Re: [PATCH 6.4 000/239] 6.4.8-rc1 review

Naresh Kamboju
2023-08-02T02:53:17Z

On Tue, 1 Aug 2023 at 15:11, Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> This is the start of the stable review cycle for the 6.4.8 release.
> There are 239 patches in this series, all will be posted as a response
> to this one. If anyone has any issues with these being applied, please
> let me know.
>
> Responses should be made by Thu, 03 Aug 2023 09:18:38 +0000.
> Anything received after that time might be too late.
>
> The whole patch series can be found in one patch at:
> https://www.kernel.org/pub/linux/kernel/v6.x/stable-review/patch-6.4.8-rc1.gz
> or in the git tree and branch at:
> git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-6.4.y
> and the diffstat can be found below.
>
> thanks,
>
> greg k-h

Following kselftest build regression found,

selftests/rseq: Play nice with binaries statically linked against
glibc 2.35+
commit 3bcbc20942db5d738221cca31a928efc09827069 upstream.

To allow running rseq and KVM's rseq selftests as statically linked
binaries, initialize the various "trampoline" pointers to point directly
at the expect glibc symbols, and skip the dlysm() lookups if the rseq
size is non-zero, i.e. the binary is statically linked *and* the libc
registered its own rseq.

Define weak versions of the symbols so as not to break linking against
libc versions that don't support rseq in any capacity.

The KVM selftests in particular are often statically linked so that they
can be run on targets with very limited runtime environments, i.e. test
machines.

Fixes: 233e667e1ae3 ("selftests/rseq: Uplift rseq selftests for
compatibility with glibc-2.35")
Cc: Aaron Lewis <aaronlewis@google.com>
Cc: kvm@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230721223352.2333911-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Build log:
----
x86_64-linux-gnu-gcc -O2 -Wall -g -I./ -isystem
/home/tuxbuild/.cache/tuxmake/builds/1/build/usr/include
-L/home/tuxbuild/.cache/tuxmake/builds/1/build/kselftest/rseq
-Wl,-rpath=./ -shared -fPIC rseq.c -lpthread -ldl -o
/home/tuxbuild/.cache/tuxmake/builds/1/build/kselftest/rseq/librseq.so
rseq.c:41:1: error: unknown type name '__weak'
41 | __weak ptrdiff_t __rseq_offset;
| ^~~~~~
rseq.c:41:18: error: expected '=', ',', ';', 'asm' or '__attribute__'
before '__rseq_offset'
41 | __weak ptrdiff_t __rseq_offset;
| ^~~~~~~~~~~~~
rseq.c:42:7: error: expected ';' before 'unsigned'
42 | __weak unsigned int __rseq_size;
| ^~~~~~~~~
| ;
rseq.c:43:7: error: expected ';' before 'unsigned'
43 | __weak unsigned int __rseq_flags;
| ^~~~~~~~~
| ;
rseq.c:45:47: error: '__rseq_offset' undeclared here (not in a
function); did you mean 'rseq_offset'?
45 | static const ptrdiff_t *libc_rseq_offset_p = &__rseq_offset;
| ^~~~~~~~~~~~~
| rseq_offset
make[3]: Leaving directory 'tools/testing/selftests/rseq'

Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>

Links:
- https://storage.tuxsuite.com/public/linaro/lkft/builds/2TNSVjRCfcIaJWQNkPwDQ9jn2ls/build.log
- https://qa-reports.linaro.org/lkft/linux-stable-rc-linux-6.4.y/build/v6.4.7-240-g2c273bf138a4/testrun/18770115/suite/kselftest-rseq/test/shardfile-rseq/details/

--
Linaro LKFT