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h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=KkYtO8mZqdaw92smrCGaZTzZI/VIzEyKkmaReuGHOucgR+tC88xl9fofAudD6UVpk k8mMgNRteA9j5G51xbINy6Vsrn2R/ZjvzJ3WLH6+D35W1zPhu88N6Lht8mUvcMEWUs dFkjBvRkKGt4/X16YT0hU7+djWqlw+f9qAt5Hw2s= From: Kevin Brodsky Date: Tue, 05 May 2026 17:05:57 +0100 Subject: [PATCH RFC v7 08/24] arm64: Initialize POR_EL1 register on cpu_resume() MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260505-kpkeys-v7-8-20c0bdd97197@arm.com> References: <20260505-kpkeys-v7-0-20c0bdd97197@arm.com> In-Reply-To: <20260505-kpkeys-v7-0-20c0bdd97197@arm.com> To: linux-hardening@vger.kernel.org Cc: Kevin Brodsky , Andrew Morton , Andy Lutomirski , Catalin Marinas , Dave Hansen , "David Hildenbrand (Arm)" , Ira Weiny , Jann Horn , Jeff Xu , Joey Gouly , Kees Cook , Linus Walleij , Marc Zyngier , Mark Brown , Matthew Wilcox , Maxwell Bland , "Mike Rapoport (IBM)" , Peter Zijlstra , Pierre Langlois , Quentin Perret , Rick Edgecombe , Ryan Roberts , Will Deacon , Yang Shi , Yeoreum Yun , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, x86@kernel.org, Lorenzo Stoakes , Thomas Gleixner , Vlastimil Babka X-Mailer: b4 0.15.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1777997220; l=1238; i=kevin.brodsky@arm.com; s=20260427; h=from:subject:message-id; bh=X72DCdJX2SxlqX4hafcg68D9WxF9xj/CvQA2EQYYzDc=; b=fim2j4aK2yghbZYMjdBQCOZyKY91r9Ul0SwmGZQdrKUeEhqyNGE1v6WJFGHlbNiKl5XqoqcSj w/Gou1BnYSkAXgMZuyZl+N93zHfpv3GYcZkYHunaDhY0KWNQFbc8UfN X-Developer-Key: i=kevin.brodsky@arm.com; a=ed25519; pk=N2QG+eJKrvkNovwhhwJhnJ4+ScVfsGCHldmqLfcMTFs= X-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 8E7A5160011 X-Stat-Signature: 6ehiuq77gq7gtdaiq6aydo1p1jtc96hs X-HE-Tag: 1777997261-242828 X-HE-Meta: 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 0DJrfvsS 1OeIIy9UVYUoScDaGX/3T4PT278FMJnSDfui+a2DbB0y3xZdYEC/JgzeEx5aKYvZFiCJud7KRPTHwY6vdZZG6lBP9APFsoSS/Z+oyLifpxGEtbAsuFAf5qT/9RJuspCpI307ZF+XZq/ZrzNykQhtmIKAuafwyEdGCncFIgy96oOerCLWoRJySEFh63Fbwqx8h0pdzcC1leSh8jzijq0oEgkNFRZJv51Kkm3XAlkWBNZXsLZpjHAlA6xAUMPfzYLCeIaV4JPS6JnQJs8Cyv2snnarPfeUPC0Rar8j2DNCVklASQ/G1DyUvRG7/TFHNYQze8ogsoxSagSsvBwcM9CNXWCaMkg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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 */ -- 2.51.2