3.16.62-rc1 review patch. If anyone has any objections, please let me know.
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From: Boris Ostrovsky boris.ostrovsky@oracle.com
commit 6a92b11169a65b3f8cc512c75a252cbd0d096ba0 upstream.
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 Link: https://lkml.kernel.org/r/20180911195538.23289-1-boris.ostrovsky@oracle.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- arch/x86/kernel/eisa.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
--- a/arch/x86/kernel/eisa.c +++ b/arch/x86/kernel/eisa.c @@ -6,11 +6,17 @@ #include <linux/ioport.h> #include <linux/eisa.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;