Re: [PATCH v2 01/10] kbuild: don't enable CC_CAN_LINK if the dummy program generates warnings
From: Nathan Chancellor <nathan@kernel.org>
Date: 2025-11-14 04:27:51
Also in:
linux-kbuild, linux-mips, linux-riscv, linux-s390, lkml, sparclinux
On Tue, Oct 14, 2025 at 03:05:16PM +0200, Thomas Weißschuh wrote:
It is possible that the kernel toolchain generates warnings when used
together with the system toolchain. This happens for example when the
older kernel toolchain does not handle new versions of sframe debug
information. While these warnings where ignored during the evaluation
of CC_CAN_LINK, together with CONFIG_WERROR the actual userprog build
will later fail.
Example warning:
.../x86_64-linux/13.2.0/../../../../x86_64-linux/bin/ld:
error in /lib/../lib64/crt1.o(.sframe); no .sframe will be created
collect2: error: ld returned 1 exit status
Make sure that the very simple example program does not generate
warnings already to avoid breaking the userprog compilations.
Fixes: ec4a3992bc0b ("kbuild: respect CONFIG_WERROR for linker and assembler")
Fixes: 3f0ff4cc6ffb ("kbuild: respect CONFIG_WERROR for userprogs")
Signed-off-by: Thomas Weißschuh <redacted>Reviewed-by: Nathan Chancellor <nathan@kernel.org> While this makes sense as a way to immediately fix the problem and align cc-can-link.sh with the other test functions like cc-option and like, it is rather unfortunate that this particular warning causes an error since the rest of the userprogs infrastructure does not care about SFrame... I wonder if there is a way to avoid it since I think this warning does not point to a fundamental problem.
quoted hunk ↗ jump to hunk
--- scripts/cc-can-link.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/scripts/cc-can-link.sh b/scripts/cc-can-link.sh index 6efcead3198989d2ab2ab6772c72d8bb61c89c4e..e67fd8d7b6841e53341045b28dc5196cc1327cbe 100755 --- a/scripts/cc-can-link.sh +++ b/scripts/cc-can-link.sh@@ -1,7 +1,7 @@ #!/bin/sh # SPDX-License-Identifier: GPL-2.0 -cat << "END" | $@ -x c - -o /dev/null >/dev/null 2>&1 +cat << "END" | $@ -Werror -Wl,--fatal-warnings -x c - -o /dev/null >/dev/null 2>&1 #include <stdio.h> int main(void) {-- 2.51.0