Re: [PATCH] hugemmap/hugemmap37: migrated task-size-overrun.c from libhugetlbfs

Cyril Hrubis <[email protected]> Tue, 4 Aug 2026 18:14:49 +0200
Newsgroups gmane.linux.ltp
Message-ID <[email protected]>
Hi!
Pushed with following diff, thanks.

Changes:

- use TDEBUG for the verbose messages
- use TST_EXP_* macros, on Linux mmap() without MAP_FIXED ignores the
  address hint and always succeeds
- moved the code that locates task_size into the test setup() so that
  it's called exactly once on test with -i 10

diff --git a/testcases/kernel/mem/hugetlb/hugemmap/hugemmap37.c b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap37.c
index c15b4ad33..addd717e3 100644
--- a/testcases/kernel/mem/hugetlb/hugemmap/hugemmap37.c
+++ b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap37.c
@@ -34,6 +34,7 @@
 #define MNTPOINT "hugetlbfs/"
 
 static long hpage_size;
+static unsigned long task_size;
 static int fd = -1;
 
 static unsigned long find_last_mapped(void)
@@ -100,10 +101,10 @@ static unsigned long find_task_size(void)
 		p = mmap((void *)addr, page_size, PROT_READ,
 			   MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, -1, 0);
 		if (p == MAP_FAILED) {
-			tst_res(TINFO | TERRNO, "Map failed at 0x%lx", addr);
+			tst_res(TDEBUG | TERRNO, "Map failed at 0x%lx", addr);
 			high = pfn;
 		} else {
-			tst_res(TINFO, "Map succeeded at 0x%lx", addr);
+			tst_res(TDEBUG, "Map succeeded at 0x%lx", addr);
 			SAFE_MUNMAP(p, page_size);
 			low = pfn;
 		}
@@ -114,45 +115,35 @@ static unsigned long find_task_size(void)
 
 static void run_test(void)
 {
-	void *p;
-	unsigned long task_size;
 	unsigned long straddle_addr;
 
-	task_size = find_task_size();
-	tst_res(TINFO, "TASK_SIZE = 0x%lx", task_size);
-
 	straddle_addr = task_size - hpage_size;
 	straddle_addr = LTP_ALIGN(straddle_addr, hpage_size);
 
 	tst_res(TINFO, "Mapping without MAP_FIXED at %lx...", straddle_addr);
-	errno = 0;
-	p = mmap((void *)straddle_addr, 2*hpage_size, PROT_READ|PROT_WRITE,
-		 MAP_SHARED, fd, 0);
-	if (p == (void *)straddle_addr) {
-		tst_res(TFAIL, "Apparently succeeded in mapping across TASK_SIZE boundary");
-		SAFE_MUNMAP(p, 2*hpage_size);
-	} else if (p != MAP_FAILED) {
-		tst_res(TPASS, "mmap without MAP_FIXED correctly avoided TASK_SIZE boundary");
-		SAFE_MUNMAP(p, 2*hpage_size);
-	} else {
-		tst_res(TPASS, "mmap without MAP_FIXED correctly failed");
-	}
+
+	TST_EXP_PASS_PTR_VOID(mmap((void *)straddle_addr, 2*hpage_size,
+	                      PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0));
+
+	if (TST_RET_PTR != MAP_FAILED)
+		SAFE_MUNMAP(TST_RET_PTR, 2*hpage_size);
 
 	tst_res(TINFO, "Mapping with MAP_FIXED at %lx...", straddle_addr);
-	errno = 0;
-	p = mmap((void *)straddle_addr, 2*hpage_size, PROT_READ|PROT_WRITE,
-		 MAP_SHARED|MAP_FIXED, fd, 0);
-	if (p != MAP_FAILED) {
-		tst_res(TFAIL, "Apparently succeeded in mapping across TASK_SIZE boundary");
-		SAFE_MUNMAP(p, 2*hpage_size);
-	} else {
-		tst_res(TPASS, "mmap with MAP_FIXED correctly failed");
-	}
+
+	TST_EXP_FAIL_PTR_VOID(mmap((void *)straddle_addr, 2*hpage_size,
+	                      PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, 0), ENOMEM);
+
+	if (TST_RET_PTR != MAP_FAILED)
+		SAFE_MUNMAP(TST_RET_PTR, 2*hpage_size);
 }
 
 static void setup(void)
 {
 	hpage_size = tst_get_hugepage_size();
+
+	task_size = find_task_size();
+	tst_res(TINFO, "TASK_SIZE = 0x%lx", task_size);
+
 	fd = tst_creat_unlinked(MNTPOINT, 0, 0600);
 }
 



-- 
Cyril Hrubis
[email protected]

-- 
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