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Re: [ARM/FDPIC v4 00/20] FDPIC ABI for ARM


Ping?

The series started here:
https://gcc.gnu.org/ml/gcc-patches/2018-11/msg01464.html

Thanks,

Christophe

On Mon, 26 Nov 2018 at 11:14, Christophe Lyon
<christophe.lyon@linaro.org> wrote:
>
> Ping?
>
> Thanks
>
> On Fri, 16 Nov 2018 at 16:48, Christophe Lyon <christophe.lyon@st.com> wrote:
> >
> > From: Christophe Lyon <christophe.lyon@linaro.org>
> >
> > Hello,
> >
> > This patch series implements the GCC contribution of the FDPIC ABI for
> > ARM targets.
> >
> > This ABI enables to run Linux on ARM MMU-less cores and supports
> > shared libraries to reduce the memory footprint.
> >
> > Without MMU, text and data segments relative distances are different
> > from one process to another, hence the need for a dedicated FDPIC
> > register holding the start address of the data segment. One of the
> > side effects is that function pointers require two words to be
> > represented: the address of the code, and the data segment start
> > address. These two words are designated as "Function Descriptor",
> > hence the "FD PIC" name.
> >
> > On ARM, the FDPIC register is r9 [1], and the target name is
> > arm-uclinuxfdpiceabi. Note that arm-uclinux exists, but uses another
> > ABI and the BFLAT file format; it does not support code sharing.
> > The -mfdpic option is enabled by default, and -mno-fdpic should be
> > used to build the Linux kernel.
> >
> > This work was developed some time ago by STMicroelectronics, and was
> > presented during Linaro Connect SFO15 (September 2015). You can watch
> > the discussion and read the slides [2].
> > This presentation was related to the toolchain published on github [3],
> > which is based on binutils-2.22, gcc-4.7, uclibc-0.9.33.2, gdb-7.5.1
> > and qemu-2.3.0, and for which pre-built binaries are available [3].
> >
> > The ABI itself is described in details in [1].
> >
> > Our Linux kernel patches have been updated and committed by Nicolas
> > Pitre (Linaro) in July 2017. They are required so that the loader is
> > able to handle this new file type. Indeed, the ELF files are tagged
> > with ELFOSABI_ARM_FDPIC. This new tag has been allocated by ARM, as
> > well as the new relocations involved.
> >
> > The binutils, QEMU and uclibc-ng patch series have been merged
> > recently. [4][5][6]
> >
> > This series provides support for architectures that support ARM and/or
> > Thumb-2 and has been tested on arm-linux-gnueabi without regression,
> > as well as arm-uclinuxfdpiceabi, using QEMU. arm-uclinuxfdpiceabi has
> > more failures than arm-linux-gnueabi, but is quite functional.
> >
> > Are the GCC patches OK for inclusion in master?
> >
> > Changes between v3 and v4:
> >
> > - improved documentation (patch 1)
> > - emit an error message (sorry) if the target architecture does not
> >   support arm nor thumb-2 modes (patch 4)
> > - handle Richard's comments on patch 4 (comments, unspec)
> > - added .align directive (patch 5)
> > - fixed use of kernel helpers (__kernel_cmpxchg, __kernel_dmb) (patch 6)
> > - code factorization in patch 7
> > - typos/internal function name in patch 8
> > - improved patch 12
> > - dropped patch 16
> > - patch 20 introduces arm_arch*_thumb_ok effective targets to help
> >   skip some tests
> > - I tested patch 2 on xtensa-buildroot-uclinux-uclibc, it adds many
> >   new tests, but a few regressions
> >   (https://gcc.gnu.org/ml/gcc-patches/2018-11/msg00713.html)
> > - I compiled and executed several LTP tests to exercise pthreads and signals
> > - I wrote and executed a simple testcase to change the interaction
> >   with __kernel_cmpxchg (ie. call the kernel helper rather than use an
> >   implementation in libgcc as requested by Richard)
> >
> > Changes between v2 and v3:
> > - added doc entry for -mfdpic new option
> > - took Kyrill's comments into account (use "Armv7" instead of "7",
> >   code factorization, use preprocessor instead of hard-coding "r9",
> >   remove leftover code for thumb1 support, fixed comments)
> > - rebase over recent trunk
> > - patches with changes: 1, 2 (commit message), 3 (rebase), 4, 6, 7, 9,
> >   14 (rebase), 19 (rebase)
> >
> > Changes between v1 and v2:
> > - fix GNU coding style
> > - exit with an error for pre-Armv7
> > - use ACLE __ARM_ARCH and remove dead code for pre-Armv4
> > - remove unsupported attempts of pre-Armv7/thumb1 support
> > - add instructions in comments next to opcodes
> > - merge patches 11 and 13
> > - fixed protected visibility handling in patch 8
> > - merged legitimize_tls_address_fdpic and
> >   legitimize_tls_address_not_fdpic as requested
> >
> > Thanks,
> >
> > Christophe.
