From patchwork Tue Dec 20 02:13:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pu Lehui X-Patchwork-Id: 13077403 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7BB68C4332F for ; Tue, 20 Dec 2022 02:12:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=9I0lJafWV8TZwi4sdvKJQeeW/+PUF77N7zBNqvyEyiQ=; b=UUYSNs3FWAKvsn jrB6Qbqz6OFbZlSM9idumRjDzhuU3UNnEABG/M4H00xYCF2U2QSHYWeCuRPtlBiQ/srw25eWCYzKk 9Vt+pQG1DU3FaqsmALp/BAknyDmwOFtbY5ZdvHUyDYw3Z0ubdILj6PiRvC5cVPXnf2vVT0reWFjy7 XF5QQ2BtPRzv2sZkW/o9q6YpDe4pAgmELiBlK4DG9LrN0lSrrIdVFVEwnA1pT2nDfHzI3vxEz4EDL ql0+ZGNg/u6qEysCgwX+tAjBHofndcTvWwrASHnLcRPcU9M5Csz54ljfn/7A//ev94uLLDJIAjoZb M7UJQ3mwn239RBPhh5Tg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p7S7Q-006tTt-26; Tue, 20 Dec 2022 02:12:36 +0000 Received: from [45.249.212.51] (helo=dggsgout11.his.huawei.com) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p7S7E-006t92-D9 for linux-riscv@lists.infradead.org; Tue, 20 Dec 2022 02:12:28 +0000 Received: from mail02.huawei.com (unknown [172.30.67.153]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4Nbg7b2RLxz4f3tqF for ; Tue, 20 Dec 2022 10:12:11 +0800 (CST) Received: from localhost.localdomain (unknown [10.67.175.61]) by APP4 (Coremail) with SMTP id gCh0CgDnT7P6GaFju6m1AA--.8438S3; Tue, 20 Dec 2022 10:12:14 +0800 (CST) From: Pu Lehui To: bpf@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , Luke Nelson , Xi Wang , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Paul Walmsley , Palmer Dabbelt , Albert Ou , Pu Lehui , Pu Lehui Subject: [RFC PATCH RESEND bpf-next 1/4] bpf: Rollback to text_poke when arch not supported ftrace direct call Date: Tue, 20 Dec 2022 10:13:16 +0800 Message-Id: <20221220021319.1655871-2-pulehui@huaweicloud.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221220021319.1655871-1-pulehui@huaweicloud.com> References: <20221220021319.1655871-1-pulehui@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgDnT7P6GaFju6m1AA--.8438S3 X-Coremail-Antispam: 1UD129KBjvJXoW7WF1UZw43uw17GF4rZrWUurg_yoW8JFykpF 43Gw13ua1jqFZrWF9rX3WkXrWYv3ykJ3yUGF47K34Fkan5Kr95tr4DZwn3XrWFkr9YvF1a yrWFqFZ0qa1UZa7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBE14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jr4l82xGYIkIc2 x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAS 0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2 IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0 Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2kIc2 xKxwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v2 6r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_GFv_WrylIxkGc2 Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_ Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMI IF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUHE__UUUUU = X-CM-SenderInfo: psxovxtxl6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221219_181226_429157_F03D943D X-CRM114-Status: UNSURE ( 9.17 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: Pu Lehui The current bpf trampoline attach to kernel functions via ftrace direct call API, while text_poke is applied for bpf2bpf attach and tail call optimization. For architectures that do not support ftrace direct call, text_poke is still able to attach bpf trampoline to kernel functions. Let's relax it by rollback to text_poke when architecture not supported. Signed-off-by: Pu Lehui --- kernel/bpf/trampoline.