From c6cd93d150a2418d0d5d6d90a5e258d4653f437f Mon Sep 17 00:00:00 2001
From: Meng-Huan Yu <menghuan@chromium.org>
Date: Fri, 12 Mar 2021 03:18:51 +0800
Subject: [PATCH] use memfd_create instead of shm_open

---
 src/os.cc | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/os.cc b/src/os.cc
index 089b92d..61f22cb 100644
--- a/src/os.cc
+++ b/src/os.cc
@@ -36,6 +36,7 @@
 #include <sys/shm.h>
 #endif
 #include <unistd.h>
+#include <sys/mman.h>
 
 #ifndef SHM_HUGETLB
 #define SHM_HUGETLB      04000  // remove when glibc defines it
@@ -580,7 +581,9 @@ bool OsLayer::AllocateTestMem(int64 length, uint64 paddr_base) {
       int shm_object;
       void *shmaddr = NULL;
 
-      shm_object = shm_open("/stressapptest", O_CREAT | O_RDWR, S_IRWXU);
+      // shm_open doesn't work because /dev/shm will not occupy all memory by
+      // default. Use memfd_create() instead.
+      shm_object = memfd_create("/stressapptest", 0);
       if (shm_object < 0) {
         int err = errno;
         string errtxt = ErrorString(err);
@@ -631,7 +634,6 @@ bool OsLayer::AllocateTestMem(int64 length, uint64 paddr_base) {
       logprintf(0, "Log: Using posix shared memory object 0x%x %s.\n",
                 shm_object, location_message);
     } while (0);
-    shm_unlink("/stressapptest");
   }
 #endif  // HAVE_SYS_SHM_H
 
-- 
2.31.0.rc2.261.g7f71774620-goog