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| author |   Boris Ostrovsky <boris.ostrovsky@oracle.com> | 2018-09-11 15:55:38 -0400 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2018-09-11 23:36:50 +0200 |
| commit | 6a92b11169a65b3f8cc512c75a252cbd0d096ba0 (patch) | |
| tree | f5fee0c92b515b594ec2d3a6c0b246608b445443 /arch/x86/kernel | |
| parent | x86/doc: Fix Documentation/x86/earlyprintk.txt (diff) | |
| download | wireguard-linux-6a92b11169a65b3f8cc512c75a252cbd0d096ba0.tar.xz wireguard-linux-6a92b11169a65b3f8cc512c75a252cbd0d096ba0.zip | |
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/kernel')
| -rw-r--r-- | arch/x86/kernel/eisa.c | 10 |
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; |