kernel/arch/riscv/include/asm/scs.h, branch linux-rolling-stable

riscv: Replace ASSEMBLY with ASSEMBLER in non-uapi headers

2025-09-16T22:25:30Z

While the GCC and Clang compilers already define __ASSEMBLER__ automatically when compiling assembly code, __ASSEMBLY__ is a macro that only gets defined by the Makefiles in the kernel. This can be very confusing when switching between userspace and kernelspace coding, or when dealing with uapi headers that rather should use __ASSEMBLER__ instead. So let's standardize on the __ASSEMBLER__ macro that is provided by the compilers now. This originally was a completely mechanical patch (done with a simple "sed -i" statement), with some manual fixups during rebasing of the patch later. Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Alexandre Ghiti Cc: linux-riscv@lists.infradead.org Signed-off-by: Thomas Huth Link: https://lore.kernel.org/r/20250606070952.498274-3-thuth@redhat.com Signed-off-by: Paul Walmsley

riscv: Use separate IRQ shadow call stacks

2023-10-27T21:43:09Z

When both CONFIG_IRQ_STACKS and SCS are enabled, also use a separate per-CPU shadow call stack. Signed-off-by: Sami Tolvanen Tested-by: Nathan Chancellor Link: https://lore.kernel.org/r/20230927224757.1154247-13-samitolvanen@google.com Signed-off-by: Palmer Dabbelt

riscv: Implement Shadow Call Stack

2023-10-27T21:43:08Z

Implement CONFIG_SHADOW_CALL_STACK for RISC-V. When enabled, the compiler injects instructions to all non-leaf C functions to store the return address to the shadow stack and unconditionally load it again before returning, which makes it harder to corrupt the return address through a stack overflow, for example. The active shadow call stack pointer is stored in the gp register, which makes SCS incompatible with gp relaxation. Use --no-relax-gp to ensure gp relaxation is disabled and disable global pointer loading. Add SCS pointers to struct thread_info, implement SCS initialization, and task switching Signed-off-by: Sami Tolvanen Tested-by: Nathan Chancellor Link: https://lore.kernel.org/r/20230927224757.1154247-12-samitolvanen@google.com Signed-off-by: Palmer Dabbelt

kernel/arch/riscv/include/asm/scs.h, branch linux-rolling-stable

riscv: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-uapi headers

riscv: Use separate IRQ shadow call stacks

riscv: Implement Shadow Call Stack

riscv: Replace ASSEMBLY with ASSEMBLER in non-uapi headers