[PATCH v3 3/3] Add mremap tests

Adhemerval Zanella Netto adhemerval.zanella@linaro.org
Mon Jul 22 18:50:29 GMT 2024



On 17/07/24 04:59, H.J. Lu wrote:
> Add tests for MREMAP_MAYMOVE and MREMAP_FIXED.  On Linux, also test
> MREMAP_DONTUNMAP.  Since MREMAP_FIXED was added to Linux kernel 2.3.31
> and MREMAP_DONTUNMAP was added to Linux kernel 5.7, mark test failure if
> MREMAP_FIXED and MREMAP_DONTUNMAP tests fail on supported Linux kernel.
> 
> Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
> ---
>  misc/Makefile                                 |  2 +
>  misc/tst-mremap1.c                            | 46 ++++++++++++++
>  misc/tst-mremap2.c                            | 54 ++++++++++++++++
>  sysdeps/generic/mremap-failure.h              | 26 ++++++++
>  sysdeps/unix/sysv/linux/Makefile              |  9 +++
>  .../unix/sysv/linux/linux-kernel-version.c    | 62 ++++++++++++++++++
>  sysdeps/unix/sysv/linux/linux-support.h       | 38 +++++++++++
>  sysdeps/unix/sysv/linux/mremap-failure.h      | 47 ++++++++++++++
>  sysdeps/unix/sysv/linux/tst-linux-mremap1.c   | 63 +++++++++++++++++++
>  9 files changed, 347 insertions(+)
>  create mode 100644 misc/tst-mremap1.c
>  create mode 100644 misc/tst-mremap2.c
>  create mode 100644 sysdeps/generic/mremap-failure.h
>  create mode 100644 sysdeps/unix/sysv/linux/linux-kernel-version.c
>  create mode 100644 sysdeps/unix/sysv/linux/linux-support.h
>  create mode 100644 sysdeps/unix/sysv/linux/mremap-failure.h
>  create mode 100644 sysdeps/unix/sysv/linux/tst-linux-mremap1.c
> 
> diff --git a/misc/Makefile b/misc/Makefile
> index 5d17c562fe..7b7f8351bf 100644
> --- a/misc/Makefile
> +++ b/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 \
> 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>

Ok.

> diff --git a/misc/tst-mremap2.c b/misc/tst-mremap2.c
> new file mode 100644
> index 0000000000..58591d43c3
> --- /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, MREMAP_FIXED);
> +  new_addr[0] = 1;
> +  new_addr[new_size - 1] = 2;
> +  xmunmap (new_addr, new_size);
> +
> +  return 0;
> +}
> +
> +#include <support/test-driver.c>

Ok.

