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charset="UTF-8" X-Rspamd-Queue-Id: 1F499180008 X-Stat-Signature: xy6m9n3g4jcabuwpheamd7phhcks4wt4 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1675856701-742303 X-HE-Meta: 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 1X17vIsH nSwIeTVsdsqZ/PMXlHJFqKg7roR/OhhxZ/FpopZYsrlU62aYNKz7p7bfRQxpE/jGkO8cdSaVSlz12e9PgFLdaiU5TZm9wDQMcEUeMLFyc6wowYSVKCJb71MFMaTowQbJMXhmZKkBQrtsHzNKEiSS5xeu2mGpNU7sPgtqbEtX64w5hXto= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000921, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Feb 7, 2023 at 7:20 PM Jiaqi Yan wrote: > > Pinging KMSAN experts, for the general guidance of > kmsan_copy_page_meta vs kmsan_unpoison_memory Oh, sorry, I've missed the previous email. copy_mc_user_highpage() is expected to copy data from the user page, for which no metadata is ever allocated. Therefore we just initialize the destination shadow with zeros instead of copying anything. kmsan_copy_page_meta() is used when the metadata is copied between two kernel pages, therefore it handles the cases when page->kmsan_shadow is NULL for the source and destination pages. It might be a good idea to use kmsan_copy_page_meta() in both cases, but to do that I want to better understand what happens when kmap_local_page(from) is called in copy_mc_user_highpage(). Where does the corresponding struct page come from?