On Thu, Jul 4, 2024 at 7:33 PM Puranjay Mohan puranjay@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#paramet...
Signed-off-by: Puranjay Mohan puranjay@kernel.org
Please ignore this patch, it doesn't work correctly for tracing_struct selftest. Sorry for the noise.
Thanks, Puranjay