From patchwork Thu Oct 3 15:16:34 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mathieu Desnoyers X-Patchwork-Id: 13821148 Received: from smtpout.efficios.com (smtpout.efficios.com [167.114.26.122]) (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 DCC971779A5; Thu, 3 Oct 2024 15:18:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=167.114.26.122 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727968730; cv=none; b=D18RH3qMXM690oRBjzE0e918zSAfZ28+wqZSRQG+sEaNNpMeSbSKdQxjy5JQ6PrOXECZvf44OYDQPPG/352OoG6BGFdWbWY/QJzM2IinwHqUqvTCA5t7FIqmBGdhm4m0XLLxTXtCa7lb+JUT2yjxIg5s1B5gqcZ6TjDRWSmmWIA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727968730; c=relaxed/simple; bh=uQvGGRjFBg81/CMoacZvVtIn7AY3sce+G3Hk/Qjw2wU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=tdRMwbZ6YyMfbuSyRY9jsyzgbW476TbdiTytjF545PrP5skLwpnLEpT+DEYDrC/2R18YLjIJnylbDcsIJ+4bUiKo6pbuLTYABWLDYcjYCIFVqZ6ukLVC51MT0e9OTxutbpQUkPWDNweeMVr3p8zlbzpm2iueUPKhBTRHFng6nDU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com; spf=pass smtp.mailfrom=efficios.com; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b=mU85fo2b; arc=none smtp.client-ip=167.114.26.122 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=efficios.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b="mU85fo2b" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=efficios.com; s=smtpout1; t=1727968724; bh=uQvGGRjFBg81/CMoacZvVtIn7AY3sce+G3Hk/Qjw2wU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mU85fo2bLIGDjHEQ16l7Q//TqPy25gR39Uz3iHNyh7HDSOk5kiZOw69UunjzQxabq PruZ3Ulfkk3NrGM2bde5AvrYpb7venBKofxhMJbmY/6r89BUAkm7tlv6yzt/+FRUmJ eTLjY1vgL591RUNznwCOq2JCTnocAjl85/5SBWhsONrXNxcE+6awzyR7XnCQXG2DBH Lw1SebxTTOEULZw9oh7qDyqsSNwnkMmQH1jURAKSFfWXxcPFinvAl01eJEZH52rMb0 xOc6xYWkOHpS9OtP5KND58X5DMByHUJGYqVEcAh3LA/AP1gXdy5l8XbodLKxicds3J 9iem7qOXN8snQ== Received: from thinkos.internal.efficios.com (96-127-217-162.qc.cable.ebox.net [96.127.217.162]) by smtpout.efficios.com (Postfix) with ESMTPSA id 4XKFgm2T3Cz62g; Thu, 3 Oct 2024 11:18:44 -0400 (EDT) From: Mathieu Desnoyers To: Steven Rostedt , Masami Hiramatsu Cc: linux-kernel@vger.kernel.org, Mathieu Desnoyers , Peter Zijlstra , Alexei Starovoitov , Yonghong Song , "Paul E . McKenney" , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Namhyung Kim , Andrii Nakryiko , bpf@vger.kernel.org, Joel Fernandes , linux-trace-kernel@vger.kernel.org, Andrii Nakryiko , Michael Jeanson Subject: [PATCH v1 4/8] tracing/bpf: guard syscall probe with preempt_notrace Date: Thu, 3 Oct 2024 11:16:34 -0400 Message-Id: <20241003151638.1608537-5-mathieu.desnoyers@efficios.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20241003151638.1608537-1-mathieu.desnoyers@efficios.com> References: <20241003151638.1608537-1-mathieu.desnoyers@efficios.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In preparation for allowing system call enter/exit instrumentation to handle page faults, make sure that bpf can handle this change by explicitly disabling preemption within the bpf system call tracepoint probes to respect the current expectations within bpf tracing code. This change does not yet allow bpf to take page faults per se within its probe, but allows its existing probes to adapt to the upcoming change. Signed-off-by: Mathieu Desnoyers Acked-by: Andrii Nakryiko Tested-by: Andrii Nakryiko # BPF parts Cc: Michael Jeanson Cc: Steven Rostedt Cc: Masami Hiramatsu Cc: Peter Zijlstra Cc: Alexei Starovoitov Cc: Yonghong Song Cc: Paul E. McKenney Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Mark Rutland Cc: Alexander Shishkin Cc: Namhyung Kim Cc: Andrii Nakryiko Cc: bpf@vger.kernel.org Cc: Joel Fernandes --- include/trace/bpf_probe.h | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/include/trace/bpf_probe.h b/include/trace/bpf_probe.h index c85bbce5aaa5..211b98d45fc6 100644 --- a/include/trace/bpf_probe.h +++ b/include/trace/bpf_probe.h @@ -53,8 +53,17 @@ __bpf_trace_##call(void *__data, proto) \ #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ __BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args)) +#define __BPF_DECLARE_TRACE_SYSCALL(call, proto, args) \ +static notrace void \ +__bpf_trace_##call(void *__data, proto) \ +{ \ + guard(preempt_notrace)(); \ + CONCATENATE(bpf_trace_run, COUNT_ARGS(args))(__data, CAST_TO_U64(args)); \ +} + #undef DECLARE_EVENT_SYSCALL_CLASS -#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS +#define DECLARE_EVENT_SYSCALL_CLASS(call, proto, args, tstruct, assign, print) \ + __BPF_DECLARE_TRACE_SYSCALL(call, PARAMS(proto), PARAMS(args)) /* * This part is compiled out, it is only here as a build time check