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

Christophe Lyon christophe.lyon@st.com
Tue Dec 11 10:27:00 GMT 2018


Ping?


On 03/12/2018 10:19, Christophe Lyon wrote:
> 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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