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>

misc/Makefile

@@ -257,6 +257,8 @@ tests := \
   tst-mntent-blank-passno \
   tst-mntent-escape \
   tst-mntent2 \
+  tst-mremap1 \
+  tst-mremap2 \
   tst-preadvwritev \
   tst-preadvwritev2 \
   tst-preadvwritev64 \

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>

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>

sysdeps/generic/mremap-failure.h

@@ -0,0 +1,25 @@
+/* mremap failure handling.  Generic version.
+   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/>.  */
+
+/* Return exit value on mremap failure with errno ERR.  */
+
+static int
+mremap_failure_exit (int err)
+{
+  return EXIT_FAILURE;
+}

sysdeps/unix/sysv/linux/Makefile

@@ -206,6 +206,7 @@ tests += \
   tst-getauxval \
   tst-gettid \
   tst-gettid-kill \
+  tst-linux-mremap1 \
   tst-memfd_create \
   tst-misalign-clone \
   tst-mlock2 \

sysdeps/unix/sysv/linux/mremap-failure.h

@@ -0,0 +1,30 @@
+/* mremap failure handling.  Linux version.
+   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 <support/check.h>
+
+/* Return exit value on mremap failure with errno ERR.  */
+
+static int
+mremap_failure_exit (int err)
+{
+  if (err != EINVAL)
+    return EXIT_FAILURE;
+
+  return EXIT_UNSUPPORTED;
+}

sysdeps/unix/sysv/linux/tst-linux-mremap1.c

@@ -0,0 +1,63 @@
+/* Test mremap with MREMAP_DONTUNMAP.
+   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>
+#include <mremap-failure.h>
+
+static int
+do_test (void)
+{
+  size_t old_size = getpagesize ();
+  size_t new_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;
+
+  /* Create an available 64-page mmap region.  */
+  size_t fixed_size = old_size * 64;
+  char *fixed_addr = xmmap (NULL, fixed_size, PROT_READ | PROT_WRITE,
+			    MAP_PRIVATE | MAP_ANONYMOUS, -1);
+  xmunmap (fixed_addr, fixed_size);
+
+  /* Add 3 * pagesize.  */
+  fixed_size += 3 * old_size;
+
+  /* Test MREMAP_DONTUNMAP.  It should return FIXED_ADDR created above.  */
+  char *new_addr = mremap (old_addr, old_size, new_size,
+			   MREMAP_DONTUNMAP | MREMAP_MAYMOVE,
+			   fixed_addr);
+  if (new_addr == MAP_FAILED)
+    return mremap_failure_exit (errno);
+  TEST_VERIFY_EXIT (fixed_addr == new_addr);
+  old_addr[0] = 3;
+  old_addr[old_size - 1] = 4;
+  new_addr[0] = 1;
+  new_addr[new_size - 1] = 2;
+  xmunmap (new_addr, new_size);
+  xmunmap (old_addr, old_size);
+
+  return 0;
+}
+
+#include <support/test-driver.c>