From: Nathan Chancellor Date: Sun, 17 May 2026 23:05:04 +0000 (-1000) Subject: kbuild: Bump minimum version of LLVM for building the kernel to 17.0.1 X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=ce3267a39a92be732429fa1a1f6d95a807a31fa7;p=thirdparty%2Fkernel%2Flinux.git kbuild: Bump minimum version of LLVM for building the kernel to 17.0.1 The current minimum version of LLVM for building the kernel is 15.0.0. However, there are two deficiencies compared to GCC that were fixed in LLVM 17 that are starting to become more noticeable. The first was a bug in LLVM's scope checker [1], where all labels in a function were validated as potential targets of an asm goto statement, even if they were not listed in the asm goto statement as targets. This becomes particularly problematic when the cleanup attribute is used, as asm goto(... : label_a); ... label_a: ... int var __free(foo); asm goto(... : label_b); ... label_b: ... will trigger an error since the scope checker will complain that the cleanup variable would be skipped when jumping from the first asm goto to label_b (which obviously cannot happen). This issue was the catalyst for commit e2ffa15b9baa ("kbuild: Disable CC_HAS_ASM_GOTO_OUTPUT on clang < 17"). Unfortunately, this issue is reproducible with regular asm goto in addition to asm goto with outputs, so that change was not entirely sufficient to avoid the issue altogether. As asm goto has effectively been required since commit a0a12c3ed057 ("asm goto: eradicate CC_HAS_ASM_GOTO") and the usage of the cleanup attribute continues to grow across the tree, raising the minimum to a version that avoids this issue altogether is a better long term solution than attempting to workaround it at every spot where it happens. The second issue is an incompatibility with GCC 8.1+ around variables marked with const being valid constant expressions for _Static_assert and other macros [2]. With GCC 8.1 being the minimum supported version since commit 118c40b7b503 ("kbuild: require gcc-8 and binutils-2.30"), this incompatibility becomes more of a maintenance burden since only clang-15 and clang-16 are affected by it. Looking at the clang version of various major distributions through Docker images, no one should be left behind as a result of this bump, as the old ones cannot clear the current minimum of 15.0.0. archlinux:latest clang version 22.1.3 debian:oldoldstable-slim Debian clang version 11.0.1-2 debian:oldstable-slim Debian clang version 14.0.6 debian:stable-slim Debian clang version 19.1.7 (3+b1) debian:testing-slim Debian clang version 21.1.8 (3+b1) debian:unstable-slim Debian clang version 21.1.8 (7+b1) fedora:42 clang version 20.1.8 (Fedora 20.1.8-4.fc42) fedora:latest clang version 21.1.8 (Fedora 21.1.8-4.fc43) fedora:44 clang version 22.1.1 (Fedora 22.1.1-2.fc44) fedora:rawhide clang version 22.1.3 (Fedora 22.1.3-1.fc45) opensuse/leap:latest clang version 17.0.6 opensuse/tumbleweed:latest clang version 21.1.8 ubuntu:jammy Ubuntu clang version 14.0.0-1ubuntu1.1 ubuntu:noble Ubuntu clang version 18.1.3 (1ubuntu1) ubuntu:questing Ubuntu clang version 20.1.8 (0ubuntu4) ubuntu:resolute Ubuntu clang version 21.1.8 (6ubuntu1) 17.0.1 is chosen as the minimum instead of 17.0.0 to ensure that the particular version of LLVM 17 has the two aforementioned bugs fixed, as the second was fixed during the 17.0.0 release candidate phase and it was not until LLVM 18 that LLVM adopted the scheme of x.0.0 being a prerelease version and x.1.0 is a release version [3] to help with scenarios such as this. Link: https://github.com/llvm/llvm-project/commit/f023f5cdb2e6c19026f04a15b5a935c041835d14 [1] Link: https://github.com/llvm/llvm-project/commit/0b2d5b967d98375793897295d651f58f6fbd3034 [2] Link: https://github.com/llvm/llvm-project/commit/4532617ae420056bf32f6403dde07fb99d276a49 [3] Acked-by: Nicolas Schier Link: https://patch.msgid.link/20260517-bump-minimum-supported-llvm-version-to-17-v2-1-b3b8cda46bdd@kernel.org Signed-off-by: Nathan Chancellor --- diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst index 9a99037270ff2..b9afce7684461 100644 --- a/Documentation/process/changes.rst +++ b/Documentation/process/changes.rst @@ -36,7 +36,7 @@ bindgen (optional) 0.71.1 bindgen --version binutils 2.30 ld -v bison 2.0 bison --version btrfs-progs 0.18 btrfs --version -Clang/LLVM (optional) 15.0.0 clang --version +Clang/LLVM (optional) 17.0.1 clang --version e2fsprogs 1.41.4 e2fsck -V flex 2.5.35 flex --version gdb 7.2 gdb --version diff --git a/Documentation/translations/it_IT/process/changes.rst b/Documentation/translations/it_IT/process/changes.rst index 7e93833b4511c..7ee54c9724189 100644 --- a/Documentation/translations/it_IT/process/changes.rst +++ b/Documentation/translations/it_IT/process/changes.rst @@ -33,7 +33,7 @@ PC Card, per esempio, probabilmente non dovreste preoccuparvi di pcmciautils. Programma Versione minima Comando per verificare la versione ====================== ================= ======================================== GNU C 8.1 gcc --version -Clang/LLVM (optional) 13.0.0 clang --version +Clang/LLVM (optional) 17.0.1 clang --version Rust (opzionale) 1.78.0 rustc --version bindgen (opzionale) 0.65.1 bindgen --version GNU make 4.0 make --version diff --git a/Documentation/translations/pt_BR/process/changes.rst b/Documentation/translations/pt_BR/process/changes.rst index 1964c1c93b345..6bbfe60fd9730 100644 --- a/Documentation/translations/pt_BR/process/changes.rst +++ b/Documentation/translations/pt_BR/process/changes.rst @@ -31,7 +31,7 @@ PC Card por exemplo, provavelmente não precisará se preocupar com o pcmciautil Programa Versão mínima Comando para verificar a versão ====================== =============== ======================================== GNU C 8.1 gcc --version -Clang/LLVM (optional) 15.0.0 clang --version +Clang/LLVM (optional) 17.0.1 clang --version Rust (optional) 1.78.0 rustc --version bindgen (optional) 0.65.1 bindgen --version GNU make 4.0 make --version diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh index b96ec2d379b63..ea2689bc9641e 100755 --- a/scripts/min-tool-version.sh +++ b/scripts/min-tool-version.sh @@ -27,7 +27,7 @@ llvm) if [ "$SRCARCH" = loongarch ]; then echo 18.0.0 else - echo 15.0.0 + echo 17.0.1 fi ;; rustc)