Merge tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
   switching from a user process to a kernel thread.

 - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj
   Raghav.

 - zsmalloc performance improvements from Sergey Senozhatsky.

 - Yue Zhao has found and fixed some data race issues around the
   alteration of memcg userspace tunables.

 - VFS rationalizations from Christoph Hellwig:
     - removal of most of the callers of write_one_page()
     - make __filemap_get_folio()'s return value more useful

 - Luis Chamberlain has changed tmpfs so it no longer requires swap
   backing. Use `mount -o noswap'.

 - Qi Zheng has made the slab shrinkers operate locklessly, providing
   some scalability benefits.

 - Keith Busch has improved dmapool's performance, making part of its
   operations O(1) rather than O(n).

 - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
   permitting userspace to wr-protect anon memory unpopulated ptes.

 - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive
   rather than exclusive, and has fixed a bunch of errors which were
   caused by its unintuitive meaning.

 - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
   which causes minor faults to install a write-protected pte.

 - Vlastimil Babka has done some maintenance work on vma_merge():
   cleanups to the kernel code and improvements to our userspace test
   harness.

 - Cleanups to do_fault_around() by Lorenzo Stoakes.

 - Mike Rapoport has moved a lot of initialization code out of various
   mm/ files and into mm/mm_init.c.

 - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
   DRM, but DRM doesn't use it any more.

 - Lorenzo has also coverted read_kcore() and vread() to use iterators
   and has thereby removed the use of bounce buffers in some cases.

 - Lorenzo has also contributed further cleanups of vma_merge().

 - Chaitanya Prakash provides some fixes to the mmap selftesting code.

 - Matthew Wilcox changes xfs and afs so they no longer take sleeping
   locks in ->map_page(), a step towards RCUification of pagefaults.

 - Suren Baghdasaryan has improved mmap_lock scalability by switching to
   per-VMA locking.

 - Frederic Weisbecker has reworked the percpu cache draining so that it
   no longer causes latency glitches on cpu isolated workloads.

 - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
   logic.

 - Liu Shixin has changed zswap's initialization so we no longer waste a
   chunk of memory if zswap is not being used.

 - Yosry Ahmed has improved the performance of memcg statistics
   flushing.

 - David Stevens has fixed several issues involving khugepaged,
   userfaultfd and shmem.

 - Christoph Hellwig has provided some cleanup work to zram's IO-related
   code paths.

 - David Hildenbrand has fixed up some issues in the selftest code's
   testing of our pte state changing.

 - Pankaj Raghav has made page_endio() unneeded and has removed it.

 - Peter Xu contributed some rationalizations of the userfaultfd
   selftests.

 - Yosry Ahmed has fixed an issue around memcg's page recalim
   accounting.

 - Chaitanya Prakash has fixed some arm-related issues in the
   selftests/mm code.

 - Longlong Xia has improved the way in which KSM handles hwpoisoned
   pages.

 - Peter Xu fixes a few issues with uffd-wp at fork() time.

 - Stefan Roesch has changed KSM so that it may now be used on a
   per-process and per-cgroup basis.

* tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
  mm,unmap: avoid flushing TLB in batch if PTE is inaccessible
  shmem: restrict noswap option to initial user namespace
  mm/khugepaged: fix conflicting mods to collapse_file()
  sparse: remove unnecessary 0 values from rc
  mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area()
  hugetlb: pte_alloc_huge() to replace huge pte_alloc_map()
  maple_tree: fix allocation in mas_sparse_area()
  mm: do not increment pgfault stats when page fault handler retries
  zsmalloc: allow only one active pool compaction context
  selftests/mm: add new selftests for KSM
  mm: add new KSM process and sysfs knobs
  mm: add new api to enable ksm per process
  mm: shrinkers: fix debugfs file permissions
  mm: don't check VMA write permissions if the PTE/PMD indicates write permissions
  migrate_pages_batch: fix statistics for longterm pin retry
  userfaultfd: use helper function range_in_vma()
  lib/show_mem.c: use for_each_populated_zone() simplify code
  mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list()
  fs/buffer: convert create_page_buffers to folio_create_buffers
  fs/buffer: add folio_create_empty_buffers helper
  ...

