From: Florian Weimer <fweimer@redhat.com>
Date: Tue, 16 May 2023 21:26:40 +0000 (+0200)
Subject: stdlib: Avoid undefined behavior in stdlib/tst-labs
X-Git-Tag: glibc-2.38~249
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=10a81dd4cf89276f7b1208ed044b93ae846800ce;p=thirdparty%2Fglibc.git

stdlib: Avoid undefined behavior in stdlib/tst-labs

The last loop could attempt to overflow beyond INT_MAX on 32-bit
architectures.

Also switch to GNU style.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
---

diff --git a/stdlib/tst-labs.c b/stdlib/tst-labs.c
index 92b456745ac..a8d2381f87b 100644
--- a/stdlib/tst-labs.c
+++ b/stdlib/tst-labs.c
@@ -25,25 +25,26 @@
 
 static int do_test (void)
 {
-  long i;
+  long int i;
 
-  TEST_COMPARE(labs(LONG_MAX), LONG_MAX);
-  TEST_COMPARE(labs(LONG_MIN + 1), LONG_MAX);
-  TEST_COMPARE(labs(-1), 1);
-  TEST_COMPARE(labs(0), 0);
-  TEST_COMPARE(labs(1), 1);
+  TEST_COMPARE (labs (LONG_MAX), LONG_MAX);
+  TEST_COMPARE (labs (LONG_MIN + 1), LONG_MAX);
+  TEST_COMPARE (labs (-1), 1);
+  TEST_COMPARE (labs (0), 0);
+  TEST_COMPARE (labs (1), 1);
 
   for (i = LONG_MIN + 1; i < LONG_MIN + INT_MAX; i += LARGE_PRIME)
-    TEST_COMPARE(labs(i), -i);
+    TEST_COMPARE (labs (i), -i);
 
-  for (i = LONG_MAX - INT_MAX; i < LONG_MAX - LARGE_PRIME; i += LARGE_PRIME)
-    TEST_COMPARE(labs(i), i);
+  for (i = LONG_MAX - INT_MAX; i < LONG_MAX - LARGE_PRIME;
+       i += LARGE_PRIME)
+    TEST_COMPARE (labs (i), i);
 
   for (i = INT_MIN + 1; i < 0; i += LARGE_PRIME)
-    TEST_COMPARE(labs(i), -i);
+    TEST_COMPARE (labs (i), -i);
 
-  for (i = 0; i < INT_MAX; i += LARGE_PRIME)
-    TEST_COMPARE(labs(i), i);
+  for (i = 0; i <= INT_MAX - LARGE_PRIME; i += LARGE_PRIME)
+    TEST_COMPARE (labs (i), i);
 
   return EXIT_SUCCESS;
 }