From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 EB4FB38B9AF; Mon, 19 Jan 2026 18:44:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768848294; cv=none; b=qz8YMHeZiQwpLiPolaOa8w8QaokhiUAkuTCzYZMuQO6/v/mPYjCnK6cJHeDEuXoiV4tm3OztIzOlgfs7tb7w9NGZ0Ov8RsfvqKBUXrssatp9oJNmjsaUt8yAwW+dYrW+QZibG3A/o4kRIP159VJR17KibPknw5iSmoxpkUT0vVQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768848294; c=relaxed/simple; bh=7+qcIN3pStM1p5Kmh6umxaTJlgxXnlEyJuEVfeiEGCI=; h=Content-Type:MIME-Version:Message-Id:In-Reply-To:References: Subject:From:To:Cc:Date; b=CHcGl9r8f2GMqpYNZOhy77IMDyH9pIIqkLpjLJ11TiW/JmLsi3FXIyfst9WxSuckwJKUYViv+1Mo0WSHr8sosxKIcJqZR1CgvD/zc/I7WKKWBQY8HRgFCaIRRUqBBQutb3up/gHkm65LkWCT863lM2ikoVo1XvoIHCoDszE3XN4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XWsXrW1G; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="XWsXrW1G" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38662C116C6; Mon, 19 Jan 2026 18:44:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768848293; bh=7+qcIN3pStM1p5Kmh6umxaTJlgxXnlEyJuEVfeiEGCI=; h=In-Reply-To:References:Subject:From:To:Cc:Date:From; b=XWsXrW1Ga6f8BkmJip2yofi1RID/M3W8y+zw193F9Hm0AkrQ+5Hq1SNWmPmofA757 ptIyZVs2BuvvL/95n3xk9g/NsujnB9eN7cReMFIMXT8C8H37sSnkwYwIpH2oCFtPn4 bXZryl7LjEYXtPkX27kwm+s/KPXqvcpPhvRmRGoiCiWgZiuUSdi9B+H/sCek/IXbmi zRwTNeKmnALLl/i4498XqQH3na2PmdXeTS9sp94dQikpqo9DlI3TTE5BPCLbKdYfXu EihZ4L6NqBtWNHIIdgRSGJZPjonK1zufFhXQaKGJOCciRCe/tznIddQlgGKx/tK1HK Pnb1Gp1SQxEWw== Content-Type: multipart/mixed; boundary="===============6140367530953031628==" Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: In-Reply-To: <20260119023732.130642-2-dongml2@chinatelecom.cn> References: <20260119023732.130642-2-dongml2@chinatelecom.cn> Subject: Re: [PATCH bpf-next v3 1/2] bpf: support bpf_get_func_arg() for BPF_TRACE_RAW_TP From: bot+bpf-ci@kernel.org To: menglong8.dong@gmail.com,andrii@kernel.org,ast@kernel.org Cc: daniel@iogearbox.net,john.fastabend@gmail.com,martin.lau@linux.dev,eddyz87@gmail.com,song@kernel.org,yonghong.song@linux.dev,kpsingh@kernel.org,sdf@fomichev.me,haoluo@google.com,jolsa@kernel.org,mattbobrowski@google.com,rostedt@goodmis.org,mhiramat@kernel.org,mathieu.desnoyers@efficios.com,bpf@vger.kernel.org,linux-kernel@vger.kernel.org,linux-trace-kernel@vger.kernel.org,ast@kernel.org,andrii@kernel.org,daniel@iogearbox.net,martin.lau@kernel.org,eddyz87@gmail.com,yonghong.song@linux.dev,clm@meta.com,ihor.solodrai@linux.dev Date: Mon, 19 Jan 2026 18:44:53 +0000 (UTC) --===============6140367530953031628== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c > index f73e08c223b5..64976009ba3c 100644 > --- a/kernel/trace/bpf_trace.c > +++ b/kernel/trace/bpf_trace.c > @@ -1734,11 +1734,11 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) > case BPF_FUNC_d_path: > return &bpf_d_path_proto; > case BPF_FUNC_get_func_arg: > - return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; > + return &bpf_get_func_arg_proto; Removing the bpf_prog_has_trampoline() check here allows all TRACING program types to use bpf_get_func_arg(), not just RAW_TP and trampoline- based types. In particular, BPF_TRACE_ITER programs can now use this helper. However, looking at do_misc_fixups() in verifier.c, the inline code generation only handles BPF_TRACE_RAW_TP specially. For other non- trampoline types like BPF_TRACE_ITER, the else branch generates: BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8) This loads nr_args from ctx-8, but ITER programs use a different context layout (e.g. struct bpf_iter__bpf_map_elem with meta, map, key, value pointers). There is no nr_args at ctx-8 for ITER programs. Would this cause ITER programs using bpf_get_func_arg() to read arbitrary memory at ctx-8, potentially leaking kernel data or causing incorrect bounds checks for subsequent argument access? > case BPF_FUNC_get_func_ret: > return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; > case BPF_FUNC_get_func_arg_cnt: > - return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; > + return &bpf_get_func_arg_cnt_proto; Same question applies here for bpf_get_func_arg_cnt() with ITER programs. > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c > index 9de0ec0c3ed9..0b281b7c41eb 100644 > --- a/kernel/bpf/verifier.c > +++ b/kernel/bpf/verifier.c > @@ -23323,8 +23323,20 @@ static int do_misc_fixups(struct bpf_verifier_env *env) > /* Implement bpf_get_func_arg inline. */ > if (prog_type == BPF_PROG_TYPE_TRACING && > insn->imm == BPF_FUNC_get_func_arg) { > + if (eatype == BPF_TRACE_RAW_TP) { > + int nr_args = btf_type_vlen(prog->aux->attach_func_proto); > + > + /* > + * skip first 'void *__data' argument in btf_trace_##name > + * typedef > + */ > + nr_args--; > + /* Save nr_args to reg0 */ > + insn_buf[0] = BPF_MOV64_IMM(BPF_REG_0, nr_args); > + } else { > + /* Load nr_args from ctx - 8 */ > + insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8); > + } This else branch now applies to BPF_TRACE_ITER as well, since the trampoline check was removed in tracing_prog_func_proto(). Should the condition be extended to also handle ITER, or should ITER be explicitly blocked from using these helpers? [ ... ] --- AI reviewed your patch. Please fix the bug or email reply why it's not a bug. See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md CI run summary: https://github.com/kernel-patches/bpf/actions/runs/21147849826 --===============6140367530953031628==--