From: Russell King - ARM Linux <linux@armlinux.org.uk>
To: Daniel Borkmann <daniel@iogearbox.net>
Cc: netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH net-next 01/13] ARM: net: bpf: enumerate the JIT scratch stack layout
Date: Tue, 10 Jul 2018 22:57:23 +0100 [thread overview]
Message-ID: <20180710215723.GN17271@n2100.armlinux.org.uk> (raw)
In-Reply-To: <41b5fc68-e15f-56f9-c55b-4f6deb61c54c@iogearbox.net>
On Tue, Jul 10, 2018 at 08:30:04PM +0200, Daniel Borkmann wrote:
> Hi Russell,
>
> thanks a lot for your work on the arm32 JIT!
>
> On 07/10/2018 02:36 PM, Russell King wrote:
> > Enumerate the contents of the JIT scratch stack layout used for storing
> > some of the JITs 64-bit registers, tail call counter and AX register.
> >
> > XXX: what about the skb_copy_bits buffer - this appears to overlap with
> > the first word of the JITs accessible stack.
>
> Could you elaborate on that case? Unless I'm missing something there should
> be no use of the skb_copy_bits buffer anymore (aka former SKB_BUFFER at
> STACK_VAR(SCRATCH_SIZE) offset), but aside from that it's not supposed to
> overlap either.
Probably an old comment - these were originally developed back in
January timeframe when there was the SKB_BUFFER stuff, but that was
removed during the 4.18 merge window. I'll kill the comment.
Thanks.
--
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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next prev parent reply other threads:[~2018-07-10 21:58 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-10 12:33 [PATCH 00/13] ARM BPF jit compiler improvements Russell King - ARM Linux
2018-07-10 12:36 ` [PATCH net-next 01/13] ARM: net: bpf: enumerate the JIT scratch stack layout Russell King
2018-07-10 18:30 ` Daniel Borkmann
2018-07-10 21:57 ` Russell King - ARM Linux [this message]
2018-07-10 12:36 ` [PATCH net-next 02/13] ARM: net: bpf: provide load/store ops with negative immediates Russell King
2018-07-10 12:36 ` [PATCH net-next 03/13] ARM: net: bpf: use negative numbers for stacked registers Russell King
2018-07-10 12:36 ` [PATCH net-next 04/13] ARM: net: bpf: remove is_on_stack() and sstk/dstk Russell King
2018-07-10 12:36 ` [PATCH net-next 05/13] ARM: net: bpf: provide accessor functions for BPF registers Russell King
2018-07-10 12:36 ` [PATCH net-next 06/13] ARM: net: bpf: 64-bit " Russell King
2018-07-10 12:36 ` [PATCH net-next 07/13] ARM: net: bpf: access eBPF scratch space using ARM FP register Russell King
2018-07-10 12:36 ` [PATCH net-next 08/13] ARM: net: bpf: use immediate forms of instructions where possible Russell King
2018-07-10 19:12 ` kbuild test robot
2018-07-10 12:36 ` [PATCH net-next 09/13] ARM: net: bpf: use ldr instructions with shifted rm register Russell King
2018-07-10 12:36 ` [PATCH net-next 10/13] ARM: net: bpf: avoid reloading 'index' Russell King
2018-07-10 12:37 ` [PATCH net-next 11/13] ARM: net: bpf: avoid reloading 'array' Russell King
2018-07-10 12:37 ` [PATCH net-next 12/13] ARM: net: bpf: always use odd/even register pair Russell King
2018-07-10 12:37 ` [PATCH net-next 13/13] ARM: net: bpf: use double-word load/stores where available Russell King
2018-07-10 17:03 ` Olof Johansson
2018-07-10 17:14 ` Russell King - ARM Linux
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