[glibc] malloc: Fix tst bug in malloc/tst-free-errno-malloc-hugetlb1.

[Yinyu Cai]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=d4ccda8e69f29ea3600c1d1cbc7e32db4e186ea4

commit d4ccda8e69f29ea3600c1d1cbc7e32db4e186ea4
Author: caiyinyu <caiyinyu@loongson.cn>
Date:   Thu Aug 14 16:28:46 2025 +0800

    malloc: Fix tst bug in malloc/tst-free-errno-malloc-hugetlb1.
    
    When transparent hugepages (THP) are configured to 32MB on x86/loongarch
    systems, the current big_size value may not be sufficiently large to
    guarantee that free(ptr) [1] will call munmap(ptr_aligned, big_size).
    
    Tested on x86_64 and loongarch64.
    
    PS: Without this patch and using 32M THP, there is a about 50% chance
    that malloc/tst-free-errno-malloc-hugetlb1 will fail on both x86_64 and
    loongarch64.
    
    [1] malloc/tst-free-errno.c:
    ...
           errno = 1789;
           /* This call to free() is supposed to call
                munmap (ptr_aligned, big_size);
              which increases the number of VMAs by 1, which is supposed
              to fail.  */
    ->     free (ptr);
           TEST_VERIFY (get_errno () == 1789);
         }
    ...
    
    Reviewed-by: Wilco Dijkstra  <Wilco.Dijkstra@arm.com>

Diff:
---
 malloc/tst-free-errno.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/malloc/tst-free-errno.c b/malloc/tst-free-errno.c
index 0e7a0f2b71..1c50860e7e 100644
--- a/malloc/tst-free-errno.c
+++ b/malloc/tst-free-errno.c
@@ -88,7 +88,7 @@ do_test (void)
 	FAIL_EXIT1 ("cannot create temporary file");
 
       /* Do a large memory allocation.  */
-      size_t big_size = 0x1000000;
+      size_t big_size = 0x3000000;
       void * volatile ptr = xmalloc (big_size - 0x100);
       char *ptr_aligned = (char *) ((uintptr_t) ptr & ~(pagesize - 1));
       /* This large memory allocation allocated a memory area