5.15-stable review patch. If anyone has any objections, please let me know.
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From: Nam Cao namcaov@gmail.com
commit 8cb22bec142624d21bc85ff96b7bad10b6220e6a upstream.
Instructions can write to x0, so we should simulate these instructions normally.
Currently, the kernel hangs if an instruction who writes to x0 is simulated.
Fixes: c22b0bcb1dd0 ("riscv: Add kprobes supported") Cc: stable@vger.kernel.org Signed-off-by: Nam Cao namcaov@gmail.com Reviewed-by: Charlie Jenkins charlie@rivosinc.com Acked-by: Guo Ren guoren@kernel.org Link: https://lore.kernel.org/r/20230829182500.61875-1-namcaov@gmail.com Signed-off-by: Palmer Dabbelt palmer@rivosinc.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/riscv/kernel/probes/simulate-insn.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/riscv/kernel/probes/simulate-insn.c b/arch/riscv/kernel/probes/simulate-insn.c index d3099d67816d..6c166029079c 100644 --- a/arch/riscv/kernel/probes/simulate-insn.c +++ b/arch/riscv/kernel/probes/simulate-insn.c @@ -24,7 +24,7 @@ static inline bool rv_insn_reg_set_val(struct pt_regs *regs, u32 index, unsigned long val) { if (index == 0) - return false; + return true; else if (index <= 31) *((unsigned long *)regs + index) = val; else