Merge tag 'v4.14.159' into 4.14-2.0.x-imx

This is the 4.14.159 stable release

Conflicts:
	arch/arm/Kconfig.debug
	arch/arm/boot/dts/imx7s.dtsi
	arch/arm/mach-imx/cpuidle-imx6sx.c
	drivers/crypto/caam/caamalg.c
	drivers/crypto/mxs-dcp.c
	drivers/dma/imx-sdma.c
	drivers/input/keyboard/imx_keypad.c
	drivers/net/can/flexcan.c
	drivers/net/can/rx-offload.c
	drivers/net/wireless/ath/ath10k/pci.c
	drivers/pci/dwc/pci-imx6.c
	drivers/spi/spi-fsl-lpspi.c
	drivers/usb/dwc3/gadget.c

1 files changed, 18 insertions, 2 deletions

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 584b14c774c1..5f966c94732b 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -565,12 +565,28 @@ static inline int PageTransCompound(struct page *page)
  *
  * Unlike PageTransCompound, this is safe to be called only while
  * split_huge_pmd() cannot run from under us, like if protected by the
- * MMU notifier, otherwise it may result in page->_mapcount < 0 false
+ * MMU notifier, otherwise it may result in page->_mapcount check false
  * positives.
+ *
+ * We have to treat page cache THP differently since every subpage of it
+ * would get _mapcount inc'ed once it is PMD mapped.  But, it may be PTE
+ * mapped in the current process so comparing subpage's _mapcount to
+ * compound_mapcount to filter out PTE mapped case.
  */
 static inline int PageTransCompoundMap(struct page *page)
 {
-	return PageTransCompound(page) && atomic_read(&page->_mapcount) < 0;
+	struct page *head;
+
+	if (!PageTransCompound(page))
+		return 0;
+
+	if (PageAnon(page))
+		return atomic_read(&page->_mapcount) < 0;
+
+	head = compound_head(page);
+	/* File THP is PMD mapped and not PTE mapped */
+	return atomic_read(&page->_mapcount) ==
+	       atomic_read(compound_mapcount_ptr(head));
 }
 
 /*