> >
> >
> > [1] https://github.com/mickael-guene/fdpic_doc/blob/master/abi.txt
> > [2] http://connect.linaro.org/resource/sfo15/sfo15-406-arm-fdpic-toolset-kernel-libraries-for-cortex-m-cortex-r-mmuless-cores/
> > [3] https://github.com/mickael-guene/fdpic_manifest
> > [4] https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commit;h=f1ac0afe481e83c9a33f247b81fa7de789edc4d9
> > [5] https://git.qemu.org/?p=qemu.git;a=commit;h=e8fa72957419c11984608062c7dcb204a6003a06
> > [6] https://cgit.uclibc-ng.org/cgi/cgit/uclibc-ng.git/commit/?id=13c46fbc1e5a021f2b9ed32d83aecc93ae5e655d
> >
> > Christophe Lyon (20):
> >   [ARM] FDPIC: Add -mfdpic option support
> >   [ARM] FDPIC: Handle arm*-*-uclinuxfdpiceabi in configure scripts
> >   [ARM] FDPIC: Force FDPIC related options unless -mno-fdpic is provided
> >   [ARM] FDPIC: Add support for FDPIC for arm architecture
> >   [ARM] FDPIC: Fix __do_global_dtors_aux and frame_dummy generation
> >   [ARM] FDPIC: Add support for c++ exceptions
> >   [ARM] FDPIC: Avoid saving/restoring r9 on stack since it is read-only
> >   [ARM] FDPIC: Enforce local/global binding for function descriptors
> >   [ARM] FDPIC: Add support for taking address of nested function
> >   [ARM] FDPIC: Implement TLS support.
> >   [ARM] FDPIC: Add support to unwind FDPIC signal frame
> >   [ARM] FDPIC: Restore r9 after we call __aeabi_read_tp
> >   [ARM] FDPIC: Force LSB bit for PC in Cortex-M architecture
> >   [ARM][testsuite] FDPIC: Skip unsupported tests
> >   [ARM][testsuite] FDPIC: Adjust scan-assembler patterns.
> >   [ARM][testsuite] FDPIC: Skip tests that don't work in PIC mode
> >   [ARM][testsuite] FDPIC: Handle *-*-uclinux*
> >   [ARM][testsuite] FDPIC: Enable tests on pie_enabled targets
> >   [ARM][testsuite] FDPIC: Adjust pr43698.c to avoid clash with uclibc.
