From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 80C70A59 for ; Mon, 17 Mar 2025 05:09:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742188195; cv=none; b=msHfmB+qkaWeGafTmTg/OtK5ghY8SMtFspGk4ImcQ0nS2xYx8G9T8xhqbRRqK5iZQhIqJ2gXXS3O/6dibFZKHXVqHX6zHHzUpePgydi5mpNRXLUHcW12C32vDrpXAjsbN0nLNXLeON8k1xmx3lFQNGK7qV/FPbq3AMHztRG8MBQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742188195; c=relaxed/simple; bh=lPKTrtWyrCXvKk8DuEMfdxVqNMamzCz3XERzcxoNKpI=; h=Date:To:From:Subject:Message-Id; b=VaBvrh4zB46iva7cuM9aBRFT2opJyUrDLKQjyiCDtq0lBUBpNP2Lsvj6zxzQ9+g2BnedI6EGg3HZd+i0oLoR7N/oD4kKN88nnpoB9bsIAvUm0bVaoDskx++p0mgSxhVJM+w+C29j8k+efwYCwVQd0AoLbrkvevJ0BGAkiCJgZlM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=ldyOQA6/; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="ldyOQA6/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DCB4FC4CEEC; Mon, 17 Mar 2025 05:09:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1742188194; bh=lPKTrtWyrCXvKk8DuEMfdxVqNMamzCz3XERzcxoNKpI=; h=Date:To:From:Subject:From; b=ldyOQA6/FJb2HvhEgo7SZGVcFoGrsSzGVDaFm+f3Aul0JcOaeZ/OLfApwdyRzCuig 0dTE5tTy8el5OCLQzbA1hor7dltR+n5ygzbNaSGZY0FSvj9LjJuJ0REL6REBF41j0/ PKTDMhwV2dXlFnqs16X9jcq8kTRavUVBqy+NqeL4= Date: Sun, 16 Mar 2025 22:09:54 -0700 To: mm-commits@vger.kernel.org,v-songbaohua@oppo.com,vbabka@suse.cz,sj@kernel.org,si.yanteng@linux.dev,simona.vetter@ffwll.ch,peterz@infradead.org,peterx@redhat.com,pasha.tatashin@soleen.com,oleg@redhat.com,mhiramat@kernel.org,lyude@redhat.com,lorenzo.stoakes@oracle.com,liam.howlett@oracle.com,kherbst@redhat.com,jhubbard@nvidia.com,jglisse@redhat.com,jgg@nvidia.com,jannh@google.com,dakr@kernel.org,corbet@lwn.net,apopple@nvidia.com,alexs@kernel.org,airlied@gmail.com,david@redhat.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] kernel-events-uprobes-handle-device-exclusive-entries-correctly-in-__replace_page.patch removed from -mm tree Message-Id: <20250317050954.DCB4FC4CEEC@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: kernel/events/uprobes: handle device-exclusive entries correctly in __replace_page() has been removed from the -mm tree. Its filename was kernel-events-uprobes-handle-device-exclusive-entries-correctly-in-__replace_page.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: David Hildenbrand Subject: kernel/events/uprobes: handle device-exclusive entries correctly in __replace_page() Date: Mon, 10 Feb 2025 20:37:50 +0100 Ever since commit b756a3b5e7ea ("mm: device exclusive memory access") we can return with a device-exclusive entry from page_vma_mapped_walk(). __replace_page() is not prepared for that, so teach it about these PFN swap PTEs. Note that device-private entries are so far not applicable on that path, because GUP would never have returned such folios (conversion to device-private happens by page migration, not in-place conversion of the PTE). There is a race between GUP and us locking the folio to look it up using page_vma_mapped_walk(), so this is likely a fix (unless something else could prevent that race, but it doesn't look like). pte_pfn() on something that is not a present pte could give use garbage, and we'd wrongly mess up the mapcount because it was already adjusted by calling folio_remove_rmap_pte() when making the entry device-exclusive. Link: https://lkml.kernel.org/r/20250210193801.781278-9-david@redhat.com Fixes: b756a3b5e7ea ("mm: device exclusive memory access") Signed-off-by: David Hildenbrand Tested-by: Alistair Popple Cc: Alex Shi Cc: Danilo Krummrich Cc: Dave Airlie Cc: Jann Horn Cc: Jason Gunthorpe Cc: Jerome Glisse Cc: John Hubbard Cc: Jonathan Corbet Cc: Karol Herbst Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Lyude Cc: "Masami Hiramatsu (Google)" Cc: Oleg Nesterov Cc: Pasha Tatashin Cc: Peter Xu Cc: Peter Zijlstra (Intel) Cc: SeongJae Park Cc: Simona Vetter Cc: Vlastimil Babka Cc: Yanteng Si Cc: Barry Song Signed-off-by: Andrew Morton --- kernel/events/uprobes.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) --- a/kernel/events/uprobes.c~kernel-events-uprobes-handle-device-exclusive-entries-correctly-in-__replace_page +++ a/kernel/events/uprobes.c @@ -173,6 +173,7 @@ static int __replace_page(struct vm_area DEFINE_FOLIO_VMA_WALK(pvmw, old_folio, vma, addr, 0); int err; struct mmu_notifier_range range; + pte_t pte; mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, mm, addr, addr + PAGE_SIZE); @@ -192,6 +193,16 @@ static int __replace_page(struct vm_area if (!page_vma_mapped_walk(&pvmw)) goto unlock; VM_BUG_ON_PAGE(addr != pvmw.address, old_page); + pte = ptep_get(pvmw.pte); + + /* + * Handle PFN swap PTES, such as device-exclusive ones, that actually + * map pages: simply trigger GUP again to fix it up. + */ + if (unlikely(!pte_present(pte))) { + page_vma_mapped_walk_done(&pvmw); + goto unlock; + } if (new_page) { folio_get(new_folio); @@ -206,7 +217,7 @@ static int __replace_page(struct vm_area inc_mm_counter(mm, MM_ANONPAGES); } - flush_cache_page(vma, addr, pte_pfn(ptep_get(pvmw.pte))); + flush_cache_page(vma, addr, pte_pfn(pte)); ptep_clear_flush(vma, addr, pvmw.pte); if (new_page) set_pte_at(mm, addr, pvmw.pte, _ Patches currently in -mm which might be from david@redhat.com are mm-factor-out-large-folio-handling-from-folio_order-into-folio_large_order.patch mm-factor-out-large-folio-handling-from-folio_nr_pages-into-folio_large_nr_pages.patch mm-let-_folio_nr_pages-overlay-memcg_data-in-first-tail-page.patch mm-let-_folio_nr_pages-overlay-memcg_data-in-first-tail-page-fix.patch mm-move-hugetlb-specific-things-in-folio-to-page.patch mm-move-_pincount-in-folio-to-page-on-32bit.patch mm-move-_entire_mapcount-in-folio-to-page-on-32bit.patch mm-rmap-pass-dst_vma-to-folio_dup_file_rmap_pte-and-friends.patch mm-rmap-pass-vma-to-__folio_add_rmap.patch mm-rmap-abstract-large-mapcount-operations-for-large-folios-hugetlb.patch bit_spinlock-__always_inline-unlock-functions.patch mm-rmap-use-folio_large_nr_pages-in-add-remove-functions.patch mm-rmap-basic-mm-owner-tracking-for-large-folios-hugetlb.patch mm-copy-on-write-cow-reuse-support-for-pte-mapped-thp.patch mm-convert-folio_likely_mapped_shared-to-folio_maybe_mapped_shared.patch mm-config_no_page_mapcount-to-prepare-for-not-maintain-per-page-mapcounts-in-large-folios.patch fs-proc-page-remove-per-page-mapcount-dependency-for-proc-kpagecount-config_no_page_mapcount.patch fs-proc-task_mmu-remove-per-page-mapcount-dependency-for-pm_mmap_exclusive-config_no_page_mapcount.patch fs-proc-task_mmu-remove-per-page-mapcount-dependency-for-mapmax-config_no_page_mapcount.patch fs-proc-task_mmu-remove-per-page-mapcount-dependency-for-smaps-smaps_rollup-config_no_page_mapcount.patch mm-stop-maintaining-the-per-page-mapcount-of-large-folios-config_no_page_mapcount.patch