Patch "s390/pci: enforce fmb page boundary rule" has been added to the 4.4-stable tree

Patch "s390/pci: enforce fmb page boundary rule" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    s390/pci: enforce fmb page boundary rule

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     s390-pci-enforce-fmb-page-boundary-rule.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 80c544ded25ac14d7cc3e555abb8ed2c2da99b84 Mon Sep 17 00:00:00 2001
From: Sebastian Ott <sebott@linux.vnet.ibm.com>
Date: Mon, 14 Mar 2016 15:47:23 +0100
Subject: s390/pci: enforce fmb page boundary rule

From: Sebastian Ott <sebott@linux.vnet.ibm.com>

commit 80c544ded25ac14d7cc3e555abb8ed2c2da99b84 upstream.

The function measurement block must not cross a page boundary. Ensure
that by raising the alignment requirement to the smallest power of 2
larger than the size of the fmb.

Fixes: d0b088531 ("s390/pci: performance statistics and debug infrastructure")
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/s390/include/asm/pci.h |    2 +-
 arch/s390/pci/pci.c         |    5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -45,7 +45,7 @@ struct zpci_fmb {
 	u64 rpcit_ops;
 	u64 dma_rbytes;
 	u64 dma_wbytes;
-} __packed __aligned(16);
+} __packed __aligned(64);
 
 enum zpci_state {
 	ZPCI_FN_STATE_RESERVED,
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -871,8 +871,11 @@ static inline int barsize(u8 size)
 
 static int zpci_mem_init(void)
 {
+	BUILD_BUG_ON(!is_power_of_2(__alignof__(struct zpci_fmb)) ||
+		     __alignof__(struct zpci_fmb) < sizeof(struct zpci_fmb));
+
 	zdev_fmb_cache = kmem_cache_create("PCI_FMB_cache", sizeof(struct zpci_fmb),
-				16, 0, NULL);
+					   __alignof__(struct zpci_fmb), 0, NULL);
 	if (!zdev_fmb_cache)
 		goto error_zdev;
 


Patches currently in stable-queue which might be from sebott@linux.vnet.ibm.com are

queue-4.4/s390-pci-enforce-fmb-page-boundary-rule.patch