[PATCH v3 00/29] Teach glibc about possible page sizes and handle gaps in ld.so

[Florian Weimer]

This series is another attempt to fix bug 31943.  If the binutils RELRO
bug is fixed, we still run into a conceptual issue with LOAD segment
gaps if the system supports multiple page sizes (or at least, if ld uses
a larger page size than required on Linux, as it happens on some
targets).  To avoid the overhead and loss of test coverage by accepting
gaps everywhere, this series teaches glibc the possible range of page
sizes for each supported architecture.

Information regarding possible page sizes is useful to application
programmers, so this is exposed in a new <sys/pagesize.h> installed
header.  It is just too tempting to use this to optimize getpagesize
etc., so the series contains some commits for that as well.  No ABI
changes necessary.

There is a new build failure on loongarch, apparently unrelated, and
reported as GCC PR116887.

Thanks,
Florian

Florian Weimer (29):
  elf: Add tests to verify that l_contiguous reflects reality
  Prepare for the addition of the <sys/pagesize.h> header
  aarch64: Add <bits/pagesize.h>
  alpha: Add <bits/pagesize.h>
  arc: Add <bits/pagesize.h>
  arm: Add <bits/pagesize.h>
  csky: Add <bits/pagesize.h>
  hppa: Add <bits/pagesize.h>
  loongarch: Add <bits/pagesize.h>
  m68k: Add <bits/pagesize.h>
  microblaze: Add <bits/pagesize.h>
  mips: Add <bits/pagesize.h>
  nios2: Add <bits/pagesize.h>
  or1k: Add <bits/pagesize.h>
  powerpc: Add <bits/pagesize.h>
  riscv: Add <bits/pagesize.h>
  s390: Add <bits/pagesize.h>
  sh: Add <bits/pagesize.h>
  sparc: Add <bits/pagesize.h>
  x86: Add <bits/pagesize.h>
  misc: Add tst-getpagesize
  elf: Extract rtld_setup_phdr function from dl_main
  configure: Add --with-ld-relro-load-gaps configure option and test
  elf: Handle ld.so with LOAD segment gaps in _dl_find_object (bug
    31943)
  Install the <sys/pagesize.h> header file
  Linux: Optimize getpagesize using <sys/pagesize.h>
  malloc: Use volatile as compiler barrier in tst-memalign, tst-valloc
  posix: Use <support/next_to_fault.h> in tst-fnmatch3
  Optimize various ways to obtain the page size using <bits/pagesize.h>

 INSTALL                               |  12 +++
 NEWS                                  |   5 +
 bits/pagesize.h                       |  10 ++
 bits/shm.h                            |   9 ++
 config.h.in                           |   3 +
 configure                             |  39 ++++++++
 configure.ac                          |  20 ++++
 elf/Makefile                          |  31 ++++++
 elf/dl-find_object.c                  |  78 +++++++++------
 elf/rtld.c                            |  84 +++++++++++-----
 elf/tst-link-map-contiguous-ldso.c    |  43 ++++++++
 elf/tst-link-map-contiguous-libc.c    |  57 +++++++++++
 elf/tst-link-map-contiguous-main.c    |  45 +++++++++
 elf/tst-program-headers.py            | 137 ++++++++++++++++++++++++++
 include/sys/pagesize.h                |   1 +
 malloc/tst-memalign.c                 |  17 ++--
 malloc/tst-valloc.c                   |  17 ++--
 manual/install.texi                   |  12 +++
 manual/resource.texi                  |  31 ++++++
 misc/Makefile                         |   3 +
 misc/sys/pagesize.h                   |  32 ++++++
 misc/tst-getpagesize.c                |  65 ++++++++++++
 posix/tst-fnmatch3.c                  |  23 ++---
 posix/unistd.h                        |  21 ++++
 sysdeps/aarch64/bits/pagesize.h       |   2 +
 sysdeps/alpha/bits/pagesize.h         |   2 +
 sysdeps/arc/bits/pagesize.h           |   2 +
 sysdeps/arm/bits/pagesize.h           |   2 +
 sysdeps/csky/bits/pagesize.h          |   2 +
 sysdeps/hppa/bits/pagesize.h          |   2 +
 sysdeps/loongarch/bits/pagesize.h     |   2 +
 sysdeps/m68k/bits/pagesize.h          |   2 +
 sysdeps/m68k/coldfire/bits/pagesize.h |   2 +
 sysdeps/microblaze/bits/pagesize.h    |   2 +
 sysdeps/mips/bits/pagesize.h          |   2 +
 sysdeps/nios2/bits/pagesize.h         |   2 +
 sysdeps/or1k/bits/pagesize.h          |   2 +
 sysdeps/powerpc/bits/pagesize.h       |   2 +
 sysdeps/riscv/bits/pagesize.h         |   2 +
 sysdeps/s390/bits/pagesize.h          |   2 +
 sysdeps/sh/bits/pagesize.h            |   2 +
 sysdeps/sparc/sparc32/bits/pagesize.h |   2 +
 sysdeps/sparc/sparc64/bits/pagesize.h |   2 +
 sysdeps/unix/sysv/linux/arc/Makefile  |   5 +
 sysdeps/unix/sysv/linux/arm/Makefile  |   3 +
 sysdeps/unix/sysv/linux/getpagesize.c |   5 +
 sysdeps/x86/bits/pagesize.h           |   2 +
 47 files changed, 758 insertions(+), 90 deletions(-)
 create mode 100644 bits/pagesize.h
 create mode 100644 elf/tst-link-map-contiguous-ldso.c
 create mode 100644 elf/tst-link-map-contiguous-libc.c
 create mode 100644 elf/tst-link-map-contiguous-main.c
 create mode 100644 elf/tst-program-headers.py
 create mode 100644 include/sys/pagesize.h
 create mode 100644 misc/sys/pagesize.h
 create mode 100644 misc/tst-getpagesize.c
 create mode 100644 sysdeps/aarch64/bits/pagesize.h
 create mode 100644 sysdeps/alpha/bits/pagesize.h
 create mode 100644 sysdeps/arc/bits/pagesize.h
 create mode 100644 sysdeps/arm/bits/pagesize.h
 create mode 100644 sysdeps/csky/bits/pagesize.h
 create mode 100644 sysdeps/hppa/bits/pagesize.h
 create mode 100644 sysdeps/loongarch/bits/pagesize.h
 create mode 100644 sysdeps/m68k/bits/pagesize.h
 create mode 100644 sysdeps/m68k/coldfire/bits/pagesize.h
 create mode 100644 sysdeps/microblaze/bits/pagesize.h
 create mode 100644 sysdeps/mips/bits/pagesize.h
 create mode 100644 sysdeps/nios2/bits/pagesize.h
 create mode 100644 sysdeps/or1k/bits/pagesize.h
 create mode 100644 sysdeps/powerpc/bits/pagesize.h
 create mode 100644 sysdeps/riscv/bits/pagesize.h
 create mode 100644 sysdeps/s390/bits/pagesize.h
 create mode 100644 sysdeps/sh/bits/pagesize.h
 create mode 100644 sysdeps/sparc/sparc32/bits/pagesize.h
 create mode 100644 sysdeps/sparc/sparc64/bits/pagesize.h
 create mode 100644 sysdeps/x86/bits/pagesize.h


base-commit: 6948ee4edf0c57c556f8d5f394d9191216d05780
-- 
2.46.2