--- /dev/null
+From 2771739a7162782c0aa6424b2e3dd874e884a15d Mon Sep 17 00:00:00 2001
+From: Muchun Song <songmuchun@bytedance.com>
+Date: Tue, 22 Mar 2022 14:41:56 -0700
+Subject: mm: fix missing cache flush for all tail pages of compound page
+
+From: Muchun Song <songmuchun@bytedance.com>
+
+commit 2771739a7162782c0aa6424b2e3dd874e884a15d upstream.
+
+The D-cache maintenance inside move_to_new_page() only consider one
+page, there is still D-cache maintenance issue for tail pages of
+compound page (e.g. THP or HugeTLB).
+
+THP migration is only enabled on x86_64, ARM64 and powerpc, while
+powerpc and arm64 need to maintain the consistency between I-Cache and
+D-Cache, which depends on flush_dcache_page() to maintain the
+consistency between I-Cache and D-Cache.
+
+But there is no issues on arm64 and powerpc since they already considers
+the compound page cache flushing in their icache flush function.
+HugeTLB migration is enabled on arm, arm64, mips, parisc, powerpc,
+riscv, s390 and sh, while arm has handled the compound page cache flush
+in flush_dcache_page(), but most others do not.
+
+In theory, the issue exists on many architectures. Fix this by not
+using flush_dcache_folio() since it is not backportable.
+
+Link: https://lkml.kernel.org/r/20220210123058.79206-3-songmuchun@bytedance.com
+Fixes: 290408d4a250 ("hugetlb: hugepage migration core")
+Signed-off-by: Muchun Song <songmuchun@bytedance.com>
+Reviewed-by: Zi Yan <ziy@nvidia.com>
+Cc: Axel Rasmussen <axelrasmussen@google.com>
+Cc: David Rientjes <rientjes@google.com>
+Cc: Fam Zheng <fam.zheng@bytedance.com>
+Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
+Cc: Lars Persson <lars.persson@axis.com>
+Cc: Mike Kravetz <mike.kravetz@oracle.com>
+Cc: Peter Xu <peterx@redhat.com>
+Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ mm/migrate.c | 7 +++++--
+ 1 file changed, 5 insertions(+), 2 deletions(-)
+
+--- a/mm/migrate.c
++++ b/mm/migrate.c
+@@ -994,9 +994,12 @@ static int move_to_new_page(struct page
+ if (!PageMappingFlags(page))
+ page->mapping = NULL;
+
+- if (likely(!is_zone_device_page(newpage)))
+- flush_dcache_page(newpage);
++ if (likely(!is_zone_device_page(newpage))) {
++ int i, nr = compound_nr(newpage);
+
++ for (i = 0; i < nr; i++)
++ flush_dcache_page(newpage + i);
++ }
+ }
+ out:
+ return rc;
--- /dev/null
+From e763243cc6cb1fcc720ec58cfd6e7c35ae90a479 Mon Sep 17 00:00:00 2001
+From: Muchun Song <songmuchun@bytedance.com>
+Date: Tue, 22 Mar 2022 14:41:59 -0700
+Subject: mm: hugetlb: fix missing cache flush in copy_huge_page_from_user()
+
+From: Muchun Song <songmuchun@bytedance.com>
+
+commit e763243cc6cb1fcc720ec58cfd6e7c35ae90a479 upstream.
+
+userfaultfd calls copy_huge_page_from_user() which does not do any cache
+flushing for the target page. Then the target page will be mapped to
+the user space with a different address (user address), which might have
+an alias issue with the kernel address used to copy the data from the
+user to.
+
+Fix this issue by flushing dcache in copy_huge_page_from_user().
