xen: check for kernel memory conflicting with memory layout

[firefly-linux-kernel-4.4.55.git] / arch / x86 / xen / setup.c

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 973d29441f965025be794e0f0650940be7422b58..9bd3f358f3d9963195fcde74d3622505b92f3ada 100644 (file)
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -27,6 +27,7 @@
 #include <xen/interface/memory.h>
 #include <xen/interface/physdev.h>
 #include <xen/features.h>
+#include <xen/hvc-console.h>
 #include "xen-ops.h"
 #include "vdso.h"
 #include "p2m.h"
@@ -790,6 +791,17 @@ char * __init xen_memory_setup(void)
 
        sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 
+       /*
+        * Check whether the kernel itself conflicts with the target E820 map.
+        * Failing now is better than running into weird problems later due
+        * to relocating (and even reusing) pages with kernel text or data.
+        */
+       if (xen_is_e820_reserved(__pa_symbol(_text),
+                       __pa_symbol(__bss_stop) - __pa_symbol(_text))) {
+               xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n");
+               BUG();
+       }
+
        xen_reserve_xen_mfnlist();
 
        /*