[PATCH RESEND] powerpc/tools: drop `-o pipefail` in gcc check scripts

[Jan Stancek]

On Mon, Nov 10, 2025 at 12:33 PM Christophe Leroy
<christophe.leroy at csgroup.eu> wrote:
>
>
>
> Le 30/10/2025 à 19:09, Jan Stancek a écrit :
> > On Mon, Oct 6, 2025 at 10:19 PM Justin Forbes <jforbes at fedoraproject.org> wrote:
> >>
> >> On Tue, Sep 23, 2025 at 9:31 AM Jan Stancek <jstancek at redhat.com> wrote:
> >>>
> >>> We've been observing rare non-deterministic kconfig failures during
> >>> olddefconfig, where ARCH_USING_PATCHABLE_FUNCTION_ENTRY was getting
> >>> disabled and with it number of other config options that depend on it.
> >>>
> >>> The reason is that gcc-check-fpatchable-function-entry.sh can fail
> >>> if `grep -q` (or scripts/dummy-tools/gcc) is fast enough to exit while
> >>> there is still someone writing on other side of pipe. `pipefail`
> >>> propagates that error up to kconfig.
> >>>
> >>> This can be seen for example with:
> >>>    # (set -e; set -o pipefail; yes | grep -q y); echo $?
> >>>    141
> >>>
> >>> or by running the actual check script in loop extensively:
> >>>    ----------------------------- 8< -------------------------------
> >>>    function kconfig()
> >>>    {
> >>>      for i in `seq 1 100`; do
> >>>        arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh \
> >>>          ./scripts/dummy-tools/gcc -mlittle-endian \
> >>>          || { echo "Oops"; exit 1; }
> >>>      done
> >>>    }
> >>>
> >>>    for ((i=0; i<$(nproc); i++)); do kconfig & done
> >>>    wait; echo "Done"
> >>>    ----------------------------- >8 -------------------------------
> >>>
> >>> Fixes: 0f71dcfb4aef ("powerpc/ftrace: Add support for -fpatchable-function-entry")
> >>> Fixes: b71c9ffb1405 ("powerpc: Add arch/powerpc/tools directory")
> >>> Reported-by: Joe Lawrence <joe.lawrence at redhat.com>
> >>> Acked-by: Joe Lawrence <joe.lawrence at redhat.com>
> >>> Signed-off-by: Jan Stancek <jstancek at redhat.com>
> >>> ---
> >>>   arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh | 1 -
> >>>   arch/powerpc/tools/gcc-check-mprofile-kernel.sh           | 1 -
> >>>   2 files changed, 2 deletions(-)
> >>>
> >>> diff --git a/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh b/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh
> >>> index 06706903503b..baed467a016b 100755
> >>> --- a/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh
> >>> +++ b/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh
> >>> @@ -2,7 +2,6 @@
> >>>   # SPDX-License-Identifier: GPL-2.0
> >>>
> >>>   set -e
> >>> -set -o pipefail
> >>>
> >>>   # To debug, uncomment the following line
> >>>   # set -x
> >>> diff --git a/arch/powerpc/tools/gcc-check-mprofile-kernel.sh b/arch/powerpc/tools/gcc-check-mprofile-kernel.sh
> >>> index 73e331e7660e..6193b0ed0c77 100755
> >>> --- a/arch/powerpc/tools/gcc-check-mprofile-kernel.sh
> >>> +++ b/arch/powerpc/tools/gcc-check-mprofile-kernel.sh
> >>> @@ -2,7 +2,6 @@
> >>>   # SPDX-License-Identifier: GPL-2.0
> >>>
> >>>   set -e
> >>> -set -o pipefail
> >>>
> >>>   # To debug, uncomment the following line
> >>>   # set -x
> >>> --
> >>> 2.47.1
> >>
> >> Would love to see this picked up, it fixes a problem we have run into
> >> with our CI.
> >>
> >> Tested-by: Justin M. Forbes <jforbes at fedoraproject.org>
> >
> > Thanks Justin.
> >
> > Would any maintainers also care to review? Ty.
> >
>
> Is the problem only with those scripts ? I see other scripts using
> pipefail in the kernel:

As far as kconfig goes, we've observed this issue only with the two
gcc-check scripts.


>
> arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh:set -o pipefail
> arch/powerpc/tools/gcc-check-mprofile-kernel.sh:set -o pipefail
> drivers/gpu/drm/ci/dt-binding-check.sh:set -euxo pipefail
> drivers/gpu/drm/ci/dtbs-check.sh:set -euxo pipefail
> drivers/gpu/drm/ci/kunit.sh:set -euxo pipefail
> drivers/gpu/drm/ci/setup-llvm-links.sh:set -euo pipefail
> scripts/check-uapi.sh:set -o pipefail
>
> Christophe
>