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index d6395215b849..386197a7952c 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -228,15 +228,11 @@ static int modify_fentry(struct bpf_trampoline *tr, void *old_addr, void *new_ad static int register_fentry(struct bpf_trampoline *tr, void *new_addr) { void *ip = tr->func.addr; - unsigned long faddr; int ret; - faddr = ftrace_location((unsigned long)ip); - if (faddr) { - if (!tr->fops) - return -ENOTSUPP; + if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS) && + !!ftrace_location((unsigned long)ip)) tr->func.ftrace_managed = true; - } if (bpf_trampoline_module_get(tr)) return -ENOENT; From patchwork Tue Dec 20 02:13:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pu Lehui X-Patchwork-Id: 13077404 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E52A9C4332F for ; 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Tue, 20 Dec 2022 02:12:40 +0000 Received: from [45.249.212.51] (helo=dggsgout11.his.huawei.com) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p7S7E-006t91-D7 for linux-riscv@lists.infradead.org; Tue, 20 Dec 2022 02:12:30 +0000 Received: from mail02.huawei.com (unknown [172.30.67.153]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4Nbg7b3LyWz4f3p5M for ; Tue, 20 Dec 2022 10:12:11 +0800 (CST) Received: from localhost.localdomain (unknown [10.67.175.61]) by APP4 (Coremail) with SMTP id gCh0CgDnT7P6GaFju6m1AA--.8438S4; Tue, 20 Dec 2022 10:12:14 +0800 (CST) From: Pu Lehui To: bpf@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , Luke Nelson , Xi Wang , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Paul Walmsley , Palmer Dabbelt , Albert Ou , Pu Lehui , Pu Lehui Subject: [RFC PATCH RESEND bpf-next 2/4] riscv, bpf: Factor out emit_call for kernel and bpf context Date: Tue, 20 Dec 2022 10:13:17 +0800 Message-Id: <20221220021319.1655871-3-pulehui@huaweicloud.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221220021319.1655871-1-pulehui@huaweicloud.com> References: <20221220021319.1655871-1-pulehui@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgDnT7P6GaFju6m1AA--.8438S4 X-Coremail-Antispam: 1UD129KBjvJXoWxurWfuw13GrWUJr4rXw47Jwb_yoW5Zr4xpF W5CFn3C3yvqFySgFyDGFs5Zw1akr4v9ry3tF93W39YkFsFqrsxKF15Ka1Yqa4Yyry8Gr4r JFsFkFnxu3WUArJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPj14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jryl82xGYIkIc2 x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAS 0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2 IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0 Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2kIc2 xKxwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v2 6r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_GFv_WrylIxkGc2 Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_ Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8Jw CI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjfUOJPEUUUU U X-CM-SenderInfo: psxovxtxl6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221219_181226_446718_E05D9E69 X-CRM114-Status: GOOD ( 11.47 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: Pu Lehui The current emit_call function is not suitable for kernel function call as it store return value to bpf R0 register. We can separate it out for common use. Meanwhile, simplify judgment logic, that is, fixed function address can use jal or auipc+jalr, while the unfixed can use only auipc+jalr. Signed-off-by: Pu Lehui --- arch/riscv/net/bpf_jit_comp64.c | 30 +++++++++++++----------------- 1 file changed, 13 insertions(+), 17 deletions(-) diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c index 5b568ba6dcfe..bf4721a99a09 100644 --- a/arch/riscv/net/bpf_jit_comp64.c +++ b/arch/riscv/net/bpf_jit_comp64.c @@ -428,12 +428,12 @@ static void emit_sext_32_rd(u8 *rd, struct rv_jit_context *ctx) *rd = RV_REG_T2; } -static int emit_jump_and_link(u8 rd, s64 rvoff, bool force_jalr, +static int emit_jump_and_link(u8 rd, s64 rvoff, bool fixed_addr, struct rv_jit_context *ctx) { s64 upper, lower; - if (rvoff && is_21b_int(rvoff) && !force_jalr) { + if (rvoff && fixed_addr && is_21b_int(rvoff)) { emit(rv_jal(rd, rvoff >> 1), ctx); return 0; } else if (in_auipc_jalr_range(rvoff)) { @@ -454,24 +454,17 @@ static bool is_signed_bpf_cond(u8 cond) cond == BPF_JSGE || cond == BPF_JSLE; } -static int emit_call(bool fixed, u64 addr, struct rv_jit_context *ctx) +static int emit_call(u64 addr, bool fixed_addr, struct rv_jit_context *ctx) { s64 off = 0; u64 ip; - u8 rd; - int ret; if (addr && ctx->insns) { ip = (u64)(long)(ctx->insns + ctx->ninsns); off = addr - ip; } - ret = emit_jump_and_link(RV_REG_RA, off, !fixed, ctx); - if (ret) - return ret; - rd = bpf_to_rv_reg(BPF_REG_0, ctx); - emit_mv(rd, RV_REG_A0, ctx); - return 0; + return emit_jump_and_link(RV_REG_RA, off, fixed_addr, ctx); } static void emit_atomic(u8 rd, u8 rs, s16 off, s32 imm, bool is64, @@ -913,7 +906,7 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, /* JUMP off */ case BPF_JMP | BPF_JA: rvoff = rv_offset(i, off, ctx); - ret = emit_jump_and_link(RV_REG_ZERO, rvoff, false, ctx); + ret = emit_jump_and_link(RV_REG_ZERO, rvoff, true, ctx); if (ret) return ret; break; @@ -1032,17 +1025,20 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, /* function call */ case BPF_JMP | BPF_CALL: { - bool fixed; + bool fixed_addr; u64 addr; mark_call(ctx); - ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass, &addr, - &fixed); + ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass, + &addr, &fixed_addr); if (ret < 0) return ret; - ret = emit_call(fixed, addr, ctx); + + ret = emit_call(addr, fixed_addr, ctx); if (ret) return ret; + + emit_mv(bpf_to_rv_reg(BPF_REG_0, ctx), RV_REG_A0, ctx); break; } /* tail call */ @@ -1057,7 +1053,7 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, break; rvoff = epilogue_offset(ctx); - ret = emit_jump_and_link(RV_REG_ZERO, rvoff, false, ctx); + ret = emit_jump_and_link(RV_REG_ZERO, rvoff, true, ctx); if (ret) return ret; break; From patchwork Tue Dec 20 02:13:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pu Lehui X-Patchwork-Id: 13077405 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A6C2DC4332F for ; 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Tue, 20 Dec 2022 02:12:43 +0000 Received: from [45.249.212.51] (helo=dggsgout11.his.huawei.com) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p7S7E-006t75-D7 for linux-riscv@lists.infradead.org; Tue, 20 Dec 2022 02:12:31 +0000 Received: from mail02.huawei.com (unknown [172.30.67.153]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4Nbg7b3w17z4f3jq3 for ; Tue, 20 Dec 2022 10:12:11 +0800 (CST) Received: from localhost.localdomain (unknown [10.67.175.61]) by APP4 (Coremail) with SMTP id gCh0CgDnT7P6GaFju6m1AA--.8438S5; Tue, 20 Dec 2022 10:12:14 +0800 (CST) From: Pu Lehui To: bpf@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , Luke Nelson , Xi Wang , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Paul Walmsley , Palmer Dabbelt , Albert Ou , Pu Lehui , Pu Lehui Subject: [RFC PATCH RESEND bpf-next 3/4] riscv, bpf: Add bpf_arch_text_poke support for RV64 Date: Tue, 20 Dec 2022 10:13:18 +0800 Message-Id: <20221220021319.1655871-4-pulehui@huaweicloud.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221220021319.1655871-1-pulehui@huaweicloud.com> References: <20221220021319.1655871-1-pulehui@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgDnT7P6GaFju6m1AA--.8438S5 X-Coremail-Antispam: 1UD129KBjvJXoW3Jr4fKF13Aw1xJFW8tFW5Jrb_yoW7uFykpF srKry5ArWkXF4fXFy7Ja1DXr1Ykw4kWFZrGrW5Kw4SyFsFgr93C3Z5Kr43tr95CrW8Cr1I vF4DKFnxuan8AaDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPj14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JrWl82xGYIkIc2 x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAS 