From: Ricardo Ribalda <ribalda@chromium.org>
To: Nathan Chancellor <nathan@kernel.org>,
Nicolas Schier <nsc@kernel.org>,
Julian Braha <julianbraha@gmail.com>,
"Lorenzo Stoakes (ARM)" <ljs@kernel.org>
Cc: linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
Ricardo Ribalda <ribalda@chromium.org>
Subject: [PATCH] kbuild: pass -fno-pic when probing for -mfentry
Date: Tue, 20 Oct 2026 06:10:52 +0000 [thread overview]
Message-ID: <20261020-pie-v1-1-9be09f2324b1@chromium.org> (raw)
Some distros (namely Debian) configure their 32-bit toolchain with
--enable-default-pie.
To properly probe for -mfentry on them we need to pass -fno-pic,
otherwise allmodconfig will fail with:
./arch/x86/include/asm/ftrace.h:9:3: error: #error Compiler does not support fentry?
Fixes: 454e00cf8ee5 ("kbuild: avoid re-running compiler and linker probes")
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
I found this while testing next with media-ci.
Full logs:
https://gitlab.freedesktop.org/linux-media/users/ribalda/-/jobs/113299249#L4729
---
scripts/Kconfig.toolchain | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/scripts/Kconfig.toolchain b/scripts/Kconfig.toolchain
index b0b9a663ddbe..53b361cf365a 100644
--- a/scripts/Kconfig.toolchain
+++ b/scripts/Kconfig.toolchain
@@ -170,8 +170,10 @@ config CC_HAS_MNOP_MCOUNT
def_bool $(cc-option,-mnop-mcount)
# s390-linux-gnu-gcc did not support -mfentry until gcc-9.
+# 32-bit x86 gcc does not support -mfentry in combination with -fpic, which will
+# be enabled by default when gcc is configured with --enable-default-pie.
config CC_HAS_MFENTRY
- def_bool $(cc-option,-mfentry)
+ def_bool $(cc-option,-fno-pic -mfentry)
config LD_OPT_FORCE_GROUP_ALLOCATION
def_string "$(ld-option-str,--force-group-allocation)"
---
base-commit: 3d229ce89862b8e82d71a9e11d6f840ca272a6d6
change-id: 20261020-pie-6774df20b0fa
Best regards,
--
Ricardo Ribalda <ribalda@chromium.org>
next reply other threads:[~2026-10-20 6:10 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-20 6:10 Ricardo Ribalda [this message]
2026-10-20 9:10 ` Lorenzo Stoakes (ARM)
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