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| author | Chenghao Duan <duanchenghao@kylinos.cn> | 2025-12-31 10:19:20 +0300 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2025-12-31 10:19:20 +0300 |
| commit | d314e1f48260cef3f869e3edc02a02c8a48b08e1 (patch) | |
| tree | 9b649b9fa10717d8b36d4d0ead364ad69a6605aa | |
| parent | eb71f5c433e1c6dff089b315881dec40a88a7baf (diff) | |
| download | linux-d314e1f48260cef3f869e3edc02a02c8a48b08e1.tar.xz | |
LoongArch: BPF: Save return address register ra to t0 before trampoline
Modify the build_prologue() function to ensure the return address
register ra is saved to t0 before entering trampoline operations.
This change ensures the accurate return address handling when a BPF
program calls another BPF program, preventing errors in the BPF-to-BPF
call chain.
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>
| -rw-r--r-- | arch/loongarch/net/bpf_jit.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c index 766ded335fd8..9729c0ff7bfc 100644 --- a/arch/loongarch/net/bpf_jit.c +++ b/arch/loongarch/net/bpf_jit.c @@ -139,6 +139,7 @@ static void build_prologue(struct jit_ctx *ctx) stack_adjust = round_up(stack_adjust, 16); stack_adjust += bpf_stack_adjust; + move_reg(ctx, LOONGARCH_GPR_T0, LOONGARCH_GPR_RA); /* Reserve space for the move_imm + jirl instruction */ for (i = 0; i < LOONGARCH_LONG_JUMP_NINSNS; i++) emit_insn(ctx, nop); |