1 files changed, 10 insertions, 56 deletions

diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 8209e6a86989..05f4fc265428 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -136,55 +136,9 @@ static inline void __uaccess_enable_hw_pan(void)
 			CONFIG_ARM64_PAN));
 }
 
-/*
- * The Tag Check Flag (TCF) mode for MTE is per EL, hence TCF0
- * affects EL0 and TCF affects EL1 irrespective of which TTBR is
- * used.
- * The kernel accesses TTBR0 usually with LDTR/STTR instructions
- * when UAO is available, so these would act as EL0 accesses using
- * TCF0.
- * However futex.h code uses exclusives which would be executed as
- * EL1, this can potentially cause a tag check fault even if the
- * user disables TCF0.
- *
- * To address the problem we set the PSTATE.TCO bit in uaccess_enable()
- * and reset it in uaccess_disable().
- *
- * The Tag check override (TCO) bit disables temporarily the tag checking
- * preventing the issue.
- */
-static inline void __uaccess_disable_tco(void)
-{
-	asm volatile(ALTERNATIVE("nop", SET_PSTATE_TCO(0),
-				 ARM64_MTE, CONFIG_KASAN_HW_TAGS));
-}
-
-static inline void __uaccess_enable_tco(void)
-{
-	asm volatile(ALTERNATIVE("nop", SET_PSTATE_TCO(1),
-				 ARM64_MTE, CONFIG_KASAN_HW_TAGS));
-}
-
-/*
- * These functions disable tag checking only if in MTE async mode
- * since the sync mode generates exceptions synchronously and the
- * nofault or load_unaligned_zeropad can handle them.
- */
-static inline void __uaccess_disable_tco_async(void)
-{
-	if (system_uses_mte_async_or_asymm_mode())
-		 __uaccess_disable_tco();
-}
-
-static inline void __uaccess_enable_tco_async(void)
-{
-	if (system_uses_mte_async_or_asymm_mode())
-		__uaccess_enable_tco();
-}
-
 static inline void uaccess_disable_privileged(void)
 {
-	__uaccess_disable_tco();
+	mte_disable_tco();
 
 	if (uaccess_ttbr0_disable())
 		return;
@@ -194,7 +148,7 @@ static inline void uaccess_disable_privileged(void)
 
 static inline void uaccess_enable_privileged(void)
 {
-	__uaccess_enable_tco();
+	mte_enable_tco();
 
 	if (uaccess_ttbr0_enable())
 		return;
@@ -302,8 +256,8 @@ do {									\
 #define get_user	__get_user
 
 /*
- * We must not call into the scheduler between __uaccess_enable_tco_async() and
- * __uaccess_disable_tco_async(). As `dst` and `src` may contain blocking
+ * We must not call into the scheduler between __mte_enable_tco_async() and
+ * __mte_disable_tco_async(). As `dst` and `src` may contain blocking
  * functions, we must evaluate these outside of the critical section.
  */
 #define __get_kernel_nofault(dst, src, type, err_label)			\
@@ -312,10 +266,10 @@ do {									\
 	__typeof__(src) __gkn_src = (src);				\
 	int __gkn_err = 0;						\
 									\
-	__uaccess_enable_tco_async();					\
+	__mte_enable_tco_async();					\
 	__raw_get_mem("ldr", *((type *)(__gkn_dst)),			\
 		      (__force type *)(__gkn_src), __gkn_err, K);	\
-	__uaccess_disable_tco_async();					\
+	__mte_disable_tco_async();					\
 									\
 	if (unlikely(__gkn_err))					\
 		goto err_label;						\
@@ -388,8 +342,8 @@ do {									\
 #define put_user	__put_user
 
 /*
- * We must not call into the scheduler between __uaccess_enable_tco_async() and
- * __uaccess_disable_tco_async(). As `dst` and `src` may contain blocking
+ * We must not call into the scheduler between __mte_enable_tco_async() and
+ * __mte_disable_tco_async(). As `dst` and `src` may contain blocking
  * functions, we must evaluate these outside of the critical section.
  */
 #define __put_kernel_nofault(dst, src, type, err_label)			\
@@ -398,10 +352,10 @@ do {									\
 	__typeof__(src) __pkn_src = (src);				\
 	int __pkn_err = 0;						\
 									\
-	__uaccess_enable_tco_async();					\
+	__mte_enable_tco_async();					\
 	__raw_put_mem("str", *((type *)(__pkn_src)),			\
 		      (__force type *)(__pkn_dst), __pkn_err, K);	\
-	__uaccess_disable_tco_async();					\
+	__mte_disable_tco_async();					\
 									\
 	if (unlikely(__pkn_err))					\
 		goto err_label;						\