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authorBoris Ostrovsky <boris.ostrovsky@oracle.com>2018-09-11 22:55:38 +0300
committerThomas Gleixner <tglx@linutronix.de>2018-09-12 00:36:50 +0300
commit6a92b11169a65b3f8cc512c75a252cbd0d096ba0 (patch)
treef5fee0c92b515b594ec2d3a6c0b246608b445443 /arch/x86
parent07e846bace717729fd20b5d99521a5f8c7d7a9cb (diff)
downloadlinux-6a92b11169a65b3f8cc512c75a252cbd0d096ba0.tar.xz
x86/EISA: Don't probe EISA bus for Xen PV guests
For unprivileged Xen PV guests this is normal memory and ioremap will not be able to properly map it. While at it, since ioremap may return NULL, add a test for pointer's validity. Reported-by: Andy Smith <andy@strugglers.net> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: hpa@zytor.com Cc: xen-devel@lists.xenproject.org Cc: jgross@suse.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180911195538.23289-1-boris.ostrovsky@oracle.com
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/eisa.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/x86/kernel/eisa.c b/arch/x86/kernel/eisa.c
index f260e452e4f8..e8c8c5d78dbd 100644
--- a/arch/x86/kernel/eisa.c
+++ b/arch/x86/kernel/eisa.c
@@ -7,11 +7,17 @@
#include <linux/eisa.h>
#include <linux/io.h>
+#include <xen/xen.h>
+
static __init int eisa_bus_probe(void)
{
- void __iomem *p = ioremap(0x0FFFD9, 4);
+ void __iomem *p;
+
+ if (xen_pv_domain() && !xen_initial_domain())
+ return 0;
- if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24))
+ p = ioremap(0x0FFFD9, 4);
+ if (p && readl(p) == 'E' + ('I' << 8) + ('S' << 16) + ('A' << 24))
EISA_bus = 1;
iounmap(p);
return 0;