LoongArch: BPF: Fix the tailcall hierarchy

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In specific use cases combining tailcalls and BPF-to-BPF calls，
MAX_TAIL_CALL_CNT won't work because of missing tail_call_cnt
back-propagation from callee to caller. This patch fixes this
tailcall issue caused by abusing the tailcall in bpf2bpf feature
on LoongArch like the way of "bpf, x64: Fix tailcall hierarchy".

Push tail_call_cnt_ptr and tail_call_cnt into the stack,
tail_call_cnt_ptr is passed between tailcall and bpf2bpf,
uses tail_call_cnt_ptr to increment tail_call_cnt.

Fixes: bb035ef0cc ("LoongArch: BPF: Support mixing bpf2bpf and tailcalls")
Reviewed-by: Geliang Tang <geliang@kernel.org>
Reviewed-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Haoran Jiang <jianghaoran@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

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Haoran Jiang 2025-08-05 19:00:22 +08:00 • committed by Huacai Chen

parent cd39d9e6b7

commit c0fcc955ff

1 changed files with 107 additions and 48 deletions

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arch/loongarch/net/bpf_jit.c

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