guoren@xxxxxxxxxx writes:
> From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
>
> The current kprobe would cause a misaligned load for the probe point.
> This patch fixup it with two half-word loads instead.
>
> Fixes: c22b0bcb1dd0 ("riscv: Add kprobes supported")
> Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
> Signed-off-by: Guo Ren <guoren@xxxxxxxxxx>
> Link: https://lore.kernel.org/linux-riscv/878rhig9zj.fsf@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
> Reported-by: Bjorn Topel <bjorn.topel@xxxxxxxxx>
> ---
> arch/riscv/kernel/probes/kprobes.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c
> index 41c7481afde3..c1160629cef4 100644
> --- a/arch/riscv/kernel/probes/kprobes.c
> +++ b/arch/riscv/kernel/probes/kprobes.c
> @@ -74,7 +74,9 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
> return -EILSEQ;
>
> /* copy instruction */
> - p->opcode = *p->addr;
> + p->opcode = (kprobe_opcode_t)(*(u16 *)probe_addr);
> + if (GET_INSN_LENGTH(p->opcode) == 4)
> + p->opcode |= (kprobe_opcode_t)(*(u16 *)(probe_addr + 2))
> << 16;
Ugh, those casts. :-( What about the memcpy variant you had in the other
thread?
