Add mremap tests

Add tests for MREMAP_MAYMOVE and MREMAP_FIXED.  On Linux, also test
MREMAP_DONTUNMAP.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
(cherry picked from commit ff0320bec2810192d453c579623482fab87bfa01)

3 files changed, 101 insertions, 1 deletions

diff --git a/misc/Makefile b/misc/Makefile
index 3d8a569d06..8cd9bbc28c 100644
--- a/misc/Makefile
+++ b/misc/Makefile
@@ -90,7 +90,7 @@ tests := tst-dirname tst-tsearch tst-fdset tst-mntent tst-hsearch \
 	 tst-preadvwritev2 tst-preadvwritev64v2 tst-warn-wide \
 	 tst-ldbl-warn tst-ldbl-error tst-dbl-efgcvt tst-ldbl-efgcvt \
 	 tst-mntent-autofs tst-syscalls tst-mntent-escape tst-select \
-	 tst-ioctl
+	 tst-ioctl tst-mremap1 tst-mremap2
 
 tests-time64 := \
   tst-select-time64 \
diff --git a/misc/tst-mremap1.c b/misc/tst-mremap1.c
new file mode 100644
index 0000000000..0469991a6c
--- /dev/null
+++ b/misc/tst-mremap1.c
@@ -0,0 +1,46 @@
+/* Test mremap with MREMAP_MAYMOVE.
+   Copyright (C) 2024 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <sys/mman.h>
+#include <support/xstdlib.h>
+#include <support/xunistd.h>
+#include <support/check.h>
+#include <support/test-driver.h>
+
+static int
+do_test (void)
+{
+  size_t old_size = getpagesize ();
+  char *old_addr = xmmap (NULL, old_size, PROT_READ | PROT_WRITE,
+			  MAP_PRIVATE | MAP_ANONYMOUS, -1);
+  old_addr[0] = 1;
+  old_addr[old_size - 1] = 2;
+
+  /* Test MREMAP_MAYMOVE.  */
+  size_t new_size = old_size + old_size;
+  char *new_addr = mremap (old_addr, old_size, new_size, MREMAP_MAYMOVE);
+  TEST_VERIFY_EXIT (new_addr != MAP_FAILED);
+  new_addr[0] = 1;
+  new_addr[new_size - 1] = 2;
+  xmunmap (new_addr, new_size);
+
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/misc/tst-mremap2.c b/misc/tst-mremap2.c
new file mode 100644
index 0000000000..45be7f0369
--- /dev/null
+++ b/misc/tst-mremap2.c
@@ -0,0 +1,54 @@
+/* Test mremap with MREMAP_FIXED.
+   Copyright (C) 2024 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <sys/mman.h>
+#include <support/xstdlib.h>
+#include <support/xunistd.h>
+#include <support/test-driver.h>
+#include <mremap-failure.h>
+
+static int
+do_test (void)
+{
+  size_t old_size = getpagesize ();
+  size_t new_size = old_size + old_size;
+  char *old_addr = xmmap (NULL, old_size, PROT_READ | PROT_WRITE,
+			  MAP_PRIVATE | MAP_ANONYMOUS, -1);
+  old_addr[0] = 1;
+  old_addr[old_size - 1] = 2;
+
+  char *fixed_addr = xmmap (NULL, new_size, PROT_READ | PROT_WRITE,
+			    MAP_PRIVATE | MAP_ANONYMOUS, -1);
+  fixed_addr[0] = 1;
+  fixed_addr[new_size - 1] = 2;
+
+  /* Test MREMAP_FIXED.  */
+  char *new_addr = mremap (old_addr, old_size, new_size,
+			   MREMAP_FIXED | MREMAP_MAYMOVE,
+			   fixed_addr);
+  if (new_addr == MAP_FAILED)
+    return mremap_failure_exit (errno);
+  new_addr[0] = 1;
+  new_addr[new_size - 1] = 2;
+  xmunmap (new_addr, new_size);
+
+  return 0;
+}
+
+#include <support/test-driver.c>