodsky Date: Mon, 09 Nov 2026 15:58:32 +0000 Subject: [PATCH RFC v10 07/22] arm64: Initialize POR_EL1 register on cpu_resume() X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261109-kpkeys-v10-7-aa6c4d9603bc@arm.com> References: <20261109-kpkeys-v10-0-aa6c4d9603bc@arm.com> In-Reply-To: <20261109-kpkeys-v10-0-aa6c4d9603bc@arm.com> To: linux-hardening@vger.kernel.org Cc: Kevin Brodsky , Andrew Morton , Ard Biesheuvel , Andy Lutomirski , Catalin Marinas , Dave Hansen , "David Hildenbrand (Arm)" , Jann Horn , Jeff Xu , Joey Gouly , Kees Cook , Linu Cherian , Linus Walleij , Marc Zyngier , Mark Brown , Matthew Wilcox , Maxwell Bland , "Mike Rapoport (IBM)" , Peter Zijlstra , Pierre Langlois , =?utf-8?q?Pierre-Cl=C3=A9ment_Tosi?= , Quentin Perret , Rick Edgecombe , Ryan Roberts , Vlastimil Babka , Will Deacon , Yang Shi , Yeoreum Yun , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, x86@kernel.org, Ira Weiny , Lorenzo Stoakes , Thomas Gleixner X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1794240029; l=1238; i=kevin.brodsky@arm.com; s=20260427; h=from:subject:message-id; bh=4EcOfPYkS35WfcSTzCjV7Pft44Nt32DKIqSeTlSaAlM=; b=aF1hedIOdeeWnADYrxt7bKksACglTWRg1rdNE6Tt2euac3s0EchtRVpNYwIndfJ4IH5PknKuN icAYPbNLp7LAakUjUWc2ZYtxrMWslhblR5VgrliKrZYqBjuZmpAYHAn X-Developer-Key: i=kevin.brodsky@arm.com; a=ed25519; pk=N2QG+eJKrvkNovwhhwJhnJ4+ScVfsGCHldmqLfcMTFs= From: Yeoreum Yun The POR_EL1 register is reset to an unknown value after cpu_suspend(). Since POR_EL1 always holds POR_EL1_INIT when entering cpu_suspend(), initialize POR_EL1 with POR_EL1_INIT before cpu_do_resume(). Signed-off-by: Yeoreum Yun Signed-off-by: Kevin Brodsky --- arch/arm64/kernel/sleep.S | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S index f093cdf71be1..e0a6ad85cd24 100644 --- a/arch/arm64/kernel/sleep.S +++ b/arch/arm64/kernel/sleep.S @@ -3,6 +3,7 @@ #include #include #include +#include #include .text @@ -134,6 +135,17 @@ SYM_FUNC_START(_cpu_resume) /* load sp from context */ ldr x2, [x0, #CPU_CTX_SP] mov sp, x2 + +#ifdef CONFIG_ARM64_POE +alternative_if_not ARM64_HAS_S1POE + b .Lskip_por_set +alternative_else_nop_endif + mov_q x2, POR_EL1_INIT + msr_s SYS_POR_EL1, x2 + /* isb can be skipped since cpu_do_resume() will do it. */ +.Lskip_por_set: +#endif /* CONFIG_ARM64_POE */ + /* * cpu_do_resume expects x0 to contain context address pointer */ -- 2.56.0