LoongArch: BPF: Make trampoline size stable

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When attach fentry/fexit BPF programs, __arch_prepare_bpf_trampoline()
is called twice with different `struct bpf_tramp_image *im`:

    bpf_trampoline_update()
        -> arch_bpf_trampoline_size()
            -> __arch_prepare_bpf_trampoline()
        -> arch_prepare_bpf_trampoline()
            -> __arch_prepare_bpf_trampoline()

Use move_imm() will emit unstable instruction sequences, so let's use
move_addr() instead to prevent subtle bugs.

(I observed this while debugging other issues with printk.)

Cc: stable@vger.kernel.org
Tested-by: Vincent Li <vincent.mc.li@gmail.com>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

...

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Hengqi Chen 2025-10-02 22:39:52 +08:00 • committed by Huacai Chen

parent a04731cbee

commit ea645cfd3d

1 changed files with 2 additions and 2 deletions

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arch/loongarch/net/bpf_jit.c

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