Merge tag 'mm-hotfixes-stable-2022-11-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc hotfixes from Andrew Morton:
 "22 hotfixes.

  Eight are cc:stable and the remainder address issues which were
  introduced post-6.0 or which aren't considered serious enough to
  justify a -stable backport"

* tag 'mm-hotfixes-stable-2022-11-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (22 commits)
  docs: kmsan: fix formatting of "Example report"
  mm/damon/dbgfs: check if rm_contexts input is for a real context
  maple_tree: don't set a new maximum on the node when not reusing nodes
  maple_tree: fix depth tracking in maple_state
  arch/x86/mm/hugetlbpage.c: pud_huge() returns 0 when using 2-level paging
  fs: fix leaked psi pressure state
  nilfs2: fix use-after-free bug of ns_writer on remount
  x86/traps: avoid KMSAN bugs originating from handle_bug()
  kmsan: make sure PREEMPT_RT is off
  Kconfig.debug: ensure early check for KMSAN in CONFIG_KMSAN_WARN
  x86/uaccess: instrument copy_from_user_nmi()
  kmsan: core: kmsan_in_runtime() should return true in NMI context
  mm: hugetlb_vmemmap: include missing linux/moduleparam.h
  mm/shmem: use page_mapping() to detect page cache for uffd continue
  mm/memremap.c: map FS_DAX device memory as decrypted
  Partly revert "mm/thp: carry over dirty bit when thp splits on pmd"
  nilfs2: fix deadlock in nilfs_count_free_blocks()
  mm/mmap: fix memory leak in mmap_region()
  hugetlbfs: don't delete error page from pagecache
  maple_tree: reorganize testing to restore module testing
  ...

3 files changed, 14 insertions, 0 deletions

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 178015a820f0..d3fdec706f1d 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -15,6 +15,7 @@
 #include <linux/context_tracking.h>
 #include <linux/interrupt.h>
 #include <linux/kallsyms.h>
+#include <linux/kmsan.h>
 #include <linux/spinlock.h>
 #include <linux/kprobes.h>
 #include <linux/uaccess.h>
@@ -301,6 +302,12 @@ static noinstr bool handle_bug(struct pt_regs *regs)
 {
 	bool handled = false;
 
+	/*
+	 * Normally @regs are unpoisoned by irqentry_enter(), but handle_bug()
+	 * is a rare case that uses @regs without passing them to
+	 * irqentry_enter().
+	 */
+	kmsan_unpoison_entry_regs(regs);
 	if (!is_valid_bugaddr(regs->ip))
 		return handled;
 
diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c
index f1bb18617156..24b48af27417 100644
--- a/arch/x86/lib/usercopy.c
+++ b/arch/x86/lib/usercopy.c
@@ -6,6 +6,7 @@
 
 #include <linux/uaccess.h>
 #include <linux/export.h>
+#include <linux/instrumented.h>
 
 #include <asm/tlbflush.h>
 
@@ -44,7 +45,9 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
 	 * called from other contexts.
 	 */
 	pagefault_disable();
+	instrument_copy_from_user_before(to, from, n);
 	ret = raw_copy_from_user(to, from, n);
+	instrument_copy_from_user_after(to, from, n, ret);
 	pagefault_enable();
 
 	return ret;
diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
index 6b3033845c6d..5804bbae4f01 100644
--- a/arch/x86/mm/hugetlbpage.c
+++ b/arch/x86/mm/hugetlbpage.c
@@ -37,8 +37,12 @@ int pmd_huge(pmd_t pmd)
  */
 int pud_huge(pud_t pud)
 {
+#if CONFIG_PGTABLE_LEVELS > 2
 	return !pud_none(pud) &&
 		(pud_val(pud) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT;
+#else
+	return 0;
+#endif
 }
 
 #ifdef CONFIG_HUGETLB_PAGE