+
+Link: https://lkml.kernel.org/r/20220210123058.79206-4-songmuchun@bytedance.com
+Fixes: fa4d75c1de13 ("userfaultfd: hugetlbfs: add copy_huge_page_from_user for hugetlb userfaultfd support")
+Signed-off-by: Muchun Song <songmuchun@bytedance.com>
+Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
+Cc: Axel Rasmussen <axelrasmussen@google.com>
+Cc: David Rientjes <rientjes@google.com>
+Cc: Fam Zheng <fam.zheng@bytedance.com>
+Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
+Cc: Lars Persson <lars.persson@axis.com>
+Cc: Peter Xu <peterx@redhat.com>
+Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
+Cc: Zi Yan <ziy@nvidia.com>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ mm/memory.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+--- a/mm/memory.c
++++ b/mm/memory.c
+@@ -4801,6 +4801,8 @@ long copy_huge_page_from_user(struct pag
+ if (rc)
+ break;
+
++ flush_dcache_page(subpage);
++
+ cond_resched();
+ }
+ return ret_val;
--- /dev/null
+From 7c25a0b89a487878b0691e6524fb5a8827322194 Mon Sep 17 00:00:00 2001
+From: Muchun Song <songmuchun@bytedance.com>
+Date: Tue, 22 Mar 2022 14:42:08 -0700
+Subject: mm: userfaultfd: fix missing cache flush in mcopy_atomic_pte() and __mcopy_atomic()
+
+From: Muchun Song <songmuchun@bytedance.com>
+
+commit 7c25a0b89a487878b0691e6524fb5a8827322194 upstream.
+
+userfaultfd calls mcopy_atomic_pte() and __mcopy_atomic() which do not
+do any cache flushing for the target page. Then the target page will be
+mapped to the user space with a different address (user address), which
+might have an alias issue with the kernel address used to copy the data
+from the user to. Fix this by insert flush_dcache_page() after
+copy_from_user() succeeds.
+
+Link: https://lkml.kernel.org/r/20220210123058.79206-7-songmuchun@bytedance.com
+Fixes: b6ebaedb4cb1 ("userfaultfd: avoid mmap_sem read recursion in mcopy_atomic")
+Fixes: c1a4de99fada ("userfaultfd: mcopy_atomic|mfill_zeropage: UFFDIO_COPY|UFFDIO_ZEROPAGE preparation")
+Signed-off-by: Muchun Song <songmuchun@bytedance.com>
+Cc: Axel Rasmussen <axelrasmussen@google.com>
+Cc: David Rientjes <rientjes@google.com>
+Cc: Fam Zheng <fam.zheng@bytedance.com>
+Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
+Cc: Lars Persson <lars.persson@axis.com>
+Cc: Mike Kravetz <mike.kravetz@oracle.com>
+Cc: Peter Xu <peterx@redhat.com>
+Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
+Cc: Zi Yan <ziy@nvidia.com>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ mm/userfaultfd.c | 3 +++
+ 1 file changed, 3 insertions(+)
+
+--- a/mm/userfaultfd.c
++++ b/mm/userfaultfd.c
+@@ -53,6 +53,8 @@ static int mcopy_atomic_pte(struct mm_st
+ /* don't free the page */
+ goto out;
+ }
++
++ flush_dcache_page(page);
+ } else {
+ page = *pagep;
+ *pagep = NULL;
+@@ -572,6 +574,7 @@ retry:
+ err = -EFAULT;
+ goto out;
+ }
++ flush_dcache_page(page);
+ goto retry;
+ } else
+ BUG_ON(page);
x86-kprobes-prohibit-probing-on-instruction-which-has-emulate-prefix.patch
kvm-x86-svm-account-for-family-17h-event-renumberings-in-amd_pmc_perf_hw_id.patch
bluetooth-fix-the-creation-of-hdev-name.patch
+mm-fix-missing-cache-flush-for-all-tail-pages-of-compound-page.patch
+mm-hugetlb-fix-missing-cache-flush-in-copy_huge_page_from_user.patch
+mm-userfaultfd-fix-missing-cache-flush-in-mcopy_atomic_pte-and-__mcopy_atomic.patch
projects / thirdparty / kernel / stable-queue.git / commitdiff
