Re: [PATCH] posix: Fix mmap for m68k and ia64 (BZ#21908)

[Adhemerval Zanella <adhemerval dot zanella at linaro dot org>]

Ping.

On 06/08/2017 11:30, Adhemerval Zanella wrote:
> Default semantic for mmap2 syscall is to take the offset in 4096-byte
> units.  However m68k and ia64 mmap2 implementation take in the
> configured pagesize units and for both architecture it can be
> different values based on how kernel was built.
> 
> This patch fixes the m68k runtime discover of mmap2 offset unit
> and adds the ia64 definition to find it at runtime.
> 
> Checked the basic tst-mmap and tst-mmap-offset on m68k (the system
> is configured with 4k, so current code is already passing on this
> system) and a sanity check on x86_64-linux-gnu (which should not be
> affected by this change).  Sergei also states that ia64 loader now
> work correctly with this change.
> 
> 	Adhemerval Zanella  <adhemerval.zanella@linaro.org>
> 	Sergei Trofimovich  <slyfox@inbox.ru>
> 
> 	* sysdeps/unix/sysv/linux/m68k/mmap_internal.h (MMAP2_PAGE_SHIFT):
> 	Rename to MMAP2_PAGE_UNIT.
> 	* sysdeps/unix/sysv/linux/mmap.c: Include mmap_internal iff
> 	__OFF_T_MATCHES_OFF64_T is not defined.
> 	* sysdeps/unix/sysv/linux/mmap_internal.h (page_unit): Declare as
> 	uint64_t.
> 	(MMAP2_PAGE_UNIT) [MMAP2_PAGE_UNIT == -1]: Redefine to page_unit.
> 	(page_unit) [MMAP2_PAGE_UNIT != -1]: Remove definition.
> ---
>  ChangeLog                                    | 12 ++++++++++++
>  sysdeps/unix/sysv/linux/ia64/mmap_internal.h | 29 ++++++++++++++++++++++++++++
>  sysdeps/unix/sysv/linux/m68k/mmap_internal.h |  2 +-
>  sysdeps/unix/sysv/linux/mmap.c               |  2 +-
>  sysdeps/unix/sysv/linux/mmap_internal.h      |  6 +++---
>  5 files changed, 46 insertions(+), 5 deletions(-)
>  create mode 100644 sysdeps/unix/sysv/linux/ia64/mmap_internal.h
> 
> diff --git a/sysdeps/unix/sysv/linux/ia64/mmap_internal.h b/sysdeps/unix/sysv/linux/ia64/mmap_internal.h
> new file mode 100644
> index 0000000..dbaaa3f
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/ia64/mmap_internal.h
> @@ -0,0 +1,29 @@
> +/* Common mmap definition for Linux implementation.  Linux/ia64 version.
> +   Copyright (C) 2017 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
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#ifndef MMAP_IA64_INTERNAL_LINUX_H
> +#define MMAP_IA64_INTERNAL_LINUX_H
> +
> +/* Linux allows PAGE_SHIFT in range of [12-16] and expect
> +   mmap2 offset to be provided in based on the configured pagesize.
> +   Determine the shift dynamically with getpagesize.  */
> +#define MMAP2_PAGE_UNIT -1
> +
> +#include_next <mmap_internal.h>
> +
> +#endif
> diff --git a/sysdeps/unix/sysv/linux/m68k/mmap_internal.h b/sysdeps/unix/sysv/linux/m68k/mmap_internal.h
> index bd8bd38..9fe9d91 100644
> --- a/sysdeps/unix/sysv/linux/m68k/mmap_internal.h
> +++ b/sysdeps/unix/sysv/linux/m68k/mmap_internal.h
> @@ -22,7 +22,7 @@
>  /* ColdFire and Sun 3 kernels have PAGE_SHIFT set to 13 and expect
>     mmap2 offset to be provided in 8K pages.  Determine the shift
>     dynamically with getpagesize.  */
> -#define MMAP2_PAGE_SHIFT -1
> +#define MMAP2_PAGE_UNIT -1
>  
>  #include_next <mmap_internal.h>
>  
> diff --git a/sysdeps/unix/sysv/linux/mmap.c b/sysdeps/unix/sysv/linux/mmap.c
> index 98c2f88..59292b6 100644
> --- a/sysdeps/unix/sysv/linux/mmap.c
> +++ b/sysdeps/unix/sysv/linux/mmap.c
> @@ -21,9 +21,9 @@
>  #include <sys/mman.h>
>  #include <sysdep.h>
>  #include <stdint.h>
> -#include <mmap_internal.h>
>  
>  #ifndef __OFF_T_MATCHES_OFF64_T
> +# include <mmap_internal.h>
>  
>  /* An architecture may override this.  */
>  # ifndef MMAP_ADJUST_OFFSET
> diff --git a/sysdeps/unix/sysv/linux/mmap_internal.h b/sysdeps/unix/sysv/linux/mmap_internal.h
> index 499e389..47c0991 100644
> --- a/sysdeps/unix/sysv/linux/mmap_internal.h
> +++ b/sysdeps/unix/sysv/linux/mmap_internal.h
> @@ -27,13 +27,13 @@
>  #endif
>  
>  #if MMAP2_PAGE_UNIT == -1
> -static int page_unit;
> -
> +static uint64_t page_unit;
>  # define MMAP_CHECK_PAGE_UNIT()			\
>    if (page_unit == 0)				\
>      page_unit = __getpagesize ();
> +# undef MMAP2_PAGE_UNIT
> +# define MMAP2_PAGE_UNIT page_unit
>  #else
> -# define page_unit MMAP2_PAGE_UNIT
>  # define MMAP_CHECK_PAGE_UNIT()
>  #endif
>  
>