On Mon, Jun 23, 2014 at 2:38 AM, Markos Chandras
<markos.chandras@xxxxxxxxxx> wrote:
> Previously, the negative offset was not checked leading to failures
> due to trying to load data beyond the skb struct boundaries. Until we
> have proper asm helpers in place, it's best if we return ENOSUPP if K
> is negative when trying to JIT the filter or 0 during runtime if we
> do an indirect load where the value of X is unknown during build time.
>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Daniel Borkmann <dborkman@xxxxxxxxxx>
> Cc: Alexei Starovoitov <ast@xxxxxxxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx
> Signed-off-by: Markos Chandras <markos.chandras@xxxxxxxxxx>
Hi Markos,
thank you for addressing all of my earlier comments.
Looks like test_bpf was quite useful in finding all of these bugs :)
For the patches that reached netdev:
Acked-by: Alexei Starovoitov <ast@xxxxxxxxxxxx>
One minor nit below:
> ---
> arch/mips/net/bpf_jit.c | 23 +++++++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
> diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c
> index 5cc92c4590cb..95728ea6cb74 100644
> --- a/arch/mips/net/bpf_jit.c
> +++ b/arch/mips/net/bpf_jit.c
> @@ -331,6 +331,12 @@ static inline void emit_srl(unsigned int dst, unsigned int src,
> emit_instr(ctx, srl, dst, src, sa);
> }
>
> +static inline void emit_slt(unsigned int dst, unsigned int src1,
> + unsigned int src2, struct jit_ctx *ctx)
> +{
> + emit_instr(ctx, slt, dst, src1, src2);
> +}
> +
> static inline void emit_sltu(unsigned int dst, unsigned int src1,
> unsigned int src2, struct jit_ctx *ctx)
> {
> @@ -816,8 +822,21 @@ static int build_body(struct jit_ctx *ctx)
> /* A <- P[k:1] */
> load_order = 0;
> load:
> + /* the interpreter will deal with the negative K */
> + if ((int)k < 0)
should be a space after cast.
