During the discussion before supporting rust on riscv, it was decided not to support gcc yet, due to differences in extension handling compared to llvm (only the version of libclang matching the c compiler is supported). Recently Jason Montleon reported [1] that building with gcc caused build issues, due to unsupported arguments being passed to libclang. After some discussion between myself and Miguel, it is better to disable gcc + rust builds to match the original intent, and subsequently support it when an appropriate set of extensions can be deduced from the version of libclang. Closes: https://lore.kernel.org/all/20240917000848.720765-2-jmontleo@xxxxxxxxxx/ [1] Link: https://lore.kernel.org/all/20240926-battering-revolt-6c6a7827413e@spud/ [2] Fixes: 70a57b247251a ("RISC-V: enable building 64-bit kernels with rust support") Cc: stable@xxxxxxxxxxxxxxx Reported-by: Jason Montleon <jmontleo@xxxxxxxxxx> Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> Acked-by: Miguel Ojeda <ojeda@xxxxxxxxxx> Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx> Link: https://lore.kernel.org/r/20241001-playlist-deceiving-16ece2f440f5@spud Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx> diff --git a/Documentation/rust/arch-support.rst b/Documentation/rust/arch-support.rst index 750ff371570a..54be7ddf3e57 100644 --- a/Documentation/rust/arch-support.rst +++ b/Documentation/rust/arch-support.rst @@ -17,7 +17,7 @@ Architecture Level of support Constraints ============= ================ ============================================== ``arm64`` Maintained Little Endian only. ``loongarch`` Maintained \- -``riscv`` Maintained ``riscv64`` only. +``riscv`` Maintained ``riscv64`` and LLVM/Clang only. ``um`` Maintained \- ``x86`` Maintained ``x86_64`` only. ============= ================ ============================================== diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 62545946ecf4..f4c570538d55 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -177,7 +177,7 @@ config RISCV select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RETHOOK if !XIP_KERNEL select HAVE_RSEQ - select HAVE_RUST if RUSTC_SUPPORTS_RISCV + select HAVE_RUST if RUSTC_SUPPORTS_RISCV && CC_IS_CLANG select HAVE_SAMPLE_FTRACE_DIRECT select HAVE_SAMPLE_FTRACE_DIRECT_MULTI select HAVE_STACKPROTECTOR
