From patchwork Sun Mar 31 09:24:04 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Pu Lehui X-Patchwork-Id: 13612186 X-Patchwork-Delegate: bpf@iogearbox.net Received: from dggsgout11.his.huawei.com (unknown [45.249.212.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2228B6E5E8; Sun, 31 Mar 2024 09:22:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711876971; cv=none; b=hv2V0jigilROcK8EYto6mRFG8DmuWtzxXZdqHtz9fMG0J+dkwO3J41ISZ+hTRcRxWrMDvtPfqrGiOO2Pa5vS9Hw9hNW0+rcY8I0q3N1C1xYo9KnGofkVAWYNtZ045WxaXdk92DZrHEodFCKU10wDs2vIdFY6zGSn/djqvoiqa+0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711876971; c=relaxed/simple; bh=NU/seP21mtWkdilB97nH/1Auom8uGHKorbHfj6W3x1U=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=t5VU4JM9HWfq6ydlfdq15M8AHsNevxb1HZ/WRW7e5KCGFbuynlYb35Qx1hbwhN8rTBK/vhMo3wMg6IQKk1cvjnlml0wLsB2fxmf42iOXZsYiZWVGRgHzQLCt/253/+2SOkeNOhmEUNNNocVPFZzGfHby5lZfh2NLhB8+aGYDVJ8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.216]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4V6pZh3SXWz4f3lgR; Sun, 31 Mar 2024 17:22:36 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id B51391A0DDA; Sun, 31 Mar 2024 17:22:44 +0800 (CST) Received: from ultra.huawei.com (unknown [10.90.53.71]) by APP4 (Coremail) with SMTP id gCh0CgCH2WtkKwlmesQWIw--.11467S3; Sun, 31 Mar 2024 17:22:44 +0800 (CST) From: Pu Lehui To: bpf@vger.kernel.org, linux-riscv@lists.infradead.org, netdev@vger.kernel.org Cc: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Palmer Dabbelt , Pu Lehui , Pu Lehui Subject: [PATCH bpf-next 1/2] riscv, bpf: Add 12-argument support for RV64 bpf trampoline Date: Sun, 31 Mar 2024 09:24:04 +0000 Message-Id: <20240331092405.822571-2-pulehui@huaweicloud.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240331092405.822571-1-pulehui@huaweicloud.com> References: <20240331092405.822571-1-pulehui@huaweicloud.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: gCh0CgCH2WtkKwlmesQWIw--.11467S3 X-Coremail-Antispam: 1UD129KBjvJXoW3Ar15Jw13Kr1kAF13Cr45ZFb_yoWxJr4Dpa 1DKrsxAFyvqa17Xa97WF1UXF1aya1qva43CFW7Gas3uFWYqr98GayFkF4jyry5GryrAw1f AFs0vF98KF17GrDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBE14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jr4l82xGYIkIc2 x26xkF7I0E14v26r4j6ryUM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAS 0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2 IY67AKxVWUGVWUXwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0 Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2kIc2 xKxwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v2 6r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_GFv_WrylIxkGc2 Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_ Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMI IF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUSYLPUUUUU = X-CM-SenderInfo: psxovxtxl6x35dzhxuhorxvhhfrp/ X-Patchwork-Delegate: bpf@iogearbox.net From: Pu Lehui This patch adds 12 function arguments support for riscv64 bpf trampoline. The current bpf trampoline supports <= sizeof(u64) bytes scalar arguments [0] and <= 16 bytes struct arguments [1]. Therefore, we focus on the situation where scalars are at most XLEN bits and aggregates whose total size does not exceed 2×XLEN bits in the riscv calling convention [2]. Link: https://elixir.bootlin.com/linux/v6.8/source/kernel/bpf/btf.c#L6184 [0] Link: https://elixir.bootlin.com/linux/v6.8/source/kernel/bpf/btf.c#L6769 [1] Link: https://github.com/riscv-non-isa/riscv-elf-psabi-doc/releases/download/draft-20230929-e5c800e661a53efe3c2678d71a306323b60eb13b/riscv-abi.pdf [2] Signed-off-by: Pu Lehui --- arch/riscv/net/bpf_jit_comp64.c | 63 +++++++++++++++++++++++---------- 1 file changed, 44 insertions(+), 19 deletions(-) diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c index 77ea306452d4..2aec69e4c116 100644 --- a/arch/riscv/net/bpf_jit_comp64.c +++ b/arch/riscv/net/bpf_jit_comp64.c @@ -14,6 +14,7 @@ #include #include "bpf_jit.h" +#define RV_MAX_ARG_REGS 8 #define RV_FENTRY_NINSNS 2 #define RV_REG_TCC RV_REG_A6 @@ -688,26 +689,43 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type poke_type, return ret; } -static void store_args(int nregs, int args_off, struct rv_jit_context *ctx) +static void store_args(int nr_arg_slots, 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); + for (i = 0; i < nr_arg_slots; i++) { + if (i < RV_MAX_ARG_REGS) { + emit_sd(RV_REG_FP, -args_off, RV_REG_A0 + i, ctx); + } else { + emit_ld(RV_REG_T1, 16 + (i - RV_MAX_ARG_REGS) * 8, RV_REG_FP, ctx); + emit_sd(RV_REG_FP, -args_off, RV_REG_T1, ctx); + } args_off -= 8; } } -static void restore_args(int nregs, int args_off, struct rv_jit_context *ctx) +static void restore_args(int nr_args_reg, int args_off, struct rv_jit_context *ctx) { int i; - for (i = 0; i < nregs; i++) { + for (i = 0; i < nr_args_reg; i++) { emit_ld(RV_REG_A0 + i, -args_off, RV_REG_FP, ctx); args_off -= 8; } } +static void restore_stack_args(int nr_args_stack, int args_off, int stk_arg_off, struct rv_jit_context *ctx) +{ + int i; + + for (i = 0; i < nr_args_stack; i++) { + emit_ld(RV_REG_T1, -(args_off - RV_MAX_ARG_REGS * 8), RV_REG_FP, ctx); + emit_sd(RV_REG_FP, -stk_arg_off, RV_REG_T1, ctx); + args_off -= 8; + stk_arg_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) { @@ -780,8 +798,8 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, { int i, ret, offset; int *branches_off = NULL; - int stack_size = 0, nregs = m->nr_args; - int retval_off, args_off, nregs_off, ip_off, run_ctx_off, sreg_off; + int stack_size = 0, nr_arg_slots = 0; + int retval_off, args_off, nregs_off, ip_off, run_ctx_off, sreg_off, stk_arg_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]; @@ -827,20 +845,21 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, * FP - sreg_off [ callee saved reg ] * * [ pads ] pads for 16 bytes alignment + * + * [ stack_argN ] + * [ ... ] + * FP - stk_arg_off [ stack_arg1 ] BPF_TRAMP_F_CALL_ORIG */ 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) + if (m->nr_args > MAX_BPF_FUNC_ARGS) return -ENOTSUPP; + for (i = 0; i < m->nr_args; i++) + nr_arg_slots += round_up(m->arg_size[i], 8) / 8; + /* room of trampoline frame to store return address and frame pointer */ stack_size += 16; @@ -850,7 +869,7 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, retval_off = stack_size; } - stack_size += nregs * 8; + stack_size += nr_arg_slots * 8; args_off = stack_size; stack_size += 8; @@ -867,8 +886,13 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, stack_size += 8; sreg_off = stack_size; + if (nr_arg_slots - RV_MAX_ARG_REGS > 0) + stack_size += (nr_arg_slots - RV_MAX_ARG_REGS) * 8; + stack_size = round_up(stack_size, 16); + stk_arg_off = stack_size; + if (!is_struct_ops) { /* For the trampoline called from function entry, * the frame of traced function and the frame of @@ -904,10 +928,10 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, emit_sd(RV_REG_FP, -ip_off, RV_REG_T1, ctx); } - emit_li(RV_REG_T1, nregs, ctx); + emit_li(RV_REG_T1, nr_arg_slots, ctx); emit_sd(RV_REG_FP, -nregs_off, RV_REG_T1, ctx); - store_args(nregs, args_off, ctx); + store_args(nr_arg_slots, args_off, ctx); /* skip to actual body of traced function */ if (flags & BPF_TRAMP_F_SKIP_FRAME) @@ -947,7 +971,8 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, } if (flags & BPF_TRAMP_F_CALL_ORIG) { - restore_args(nregs, args_off, ctx); + restore_args(min_t(int, nr_arg_slots, RV_MAX_ARG_REGS), args_off, ctx); + restore_stack_args(nr_arg_slots - RV_MAX_ARG_REGS, args_off, stk_arg_off, ctx); ret = emit_call((const u64)orig_call, true, ctx); if (ret) goto out; @@ -982,7 +1007,7 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, } if (flags & BPF_TRAMP_F_RESTORE_REGS) - restore_args(nregs, args_off, ctx); + restore_args(min_t(int, nr_arg_slots, RV_MAX_ARG_REGS), args_off, ctx); if (save_ret) { emit_ld(RV_REG_A0, -retval_off, RV_REG_FP, ctx);