libelf: avoid UB in elf_xen_feature_{get,set}()

When the left shift amount is up to 31, the shifted quantity wants to be of unsigned int (or wider) type. While there also adjust types: get doesn't alter the array and returns a boolean, while both don't really accept negative "nr". Drop a stray blank each as well. Signed-off-by: Jan Beulich <[email protected]> Reviewed-by: Andrew Cooper <[email protected]> Release-Acked-By: Oleksii Kurochko <[email protected]>
xen-project · Jun 21, 2024 · 9e7c26a · 9e7c26a
1 parent c5746b0
commit 9e7c26a
Showing 1 changed file with 4 additions and 4 deletions.
diff --git a/xen/include/xen/libelf.h b/xen/include/xen/libelf.h
@@ -445,13 +445,13 @@ struct elf_dom_parms {
     uint64_t virt_kend;
 };
 
-static inline void elf_xen_feature_set(int nr, uint32_t * addr)
+static inline void elf_xen_feature_set(unsigned int nr, uint32_t *addr)
 {
-    addr[nr >> 5] |= 1 << (nr & 31);
+    addr[nr >> 5] |= 1U << (nr & 31);
 }
-static inline int elf_xen_feature_get(int nr, uint32_t * addr)
+static inline bool elf_xen_feature_get(unsigned int nr, const uint32_t *addr)
 {
-    return !!(addr[nr >> 5] & (1 << (nr & 31)));
+    return addr[nr >> 5] & (1U << (nr & 31));
 }
 
 elf_errorstatus elf_xen_parse_features(const char *features,