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LoongArch: BPF: Adjust the jump offset of tail calls

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Call the next bpf prog and skip the first instruction of TCC
initialization.

A total of 7 instructions are skipped:
'move t0, ra'			1 inst
'move_imm + jirl'		5 inst
'addid REG_TCC, zero, 0'	1 inst

Relevant test cases: the tailcalls test item in selftests/bpf.

Cc: stable@vger.kernel.org
Fixes: 677e6123e3d2 ("LoongArch: BPF: Disable trampoline for kernel module function trace")
Signed-off-by: Chenghao Duan <duanchenghao@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This commit is contained in:
Chenghao Duan 2025-12-31 15:19:21 +08:00 committed by Huacai Chen
parent d314e1f482
commit 61319d15a5
1 changed files with 1 additions and 1 deletions
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2
arch/loongarch/net/bpf_jit.c
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@ -239,7 +239,7 @@ static void __build_epilogue(struct jit_ctx *ctx, bool is_tail_call)
* Call the next bpf prog and skip the first instruction
* of TCC initialization.
*/
emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_T3, 6);
emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_T3, 7);
}
}