The patch below does not apply to the v6.11-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

Thanks, Sasha

------------------ original commit in Linus's tree ------------------

From 33549fcf37ec461f398f0a41e1c9948be2e5aca4 Mon Sep 17 00:00:00 2001 From: Conor Dooley conor.dooley@microchip.com Date: Tue, 1 Oct 2024 12:28:13 +0100 Subject: [PATCH] RISC-V: disallow gcc + rust builds

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@redhat.com/ [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@vger.kernel.org Reported-by: Jason Montleon jmontleo@redhat.com Signed-off-by: Conor Dooley conor.dooley@microchip.com Acked-by: Miguel Ojeda ojeda@kernel.org Reviewed-by: Nathan Chancellor nathan@kernel.org Link: https://lore.kernel.org/r/20241001-playlist-deceiving-16ece2f440f5@spud Signed-off-by: Palmer Dabbelt palmer@rivosinc.com --- Documentation/rust/arch-support.rst | 2 +- arch/riscv/Kconfig | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/rust/arch-support.rst b/Documentation/rust/arch-support.rst index 750ff371570a0..54be7ddf3e57a 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 62545946ecf43..f4c570538d55b 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