diff options
| author | Nathan Chancellor <nathan@kernel.org> | 2024-11-21 11:22:18 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-12-17 14:07:53 -0800 |
| commit | aef25be35d23ec768eed08bfcf7ca3cf9685bc28 (patch) | |
| tree | 39e08075e3979d5a48dffb0eb04ce52cc555491c | |
| parent | 5529876063e110ea49326138149fdf2a28a484dd (diff) | |
hexagon: Disable constant extender optimization for LLVM prior to 19.1.0
The Hexagon-specific constant extender optimization in LLVM may crash on
Linux kernel code [1], such as fs/bcache/btree_io.c after
commit 32ed4a620c54 ("bcachefs: Btree path tracepoints") in 6.12:
clang: llvm/lib/Target/Hexagon/HexagonConstExtenders.cpp:745: bool (anonymous namespace)::HexagonConstExtenders::ExtRoot::operator<(const HCE::ExtRoot &) const: Assertion `ThisB->getParent() == OtherB->getParent()' failed.
Stack dump:
0. Program arguments: clang --target=hexagon-linux-musl ... fs/bcachefs/btree_io.c
1. <eof> parser at end of file
2. Code generation
3. Running pass 'Function Pass Manager' on module 'fs/bcachefs/btree_io.c'.
4. Running pass 'Hexagon constant-extender optimization' on function '@__btree_node_lock_nopath'
Without assertions enabled, there is just a hang during compilation.
This has been resolved in LLVM main (20.0.0) [2] and backported to LLVM
19.1.0 but the kernel supports LLVM 13.0.1 and newer, so disable the
constant expander optimization using the '-mllvm' option when using a
toolchain that is not fixed.
Cc: stable@vger.kernel.org
Link: https://github.com/llvm/llvm-project/issues/99714 [1]
Link: https://github.com/llvm/llvm-project/commit/68df06a0b2998765cb0a41353fcf0919bbf57ddb [2]
Link: https://github.com/llvm/llvm-project/commit/2ab8d93061581edad3501561722ebd5632d73892 [3]
Reviewed-by: Brian Cain <bcain@quicinc.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | arch/hexagon/Makefile | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/hexagon/Makefile b/arch/hexagon/Makefile index 92d005958dfb..ff172cbe5881 100644 --- a/arch/hexagon/Makefile +++ b/arch/hexagon/Makefile @@ -32,3 +32,9 @@ KBUILD_LDFLAGS += $(ldflags-y) TIR_NAME := r19 KBUILD_CFLAGS += -ffixed-$(TIR_NAME) -DTHREADINFO_REG=$(TIR_NAME) -D__linux__ KBUILD_AFLAGS += -DTHREADINFO_REG=$(TIR_NAME) + +# Disable HexagonConstExtenders pass for LLVM versions prior to 19.1.0 +# https://github.com/llvm/llvm-project/issues/99714 +ifneq ($(call clang-min-version, 190100),y) +KBUILD_CFLAGS += -mllvm -hexagon-cext=false +endif |