From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Tue, 22 Apr 2025 17:30:06 +0000 (-0300)
Subject: string: Fix UB on generic strcmp
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=278994710b977b423c172f7626a64026d447d8dd;p=thirdparty%2Fglibc.git

string: Fix UB on generic strcmp

Building with ubsan it trigger:

UBSAN: Undefined behaviour in ../string/strcmp.c:92:12 shift exponent 32 is too large for 32-bit type 'int'

Use an unsigned constant literal for MERGE, since op_t is defined
as unsigned.
---

diff --git a/string/strcmp.c b/string/strcmp.c
index f79dd926d3..3a325115b2 100644
--- a/string/strcmp.c
+++ b/string/strcmp.c
@@ -89,7 +89,7 @@ strcmp_unaligned_loop (const op_t *x1, const op_t *x2, op_t w1, uintptr_t ofs)
 
       /* Load the final word of P1 and align the final partial of P2.  */
       w1 = *x1++;
-      w2 = MERGE (w2b, sh_1, 0, sh_2);
+      w2 = MERGE (w2b, sh_1, 0UL, sh_2);
     }
 
   return final_cmp (w1, w2);