From nobody Tue Oct 7 00:25:43 2025 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 146FC2E3715; Wed, 16 Jul 2025 04:39:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.242.206.163 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752640765; cv=none; b=sPT3cUbO+/b2uWSHL+/wpmOuWe+G0PAq2CHNsxwMfkFNPJCgIT+QDEo373YeHXfynVzByU+HMcCXkyOBOyeIA6NJ+HPJkjI0uMUn5MtFS5vWkxhIFogKsFqILsdgsQcB2ejGD0aAZ4omeezPKdpoejF/GlQrn/GAAI1QmpznQoA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752640765; c=relaxed/simple; bh=7HDOCBc6V6kKoG+jOtt6yyv5DEob+bLWWJqp9Btf4n0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Pe3Ld7M6apNtHslSaWW4qdKRm1pQaJgJQNH3jQFjFgcgw0sLYK1yj4H6rD7vZO0DxGnd5OvZCFY3zuVwr9Jsqw6gLk/WYkxl3Mq11melqsWxveg0QPqrkWi708T39jO+SKkjafkMt5XJ2oOaCHyoaX4hUQq/dnp9XSdmFLTswYg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn; spf=pass smtp.mailfrom=loongson.cn; arc=none smtp.client-ip=114.242.206.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=loongson.cn Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8CxaWr3LHdoluoqAQ--.27156S3; Wed, 16 Jul 2025 12:39:19 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by front1 (Coremail) with SMTP id qMiowJAxVOTzLHdonVQZAA--.5847S2; Wed, 16 Jul 2025 12:39:16 +0800 (CST) From: Tiezhu Yang To: Huacai Chen , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: Hengqi Chen , bpf@vger.kernel.org, loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [RFC PATCH] LoongArch: BPF: Add struct ops support for trampoline Date: Wed, 16 Jul 2025 12:39:15 +0800 Message-ID: <20250716043915.15034-1-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.42.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: qMiowJAxVOTzLHdonVQZAA--.5847S2 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBj93XoWxtrWxKry3XryDJrWkCFyxtFc_yoWxGFy3pr yqkF48CFyUK3W2gF4kJr1j9r1rXFsakasxKayUJrZ5KrZxZFyrWF1UKr13WFW3X3WDZryx uwnYyw4vvF1xArcCm3ZEXasCq-sJn29KB7ZKAUJUUUU5529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUk0b4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1Y6r17M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Jr0_JF4l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Jr0_Gr1l84ACjcxK6I8E87Iv67AKxVWxJr0_GcWl84ACjcxK6I8E87Iv6xkF7I0E14v2 6F4UJVW0owAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07AIYIkI8VC2zVCFFI0UMc 02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUXVWUAwAv7VC2z280aVAF wI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JMxAIw28IcxkI7V AKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCj r7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6x IIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVWUJVW8JwCI42IY6xAI w20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x 0267AKxVWUJVW8JbIYCTnIWIevJa73UjIFyTuYvjxU7_MaUUUUU Content-Type: text/plain; charset="utf-8" Use BPF_TRAMP_F_INDIRECT flag to detect struct ops and emit proper prologue and epilogue for this case. With this patch, all of the struct_ops related testcases (except struct_ops_multi_pages) passed on LoongArch. The testcase struct_ops_multi_pages failed is because the actual image_pages_cnt is 40 which is bigger than MAX_TRAMP_IMAGE_PAGES. Before: $ sudo ./test_progs -t struct_ops -d struct_ops_multi_pages ... WATCHDOG: test case struct_ops_module/struct_ops_load executes for 10 sec= onds... After: $ sudo ./test_progs -t struct_ops -d struct_ops_multi_pages ... #15 bad_struct_ops:OK ... #399 struct_ops_autocreate:OK ... #400 struct_ops_kptr_return:OK ... #401 struct_ops_maybe_null:OK ... #402 struct_ops_module:OK ... #404 struct_ops_no_cfi:OK ... #405 struct_ops_private_stack:SKIP ... #406 struct_ops_refcounted:OK Summary: 8/25 PASSED, 3 SKIPPED, 0 FAILED Signed-off-by: Tiezhu Yang --- This is a RFC patch, based on 6.16-rc6 and the following series: [PATCH v3 0/5] Support trampoline for LoongArch https://lore.kernel.org/loongarch/20250709055029.723243-1-duanchenghao@kyli= nos.cn/ arch/loongarch/net/bpf_jit.c | 71 ++++++++++++++++++++++++------------ 1 file changed, 47 insertions(+), 24 deletions(-) diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c index 6820558afce5..7663b84a4ff1 100644 --- a/arch/loongarch/net/bpf_jit.c +++ b/arch/loongarch/net/bpf_jit.c @@ -1599,6 +1599,7 @@ static int __arch_prepare_bpf_trampoline(struct jit_c= tx *ctx, struct bpf_tramp_i struct bpf_tramp_links *fentry =3D &tlinks[BPF_TRAMP_FENTRY]; struct bpf_tramp_links *fexit =3D &tlinks[BPF_TRAMP_FEXIT]; struct bpf_tramp_links *fmod_ret =3D &tlinks[BPF_TRAMP_MODIFY_RETURN]; + bool is_struct_ops =3D flags & BPF_TRAMP_F_INDIRECT; int ret, save_ret; void *orig_call =3D func_addr; u32 **branches =3D NULL; @@ -1674,18 +1675,31 @@ static int __arch_prepare_bpf_trampoline(struct jit= _ctx *ctx, struct bpf_tramp_i =20 stack_size =3D round_up(stack_size, 16); =20 - /* For the trampoline called from function entry */ - /* RA and FP for parent function*/ - emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, -16); - emit_insn(ctx, std, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, 8); - emit_insn(ctx, std, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, 0); - emit_insn(ctx, addid, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, 16); - - /* RA and FP for traced function*/ - emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, -stack_size); - emit_insn(ctx, std, LOONGARCH_GPR_T0, LOONGARCH_GPR_SP, stack_size - 8); - emit_insn(ctx, std, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size - 16); - emit_insn(ctx, addid, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size); + if (!is_struct_ops) { + /* + * For the trampoline called from function entry, + * the frame of traced function and the frame of + * trampoline need to be considered. + */ + emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, -16); + emit_insn(ctx, std, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, 8); + emit_insn(ctx, std, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, 0); + emit_insn(ctx, addid, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, 16); + + emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, -stack_size); + emit_insn(ctx, std, LOONGARCH_GPR_T0, LOONGARCH_GPR_SP, stack_size - 8); + emit_insn(ctx, std, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size - 16); + emit_insn(ctx, addid, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size); + } else { + /* + * For the trampoline called directly, just handle + * the frame of trampoline. + */ + emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, -stack_size); + emit_insn(ctx, std, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, stack_size - 8); + emit_insn(ctx, std, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size - 16); + emit_insn(ctx, addid, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size); + } =20 /* callee saved register S1 to pass start time */ emit_insn(ctx, std, LOONGARCH_GPR_S1, LOONGARCH_GPR_FP, -sreg_off); @@ -1772,21 +1786,30 @@ static int __arch_prepare_bpf_trampoline(struct jit= _ctx *ctx, struct bpf_tramp_i =20 emit_insn(ctx, ldd, LOONGARCH_GPR_S1, LOONGARCH_GPR_FP, -sreg_off); =20 - /* trampoline called from function entry */ - emit_insn(ctx, ldd, LOONGARCH_GPR_T0, LOONGARCH_GPR_SP, stack_size - 8); - emit_insn(ctx, ldd, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size - 16); - emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, stack_size); + if (!is_struct_ops) { + /* trampoline called from function entry */ + emit_insn(ctx, ldd, LOONGARCH_GPR_T0, LOONGARCH_GPR_SP, stack_size - 8); + emit_insn(ctx, ldd, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size - 16); + emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, stack_size); + + emit_insn(ctx, ldd, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, 8); + emit_insn(ctx, ldd, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, 0); + emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, 16); =20 - emit_insn(ctx, ldd, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, 8); - emit_insn(ctx, ldd, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, 0); - emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, 16); + if (flags & BPF_TRAMP_F_SKIP_FRAME) + /* return to parent function */ + emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_RA, 0); + else + /* return to traced function */ + emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_T0, 0); + } else { + /* trampoline called directly */ + emit_insn(ctx, ldd, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, stack_size - 8); + emit_insn(ctx, ldd, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size - 16); + emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, stack_size); =20 - if (flags & BPF_TRAMP_F_SKIP_FRAME) - /* return to parent function */ emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_RA, 0); - else - /* return to traced function */ - emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_T0, 0); + } =20 ret =3D ctx->idx; out: --=20 2.42.0