[LTP] [PATCH v3] Migrating the libhugetlbfs/testcases/shm-gettest.c test

[Sachin P Bappalige]

Test Description: This testcase creates shared memory segments
backed by hugepages, writes  specific patterns to each segment,
verifies pattern and detaches a shared memory segments in a loop.

This looping test was added to verify the functionality of
large page backed shared memory segments. A segment is created,
written, verified, and detached a specified number of times.

-Updated 'kernel/mem/.gitignore'
-Updated 'runtest/hugetlb' for number of iterations with -i 5

Signed-off-by: Sachin P Bappalige <sachinpb@linux.vnet.ibm.com>
---
v3:
 -Addressed v2 comments
 -Updated 'runtest/hugetlb' for number of iterations with -i 5

v2:
 -Fixed coding style errors as per 'make check'
 -Reporting TPASS moved inside do_shmtest() function
 -Moved testcase file from folder hugemmap to hugeshmget
 -Renamed testcase 'hugepage35.c' to hugeshmget06.c 
 -Updated 'kernel/mem/.gitignore'
 -Updated 'runtest/hugetlb' for number of iterations with -i 10
---
 runtest/hugetlb                               |  1 +
 testcases/kernel/mem/.gitignore               |  1 +
 .../mem/hugetlb/hugeshmget/hugeshmget06.c     | 84 +++++++++++++++++++
 3 files changed, 86 insertions(+)
 create mode 100644 testcases/kernel/mem/hugetlb/hugeshmget/hugeshmget06.c

diff --git a/runtest/hugetlb b/runtest/hugetlb
index 299c07ac9..7d8715922 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 -i 5
 
 hugeshmctl01 hugeshmctl01 -i 5
 hugeshmctl02 hugeshmctl02 -i 5
diff --git a/testcases/kernel/mem/.gitignore b/testcases/kernel/mem/.gitignore
index c96fe8bfc..d88484fa1 100644
--- a/testcases/kernel/mem/.gitignore
+++ b/testcases/kernel/mem/.gitignore
@@ -47,6 +47,7 @@
 /hugetlb/hugeshmget/hugeshmget02
 /hugetlb/hugeshmget/hugeshmget03
 /hugetlb/hugeshmget/hugeshmget05
+/hugetlb/hugeshmget/hugeshmget06
 /ksm/ksm01
 /ksm/ksm02
 /ksm/ksm03
diff --git a/testcases/kernel/mem/hugetlb/hugeshmget/hugeshmget06.c b/testcases/kernel/mem/hugetlb/hugeshmget/hugeshmget06.c
new file mode 100644
index 000000000..3491df868
--- /dev/null
+++ b/testcases/kernel/mem/hugetlb/hugeshmget/hugeshmget06.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2005-2006, IBM Corporation.
+ * Author: David Gibson & Adam Litke
+ */
+
+/*\
+ * DESCRIPTION
+ *	hugeshmget06 -
+ * This testcase creates shared memory segments backed by hugepages,
+ * writes specific patterns to each segment, verifies pattern,
+ * and detaches a shared memory segments in a loop.
+ * It ensures that the hugepage backed shared memory functionalities
+ * works correctly by validating the data written to segment.
+ */
+
+#include "hugetlb.h"
+#include "tst_safe_sysv_ipc.h"
+
+#define MNTPOINT "hugetlbfs/"
+#define NR_HUGEPAGES 4
+
+static long hpage_size;
+static int shmid = -1, key = -1;
+
+static void do_shmtest(void)
+{
+	size_t i, j;
+	char pattern;
+	char *shmaddr;
+
+	shmaddr = SAFE_SHMAT(shmid, 0, SHM_RND);
+	tst_res(TINFO, "shmaddr: %p\n", shmaddr);
+
+	for (i = 0; i < NR_HUGEPAGES; i++) {
+		pattern = 65 + (i % 26);
+		tst_res(TINFO, "Touching %p with %c\n",
+		shmaddr + (i * hpage_size), pattern);
+		memset(shmaddr + (i * hpage_size), pattern, hpage_size);
+	}
+
+	for (i = 0; i < NR_HUGEPAGES; i++) {
+		pattern = 65 + (i % 26);
+		tst_res(TINFO, "Verifying %p\n", (shmaddr + (i * hpage_size)));
+		for (j = 0; j < (size_t)hpage_size; j++)
+			if (*(shmaddr + (i * hpage_size) + j) != pattern) {
+				tst_res(TFAIL, "Got wrong byte 0x%02x expected 0x%02x",
+						*(shmaddr + (i * hpage_size) + j),
+						pattern);
+				return;
+			}
+	}
+	SAFE_SHMDT((const void *)shmaddr);
+	tst_res(TPASS, "shm hugepages works correctly");
+}
+
+static void run_test(void)
+{
+	do_shmtest();
+}
+
+static void setup(void)
+{
+	hpage_size = tst_get_hugepage_size();
+	tst_res(TINFO, "hugepage size is  %ld", hpage_size);
+	shmid = SAFE_SHMGET(key, NR_HUGEPAGES * hpage_size, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W);
+	tst_res(TINFO, "shmid: 0x%x\n", shmid);
+}
+
+static void cleanup(void)
+{
+	if (shmid >= 0)
+		SAFE_SHMCTL(shmid, IPC_RMID, NULL);
+}
+
+static struct tst_test test = {
+	.needs_root = 1,
+	.mntpoint = MNTPOINT,
+	.needs_hugetlbfs = 1,
+	.setup = setup,
+	.cleanup = cleanup,
+	.test_all = run_test,
+	.hugepages = {NR_HUGEPAGES, TST_NEEDS},
+};
-- 
2.43.0