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

[Puranjay Mohan]

On Thu, Jul 4, 2024 at 7:33 PM Puranjay Mohan <puranjay at kernel.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 at kernel.org>

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

Thanks,
Puranjay