Re: [PATCH] arm64/bpf: use movn/movk/movk sequence to generate kernel addresses
From: Daniel Borkmann <daniel@iogearbox.net>
Date: 2018-11-30 10:07:37
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On 11/27/2018 07:24 PM, Daniel Borkmann wrote:
On 11/27/2018 07:22 PM, Will Deacon wrote:quoted
Hi Ard, On Fri, Nov 23, 2018 at 06:29:02PM +0100, Ard Biesheuvel wrote:quoted
On arm64, all executable code is guaranteed to reside in the vmalloc space (or the module space), and so jump targets will only use 48 bits at most, and the remaining bits are guaranteed to be 0x1. This means we can generate an immediate jump address using a sequence of one MOVN (move wide negated) and two MOVK instructions, where the first one sets the lower 16 bits but also sets all top bits to 0x1. Signed-off-by: Ard Biesheuvel <redacted> ---Acked-by: Will Deacon <redacted> Denial, Alexei, shall I take this via arm64, or would you rather take it via davem?Yeah we can take it via bpf trees, thanks.
And now applied, thanks! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel