Re: git: ccb59683b983 - main - arm64: add tests for swp/swpb emulation

On 15 May 2023, at 16:42, Kyle Evans <kevans@FreeBSD.org> wrote:
> 
> The branch main has been updated by kevans:
> 
> URL: https://cgit.FreeBSD.org/src/commit/?id=ccb59683b98360afaf5b5bb641a68fea22c68d0b
> 
> commit ccb59683b98360afaf5b5bb641a68fea22c68d0b
> Author:     Kyle Evans <kevans@FreeBSD.org>
> AuthorDate: 2023-05-15 15:42:16 +0000
> Commit:     Kyle Evans <kevans@FreeBSD.org>
> CommitDate: 2023-05-15 15:42:16 +0000
> 
>    arm64: add tests for swp/swpb emulation
> 
>    One test is suitable to be hooked up to the build, so I've done this
>    here.  The other test lives in tools/regression because failure is a
>    bit more subjective -- generally, one runs it for some unbounded amount
>    of time and observe if it eventually exits because two threads acquired
>    the same mutex.
> 
>    Reviewed by:    imp, mmel
>    Sponsored by:   Stormshield
>    Sponsored by:   Klara, Inc.
>    Differential Revision:  https://reviews.freebsd.org/D39668
> ---
> etc/mtree/BSD.tests.dist                          |   2 +
> tests/sys/Makefile                                |   1 +
> tests/sys/compat32/Makefile                       |   6 +
> tests/sys/compat32/Makefile.inc                   |   4 +
> tests/sys/compat32/aarch64/Makefile               |  24 ++
> tests/sys/compat32/aarch64/common.sh              |   9 +
> tests/sys/compat32/aarch64/swp_cond_test.sh       |  14 +
> tests/sys/compat32/aarch64/swp_cond_test_impl.S   | 413 ++++++++++++++++++++++
> tests/sys/compat32/aarch64/swp_test.sh            |  14 +
> tests/sys/compat32/aarch64/swp_test_impl.S        | 216 +++++++++++
> tools/regression/compat32/aarch64/Makefile        |   4 +
> tools/regression/compat32/aarch64/swp_test_impl.S | 410 +++++++++++++++++++++
> 12 files changed, 1117 insertions(+)
> 
> ...
> diff --git a/tests/sys/compat32/aarch64/Makefile b/tests/sys/compat32/aarch64/Makefile
> new file mode 100644
> index 000000000000..716182b15d9c
> --- /dev/null
> +++ b/tests/sys/compat32/aarch64/Makefile
> @@ -0,0 +1,24 @@
> +PACKAGE= tests
> +FILESGROUPS+= asmprogs
> +
> +ACFLAGS= -target armv7-unknown-freebsd${OS_REVISION} -nostdlib -Wl,-e -Wl,main -static

This won’t work with GCC, nor will it work with an LLVM built with only
AArch64 enabled as a target (e.g. -DWITHOUT_LLVM_TARGET_ALL
-DWITHOUT_LLVM_TARGET_ARM; latter is needed since we do default to
enabling ARM if AArch64 is even for a cut-down toolchain so that -m32
works). This is why the freebsd32 sigcode in arm64 kernels is written
as hex (with disassembly comments) rather than assembled from proper
source.

Jess