> >   [ARM][testsuite] FDPIC: Skip tests using architectures unsupported by
> >     FDPIC
> >
> >  config/futex.m4                                    |   2 +-
> >  config/tls.m4                                      |   2 +-
> >  gcc/config.gcc                                     |  13 +-
> >  gcc/config/arm/arm-c.c                             |   2 +
> >  gcc/config/arm/arm-protos.h                        |   1 +
> >  gcc/config/arm/arm.c                               | 485 ++++++++++++++++++---
> >  gcc/config/arm/arm.h                               |  16 +-
> >  gcc/config/arm/arm.md                              | 125 +++++-
> >  gcc/config/arm/arm.opt                             |   4 +
> >  gcc/config/arm/bpabi.h                             |   4 +-
> >  gcc/config/arm/linux-eabi.h                        |   7 +-
> >  gcc/config/arm/uclinuxfdpiceabi.h                  |  53 +++
> >  gcc/config/arm/unspecs.md                          |   1 +
> >  gcc/doc/invoke.texi                                |  20 +-
> >  gcc/ginclude/unwind-arm-common.h                   |   2 +-
> >  gcc/testsuite/g++.dg/abi/forced.C                  |   2 +-
> >  gcc/testsuite/g++.dg/abi/guard2.C                  |   2 +-
> >  gcc/testsuite/g++.dg/cpp0x/noexcept03.C            |   2 +-
> >  gcc/testsuite/g++.dg/ext/cleanup-10.C              |   2 +-
> >  gcc/testsuite/g++.dg/ext/cleanup-11.C              |   2 +-
> >  gcc/testsuite/g++.dg/ext/cleanup-8.C               |   2 +-
> >  gcc/testsuite/g++.dg/ext/cleanup-9.C               |   2 +-
> >  gcc/testsuite/g++.dg/ext/sync-4.C                  |   2 +-
> >  gcc/testsuite/g++.dg/ipa/comdat.C                  |   2 +-
> >  gcc/testsuite/g++.dg/ipa/devirt-c-7.C              |   3 +-
> >  gcc/testsuite/g++.dg/ipa/ivinline-1.C              |   2 +-
> >  gcc/testsuite/g++.dg/ipa/ivinline-2.C              |   2 +-
> >  gcc/testsuite/g++.dg/ipa/ivinline-3.C              |   2 +-
> >  gcc/testsuite/g++.dg/ipa/ivinline-4.C              |   2 +-
> >  gcc/testsuite/g++.dg/ipa/ivinline-5.C              |   2 +-
> >  gcc/testsuite/g++.dg/ipa/ivinline-7.C              |   2 +-
> >  gcc/testsuite/g++.dg/ipa/ivinline-8.C              |   2 +-
> >  gcc/testsuite/g++.dg/ipa/ivinline-9.C              |   2 +-
> >  gcc/testsuite/g++.dg/other/anon5.C                 |   1 +
> >  gcc/testsuite/g++.dg/tls/pr79288.C                 |   2 +-
> >  gcc/testsuite/gcc.c-torture/compile/pr82096.c      |   2 +-
> >  gcc/testsuite/gcc.dg/20020312-2.c                  |   1 +
> >  gcc/testsuite/gcc.dg/20041106-1.c                  |   2 +-
> >  gcc/testsuite/gcc.dg/addr_equal-1.c                |   3 +-
> >  gcc/testsuite/gcc.dg/cleanup-10.c                  |   2 +-
> >  gcc/testsuite/gcc.dg/cleanup-11.c                  |   2 +-
> >  gcc/testsuite/gcc.dg/cleanup-8.c                   |   2 +-
> >  gcc/testsuite/gcc.dg/cleanup-9.c                   |   2 +-
> >  gcc/testsuite/gcc.dg/const-1.c                     |   2 +-
> >  gcc/testsuite/gcc.dg/fdata-sections-1.c            |   2 +-
> >  gcc/testsuite/gcc.dg/fdata-sections-2.c            |   2 +-
> >  gcc/testsuite/gcc.dg/ipa/pure-const-1.c            |   2 +-
> >  gcc/testsuite/gcc.dg/noreturn-8.c                  |   2 +-
> >  gcc/testsuite/gcc.dg/pr33826.c                     |   3 +-
> >  gcc/testsuite/gcc.dg/pr39323-1.c                   |   2 +-
> >  gcc/testsuite/gcc.dg/pr39323-2.c                   |   2 +-
> >  gcc/testsuite/gcc.dg/pr39323-3.c                   |   2 +-
