[Xen-devel] [RFC 02/29] xen/arm: don't allow dom0 to access to vpl011 UART0 memory range

[Julien Grall <julien.grall@xxxxxxxxxx>]

As vpl011 UART is not initialized for dom 0, when the domain tries to access to
this range, a segfault will occur in Xen. The right behaviour should be a data
abort for the guest.

Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
---
 xen/arch/arm/vpl011.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/vpl011.c b/xen/arch/arm/vpl011.c
index 9472d0a..13ba623 100644
--- a/xen/arch/arm/vpl011.c
+++ b/xen/arch/arm/vpl011.c
@@ -85,7 +85,9 @@ static void uart0_print_char(char c)
 
 static int uart0_mmio_check(struct vcpu *v, paddr_t addr)
 {
-    return addr >= UART0_START && addr < UART0_END;
+    struct domain *d = v->domain;
+
+    return d->domain_id != 0 && addr >= UART0_START && addr < UART0_END;
 }
 
 static int uart0_mmio_read(struct vcpu *v, mmio_info_t *info)
-- 
Julien Grall


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