Merge tag 'asoc-v5.7' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

ASoC: Updates for v5.7

This is a very big update for the core since Morimoto-san has been
rather busy continuing his refactorings to clean up a lot of the cruft
that we have accumilated over the years.  We've also gained several new
drivers, including initial (but still not complete) parts of the Intel
SoundWire support.

 - Lots of refactorings to modernize the code from Morimoto-san.
 - Conversion of SND_SOC_ALL_CODECS to use imply from Geert Uytterhoeven.
 - Continued refactoring and fixing of the Intel support.
 - Soundwire and more advanced clocking support for Realtek RT5682.
 - Support for amlogic GX, Meson 8, Meson 8B and T9015 DAC, Broadcom
   DSL/PON, Ingenic JZ4760 and JZ4770, Realtek RL6231, and TI TAS2563 and
   TLV320ADCX140.

1 files changed, 36 insertions, 2 deletions

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 7a8e84f86831..311c0dadf71c 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -161,6 +161,31 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
 	return pages;
 }
 
+/*
+ * Used when setting automatic NUMA hinting protection where it is
+ * critical that a numa hinting PMD is not confused with a bad PMD.
+ */
+static inline int pmd_none_or_clear_bad_unless_trans_huge(pmd_t *pmd)
+{
+	pmd_t pmdval = pmd_read_atomic(pmd);
+
+	/* See pmd_none_or_trans_huge_or_clear_bad for info on barrier */
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	barrier();
+#endif
+
+	if (pmd_none(pmdval))
+		return 1;
+	if (pmd_trans_huge(pmdval))
+		return 0;
+	if (unlikely(pmd_bad(pmdval))) {
+		pmd_clear_bad(pmd);
+		return 1;
+	}
+
+	return 0;
+}
+
 static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
 		pud_t *pud, unsigned long addr, unsigned long end,
 		pgprot_t newprot, int dirty_accountable, int prot_numa)
@@ -178,8 +203,17 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
 		unsigned long this_pages;
 
 		next = pmd_addr_end(addr, end);
-		if (!is_swap_pmd(*pmd) && !pmd_trans_huge(*pmd) && !pmd_devmap(*pmd)
-				&& pmd_none_or_clear_bad(pmd))
+
+		/*
+		 * Automatic NUMA balancing walks the tables with mmap_sem
+		 * held for read. It's possible a parallel update to occur
+		 * between pmd_trans_huge() and a pmd_none_or_clear_bad()
+		 * check leading to a false positive and clearing.
+		 * Hence, it's necessary to atomically read the PMD value
+		 * for all the checks.
+		 */
+		if (!is_swap_pmd(*pmd) && !pmd_devmap(*pmd) &&
+		     pmd_none_or_clear_bad_unless_trans_huge(pmd))
 			goto next;
 
 		/* invoke the mmu notifier if the pmd is populated */