> >  gcc/testsuite/gcc.dg/pr65780-1.c                   |   2 +-
> >  gcc/testsuite/gcc.dg/pr65780-2.c                   |   2 +-
> >  gcc/testsuite/gcc.dg/pr67338.c                     |   2 +-
> >  gcc/testsuite/gcc.dg/pr78185.c                     |   2 +-
> >  gcc/testsuite/gcc.dg/pr83100-1.c                   |   2 +-
> >  gcc/testsuite/gcc.dg/pr83100-4.c                   |   2 +-
> >  gcc/testsuite/gcc.dg/strlenopt-12g.c               |   2 +-
> >  gcc/testsuite/gcc.dg/strlenopt-14g.c               |   2 +-
> >  gcc/testsuite/gcc.dg/strlenopt-14gf.c              |   2 +-
> >  gcc/testsuite/gcc.dg/strlenopt-16g.c               |   2 +-
> >  gcc/testsuite/gcc.dg/strlenopt-17g.c               |   2 +-
> >  gcc/testsuite/gcc.dg/strlenopt-18g.c               |   2 +-
> >  gcc/testsuite/gcc.dg/strlenopt-1f.c                |   2 +-
> >  gcc/testsuite/gcc.dg/strlenopt-22g.c               |   2 +-
> >  gcc/testsuite/gcc.dg/strlenopt-2f.c                |   2 +-
> >  gcc/testsuite/gcc.dg/strlenopt-31g.c               |   2 +-
> >  gcc/testsuite/gcc.dg/strlenopt-33g.c               |   2 +-
> >  gcc/testsuite/gcc.dg/strlenopt-4g.c                |   2 +-
> >  gcc/testsuite/gcc.dg/strlenopt-4gf.c               |   2 +-
> >  gcc/testsuite/gcc.dg/strncmp-2.c                   |   2 +-
> >  gcc/testsuite/gcc.dg/struct-ret-3.c                |   2 +-
> >  gcc/testsuite/gcc.dg/torture/ipa-pta-1.c           |   2 +-
> >  gcc/testsuite/gcc.dg/torture/pr69760.c             |   2 +-
> >  gcc/testsuite/gcc.dg/tree-ssa/alias-2.c            |   2 +-
> >  gcc/testsuite/gcc.dg/tree-ssa/ipa-split-5.c        |   2 +-
> >  gcc/testsuite/gcc.dg/tree-ssa/loadpre6.c           |   2 +-
> >  gcc/testsuite/gcc.target/arm/20051215-1.c          |   1 +
> >  .../gcc.target/arm/armv6-unaligned-load-ice.c      |   1 +
> >  .../gcc.target/arm/attr-unaligned-load-ice.c       |   1 +
> >  gcc/testsuite/gcc.target/arm/attr_arm-err.c        |   1 +
> >  gcc/testsuite/gcc.target/arm/data-rel-2.c          |   1 +
> >  gcc/testsuite/gcc.target/arm/data-rel-3.c          |   1 +
> >  gcc/testsuite/gcc.target/arm/div64-unwinding.c     |   2 +-
> >  gcc/testsuite/gcc.target/arm/eliminate.c           |   2 +-
> >  gcc/testsuite/gcc.target/arm/ftest-armv4-arm.c     |   1 +
> >  gcc/testsuite/gcc.target/arm/ftest-armv4t-arm.c    |   1 +
> >  gcc/testsuite/gcc.target/arm/ftest-armv4t-thumb.c  |   1 +
> >  gcc/testsuite/gcc.target/arm/ftest-armv5t-arm.c    |   1 +
> >  gcc/testsuite/gcc.target/arm/ftest-armv5t-thumb.c  |   1 +
> >  gcc/testsuite/gcc.target/arm/ftest-armv5te-arm.c   |   1 +
> >  gcc/testsuite/gcc.target/arm/ftest-armv5te-thumb.c |   1 +
> >  gcc/testsuite/gcc.target/arm/ftest-armv6-arm.c     |   1 +
> >  gcc/testsuite/gcc.target/arm/ftest-armv6-thumb.c   |   1 +
> >  gcc/testsuite/gcc.target/arm/ftest-armv6k-arm.c    |   1 +
> >  gcc/testsuite/gcc.target/arm/ftest-armv6k-thumb.c  |   1 +
> >  gcc/testsuite/gcc.target/arm/ftest-armv6m-thumb.c  |   1 +
> >  gcc/testsuite/gcc.target/arm/ftest-armv6t2-arm.c   |   1 +
> >  gcc/testsuite/gcc.target/arm/ftest-armv6t2-thumb.c |   1 +
> >  gcc/testsuite/gcc.target/arm/ftest-armv6z-arm.c    |   1 +
> >  gcc/testsuite/gcc.target/arm/ftest-armv6z-thumb.c  |   1 +
> >  gcc/testsuite/gcc.target/arm/g2.c                  |   1 +
> >  gcc/testsuite/gcc.target/arm/interrupt-1.c         |   6 +-
> >  gcc/testsuite/gcc.target/arm/interrupt-2.c         |   6 +-