> diff --git a/sysdeps/generic/mremap-failure.h b/sysdeps/generic/mremap-failure.h
> new file mode 100644
> index 0000000000..139a6b1fa2
> --- /dev/null
> +++ b/sysdeps/generic/mremap-failure.h
> @@ -0,0 +1,26 @@
> +/* 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 when FLAGS is
> +   passed to mremap.  */
> +
> +static int
> +mremap_failure_exit (int err, int flags)
> +{
> +  return EXIT_FAILURE;
> +}
> diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
> index 097b5a26fc..c464f85bb7 100644
> --- a/sysdeps/unix/sysv/linux/Makefile
> +++ b/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 \
> @@ -661,3 +662,11 @@ tests-internal += \
>    tst-rseq-nptl \
>    # tests-internal
>  endif
> +
> +ifeq ($(subdir),support)
> +linux-support-routines += \
> +  linux-kernel-version \
> +# linux-support-routines
> +libsupport-routines += $(linux-support-routines)
> +libsupport-static-only-routines += $(linux-support-routines)
> +endif
> diff --git a/sysdeps/unix/sysv/linux/linux-kernel-version.c b/sysdeps/unix/sysv/linux/linux-kernel-version.c
> new file mode 100644
> index 0000000000..2968c528b6
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/linux-kernel-version.c
> @@ -0,0 +1,62 @@
> +/* Initialize CPU feature data.  AArch64 version.
> +   This file is part of the GNU C Library.
> +   Copyright (C) 2017-2024 Free Software Foundation, Inc.
> +
> +   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 <sys/utsname.h>
> +#include <support/check.h>
> +#include <linux-support.h>
> +
> +unsigned int
> +make_linux_kernel_version (unsigned int version, unsigned int patch,
> +			   unsigned int sub)
> +{
> +  TEST_VERIFY_EXIT (version <= 0xff);
> +  TEST_VERIFY_EXIT (patch <= 0xff);
> +  TEST_VERIFY_EXIT (sub <= 0xffff);
> +  /* Return an unsigned int with VVPPSSSS.  */
> +  return (version << 24) | (patch << 16) | sub;
> +}
> +
> +unsigned int
> +get_linux_kernel_version (void)
> +{
> +  struct utsname buf;
> +  const char *p = &buf.release[0];
> +  unsigned int version;
> +  unsigned int patch;
> +  unsigned int sub;
> +
> +  TEST_VERIFY_EXIT (uname (&buf) == 0);
> +
> +  /* Get kernel version.  */
> +  for (version = 0; *p >= '0' && *p <= '9'; p++)
> +    version = version * 10 + *p - '0';
> +  TEST_VERIFY_EXIT (*p == '.');
> +  p++;
> +
> +  /* Get kernel patch level.  */
> +  for (patch = 0; *p >= '0' && *p <= '9'; p++)
> +    patch = patch * 10 + *p - '0';
> +  TEST_VERIFY_EXIT (*p == '.');
> +  p++;
> +
> +  /* Get kernel sub level.  */
> +  for (sub = 0; *p >= '0' && *p <= '9'; p++)
> +    sub = sub * 10 + *p - '0';
> +
> +  return make_linux_kernel_version (version, patch, sub);
> +}
> diff --git a/sysdeps/unix/sysv/linux/linux-support.h b/sysdeps/unix/sysv/linux/linux-support.h
> new file mode 100644
> index 0000000000..a7c03040b1
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/linux-support.h
> @@ -0,0 +1,38 @@
> +/* Linux-specific support functions.
> +   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/>.  */
> +
> +#ifndef LINUX_SUPPORT_H
> +#define LINUX_SUPPORT_H
> +
> +#include <sys/cdefs.h>
> +
> +__BEGIN_DECLS
> +
> +/* Return an unsigned int from version, patch level and sub level of
> +   Linux kernel.  */
> +extern unsigned int make_linux_kernel_version (unsigned int __version,
> +					       unsigned int __patch,
> +					       unsigned int __sub);
> +
> +/* Similar to make_linux_kernel_version, but version, patch level and
> +   sub level are retrieved from the uname system call.  */
> +extern unsigned int get_linux_kernel_version (void);
> +
> +__END_DECLS
> +
> +#endif /* LINUX_SUPPORT_H */
> diff --git a/sysdeps/unix/sysv/linux/mremap-failure.h b/sysdeps/unix/sysv/linux/mremap-failure.h
> new file mode 100644
> index 0000000000..bf6ffb819c
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/mremap-failure.h
> @@ -0,0 +1,47 @@
> +/* 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>
> +#include <linux-support.h>
> +
> +/* Return exit value on mremap failure with errno ERR when FLAGS is
> +   passed to mremap.  */
> +
> +static int
> +mremap_failure_exit (int err, int flags)
> +{
> +  if (err != EINVAL)
> +    return EXIT_FAILURE;
> +
> +  unsigned int kernel = get_linux_kernel_version ();
> +  TEST_VERIFY_EXIT (kernel != 0);
> +
> +  /* Since MREMAP_FIXED was added to Linux kernel 2.3.31, return
> +     EXIT_FAILURE if the kernel is 2.3.31 or newer.  */
> +  if (flags == MREMAP_FIXED
> +      && kernel >= make_linux_kernel_version (2, 3, 31))
> +    return EXIT_FAILURE;
> +
> +  /* Since MREMAP_DONTUNMAP was added to Linux kernel 5.7, return
> +     EXIT_FAILURE if the kernel is 5.7 or newer.  */
> +  if (flags == MREMAP_DONTUNMAP
> +      && kernel >= make_linux_kernel_version (5, 7, 0))
> +    return EXIT_FAILURE;
> +
> +  return EXIT_UNSUPPORTED;
> +}

I still think we should test for functionality and not tie the tests
for an specific Linux version.  So just set unsupported if mremap
MREMAP_DONTUNMAP fails with EINVAL.

> diff --git a/sysdeps/unix/sysv/linux/tst-linux-mremap1.c b/sysdeps/unix/sysv/linux/tst-linux-mremap1.c
> new file mode 100644
> index 0000000000..599f6a6009
> --- /dev/null
> +++ b/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, MREMAP_DONTUNMAP);
> +  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>


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