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

On 12/3/25 9:29 AM, Naveen N Rao wrote:

On Tue, Sep 23, 2025 at 05:32:16PM +0200, Jan Stancek wrote:

quoted

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")

The latter fixes tag should probably tag one of the below commits which
actually introduced pipefail, or introduced it in Kconfig:
Fixes: 8c50b72a3b4f ("powerpc/ftrace: Add Kconfig & Make glue for mprofile-kernel")
   or:
Fixes: abba759796f9 ("powerpc/kbuild: move -mprofile-kernel check to Kconfig")

quoted

Reported-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Jan Stancek <jstancek@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(-)

Other than that, thanks for fixing this. This LGTM.
Reviewed-by: Naveen N Rao (AMD) <naveen@kernel.org>

Maddy/Michael,
Can you please pick this up?

Thanks naveen. Will put it in one of the -rc

Maddy

Thanks,
Naveen