From nobody Thu Oct 9 13:21:57 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B9B522874FD for ; Wed, 18 Jun 2025 09:30:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750239015; cv=none; b=ne2kTnLUtGo/W7HDNKFlJFwAZiQNRHGUSajVDu/rvl6seC3H+8aRkPZr4MmYnni3M0Z7NS0KX/FJfb2et6/BCnnke4e9AJ7RuP6BVnbrM9jGhRxp5usEcA28nxG9gX5/K+1853ESqMXTfKdAFjgUAngv6wXJKSNZ0M2J2vmqJWA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750239015; c=relaxed/simple; bh=OvoYifwEu2fBfkD0FjsApyBqsUv2Po5f7uUa/yrPNr8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Cww0bbz1jZinTtQsSoo/M6O+fxt88nzuDtSz7ykI0XX2BMVrFXxlX95bxlVcaUL+hbycEVLkf+Q00RYYT7AAC5AlLgBHAkomvJsbxMSXWplDRvAbKN3fz6Hk3VX67fQe1ufLWv91kFnODeIsytHpTeurAQgGs24S7EUuIZ5lpQI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 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 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 79D161D15; Wed, 18 Jun 2025 02:29:52 -0700 (PDT) Received: from e129823.cambridge.arm.com (e129823.arm.com [10.1.197.6]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id CCF123F58B; Wed, 18 Jun 2025 02:30:09 -0700 (PDT) From: Yeoreum Yun To: catalin.marinas@arm.com, pcc@google.com, will@kernel.org, broonie@kernel.org, anshuman.khandual@arm.com, joey.gouly@arm.com, maz@kernel.org, oliver.upton@linux.dev, frederic@kernel.org, hardevsinh.palaniya@siliconsignals.io, samuel.holland@sifive.com, palmer@rivosinc.com, charlie@rivosinc.com, thiago.bauermann@linaro.org, bgray@linux.ibm.com, tglx@linutronix.de, puranjay@kernel.org, david@redhat.com, yang@os.amperecomputing.com, mbenes@suse.cz, joel.granados@kernel.org Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Yeoreum Yun Subject: [PATCH v7 3/8] arm64/kernel: support store-only mte tag check Date: Wed, 18 Jun 2025 10:29:52 +0100 Message-Id: <20250618092957.2069907-4-yeoreum.yun@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250618092957.2069907-1-yeoreum.yun@arm.com> References: <20250618092957.2069907-1-yeoreum.yun@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Introduce new flag -- MTE_CTRL_STORE_ONLY used to set store-only tag check. This flag isn't overridden by prefered tcf flag setting but set together with prefered setting of way to report tag check fault. Signed-off-by: Yeoreum Yun Reviewed-by: Mark Brown --- arch/arm64/include/asm/processor.h | 2 ++ arch/arm64/kernel/mte.c | 11 ++++++++++- arch/arm64/kernel/process.c | 6 +++++- 3 files changed, 17 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/pr= ocessor.h index 1bf1a3b16e88..61d62bfd5a7b 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -23,6 +23,8 @@ #define MTE_CTRL_TCF_ASYNC (1UL << 17) #define MTE_CTRL_TCF_ASYMM (1UL << 18) =20 +#define MTE_CTRL_STORE_ONLY (1UL << 19) + #ifndef __ASSEMBLY__ =20 #include diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c index 2fbfd27ff5f2..e5e773844889 100644 --- a/arch/arm64/kernel/mte.c +++ b/arch/arm64/kernel/mte.c @@ -200,7 +200,7 @@ static void mte_update_sctlr_user(struct task_struct *t= ask) * program requested values go with what was requested. */ resolved_mte_tcf =3D (mte_ctrl & pref) ? pref : mte_ctrl; - sctlr &=3D ~SCTLR_EL1_TCF0_MASK; + sctlr &=3D ~(SCTLR_EL1_TCF0_MASK | SCTLR_EL1_TCSO0_MASK); /* * Pick an actual setting. The order in which we check for * set bits and map into register values determines our @@ -212,6 +212,10 @@ static void mte_update_sctlr_user(struct task_struct *= task) sctlr |=3D SYS_FIELD_PREP_ENUM(SCTLR_EL1, TCF0, ASYNC); else if (resolved_mte_tcf & MTE_CTRL_TCF_SYNC) sctlr |=3D SYS_FIELD_PREP_ENUM(SCTLR_EL1, TCF0, SYNC); + + if (mte_ctrl & MTE_CTRL_STORE_ONLY) + sctlr |=3D SYS_FIELD_PREP(SCTLR_EL1, TCSO0, 1); + task->thread.sctlr_user =3D sctlr; } =20 @@ -371,6 +375,9 @@ long set_mte_ctrl(struct task_struct *task, unsigned lo= ng arg) (arg & PR_MTE_TCF_SYNC)) mte_ctrl |=3D MTE_CTRL_TCF_ASYMM; =20 + if (arg & PR_MTE_STORE_ONLY) + mte_ctrl |=3D MTE_CTRL_STORE_ONLY; + task->thread.mte_ctrl =3D mte_ctrl; if (task =3D=3D current) { preempt_disable(); @@ -398,6 +405,8 @@ long get_mte_ctrl(struct task_struct *task) ret |=3D PR_MTE_TCF_ASYNC; if (mte_ctrl & MTE_CTRL_TCF_SYNC) ret |=3D PR_MTE_TCF_SYNC; + if (mte_ctrl & MTE_CTRL_STORE_ONLY) + ret |=3D PR_MTE_STORE_ONLY; =20 return ret; } diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index a5ca15daeb8a..fc49f2b3ded1 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -849,10 +849,14 @@ long set_tagged_addr_ctrl(struct task_struct *task, u= nsigned long arg) if (is_compat_thread(ti)) return -EINVAL; =20 - if (system_supports_mte()) + if (system_supports_mte()) { valid_mask |=3D PR_MTE_TCF_SYNC | PR_MTE_TCF_ASYNC \ | PR_MTE_TAG_MASK; =20 + if (cpus_have_cap(ARM64_MTE_STORE_ONLY)) + valid_mask |=3D PR_MTE_STORE_ONLY; + } + if (arg & ~valid_mask) return -EINVAL; =20 --=20 LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}