[Xen-devel] [PATCH] libxc: fix out of range shift in populate_acpi_pages

[Wei Liu <wei.liu2@xxxxxxxxxx>]

"unsigned int" is only 4-byte long and "4" is treated as int. The shift
would overflow.  Use "unsigned long" (to match the type of idx) and
"4UL" instead.

Caught by clang compilation test.

Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
---
Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
---
 tools/libxc/xc_dom_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/libxc/xc_dom_core.c b/tools/libxc/xc_dom_core.c
index 87b450c..b3feb42 100644
--- a/tools/libxc/xc_dom_core.c
+++ b/tools/libxc/xc_dom_core.c
@@ -1048,7 +1048,7 @@ static int populate_acpi_pages(struct xc_dom_image *dom,
     xc_interface *xch = dom->xch;
     uint32_t domid = dom->guest_domid;
     unsigned long idx;
-    unsigned int first_high_idx = (4 << 30) >> PAGE_SHIFT; /* 4GB */
+    unsigned long first_high_idx = (4UL << 30) >> PAGE_SHIFT; /* 4GB */
 
     for ( ; num_pages; num_pages--, extents++ )
     {
-- 
2.1.4


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