diff mbox series

[v3,3/3] Add mremap tests

Message ID 20240717075904.2365688-4-hjl.tools@gmail.com
State New
Headers show
Series linux: Update the mremap C implementation [BZ #31968] | expand

Commit Message

H.J. Lu July 17, 2024, 7:59 a.m. UTC
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

Comments

Adhemerval Zanella Netto July 22, 2024, 6:50 p.m. UTC | #1
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>
H.J. Lu July 22, 2024, 9:13 p.m. UTC | #2
On Tue, Jul 23, 2024, 2:50 AM Adhemerval Zanella Netto <
adhemerval.zanella@linaro.org> wrote:

>
>
> 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.
>

Do you have suggestions to make the test
to fail on supported kernel without the
mremap fix?


> > 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>
>
> H.J.
Adhemerval Zanella Netto July 23, 2024, 4:35 p.m. UTC | #3
On 22/07/24 18:13, H.J. Lu wrote:
> On Tue, Jul 23, 2024, 2:50 AM Adhemerval Zanella Netto <adhemerval.zanella@linaro.org <mailto:adhemerval.zanella@linaro.org>> wrote:
> 
> 
> 
>     On 17/07/24 04:59, H.J. Lu wrote:

>     > +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.
> 
> 
> Do you have suggestions to make the test
> to fail on supported kernel without the
> mremap fix?

I don't think we should for this specific case, we are testing that the libc
is passing the correct arguments to the kernel; so either EINVAL (meaning
invalid/unsupported flags) or a successful call is expected (assuming that
the mremap usage is valid).
H.J. Lu July 23, 2024, 10:11 p.m. UTC | #4
On Wed, Jul 24, 2024, 12:35 AM Adhemerval Zanella Netto <
adhemerval.zanella@linaro.org> wrote:

>
>
> On 22/07/24 18:13, H.J. Lu wrote:
> > On Tue, Jul 23, 2024, 2:50 AM Adhemerval Zanella Netto <
> adhemerval.zanella@linaro.org <mailto:adhemerval.zanella@linaro.org>>
> wrote:
> >
> >
> >
> >     On 17/07/24 04:59, H.J. Lu wrote:
>
> >     > +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.
> >
> >
> > Do you have suggestions to make the test
> > to fail on supported kernel without the
> > mremap fix?
>
> I don't think we should for this specific case, we are testing that the
> libc
> is passing the correct arguments to the kernel; so either EINVAL (meaning
> invalid/unsupported flags) or a successful call is expected (assuming that
> the mremap usage is valid).
>

?  If a test case doesn't fail when glibc is wrong, it is useless.


>
Adhemerval Zanella Netto July 24, 2024, 3:20 p.m. UTC | #5
On 23/07/24 19:11, H.J. Lu wrote:
> 
> On Wed, Jul 24, 2024, 12:35 AM Adhemerval Zanella Netto <adhemerval.zanella@linaro.org <mailto:adhemerval.zanella@linaro.org>> wrote:
> 
> 
> 
>     On 22/07/24 18:13, H.J. Lu wrote:
>     > On Tue, Jul 23, 2024, 2:50 AM Adhemerval Zanella Netto <adhemerval.zanella@linaro.org <mailto:adhemerval.zanella@linaro.org> <mailto:adhemerval.zanella@linaro.org <mailto:adhemerval.zanella@linaro.org>>> wrote:
>     >
>     >
>     >
>     >     On 17/07/24 04:59, H.J. Lu wrote:
> 
>     >     > +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.
>     >
>     >
>     > Do you have suggestions to make the test
>     > to fail on supported kernel without the
>     > mremap fix?
> 
>     I don't think we should for this specific case, we are testing that the libc
>     is passing the correct arguments to the kernel; so either EINVAL (meaning
>     invalid/unsupported flags) or a successful call is expected (assuming that
>     the mremap usage is valid).
> 
> 
> ?  If a test case doesn't fail when glibc is wrong, it is useless.

Maybe something like the below then:

#include <errno.h>
#include <stdio.h>
#include <sys/mman.h>

#ifndef MREMAP_DONTUNMAP
#define MREMAP_DONTUNMAP 4
#endif

int main (int argc, char *argv[])
{
  void * r = mremap (0, 4096, 4096, MREMAP_MAYMOVE | MREMAP_DONTUNMAP, 0);
  printf ("r=%p (errno=%d)\n", r, errno);
}

And check for EFAULT to assume MREMAP_DONTUNMAP support.

On a 5.4 kernel:

$ ./t
r=0xffffffffffffffff (errno=22)

While on a 6.5 kernel:

$ ./t
r=0xffffffffffffffff (errno=14)
diff mbox series

Patch

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>
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>
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;
+}
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>