4.14-stable review patch. If anyone has any objections, please let me know.
------------------ From: Boris Ostrovsky <[email protected]> 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 <[email protected]> Signed-off-by: Boris Ostrovsky <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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 @@ -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;
