From: Sebastian Ott <sebott@linux.vnet.ibm.com>
Date: Mon, 14 Mar 2016 14:47:23 +0000 (+0100)
Subject: s390/pci: enforce fmb page boundary rule
X-Git-Tag: v3.16.35~116
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=ebf6a6c6ccefdb906b496f54775aa64008699d28;p=thirdparty%2Fkernel%2Fstable.git

s390/pci: enforce fmb page boundary rule

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: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
index 7672152a93acd..d2d23f88464fd 100644
--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -44,7 +44,7 @@ struct zpci_fmb {
 	u64 rpcit_ops;
 	u64 dma_rbytes;
 	u64 dma_wbytes;
-} __packed __aligned(16);
+} __packed __aligned(64);
 
 #define ZPCI_MSI_VEC_BITS	11
 #define ZPCI_MSI_VEC_MAX	(1 << ZPCI_MSI_VEC_BITS)
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 7558654ed33ea..950e7e3507803 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -845,8 +845,11 @@ 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;