linux-kernel - Re: [PATCH bpf-next] arm64, bpf: Add 12-argument support for bpf trampoline

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CANk7y0gjBh7F=_woAEs3pQXgCqeX5ojEm3g7=4tyWsc-vmjBfA@mail.gmail.com>
Date: Thu, 4 Jul 2024 20:09:00 +0200
From: Puranjay Mohan <puranjay12@...il.com>
To: Puranjay Mohan <puranjay@...nel.org>
Cc: Alexei Starovoitov <ast@...nel.org>, Daniel Borkmann <daniel@...earbox.net>, 
	Andrii Nakryiko <andrii@...nel.org>, Martin KaFai Lau <martin.lau@...ux.dev>, 
	Eduard Zingerman <eddyz87@...il.com>, Song Liu <song@...nel.org>, 
	Yonghong Song <yonghong.song@...ux.dev>, John Fastabend <john.fastabend@...il.com>, 
	KP Singh <kpsingh@...nel.org>, Stanislav Fomichev <sdf@...gle.com>, Hao Luo <haoluo@...gle.com>, 
	Jiri Olsa <jolsa@...nel.org>, Xu Kuohai <xukuohai@...weicloud.com>, 
	Catalin Marinas <catalin.marinas@....com>, Will Deacon <will@...nel.org>, 
	Mykola Lysenko <mykolal@...com>, Shuah Khan <shuah@...nel.org>, bpf@...r.kernel.org, 
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org, 
	linux-kselftest@...r.kernel.org
Subject: Re: [PATCH bpf-next] arm64, bpf: Add 12-argument support for bpf trampoline

On Thu, Jul 4, 2024 at 7:33 PM Puranjay Mohan <puranjay@...nel.org> wrote:
>
> The arm64 bpf JIT currently supports attaching the trampoline to
> functions with <= 8 arguments. This is because up to 8 arguments can be
> passed in registers r0-r7. If there are more than 8 arguments then the
> 9th and later arguments are passed on the stack, with SP pointing to the
> first stacked argument. See aapcs64[1] for more details.
>
> Add the support of storing and restoring arguments passed on the stack
> to the arm64 bpf trampoline. This will allow attaching the trampoline to
> functions that take 12 arguments.
>
> [1] https://github.com/ARM-software/abi-aa/blob/main/aapcs64/aapcs64.rst#parameter-passing
>
> Signed-off-by: Puranjay Mohan <puranjay@...nel.org>

Please ignore this patch, it doesn't work correctly for tracing_struct selftest.
Sorry for the noise.

Thanks,
Puranjay