From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 7870E463B83 for ; Tue, 4 Aug 2026 13:46:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785851193; cv=none; b=ibDJ5lXR5oqcJb5C6Eu1i2e5ztcBpKxT+hMCmPm1SPod7Gnxew9Ip6+59+I2VifF2Nu4Yuq6B4XY2EMD64nuk4dtnpQzBVla4ftK6NJxBCh9rHjjiYUzksOtCBimLkmIXvz4DcYOexY/gdMgTAD7uPrl9gfKS7TZAIx/oLjbTwI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785851193; c=relaxed/simple; bh=L1Pakl2FgMMlFwWq9tm/DGNN/QvUyCNeCMiwTuMPQ6c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MxwUD1kEAEDoX+GXcISZNT+5PE/xvbFGnyRXsd8PIP1vGMc+HvvbCINF+9oZwAAZDHplSXSo538ntkCxkg+hlEtln3JZtj3epJqd7m3bzsigx7/o/jlKJgJKKneQMRyaXPBAzh+KLJWuAWkkPYtXiWj3WeEAXwFihTfbviWznqA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=MyIv5HM7; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="MyIv5HM7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F28B11F000E9; Tue, 4 Aug 2026 13:46:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785851192; bh=2MZiUnLZdA0MHxE7oKThCXWe4AzHF7JSoVT3D98WNpM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=MyIv5HM7On3T/jv4SrBCz678R3PuekPyASJgKmDXHxEksCqblsV+qURiiXCEOP1/b AvKYlqZmskJtsTP8xhWDi+PDSCi7OZpld3VXIc32aBGozS0zTtlCbxLF8srMUOMKvd jgeJ88MXSDgw7uNyemvqEk4DA42Gut/21o0kL6YQ/fopDWbVUkI1iQ+Przy+NCFyeI eZntXgrJwelLfeAJywK5bItbuR5HxuRRwa+9ifsZWfDEsKD4i4PkAb0IoS/CD2BvEw 1gLVja/TTovRyBVOrORpWOFTCOS6h4FeQB2OKs9IfMcVU6WGgNp4D52p97/SsPksgh WvYbFVJ/U9IOw== From: Puranjay Mohan To: bpf@vger.kernel.org Cc: Puranjay Mohan , "Alexei Starovoitov" , "Daniel Borkmann" , "Andrii Nakryiko" , "Martin KaFai Lau" , "Eduard Zingerman" , "Kumar Kartikeya Dwivedi" , "Song Liu" , "Yonghong Song" Subject: [PATCH bpf-next v5 3/6] bpf: Inline bpf_iter_num_next() kfunc Date: Tue, 4 Aug 2026 06:45:55 -0700 Message-ID: <20260804134601.2305303-4-puranjay@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260804134601.2305303-1-puranjay@kernel.org> References: <20260804134601.2305303-1-puranjay@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit bpf_iter_num_next() runs on every bpf_for() iteration, so inlining it drops a call from the loop body. R1 points to the iterator; the returned pointer to s->cur is R1 itself, since s->cur is first. s->cur and s->end are int, so the kfunc's s->cur + 1 >= s->end is a signed 32-bit compare and the inlined code needs no sign extension. Signed-off-by: Puranjay Mohan --- kernel/bpf/verifier.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index e0c91f6412228..6bfd715aaa379 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -20030,6 +20030,23 @@ int bpf_fixup_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, insn_buf[i++] = BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 0); insn_buf[i++] = BPF_MOV64_IMM(BPF_REG_0, -E2BIG); *cnt = i; + } else if (desc->func_id == special_kfunc_list[KF_bpf_iter_num_next]) { + /* inline bpf_iter_num_next(&it); R1=&it, returns &s->cur or NULL */ + int i = 0; + + /* r0 = s->cur + 1; if ((s32)r0 >= s->end) goto done; */ + insn_buf[i++] = BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, 0); + insn_buf[i++] = BPF_ALU32_IMM(BPF_ADD, BPF_REG_0, 1); + insn_buf[i++] = BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 4); + insn_buf[i++] = BPF_JMP32_REG(BPF_JSGE, BPF_REG_0, BPF_REG_2, 3); + /* s->cur = r0; return &s->cur; */ + insn_buf[i++] = BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0); + insn_buf[i++] = BPF_MOV64_REG(BPF_REG_0, BPF_REG_1); + insn_buf[i++] = BPF_JMP_A(2); + /* done: s->cur = s->end = 0; return NULL; */ + insn_buf[i++] = BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 0); + insn_buf[i++] = BPF_MOV64_IMM(BPF_REG_0, 0); + *cnt = i; } if (env->insn_aux_data[insn_idx].arg_prog) { -- 2.53.0-Meta