Re: [PATCH riscv-next] riscv: bpf: Fix eBPF's exception tables

From: Jisheng Zhang
Date: Mon Jan 10 2022 - 12:05:25 EST


On Tue, Jan 11, 2022 at 12:52:08AM +0800, Jisheng Zhang wrote:
> eBPF's exception tables needs to be modified to relative synchronously.
>
> Suggested-by: Tong Tiangen <tongtiangen@xxxxxxxxxx>
> Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
> ---
> arch/riscv/net/bpf_jit_comp64.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c
> index 69bab7e28f91..44c97535bc15 100644
> --- a/arch/riscv/net/bpf_jit_comp64.c
> +++ b/arch/riscv/net/bpf_jit_comp64.c
> @@ -498,7 +498,7 @@ static int add_exception_handler(const struct bpf_insn *insn,
> offset = pc - (long)&ex->insn;
> if (WARN_ON_ONCE(offset >= 0 || offset < INT_MIN))
> return -ERANGE;
> - ex->insn = pc;
> + ex->insn = offset;

Hi Palmer,

Tong pointed out this issue but there was something wrong with my email
forwarding address, so I didn't get his reply. Today, I searched on
lore.kernel.org just found his reply, sorry for inconvenience.

Thanks

>
> /*
> * Since the extable follows the program, the fixup offset is always
> --
> 2.34.1
>
>
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