> >  gcc/testsuite/gcc.target/arm/ivopts-2.c            |   2 +-
> >  gcc/testsuite/gcc.target/arm/ivopts-3.c            |   2 +-
> >  gcc/testsuite/gcc.target/arm/ivopts-4.c            |   2 +-
> >  gcc/testsuite/gcc.target/arm/ivopts-5.c            |   2 +-
> >  gcc/testsuite/gcc.target/arm/macro_defs1.c         |   1 +
> >  gcc/testsuite/gcc.target/arm/mmx-1.c               |   1 +
> >  gcc/testsuite/gcc.target/arm/pr19599.c             |   1 +
> >  gcc/testsuite/gcc.target/arm/pr40887.c             |   1 +
> >  gcc/testsuite/gcc.target/arm/pr43597.c             |   2 +-
> >  gcc/testsuite/gcc.target/arm/pr43698.c             |   4 +-
> >  gcc/testsuite/gcc.target/arm/pr43920-2.c           |   2 +-
> >  gcc/testsuite/gcc.target/arm/pr45701-1.c           |   4 +-
> >  gcc/testsuite/gcc.target/arm/pr45701-2.c           |   4 +-
> >  gcc/testsuite/gcc.target/arm/pr59858.c             |   1 +
> >  gcc/testsuite/gcc.target/arm/pr61948.c             |   1 +
> >  gcc/testsuite/gcc.target/arm/pr65647-2.c           |   1 +
> >  gcc/testsuite/gcc.target/arm/pr66912.c             |   2 +-
> >  gcc/testsuite/gcc.target/arm/pr70830.c             |   3 +-
> >  gcc/testsuite/gcc.target/arm/pr77933-1.c           |   1 +
> >  gcc/testsuite/gcc.target/arm/pr77933-2.c           |   1 +
> >  gcc/testsuite/gcc.target/arm/pr79058.c             |   1 +
> >  gcc/testsuite/gcc.target/arm/pr83712.c             |   1 +
> >  .../gcc.target/arm/pragma_arch_switch_2.c          |   1 +
> >  gcc/testsuite/gcc.target/arm/scd42-1.c             |   1 +
> >  gcc/testsuite/gcc.target/arm/scd42-2.c             |   1 +
> >  gcc/testsuite/gcc.target/arm/scd42-3.c             |   1 +
> >  gcc/testsuite/gcc.target/arm/sibcall-1.c           |   1 +
> >  gcc/testsuite/gcc.target/arm/stack-checking.c      |   2 +-
> >  gcc/testsuite/gcc.target/arm/stack-red-zone.c      |   2 +-
> >  gcc/testsuite/gcc.target/arm/synchronize.c         |   2 +-
> >  gcc/testsuite/gcc.target/arm/tail-long-call.c      |   1 +
> >  gcc/testsuite/gcc.target/arm/tlscall.c             |   1 +
> >  gcc/testsuite/gcc.target/arm/vfp-longcall-apcs.c   |   1 +
> >  gcc/testsuite/lib/target-supports.exp              |  10 +
> >  libatomic/configure                                |   8 +-
> >  libatomic/configure.tgt                            |   2 +-
> >  libgcc/config.host                                 |   4 +-
> >  libgcc/config/arm/linux-atomic.c                   |  55 ++-
> >  libgcc/config/arm/unwind-arm.c                     |   5 +
> >  libgcc/config/arm/unwind-arm.h                     |  31 +-
> >  libgcc/crtstuff.c                                  |  18 +
> >  libgcc/unwind-arm-common.inc                       | 216 +++++++++
> >  libgcc/unwind-pe.h                                 |  17 +
> >  libitm/configure                                   |  20 +-
> >  libitm/configure.tgt                               |   2 +-
> >  libsanitizer/configure.tgt                         |   3 +
> >  libstdc++-v3/acinclude.m4                          |  12 +-
> >  libstdc++-v3/configure                             |  36 +-
> >  libstdc++-v3/configure.host                        |   6 +-
> >  libstdc++-v3/libsupc++/eh_personality.cc           |  10 +-
> >  libtool.m4                                         |  14 +-
> >  156 files changed, 1209 insertions(+), 217 deletions(-)
> >  create mode 100644 gcc/config/arm/uclinuxfdpiceabi.h
> >
> > --
> > 2.6.3
> >


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