From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794318707; b=hVcmXCb9MnInx3oNd8L5UPR2BKfMaAeiMcgiEVWyM4wnmp45QlAvyYbSfvhdamEyJn6i PO9RnaNcStGyCv0zAzU1VbqRjl/cSWf5N6YRhzVx4WxtnMmAw6SwroWEi7dr5GqbaMMv0 djALbNUlX23S2OFMeEeGb4aaZEWSOKBwZN3h5LDXY3gKu0/k8aseWniOfxOmWZ/5ETyrV gCcOjVGuhLjshmfrQRjqhbV4MNcWbb233BPikUed/TP7b/iaZdoUn2xtawJpMZbBMm1Fw U6XuiwftIYTW6cFYMOk9KScn+4UhIXVDkasfZ5vzQtQtRnZ9i2U4ORFGKDGkl8C+7fg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794318707; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=DgMB87bjjOhJubk+hnBQVvUaHtmOByTmAGnQuDuOPkc=; b=uVfbG7lzFZTKwJ1oRQQWEx67TYtpN5NsADfg82sD9/bD8VB0G5wtrmw1mpltS/9aEg2u gLRPqOT+pKfzCF+DlSxfEdqL3gpjp7HN3FifZHXpmXhhP/LkrVoryX+CGdKxu+WQGcbJH wQ6qfLEgSK9iA8PXjUk6pE1FGygrvBys0YMtPdFIQL2nG4aIV4CLAZR5PXJWduRbw+8dM W9brjOZ3SMefYvLvxnPTTI7NjRaBnfrDCjB1l38ODCoTVMTTOnPlSkeSDUUGKNHHGsV4s VwnXqwVp1Ec9BbeGaBqPeR8Wws+jiGW1pf2RkqLAPt+54oJFIB4J8vs/YXIXYAcdKAg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=L35YLwyk; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1BE29606A32E; Tue, 10 Nov 2026 13:51:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=L35YLwyk Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5968F1F0089F; Tue, 10 Nov 2026 13:51:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794318706; bh=DgMB87bjjOhJubk+hnBQVvUaHtmOByTmAGnQuDuOPkc=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=L35YLwykVOSrGxvbsrb1u3khnVzNXdXgakJy4Rkd8urakgak65Pxog7+j9n13CK34 oRXOCloZFEVBh8KHZtaASdAn7zOxHwlsMKpYDKZEjz+2xdMk3RHSg5SZjzrFO4cudu KGKXJGspaknuLBzI44niWPugCnd0bp/kCSgeQ0Y6REwQGNV7kcCuJaV8weXy+EERYN /PUHMwKxtwy7/Jkpju2j1tUoSPXz4Mr4CbbJJssA+A3UfX7gpcw4Jhb8xRTxOJCWCo p1eSmUoVXOTAWGk6Gz5VbeeR8JwJZ0dkwfxiLhwru5TtiaQX6nyYqgcickCDQVOqRo UvQfdeWId7beA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v6 3/6] riscv: accept the atomic extensions this kernel was built with Reply-To: sashiko-reviews@lists.linux.dev To: "Vladimir Kondratiev" Cc: bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org, ojeda@kernel.org, gary@garyguo.net In-Reply-To: <20261110-lrsc-only-v6-3-bafc3cc0fcae@mobileye.com> References: <20261110-lrsc-only-v6-0-bafc3cc0fcae@mobileye.com> <20261110-lrsc-only-v6-3-bafc3cc0fcae@mobileye.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 10 Nov 2026 13:51:45 +0000 X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Thank you for your contribution! Sashiko AI review found 1 potential issue to consider: - [Medium] riscv: hwprobe_one_pair() falsely reports IMA base on zalrsc-only harts -- commit 28e749f3a8a1535f66a4515b72ef2377c9c49282 Author: Vladimir Kondratiev riscv: accept the atomic extensions this kernel was built with This commit updates riscv_early_of_processor_hartid() to accept harts whose riscv,isa-extensions property lists "zalrsc" (and "zaamo" when CONFIG_RISCV_ISA_ZAAMO is enabled) instead of "a". > diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c > index 3dbc8cc557dd1..9ba0d49c87bc3 100644 > --- a/arch/riscv/kernel/cpu.c > +++ b/arch/riscv/kernel/cpu.c > @@ -82,12 +82,29 @@ int __init riscv_early_of_processor_hartid(struct dev= ice_node *node, unsigned lo > return -ENODEV; > =20 > if (of_property_match_string(node, "riscv,isa-extensions", "i") < 0 || > - of_property_match_string(node, "riscv,isa-extensions", "m") < 0 || > - of_property_match_string(node, "riscv,isa-extensions", "a") < 0) { > - pr_warn("CPU with hartid=3D%lu does not support ima", *hart); > + of_property_match_string(node, "riscv,isa-extensions", "m") < 0) { > + pr_warn("CPU with hartid=3D%lu does not support im", *hart); > return -ENODEV; > } > =20 > + /* > + * Require the atomic extensions this kernel was built with. "a" > + * covers both; otherwise LR/SC is always needed and AMO is needed > + * when the kernel uses it. > + */ > + if (of_property_match_string(node, "riscv,isa-extensions", "a") < 0) { > + if (of_property_match_string(node, "riscv,isa-extensions", "zalrsc") <= 0) { > + pr_warn("CPU with hartid=3D%lu does not support zalrsc", *hart); > + return -ENODEV; > + } > + > + if (IS_ENABLED(CONFIG_RISCV_ISA_ZAAMO) && > + of_property_match_string(node, "riscv,isa-extensions", "zaamo") < = 0) { > + pr_warn("CPU with hartid=3D%lu does not support zaamo", *hart); > + return -ENODEV; > + } > + } [Severity: Medium] As reported by Conor Dooley on v4 [1], when CONFIG_RISCV_ISA_ZAAMO is disabled and a hart boots with only "zalrsc" (without "a" or "zaamo"), does hwprobe_one_pair() still report RISCV_HWPROBE_BASE_BEHAVIOR_IMA for RISCV_HWPROBE_KEY_BASE_BEHAVIOR? arch/riscv/kernel/sys_hwprobe.c:hwprobe_one_pair() { ... case RISCV_HWPROBE_KEY_BASE_BEHAVIOR: pair->value =3D RISCV_HWPROBE_BASE_BEHAVIOR_IMA; break; ... } RISCV_HWPROBE_BASE_BEHAVIOR_IMA advertises full rv32ima or rv64ima support, including Zaamo AMO instructions, so userspace querying hwprobe on a zalrsc-only hart will be told that AMO instructions are supported and can fault with SIGILL when executing them. [1] https://lore.kernel.org/r/20261103-pushcart-very-04a34d0ffb0e@spud --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261110-lrsc-only-= v6-0-bafc3cc0fcae@mobileye.com?part=3D3