linux-kbuild.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "Thomas Weißschuh" <thomas.weissschuh@linutronix.de>
To: Masahiro Yamada <masahiroy@kernel.org>,
	 Nathan Chancellor <nathan@kernel.org>,
	 Nicolas Schier <nicolas.schier@linux.dev>,
	 Nick Desaulniers <nick.desaulniers+lkml@gmail.com>,
	 Bill Wendling <morbo@google.com>,
	Justin Stitt <justinstitt@google.com>
Cc: linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
	llvm@lists.linux.dev, stable@vger.kernel.org,
	"Thomas Weißschuh" <thomas.weissschuh@linutronix.de>
Subject: [PATCH] kbuild: userprogs: use correct linker when mixing clang and GNU ld
Date: Thu, 24 Jul 2025 10:32:45 +0200	[thread overview]
Message-ID: <20250724-userprogs-clang-gnu-ld-v1-1-3d3d071e53a7@linutronix.de> (raw)

The userprogs infrastructure does not expect clang being used with GNU ld
and in that case uses /usr/bin/ld for linking, not the configured $(LD).
This fallback is problematic as it will break when cross-compiling.
Mixing clang and GNU ld is used for example when building for SPARC64,
as ld.lld is not sufficient; see Documentation/kbuild/llvm.rst.

Relax the check around --ld-path so it gets used for all linkers.

Fixes: dfc1b168a8c4 ("kbuild: userprogs: use correct lld when linking through clang")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
Nathan, you originally proposed the check for $(CONFIG_LD_IS_LLD) [0],
could you take a look at this?

[0] https://lore.kernel.org/all/20250213175437.GA2756218@ax162/
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index c09766beb7eff4780574682b8ea44475fc0a5188..e300c6546c845c300edb5f0033719963c7da8f9b 100644
--- a/Makefile
+++ b/Makefile
@@ -1134,7 +1134,7 @@ KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CPPFLAGS) $(KBUILD
 KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS))
 
 # userspace programs are linked via the compiler, use the correct linker
-ifeq ($(CONFIG_CC_IS_CLANG)$(CONFIG_LD_IS_LLD),yy)
+ifneq ($(CONFIG_CC_IS_CLANG),)
 KBUILD_USERLDFLAGS += --ld-path=$(LD)
 endif
 

---
base-commit: 6832a9317eee280117cd695fa885b2b7a7a38daf
change-id: 20250723-userprogs-clang-gnu-ld-7a1c16fc852d

Best regards,
-- 
Thomas Weißschuh <thomas.weissschuh@linutronix.de>


             reply	other threads:[~2025-07-24  8:33 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-07-24  8:32 Thomas Weißschuh [this message]
2025-07-24 23:10 ` [PATCH] kbuild: userprogs: use correct linker when mixing clang and GNU ld Nathan Chancellor
2025-07-25 10:36   ` Thomas Weißschuh
2025-07-26 10:34     ` Masahiro Yamada
2025-07-30  0:47     ` Nathan Chancellor

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20250724-userprogs-clang-gnu-ld-v1-1-3d3d071e53a7@linutronix.de \
    --to=thomas.weissschuh@linutronix.de \
    --cc=justinstitt@google.com \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=llvm@lists.linux.dev \
    --cc=masahiroy@kernel.org \
    --cc=morbo@google.com \
    --cc=nathan@kernel.org \
    --cc=nick.desaulniers+lkml@gmail.com \
    --cc=nicolas.schier@linux.dev \
    --cc=stable@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).