0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2 IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0 Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2kIc2 xKxwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v2 6r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_GFv_WrylIxkGc2 Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_ Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8Jw CI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjfUojjgUUUU U X-CM-SenderInfo: psxovxtxl6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221219_181226_505472_19072282 X-CRM114-Status: GOOD ( 16.91 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: Pu Lehui Implement bpf_arch_text_poke for RV64. For call scenario, ftrace framework reserve 4 nops for RV64 kernel function as function entry, and use auipc+jalr instructions to call kernel or module functions. However, since the auipc+jalr call instructions is non-atomic operation, we need to use stop-machine to make sure instruction patching in atomic context. As for jump scenario, since we only jump inside the trampoline, a jal instruction is sufficient. Signed-off-by: Pu Lehui --- arch/riscv/net/bpf_jit.h | 5 ++ arch/riscv/net/bpf_jit_comp64.c | 131 +++++++++++++++++++++++++++++++- 2 files changed, 134 insertions(+), 2 deletions(-) diff --git a/arch/riscv/net/bpf_jit.h b/arch/riscv/net/bpf_jit.h index d926e0f7ef57..bf9802a63061 100644 --- a/arch/riscv/net/bpf_jit.h +++ b/arch/riscv/net/bpf_jit.h @@ -573,6 +573,11 @@ static inline u32 rv_fence(u8 pred, u8 succ) return rv_i_insn(imm11_0, 0, 0, 0, 0xf); } +static inline u32 rv_nop(void) +{ + return rv_i_insn(0, 0, 0, 0, 0x13); +} + /* RVC instrutions. */ static inline u16 rvc_addi4spn(u8 rd, u32 imm10) diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c index bf4721a99a09..fa8b03c52463 100644 --- a/arch/riscv/net/bpf_jit_comp64.c +++ b/arch/riscv/net/bpf_jit_comp64.c @@ -8,6 +8,8 @@ #include #include #include +#include +#include #include "bpf_jit.h" #define RV_REG_TCC RV_REG_A6 @@ -238,7 +240,7 @@ static void __build_epilogue(bool is_tail_call, struct rv_jit_context *ctx) if (!is_tail_call) emit_mv(RV_REG_A0, RV_REG_A5, ctx); emit_jalr(RV_REG_ZERO, is_tail_call ? RV_REG_T3 : RV_REG_RA, - is_tail_call ? 4 : 0, /* skip TCC init */ + is_tail_call ? 20 : 0, /* skip reserved nops and TCC init */ ctx); } @@ -615,6 +617,127 @@ static int add_exception_handler(const struct bpf_insn *insn, return 0; } +struct text_poke_args { + void *addr; + const void *insns; + size_t len; + atomic_t cpu_count; +}; + +static int do_text_poke(void *data) +{ + int ret = 0; + struct text_poke_args *patch = data; + + if (atomic_inc_return(&patch->cpu_count) == num_online_cpus()) { + ret = patch_text_nosync(patch->addr, patch->insns, patch->len); + atomic_inc(&patch->cpu_count); + } else { + while (atomic_read(&patch->cpu_count) <= num_online_cpus()) + cpu_relax(); + smp_mb(); + } + + return ret; +} + +static int bpf_text_poke_stop_machine(void *addr, const void *insns, size_t len) +{ + struct text_poke_args patch = { + .addr = addr, + .insns = insns, + .len = len, + .cpu_count = ATOMIC_INIT(0), + }; + + return stop_machine(do_text_poke, &patch, cpu_online_mask); +} + +static int gen_call_or_nops(void *target, void *ip, u32 *insns) +{ + int i, ret; + s64 rvoff; + struct rv_jit_context ctx; + + ctx.ninsns = 0; + ctx.insns = (u16 *)insns; + + if (!target) { + for (i = 0; i < 4; i++) + emit(rv_nop(), &ctx); + return 0; + } + + rvoff = (s64)(target - ip); + emit(rv_sd(RV_REG_SP, -8, RV_REG_RA), &ctx); + ret = emit_jump_and_link(RV_REG_RA, rvoff, false, &ctx); + if (ret) + return ret; + emit(rv_ld(RV_REG_RA, -8, RV_REG_SP), &ctx); + + return 0; + +} + +static int bpf_text_poke_call(void *ip, void *old_addr, void *new_addr) +{ + int ret; + u32 old_insns[4], new_insns[4]; + + ret = gen_call_or_nops(old_addr, ip + 4, old_insns); + if (ret) + return ret; + + ret = gen_call_or_nops(new_addr, ip + 4, new_insns); + if (ret) + return ret; + + mutex_lock(&text_mutex); + if (memcmp(ip, old_insns, sizeof(old_insns))) { + ret = -EFAULT; + goto out; + } + + if (memcmp(ip, new_insns, sizeof(new_insns))) + ret = bpf_text_poke_stop_machine(ip, new_insns, sizeof(new_insns)); +out: + mutex_unlock(&text_mutex); + return ret; +} + +static int bpf_text_poke_jump(void *ip, void *old_addr, void *new_addr) +{ + int ret; + u32 old_insn, new_insn; + + old_insn = old_addr ? rv_jal(RV_REG_ZERO, (s64)(old_addr - ip) >> 1) : rv_nop(); + new_insn = new_addr ? rv_jal(RV_REG_ZERO, (s64)(new_addr - ip) >> 1) : rv_nop(); + + mutex_lock(&text_mutex); + if (memcmp(ip, &old_insn, sizeof(old_insn))) { + ret = -EFAULT; + goto out; + } + + if (memcmp(ip, &new_insn, sizeof(new_insn))) + ret = patch_text_nosync(ip, &new_insn, sizeof(new_insn)); +out: + mutex_unlock(&text_mutex); + return ret; +} + +int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type poke_type, + void *old_addr, void *new_addr) +{ + if (!is_kernel_text((unsigned long)ip) && + !is_bpf_text_address((unsigned long)ip)) + return -ENOTSUPP; + + return poke_type == BPF_MOD_CALL ? + bpf_text_poke_call(ip, old_addr, new_addr) : + bpf_text_poke_jump(ip, old_addr, new_addr); +} + int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, bool extra_pass) { @@ -1266,7 +1389,7 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, void bpf_jit_build_prologue(struct rv_jit_context *ctx) { - int stack_adjust = 0, store_offset, bpf_stack_adjust; + int i, stack_adjust = 0, store_offset, bpf_stack_adjust; bool is_main_prog = ctx->prog->aux->func_idx == 0; bpf_stack_adjust = round_up(ctx->prog->aux->stack_depth, 16); @@ -1294,6 +1417,10 @@ void bpf_jit_build_prologue(struct rv_jit_context *ctx) store_offset = stack_adjust - 8; + /* reserve 4 nop insns */ + for (i = 0; i < 4; i++) + emit(rv_nop(), ctx); + /* First instruction is always setting the tail-call-counter * (TCC) register. This instruction is skipped for tail calls. * Force using a 4-byte (non-compressed) instruction. From patchwork Tue Dec 20 02:13:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pu Lehui X-Patchwork-Id: 13077406 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AFEA7C001B2 for ; Tue, 20 Dec 2022 02:12:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=VcOqjgcZy697z3JTIPbvxuYeDajy1GbtMqGEzUSdlbM=; b=ifOLH94h0G5UvP csfQiUBldatPTfDwVDdOGC/oGpoc3U0NowUv+V5CvD8kOB5VtungRCGAUmpjsCejcMQfF6y0cVULb JYedPquTJv5tg0IKx3GyfbASiWDPKLgHyrAGRAH7/r21wZmCjdzp/o/NTxpm7X6T3o4OQ0AyVTfIg jQJerWgAU7MZjPM/rMxEhv4Na7mtHcBVL53zHyIEyM5nmz01NIoYvk5Dv22+uREEMRCGWDAp26UMq 4r2V9lBYSW4mfPMQL2Sw8FgQVxD+EyOZxmSIoWRbK/lfWOhcgGQo3hPg/zrDpWilnj5tlbG7CF70V PWYotxHS4xi7EnEV/4lw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p7S7a-006tep-Mu; Tue, 20 Dec 2022 02:12:46 +0000 Received: from [45.249.212.51] (helo=dggsgout11.his.huawei.com) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p7S7E-006t93-DA for linux-riscv@lists.infradead.org; Tue, 20 Dec 2022 02:12:31 +0000 Received: from mail02.huawei.com (unknown [172.30.67.153]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4Nbg7b4jmJz4f3vdT for ; Tue, 20 Dec 2022 10:12:11 +0800 (CST) Received: from localhost.localdomain (unknown [10.67.175.61]) by APP4 (Coremail) with SMTP id gCh0CgDnT7P6GaFju6m1AA--.8438S6; Tue, 20 Dec 2022 10:12:14 +0800 (CST) From: Pu Lehui To: bpf@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , Luke Nelson , Xi Wang , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Paul Walmsley , Palmer Dabbelt , Albert Ou , Pu Lehui , Pu Lehui Subject: [RFC PATCH RESEND bpf-next 4/4] riscv, bpf: Add bpf trampoline support for RV64 Date: Tue, 20 Dec 2022 10:13:19 +0800 Message-Id: <20221220021319.1655871-5-pulehui@huaweicloud.