save/restore: Use page-aligned allocations for hypercall args that are

mlock()ed across other hypercall invocations, to avoid aliasing with
other hypercall arguments, causing spurious unlocking.

Signed-off-by: Tim Deegan <Tim.Deegan@citrix.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/tools/libxc/xg_private.h b/tools/libxc/xg_private.h
index 2ed3f55849..2b863f7b74 100644
--- a/tools/libxc/xg_private.h
+++ b/tools/libxc/xg_private.h
@@ -7,6 +7,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <malloc.h>
 #include <sys/mman.h>
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -176,4 +177,21 @@ int xc_copy_to_domain_page(int xc_handle, uint32_t domid,
 int pin_table(int xc_handle, unsigned int type, unsigned long mfn,
               domid_t dom);
 
+/* Grrr portability */
+static inline void *xg_memalign(size_t alignment, size_t size)
+{
+#if defined(_POSIX_C_SOURCE) && !defined(__sun__)
+    int ret;
+    void *ptr;
+    ret = posix_memalign(&ptr, alignment, size);
+    if (ret != 0)
+        return NULL;
+    return ptr;
+#elif defined(_BSD)
+    return valloc(size);
+#else
+    return memalign(alignment, size);
+#endif
+}
+
 #endif /* XG_PRIVATE_H */