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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-Stat-Signature: mjo1r7qw1bsu9e6b4idce6dxafg1aqif X-Rspamd-Queue-Id: C36DC180003 X-Rspam-User: X-Rspamd-Server: rspam08 X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-HE-Tag: 1793831517-949639 X-HE-Meta: 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 lkAZmVW5 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 X-Archived-By: 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