get_insn_nofault uses get_insn with pagefaults dissabled, allowing it to be called in an atomic context.
Signed-off-by: Jesse Taube jesse@rivosinc.com --- Unsure if copy_from_kernel_nofault is an acceptable replacement for direct dereference in __read_insn.
RFC -> V1: - Add new function instead of using copy_from_user_nofault --- arch/riscv/include/asm/insn.h | 1 + arch/riscv/kernel/insn.c | 14 ++++++++++++++ 2 files changed, 15 insertions(+)
diff --git a/arch/riscv/include/asm/insn.h b/arch/riscv/include/asm/insn.h index ba74e5b8262c..f87e0a48f786 100644 --- a/arch/riscv/include/asm/insn.h +++ b/arch/riscv/include/asm/insn.h @@ -553,6 +553,7 @@ static inline void riscv_insn_insert_utype_itype_imm(u32 *utype_insn, u32 *itype #include <asm/ptrace.h>
int get_insn(struct pt_regs *regs, ulong epc, ulong *r_insn); +int get_insn_nofault(struct pt_regs *regs, ulong epc, ulong *r_insn); unsigned long get_step_address(struct pt_regs *regs, u32 code);
#endif /* _ASM_RISCV_INSN_H */ diff --git a/arch/riscv/kernel/insn.c b/arch/riscv/kernel/insn.c index dd2a6ef9fd25..c8f77c0093c9 100644 --- a/arch/riscv/kernel/insn.c +++ b/arch/riscv/kernel/insn.c @@ -2,6 +2,9 @@ /* * Copyright 2025 Rivos, Inc */ + +#include <linux/uaccess.h> + #include <asm/insn.h> #include <asm/ptrace.h> #include <asm/uaccess.h> @@ -74,6 +77,17 @@ int get_insn(struct pt_regs *regs, ulong epc, ulong *r_insn) } }
+int get_insn_nofault(struct pt_regs *regs, ulong epc, ulong *r_insn) +{ + int ret; + + pagefault_disable(); + ret = get_insn(regs, epc, r_insn); + pagefault_enable(); + + return ret; +} + /* Calculate the new address for after a step */ unsigned long get_step_address(struct pt_regs *regs, u32 code) {