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221220021319.1655871-1-pulehui@huaweicloud.com> References: <20221220021319.1655871-1-pulehui@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgDnT7P6GaFju6m1AA--.8438S6 X-Coremail-Antispam: 1UD129KBjvJXoW3ur4fCw15AryfZw4kCrW5trb_yoWDXw1Upa nrKrW3AFW0qF4FqaykXF1UXF4aya1qvFnIkFy3Grnayr45XrZYkw1rKF4Yvr98Crn5Zr13 JFs0ya90kF17WrJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPI14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F 4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq 3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7 IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4U M4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2 kIc2xKxwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E 14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_GFv_WrylIx kGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAF wI0_Gr1j6F4UJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr 0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8Jr0_Cr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUQ SdkUUUUU= X-CM-SenderInfo: psxovxtxl6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221219_181226_535519_CE8F2CAA X-CRM114-Status: GOOD ( 18.55 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: Pu Lehui BPF trampoline is the critical infrastructure of the bpf subsystem, acting as a mediator between kernel functions and BPF programs. Numerous important features, such as using ebpf program for zero overhead kernel introspection, rely on this key component. We can't wait to support bpf trampoline on RV64. The implementation of bpf trampoline was closely to x86 and arm64 for future development. The related tests have passed, as well as the test_verifier with no new failure ceses. Signed-off-by: Pu Lehui --- arch/riscv/net/bpf_jit_comp64.c | 322 ++++++++++++++++++++++++++++++++ 1 file changed, 322 insertions(+) diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c index fa8b03c52463..11c001782e7b 100644 --- a/arch/riscv/net/bpf_jit_comp64.c +++ b/arch/riscv/net/bpf_jit_comp64.c @@ -738,6 +738,328 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type poke_type, bpf_text_poke_jump(ip, old_addr, new_addr); } +static void store_args(int nregs, int args_off, struct rv_jit_context *ctx) +{ + int i; + + for (i = 0; i < nregs; i++) { + emit_sd(RV_REG_FP, -args_off, RV_REG_A0 + i, ctx); + args_off -= 8; + } +} + +static void restore_args(int nregs, int args_off, struct rv_jit_context *ctx) +{ + int i; + + for (i = 0; i < nregs; i++) { + emit_ld(RV_REG_A0 + i, -args_off, RV_REG_FP, ctx); + args_off -= 8; + } +} + +static int invoke_bpf_prog(struct bpf_tramp_link *l, int args_off, int retval_off, + int run_ctx_off, bool save_ret, struct rv_jit_context *ctx) +{ + u32 insn; + int ret, branch_off, offset; + struct bpf_prog *p = l->link.prog; + int cookie_off = offsetof(struct bpf_tramp_run_ctx, bpf_cookie); + + if (l->cookie) { + emit_imm(RV_REG_T1, l->cookie, ctx); + emit_sd(RV_REG_FP, -run_ctx_off + cookie_off, RV_REG_T1, ctx); + } else { + emit_sd(RV_REG_FP, -run_ctx_off + cookie_off, RV_REG_ZERO, ctx); + } + + /* arg1: prog */ + emit_imm(RV_REG_A0, (const s64)p, ctx); + /* arg2: &run_ctx */ + emit_addi(RV_REG_A1, RV_REG_FP, -run_ctx_off, ctx); + ret = emit_call((const u64)bpf_trampoline_enter(p), true, ctx); + if (ret) + return ret; + + /* if (__bpf_prog_enter(prog) == 0) + * goto skip_exec_of_prog; + */ + branch_off = ctx->ninsns; + /* nop reserved for conditional jump */ + emit(rv_nop(), ctx); + + /* store prog start time */ + emit_mv(RV_REG_S1, RV_REG_A0, ctx); + + /* arg1: &args_off */ + emit_addi(RV_REG_A0, RV_REG_FP, -args_off, ctx); + if (!p->jited) + /* arg2: progs[i]->insnsi for interpreter */ + emit_imm(RV_REG_A1, (const s64)p->insnsi, ctx); + ret = emit_call((const u64)p->bpf_func, true, ctx); + if (ret) + return ret; + + if (save_ret) + emit_sd(RV_REG_FP, -retval_off, regmap[BPF_REG_0], ctx); + + /* update branch with beqz */ + offset = ninsns_rvoff(ctx->ninsns - branch_off); + insn = rv_beq(RV_REG_A0, RV_REG_ZERO, offset >> 1); + *(u32 *)(ctx->insns + branch_off) = insn; + + /* arg1: prog */ + emit_imm(RV_REG_A0, (const s64)p, ctx); + /* arg2: prog start time */ + emit_mv(RV_REG_A1, RV_REG_S1, ctx); + /* arg3: &run_ctx */ + emit_addi(RV_REG_A2, RV_REG_FP, -run_ctx_off, ctx); + ret = emit_call((const u64)bpf_trampoline_exit(p), true, ctx); + + return ret; +} + +static int invoke_bpf_mod_ret(struct bpf_tramp_links *tl, int args_off, int retval_off, + int run_ctx_off, int *branches_off, struct rv_jit_context *ctx) +{ + int i, ret; + + /* cleanup to avoid garbage return value confusion */ + emit_sd(RV_REG_FP, -retval_off, RV_REG_ZERO, ctx); + for (i = 0; i < tl->nr_links; i++) { + ret = invoke_bpf_prog(tl->links[i], args_off, retval_off, + run_ctx_off, true, ctx); + if (ret) + return ret; + emit_ld(RV_REG_T1, -retval_off, RV_REG_FP, ctx); + branches_off[i] = ctx->ninsns; + /* nop reserved for conditional jump */ + emit(rv_nop(), ctx); + } + + return 0; +} + +static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, + const struct btf_func_model *m, + struct bpf_tramp_links *tlinks, + void *func_addr, u32 flags, + struct rv_jit_context *ctx) +{ + int i, ret, offset; + int *branches_off = NULL; + int stack_size = 0, nregs = m->nr_args; + int retaddr_off, fp_off, retval_off, args_off; + int nregs_off, ip_off, run_ctx_off, sreg_off; + struct bpf_tramp_links *fentry = &tlinks[BPF_TRAMP_FENTRY]; + struct bpf_tramp_links *fexit = &tlinks[BPF_TRAMP_FEXIT]; + struct bpf_tramp_links *fmod_ret = &tlinks[BPF_TRAMP_MODIFY_RETURN]; + void *orig_call = func_addr; + bool save_ret; + u32 insn; + + /* Generated trampoline stack layout: + * + * FP - 8 [ RA of parent func ] return address of parent + * function + * FP - retaddr_off [ RA of traced func ] return address of traced + * function + * FP - fp_off [ FP of parent func ] + * + * FP - retval_off [ return value ] BPF_TRAMP_F_CALL_ORIG or + * BPF_TRAMP_F_RET_FENTRY_RET + * [ argN ] + * [ ... ] + * FP - args_off [ arg1 ] + * + * FP - nregs_off [ regs count ] + * + * FP - ip_off [ traced func ] BPF_TRAMP_F_IP_ARG + * + * FP - run_ctx_off [ bpf_tramp_run_ctx ] + * + * FP - sreg_off [ callee saved reg ] + * + * [ pads ] pads for 16 bytes alignment + */ + + if (flags & (BPF_TRAMP_F_ORIG_STACK | BPF_TRAMP_F_SHARE_IPMODIFY)) + return -ENOTSUPP; + + /* extra regiters for struct arguments */ + for (i = 0; i < m->nr_args; i++) + if (m->arg_flags[i] & BTF_FMODEL_STRUCT_ARG) + nregs += round_up(m->arg_size[i], 8) / 8 - 1; + + /* 8 arguments passed by registers */ + if (nregs > 8) + return -ENOTSUPP; + + /* room for parent function return address */ + stack_size += 8; + + stack_size += 8; + retaddr_off = stack_size; + + stack_size += 8; + fp_off = stack_size; + + save_ret = flags & (BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_RET_FENTRY_RET); + if (save_ret) { + stack_size += 8; + retval_off = stack_size; + } + + stack_size += nregs * 8; + args_off = stack_size; + + stack_size += 8; + nregs_off = stack_size; + + if (flags & BPF_TRAMP_F_IP_ARG) { + stack_size += 8; + ip_off = stack_size; + } + + stack_size += round_up(sizeof(struct bpf_tramp_run_ctx), 8); + run_ctx_off = stack_size; + + stack_size += 8; + sreg_off = stack_size; + + stack_size = round_up(stack_size, 16); + + emit_addi(RV_REG_SP, RV_REG_SP, -stack_size, ctx); + + emit_sd(RV_REG_SP, stack_size - retaddr_off, RV_REG_RA, ctx); + emit_sd(RV_REG_SP, stack_size - fp_off, RV_REG_FP, ctx); + + emit_addi(RV_REG_FP, RV_REG_SP, stack_size, ctx); + + /* callee saved register S1 to pass start time */ + emit_sd(RV_REG_FP, -sreg_off, RV_REG_S1, ctx); + + /* store ip address of the traced function */ + if (flags & BPF_TRAMP_F_IP_ARG) { + emit_imm(RV_REG_T1, (const s64)func_addr, ctx); + emit_sd(RV_REG_FP, -ip_off, RV_REG_T1, ctx); + } + + emit_li(RV_REG_T1, nregs, ctx); + emit_sd(RV_REG_FP, -nregs_off, RV_REG_T1, ctx); + + store_args(nregs, args_off, ctx); + + /* skip to actual body of traced function */ + if (flags & BPF_TRAMP_F_SKIP_FRAME) + orig_call += 16; + + if (flags & BPF_TRAMP_F_CALL_ORIG) { + emit_imm(RV_REG_A0, (const s64)im, ctx); + ret = emit_call((const u64)__bpf_tramp_enter, true, ctx); + if (ret) + return ret; + } + + for (i = 0; i < fentry->nr_links; i++) { + ret = invoke_bpf_prog(fentry->links[i], args_off, retval_off, run_ctx_off, + flags & BPF_TRAMP_F_RET_FENTRY_RET, ctx); + if (ret) + return ret; + } + + if (fmod_ret->nr_links) { + branches_off = kcalloc(fmod_ret->nr_links, sizeof(int), GFP_KERNEL); + if (!branches_off) + return -ENOMEM; + + ret = invoke_bpf_mod_ret(fmod_ret, args_off, retval_off, run_ctx_off, + branches_off, ctx); + if (ret) + return ret; + } + + if (flags & BPF_TRAMP_F_CALL_ORIG) { + restore_args(nregs, args_off, ctx); + ret = emit_call((const u64)orig_call, true, ctx); + if (ret) + return ret; + emit_sd(RV_REG_FP, -retval_off, RV_REG_A0, ctx); + /* nop reserved for bpf_tramp_image_put */ + im->ip_after_call = ctx->insns + ctx->ninsns; + emit(rv_nop(), ctx); + } + + /* update branches saved in invoke_bpf_mod_ret with bnez */ + for (i = 0; i < fmod_ret->nr_links; i++) { + offset = ninsns_rvoff(ctx->ninsns - branches_off[i]); + insn = rv_bne(RV_REG_T1, RV_REG_ZERO, offset >> 1); + *(u32 *)(ctx->insns + branches_off[i]) = insn; + } + + for (i = 0; i < fexit->nr_links; i++) { + ret = invoke_bpf_prog(fexit->links[i], args_off, retval_off, + run_ctx_off, false, ctx); + if (ret) + return ret; + } + + if (flags & BPF_TRAMP_F_CALL_ORIG) { + im->ip_epilogue = ctx->insns + ctx->ninsns; + emit_imm(RV_REG_A0, (const s64)im, ctx); + ret = emit_call((const u64)__bpf_tramp_exit, true, ctx); + if (ret) + return ret; + } + + if (flags & BPF_TRAMP_F_RESTORE_REGS) + restore_args(nregs, args_off, ctx); + + if (save_ret) + emit_ld(RV_REG_A0, -retval_off, RV_REG_FP, ctx); + + emit_ld(RV_REG_S1, -sreg_off, RV_REG_FP, ctx); + + if (flags & BPF_TRAMP_F_SKIP_FRAME) + /* return address of parent function */ + emit_ld(RV_REG_RA, stack_size - 8, RV_REG_SP, ctx); + else + /* return address of traced function */ + emit_ld(RV_REG_RA, stack_size - retaddr_off, RV_REG_SP, ctx); + + emit_ld(RV_REG_FP, stack_size - fp_off, RV_REG_SP, ctx); + emit_addi(RV_REG_SP, RV_REG_SP, stack_size, ctx); + + emit_jalr(RV_REG_ZERO, RV_REG_RA, 0, ctx); + + bpf_flush_icache(ctx->insns, ctx->insns + ctx->ninsns); + + kfree(branches_off); + + return ctx->ninsns; + +} + +int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, + void *image_end, const struct btf_func_model *m, + u32 flags, struct bpf_tramp_links *tlinks, + void *func_addr) +{ + int ret; + struct rv_jit_context ctx; + + ctx.ninsns = 0; + ctx.insns = image; + ret = __arch_prepare_bpf_trampoline(im, m, tlinks, func_addr, flags, &ctx); + if (ret < 0) + return ret; + + if (ninsns_rvoff(ret) > (long)image_end - (long)image) + return -EFBIG; + + return ninsns_rvoff(ret); +} + int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, bool extra_pass) {