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=1793831516; b=1J9/oYE81wuSKHIBPeLHcXLx1/A+BmeO15hv+QIUe2UQJLIfU9T1cdhbaaOQX3ZSPuUD e7+FUcjzoPBTsdt9Zi/8q+jfC3CCACcOjyaGzIQ05JLiGcPQOxZTk08SgiDWqCSWFK0aB 25r7lyj3+UPPUT0CULgOKrJojUCuSAUSYfMUlqZiMN7pIKmR1HknJecw+3ARD/PmT0DvC J85/NcTu141V6mHnNxFmL53quIVMBWNUAxl2OwszO7kLP6b+nxiHwVKo9j8B/ES5iw1Oy HkLV7WN9FEft4u+cs58i3ATrbHQb/zbkezZgqznrVCcTslCxsTzBI5ovYv1ewFtinXw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793831516; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=IZQGrkSDxvYhOH9fwbZBQNsu+CCHkAHmzOvW9coQa1A=; b=R4lgxQSun9I5twS45Dw78vP+H3m0wCvNfuTYxtDE8t0paOUSgaCYqflXE6DLqwGsuEAb RA0ZHn5QETe/fRttrkWybhJt/Oz+mUsfOJXghC7cyB+I5sa4sStKsPBe6whyJcU+PKsqp suN1tNrK/MiFIeTuwWYBV7XeGk6tq4S4fFGXgjq+qIgMx1056Y8BTWmEZv9/X0YvpQaIL ubKdAVonYU1dcUHJDJrUxtUYKX1XDEpj0Uo3L/SQaQi3RrmwPF3HJEIgRShh4RW1dzHNd XALCjbQEQaX1Ylkct+P7GVUpwRre3UBpYPGpdRjqIKxW7j27Bq/2ecIkGGtxQPuzirA== 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=oJ2Pr3YC; 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 46C5F606A33A for ; Wed, 4 Nov 2026 22:31:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=oJ2Pr3YC Received: by smtp.kernel.org (Postfix) with ESMTPSA id F2E521F00A1A; Wed, 4 Nov 2026 22:31:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793831516; bh=IZQGrkSDxvYhOH9fwbZBQNsu+CCHkAHmzOvW9coQa1A=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=oJ2Pr3YCv8dGpxd1xuaOrMwBYV5a9uJr7xhfDvM8vD7VPOlh8TaPvZKNZpepXtr1N f9aLC7HUTzzF9ZB0C/3KBjub7+Ms40UFnUqCjaL055Wwqp7XGDFW+c+sMTyZxhghO6 4L8fvkKe6BUWGHiFDUK7vJR8JyvB9nEFAiFlh2fGtbAA2aQDVAGtAveu7Wq3e5+r7z g/thipPF5Vcukvu5HkKuDNwQIFqBF/HyGAe0zbFsqZJlpx6lR0WczSy9qBrZ/u6jT8 35qox3c7eqNJHZ4D+YPLBmar7ocYtv4uzBvf6J6Llu/3Vam4xvYgWykqpC9dipK+ue 0CFkN7/FKW7Zw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [RFC PATCH v3 1/3] mm, x86: support copying a folio using non-temporal stores Reply-To: sashiko-reviews@lists.linux.dev To: "Huan Nguyen" , tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, Liam.Howlett@oracle.com, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, trondmy@kernel.org, anna@kernel.org, ziy@nvidia.com, matthew.brost@intel.com, joshua.hahnjy@gmail.com, rakie.kim@sk.com, byungchul@sk.com, gourry@gourry.net, ying.huang@linux.alibaba.com, apopple@nvidia.com, rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, jackmanb@google.com, hannes@cmpxchg.org, shivankg@amd.com Cc: rientjes@google.com, dave@stgolabs.net, nifan.cxl@gmail.com, fvdl@google.com, jic23@kernel.org, rkodsara@amd.com, bharata@amd.com, sj@kernel.org, weixugc@google.com, xuezhengchu@huawei.com, yiannis@zptcorp.com, yiannis.nikolakop@gmail.com, dimitrios.palyvos@zptcorp.com, alirad.malek@zptcorp.com, ryan.roberts@arm.com, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, "Chuck Lever" , "Jeff Layton" In-Reply-To: <20261103223025.2482227-2-nhuhuan@google.com> References: <20260730-rfc-nt-demote-v2-0-452dbe3b5073@zptcorp.com> <20261103223025.2482227-1-nhuhuan@google.com> <20261103223025.2482227-2-nhuhuan@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 04 Nov 2026 22:31:53 +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(= s) to consider: - [Low] x86/mm: missing KCFI_REFERENCE() for copy_mc_page_nt() -- commit c8614f6dfdf00a57c43828a75e8413d839e5a48b Author: Huan Nguyen mm, x86: support copying a folio using non-temporal stores This commit adds copy_mc_page_nt(), copy_mc_highpage_nt(), and folio_mc_copy_nt() to support machine-check safe copying of folios on x86_64 using non-temporal stores. > diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_6= 4.h > index 1895c207f629a..f37126b562390 100644 > --- a/arch/x86/include/asm/page_64.h > +++ b/arch/x86/include/asm/page_64.h > @@ -114,7 +114,9 @@ static inline void clear_page(void *addr) > clear_pages(addr, 1); > } > =20 > +#define __HAVE_ARCH_COPY_PAGE_NT 1 > void copy_page(void *to, void *from); > +unsigned long copy_mc_page_nt(void *to, const void *from); > KCFI_REFERENCE(copy_page); [Severity: Low] In arch/x86/lib/copy_page_64.S, copy_mc_page_nt() is defined using SYM_TYPED_FUNC_START(copy_mc_page_nt) and exported from assembly via EXPORT_SYMBOL_GPL(copy_mc_page_nt): arch/x86/lib/copy_page_64.S: SYM_TYPED_FUNC_START(copy_mc_page_nt) ... SYM_FUNC_END(copy_mc_page_nt) EXPORT_SYMBOL_GPL(copy_mc_page_nt) When CONFIG_CFI_CLANG is enabled, SYM_TYPED_FUNC_START(copy_mc_page_nt) emi= ts a relocation against __kcfi_typeid_copy_mc_page_nt. Because Clang only emits __kcfi_typeid_ symbols in C translation units where the function has = its address taken, and EXPORT_SYMBOL_GPL() in an assembly file does not include the C-only __ADDRESSABLE() annotation, nothing in C takes the address of copy_mc_page_nt() (which is only called directly from copy_mc_highpage_nt()= in include/linux/highmem.h). Will building with CONFIG_CFI_CLANG=3Dy fail at link time with an undefined reference to __kcfi_typeid_copy_mc_page_nt unless KCFI_REFERENCE(copy_mc_page_nt) is added alongside KCFI_REFERENCE(copy_page) in arch/x86/include/asm/page_64.h? --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261103223025.2482= 227-1-nhuhuan@google.com?part=3D1