From patchwork Mon Sep 9 20:16:48 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mathieu Desnoyers X-Patchwork-Id: 13797536 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 DDBDA17D34D; Mon, 9 Sep 2024 20:17:17 +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=1725913039; cv=none; b=iJbL2us3F18EvzfrfyFV7QozJj1Mt+O5+8f4a/xIjn7hIu1r7bv4cB1P5bAxmx1sZOq/TZrWFY/dmZCEVijyCZUuFVbg/2EsP+VlpOlaO8RkkYkkgm5W326bZ9k+DC83tHIlYGwX43L9oRvpaG7MK8GpgoabU4BDcf371zVTlI0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725913039; c=relaxed/simple; bh=gZzsG8gL/ErZCAElJk9KWuSYSEgbv2rStlG0oF8Ol54=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ZUmNIDio2J2kgGs/hFIeDC8X0Jp4rU/AZwaOdkJ3jub+Noj7TJLaInml0LXGs1ZaN7OghLotsUQIFhQM+OEZMrsxCO/sHOWgjbcruL+yoWtGxhFdTltGABzqQq9F0dKuxYP1Hpsm2lSZbUO4z4rnzAvrxmvGzNrxAydEZdpUHCI= 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=Vfow65t8; 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="Vfow65t8" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=efficios.com; s=smtpout1; t=1725913036; bh=gZzsG8gL/ErZCAElJk9KWuSYSEgbv2rStlG0oF8Ol54=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Vfow65t8A1jy2u7v7GVENaO55NLiN2wwLYGszpjfoA8lYMsJfPEV/1jVHoDptb7dX OWHk/cEb1Q3AiCCqD1IT678F6wJ7rCQthZ7e+SblHGRabqb4wudu7yOJkq+ixC7PrW A+oNy9yIPlCChhuRqGK89C1n6+L08wUp4q8gYqbpHpMkjuJQ90TsAIsGQFzNowrvr0 t8Q2k/X1PoOIsj862/vpd3JJIK7fT3EGhlQJqBglCRVyUKg/Bdn8NGw8Q8C5k/janp Arav1oxzlIYPzyRs34q4iONXqDwUUq2L/5FBer155OKHqFwjKuRTSciXK97sJe0Wzo wTdq9FHvXkMMw== 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 4X2dRJ4kDHz1KQY; Mon, 9 Sep 2024 16:17:16 -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, Michael Jeanson Subject: [PATCH 4/8] tracing/bpf: guard syscall probe with preempt_notrace Date: Mon, 9 Sep 2024 16:16:48 -0400 Message-Id: <20240909201652.319406-5-mathieu.desnoyers@efficios.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240909201652.319406-1-mathieu.desnoyers@efficios.com> References: <20240909201652.319406-1-mathieu.desnoyers@efficios.com> Precedence: bulk X-Mailing-List: bpf@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 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 Acked-by: Andrii Nakryiko --- 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