From: Menglong Dong Date: Tue, 24 Feb 2026 09:22:06 +0000 (+0800) Subject: bpf,s390: introduce emit_store_stack_imm64() for trampoline X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=339193c44e75d302bae11e93cbb76980912df660;p=thirdparty%2Fkernel%2Flinux.git bpf,s390: introduce emit_store_stack_imm64() for trampoline Introduce a helper to store 64-bit immediate on the trampoline stack with a help of a register. Signed-off-by: Menglong Dong Acked-by: Ilya Leoshkevich Link: https://lore.kernel.org/r/20260224092208.1395085-2-dongml2@chinatelecom.cn Signed-off-by: Alexei Starovoitov --- diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index 2112267486623..d72d682ad2204 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -2513,6 +2513,13 @@ static void load_imm64(struct bpf_jit *jit, int dst_reg, u64 val) EMIT6_IMM(0xc00d0000, dst_reg, val); } +static void emit_store_stack_imm64(struct bpf_jit *jit, int tmp_reg, int stack_off, u64 imm) +{ + load_imm64(jit, tmp_reg, imm); + /* stg %tmp_reg,stack_off(%r15) */ + EMIT6_DISP_LH(0xe3000000, 0x0024, tmp_reg, REG_0, REG_15, stack_off); +} + static int invoke_bpf_prog(struct bpf_tramp_jit *tjit, const struct btf_func_model *m, struct bpf_tramp_link *tlink, bool save_ret) @@ -2527,10 +2534,7 @@ static int invoke_bpf_prog(struct bpf_tramp_jit *tjit, * run_ctx.cookie = tlink->cookie; */ - /* %r0 = tlink->cookie */ - load_imm64(jit, REG_W0, tlink->cookie); - /* stg %r0,cookie_off(%r15) */ - EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W0, REG_0, REG_15, cookie_off); + emit_store_stack_imm64(jit, REG_W0, cookie_off, tlink->cookie); /* * if ((start = __bpf_prog_enter(p, &run_ctx)) == 0) @@ -2750,13 +2754,8 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, * arg_cnt = m->nr_args; */ - if (flags & BPF_TRAMP_F_IP_ARG) { - /* %r0 = func_addr */ - load_imm64(jit, REG_0, (u64)func_addr); - /* stg %r0,ip_off(%r15) */ - EMIT6_DISP_LH(0xe3000000, 0x0024, REG_0, REG_0, REG_15, - tjit->ip_off); - } + if (flags & BPF_TRAMP_F_IP_ARG) + emit_store_stack_imm64(jit, REG_0, tjit->ip_off, (u64)func_addr); /* lghi %r0,nr_bpf_args */ EMIT4_IMM(0xa7090000, REG_0, nr_bpf_args); /* stg %r0,arg_cnt_off(%r15) */