From 392c9625439e00e1bc71ca799dff2c5d2bf24161 Mon Sep 17 00:00:00 2001
From: richardsonnick <nic.rr@icloud.com>
Date: Tue, 23 Dec 2025 16:40:02 -0500
Subject: [PATCH] correct mmap error check

Update mmap error validation to check for MAP_FAILED instead of NULL.
POSIX specifies that mmap returns MAP_FAILED (-1) on failure.
---
 programs/fileio.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/programs/fileio.c b/programs/fileio.c
index 4000c5b62f4..a0dcad81745 100644
--- a/programs/fileio.c
+++ b/programs/fileio.c
@@ -1050,7 +1050,9 @@ static size_t FIO_setDictBufferMMap(FIO_Dict_t* dict, const char* fileName, FIO_
     }
 
     *bufferPtr = mmap(NULL, (size_t)fileSize, PROT_READ, MAP_PRIVATE, fileHandle, 0);
-    if (*bufferPtr==NULL) EXM_THROW(34, "%s", strerror(errno));
+    if (*bufferPtr == MAP_FAILED) {
+      EXM_THROW(34, "%s", strerror(errno))
+    }
 
     close(fileHandle);
     return (size_t)fileSize;