Re: [PATCH v4 net-next] arm: eBPF JIT compiler
Hi David, On Tue, Aug 22, 2017 at 10:02 PM, David Miller wrote: > > You posted this 4 times. :-( > > I hope I applied the right one. All 4 of these are the same patch. I mistakenly sent it 4 times. My apologies for that. > > Go check net-next and please send me any necessary fix up patches. I just checked. Its the correct patch. Thanks a lot David. :)
Re: [PATCH v4 net-next] arm: eBPF JIT compiler
You posted this 4 times. :-( I hope I applied the right one. Go check net-next and please send me any necessary fix up patches. Thanks.
Re: [PATCH v4 net-next] arm: eBPF JIT compiler
On 08/22/2017 05:08 PM, Daniel Borkmann wrote:
On 08/22/2017 08:36 AM, Shubham Bansal wrote:
[...]
+
+static int out_offset = -1; /* initialized on the first pass of build_body() */
Hm, why is this a global var actually? There can be
multiple parallel calls to bpf_int_jit_compile(), we
don't take a global lock on this. Unless I'm missing
something this should really reside in jit_ctx, no?
Hm, okay, it's for generating the out jmp offsets in
tail call emission which are supposed to always be the
same relative offsets; should be fine then.
Given this is on emit_bpf_tail_call(), did you get
tail calls working the way I suggested to test?
+static int emit_bpf_tail_call(struct jit_ctx *ctx)
{
[...]
+const int idx0 = ctx->idx;
+#define cur_offset (ctx->idx - idx0)
+#define jmp_offset (out_offset - (cur_offset))
[...]
+
+/* out: */
+if (out_offset == -1)
+out_offset = cur_offset;
+if (cur_offset != out_offset) {
+pr_err_once("tail_call out_offset = %d, expected %d!\n",
+cur_offset, out_offset);
+return -1;
+}
+return 0;
+#undef cur_offset
+#undef jmp_offset
}
Re: [PATCH v4 net-next] arm: eBPF JIT compiler
On 08/22/2017 08:36 AM, Shubham Bansal wrote:
[...]
+
+static int out_offset = -1; /* initialized on the first pass of build_body() */
Hm, why is this a global var actually? There can be
multiple parallel calls to bpf_int_jit_compile(), we
don't take a global lock on this. Unless I'm missing
something this should really reside in jit_ctx, no?
Given this is on emit_bpf_tail_call(), did you get
tail calls working the way I suggested to test?
+static int emit_bpf_tail_call(struct jit_ctx *ctx)
{
[...]
+ const int idx0 = ctx->idx;
+#define cur_offset (ctx->idx - idx0)
+#define jmp_offset (out_offset - (cur_offset))
[...]
+
+ /* out: */
+ if (out_offset == -1)
+ out_offset = cur_offset;
+ if (cur_offset != out_offset) {
+ pr_err_once("tail_call out_offset = %d, expected %d!\n",
+ cur_offset, out_offset);
+ return -1;
+ }
+ return 0;
+#undef cur_offset
+#undef jmp_offset
}
Re: [PATCH v4 net-next] arm: eBPF JIT compiler
Please ignore this mail. Sent it by mistake. Sent the correct patch later on.
Re: [PATCH v4 net-next] arm: eBPF JIT compiler
Russell, David, Alexei, Daniel and Kees. Please check this patch and lets finish it. Thanks.
