From 4dd323029094d93dbc8d174fe744fd7f54f0a7a4 Mon Sep 17 00:00:00 2001 From: Roger Pau Monne Date: Wed, 13 Aug 2025 14:48:08 +0200 Subject: [PATCH] pdx: cast PAGE_SIZE value ahead of shifting MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Coverity complains that: In expression 0x1000 << bottom_shift, left shifting by more than 31 bits has undefined behavior. The shift amount, bottom_shift, is as much as 63. Cast PAGE_SIZE to paddr_t so it has the right width. Reported-by: Andrew Cooper Coverity ID: 1662707 Fixes: bac2000063ba ('x86-64: reduce range spanned by 1:1 mapping and frame table indexes') Signed-off-by: Roger Pau Monné Reviewed-by: Andrew Cooper --- xen/common/pdx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/xen/common/pdx.c b/xen/common/pdx.c index 9e6b36086f..06536cc639 100644 --- a/xen/common/pdx.c +++ b/xen/common/pdx.c @@ -274,7 +274,7 @@ bool __init pfn_pdx_compression_setup(paddr_t base) pfn_pdx_hole_shift = hole_shift; pfn_pdx_bottom_mask = (1UL << bottom_shift) - 1; - ma_va_bottom_mask = (PAGE_SIZE << bottom_shift) - 1; + ma_va_bottom_mask = ((paddr_t)PAGE_SIZE << bottom_shift) - 1; pfn_hole_mask = ((1UL << hole_shift) - 1) << bottom_shift; pfn_top_mask = ~(pfn_pdx_bottom_mask | pfn_hole_mask); ma_top_mask = pfn_top_mask << PAGE_SHIFT;