Re: [PATCH net-next 2/3] arm64: bpf: optimize JMP_CALL

Hi Will, On Mon, Jun 6, 2016 at 10:05 AM, Will Deacon wrote: > On Sat, Jun 04, 2016 at 03:00:29PM -0700, Zi Shen Lim wrote: >> Remove superfluous stack frame, saving us 3 instructions for >> every JMP_CALL. >> >> Signed-off-by: Zi Shen Lim >> --- >>

Re: [PATCH net-next 1/3] arm64: bpf: implement bpf_tail_call() helper

Hi Daniel, On Sun, Jun 5, 2016 at 12:53 AM, Daniel Borkmann wrote: > On 06/05/2016 01:46 AM, kbuild test robot wrote: >> >> Hi, >> >> [auto build test ERROR on net-next/master] >> >> url: >>

Re: [PATCH net-next] bpf: arm64: remove callee-save registers use for tmp registers

Hi Yang, On Mon, May 16, 2016 at 4:09 PM, Yang Shi wrote: > In the current implementation of ARM64 eBPF JIT, R23 and R24 are used for > tmp registers, which are callee-saved registers. This leads to variable size > of JIT prologue and epilogue. The latest blinding constant

Re: [PATCH net-next 2/5] bpf: move clearing of A/X into classic to eBPF migration prologue

On Thu, Dec 17, 2015 at 2:51 PM, Daniel Borkmann wrote: > Back in the days where eBPF (or back then "internal BPF" ;->) was not > exposed to user space, and only the classic BPF programs internally > translated into eBPF programs, we missed the fact that for classic BPF > A

Re: [PATCH] arm64: bpf: fix buffer pointer

On Wed, Nov 18, 2015 at 1:07 PM, Shi, Yang wrote: > On 11/18/2015 12:56 AM, Zi Shen Lim wrote: >> emit_a64_mov_i64(r3, size, ctx); >> - emit(A64_ADD_I(1, r4, fp, MAX_BPF_STACK), ctx); >> + emit(A64_SUB_I(1, r4, fp, STACK_SIZE),

Re: [PATCH V4 2/2] arm64: bpf: make BPF prologue and epilogue align with ARM64 AAPCS

On Mon, Nov 16, 2015 at 2:35 PM, Yang Shi wrote: > Save and restore FP/LR in BPF prog prologue and epilogue, save SP to FP > in prologue in order to get the correct stack backtrace. > > However, ARM64 JIT used FP (x29) as eBPF fp register, FP is subjected to > change during

Re: [PATCH V3 2/2] arm64: bpf: make BPF prologue and epilogue align with ARM64 AAPCS

Yang, I noticed another thing... On Fri, Nov 13, 2015 at 10:09 AM, Yang Shi wrote: > Save and restore FP/LR in BPF prog prologue and epilogue, save SP to FP > in prologue in order to get the correct stack backtrace. > > However, ARM64 JIT used FP (x29) as eBPF fp register,

Re: [PATCH 1/2] arm64: bpf: fix JIT frame pointer setup

On Thu, Nov 12, 2015 at 1:57 PM, Yang Shi wrote: > BPF fp should point to the top of the BPF prog stack. The original > implementation made it point to the bottom incorrectly. > Move A64_SP to fp before reserve BPF prog stack space. > > CC: Zi Shen Lim >

Re: [PATCH 2/2] arm64: bpf: make BPF prologue and epilogue align with ARM64 AAPCS

On Thu, Nov 12, 2015 at 1:57 PM, Yang Shi wrote: > > Save and restore FP/LR in BPF prog prologue and epilogue, save SP to FP > in prologue in order to get the correct stack backtrace. > > However, ARM64 JIT used FP (x29) as eBPF fp register, FP is subjected to > change during

Re: [PATCH 1/2] arm64: bpf: add 'store immediate' instruction

On Thu, Nov 12, 2015 at 11:33 AM, Shi, Yang wrote: > On 11/11/2015 4:39 AM, Will Deacon wrote: >> >> Wait a second, we're both talking rubbish here :) The STR (immediate) >> form is referring to the addressing mode, whereas this patch wants to >> store an immediate value to

Re: [PATCH] arm64: bpf: fix JIT stack setup

On Tue, Nov 10, 2015 at 11:46 AM, Shi, Yang <yang@linaro.org> wrote: > On 11/9/2015 12:00 PM, Z Lim wrote: >> >> How about splitting this into two patches? One for the BPF-related >> bug, and another for A64 FP-handling. > > I'm not sure if this is a good app

Re: [PATCH] arm64: bpf: fix JIT stack setup

On Mon, Nov 9, 2015 at 10:08 AM, Shi, Yang wrote: > I added it to stay align with ARMv8 AAPCS to maintain the correct FP during > function call. It makes us get correct stack backtrace. > > I think we'd better to keep compliant with ARMv8 AAPCS in BPF JIT prologue > too. > >

Re: [PATCH] arm64: bpf: fix JIT stack setup

On Sat, Nov 7, 2015 at 6:27 PM, Alexei Starovoitov wrote: > On Fri, Nov 06, 2015 at 09:36:17PM -0800, Yang Shi wrote: >> ARM64 JIT used FP (x29) as eBPF fp register, but FP is subjected to >> change during function call so it may cause the BPF prog stack base address

Re: [PATCH] bpf: add mod default A and X test cases

On Wed, Nov 4, 2015 at 11:36 AM, Yang Shi wrote: > When running "mod X" operation, if X is 0 the filter has to be halt. > Add new test cases to cover A = A mod X if X is 0, and A = A mod 1. > > CC: Xi Wang > CC: Zi Shen Lim >