[LTP] [PATCH] Hugetlb: Migrating libhugetlbfs shm-perms

[Spoorthy]

Migrating the libhugetlbfs/tests/shm-perms.c test

Test Description: Test shared memory behavior when multiple threads are attached
to a segment with different permissions. A segment is created
and children attach read-only to check reservation accounting.

Signed-off-by: Spoorthy <spoorthy@linux.ibm.com>
---
 runtest/hugetlb                               |  1 +
 testcases/kernel/mem/.gitignore               |  1 +
 .../mem/hugetlb/hugeshmat/hugeshmat06.c       | 86 +++++++++++++++++++
 3 files changed, 88 insertions(+)
 create mode 100644 testcases/kernel/mem/hugetlb/hugeshmat/hugeshmat06.c

diff --git a/runtest/hugetlb b/runtest/hugetlb
index 299c07ac9..240701b2b 100644
--- a/runtest/hugetlb
+++ b/runtest/hugetlb
@@ -44,6 +44,7 @@ hugeshmat02 hugeshmat02 -i 5
 hugeshmat03 hugeshmat03 -i 5
 hugeshmat04 hugeshmat04 -i 5
 hugeshmat05 hugeshmat05 -i 5
+hugeshmat06 hugeshmat06
 
 hugeshmctl01 hugeshmctl01 -i 5
 hugeshmctl02 hugeshmctl02 -i 5
diff --git a/testcases/kernel/mem/.gitignore b/testcases/kernel/mem/.gitignore
index 7258489ed..9f7fb1e76 100644
--- a/testcases/kernel/mem/.gitignore
+++ b/testcases/kernel/mem/.gitignore
@@ -39,6 +39,7 @@
 /hugetlb/hugeshmat/hugeshmat03
 /hugetlb/hugeshmat/hugeshmat04
 /hugetlb/hugeshmat/hugeshmat05
+/hugetlb/hugeshmat/hugeshmat06
 /hugetlb/hugeshmctl/hugeshmctl01
 /hugetlb/hugeshmctl/hugeshmctl02
 /hugetlb/hugeshmctl/hugeshmctl03
diff --git a/testcases/kernel/mem/hugetlb/hugeshmat/hugeshmat06.c b/testcases/kernel/mem/hugetlb/hugeshmat/hugeshmat06.c
new file mode 100644
index 000000000..ca36ae2f4
--- /dev/null
+++ b/testcases/kernel/mem/hugetlb/hugeshmat/hugeshmat06.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/*
+ * Copyright (C) 2005-2006 IBM Corporation.
+ * Author: David Gibson & Adam Litke
+ */
+
+/*\
+ * [Description]
+ *
+ * Test shared memory behavior when multiple threads are attached  
+ * to a segment with different permissions.  A segment is created  
+ * and children attach read-only to check reservation accounting.  
+ */
+
+
+#include "tst_safe_sysv_ipc.h"
+#include "hugetlb.h"
+
+#define SEGMENT_SIZE ((size_t) 0x4000000)
+#define SEGMENT_KEY (0x82ba15ff)
+#define STRIDE (0x200000)
+#define MNTPOINT "hugetlbfs/"
+
+static int global_shmid = -1;
+
+void *shm_addr = NULL;
+static long hpage_size;
+
+int attach_segment(size_t segsize, int shmflags, int shmperms)
+{
+    int shmid;
+    shmid = SAFE_SHMGET(SEGMENT_KEY, segsize, shmflags);
+    shm_addr = SAFE_SHMAT(shmid, shm_addr, shmperms); 
+    global_shmid = shmid;
+    return shmid;
+}
+
+static void setup(void)
+{
+    hpage_size = tst_get_hugepage_size();
+}
+
+static void run_test(void)
+{
+    char *p;
+    int i, iterations;
+    long total_hpages = SAFE_READ_MEMINFO(MEMINFO_HPAGE_TOTAL);
+    if (hpage_size > SEGMENT_SIZE)
+        tst_res(TCONF,"Page size is too large for configured SEGMENT_SIZE");
+    
+    iterations = (total_hpages * hpage_size) / SEGMENT_SIZE + 1;
+    SAFE_MALLOC(sizeof(pid_t) * iterations);
+    attach_segment(SEGMENT_SIZE, IPC_CREAT | SHM_HUGETLB | 0640, 0);
+    p = (char *)shm_addr;
+    for (i = 0; i < 4; i++, p += STRIDE)
+        memset(p, 0x55, STRIDE);
+    
+    SAFE_SHMDT((const void *)shm_addr);
+    for (i = 0; i < iterations; i++)
+    {
+        SAFE_FORK();
+        attach_segment(0, 0, SHM_RDONLY);
+        SAFE_SHMDT((const void *)shm_addr);
+    }
+    tst_reap_children();
+    tst_res(TPASS, "Successfully tested shared memory behavior when multiple threads are attached");
+}
+
+static void cleanup(void)
+{
+    if (global_shmid >= 0)
+        SAFE_SHMCTL(global_shmid, IPC_RMID, NULL);
+}
+
+static struct tst_test test = {
+	.needs_root = 1,
+	.mntpoint = MNTPOINT,
+	.needs_hugetlbfs = 1,
+	.needs_tmpdir = 1,
+	.forks_child = 1,
+	.setup = setup,
+	.cleanup = cleanup,
+	.test_all = run_test,
+	.hugepages = {32, TST_NEEDS},
+};
+
-- 
2.39.3