From patchwork Mon Sep 9 20:16:51 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mathieu Desnoyers X-Patchwork-Id: 13797550 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 D7B8318A94C; Mon, 9 Sep 2024 20:17:19 +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=1725913043; cv=none; b=CpFEW2wg40RbBjlL0pgbhVrjG8jwF7+imYg3yWVGkVQoesQA+lVIyOTrzVto7MlfGLOrNyLi8tJCwuEiTm4FeZRntSalJ6V4ziHkb1iAdwI1Cn+sym9JCbRjZvIbDXzsvD4KpIWtCzyZZ8uw2TszdT/R82i0wOPjKaNDxw7A6lY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725913043; c=relaxed/simple; bh=uJq5iVZHWqF4O/NYGe5n5RCWahHYrd6IuFGzrAbE8HA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=n3IX58NeBkO1jfLlmsnRFE7zemkkeDV+8PqGUbai8ELv9+b2ELPqB3brZj/e+/kSHoDG5Kl7xkoDgs5PFNhgUviWfd6ZpvtlEkAQMh268c/BjSRJ6Taw2Hiz+V8y8LFJ1HUSSGYRVXuPwv1K3zKm1pgCAjUazN+1CwYkehi6Pgo= 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=ncuHpAKi; 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="ncuHpAKi" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=efficios.com; s=smtpout1; t=1725913038; bh=uJq5iVZHWqF4O/NYGe5n5RCWahHYrd6IuFGzrAbE8HA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ncuHpAKiQfumGWJAbDQIvuzPkv1Z53jIBpwWI7c13yOWIUsN9YbrY4R0tBBkkJVQx ircMRIIvTkPdHtESew4A0PcIa6I8RJi+BakYvq6wLfm0otntEUA2b6g4F48b1ktRaP /Aa6cY9mNwSoAi7YXx/X0bY4O7IZIQIEdwzUpzXQVYzDBdR0Gk4SYZ2xQLzLmC2tEc SPIvMH9pZja73R+WzWvOEEAiEdYAs6toE5wqtQWf14it8SFQBiTmH9zKLE67G5W5m/ /ZFcq///C8QiXS02LrsOZEBTIefxia/Vcn22yxsFUuf4mkD4ZG/o2HLTRkuBS5oPng RRpDTa9AdoWwA== 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 4X2dRK5MD6z1KhL; Mon, 9 Sep 2024 16:17:17 -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 7/8] tracing/perf: Add might_fault check to syscall probes Date: Mon, 9 Sep 2024 16:16:51 -0400 Message-Id: <20240909201652.319406-8-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: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Add a might_fault() check to validate that the perf sys_enter/sys_exit probe callbacks are indeed called from a context where page faults can be handled. 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 --- include/trace/perf.h | 1 + kernel/trace/trace_syscalls.c | 2 ++ 2 files changed, 3 insertions(+) diff --git a/include/trace/perf.h b/include/trace/perf.h index 5650c1bad088..321bfd7919f6 100644 --- a/include/trace/perf.h +++ b/include/trace/perf.h @@ -84,6 +84,7 @@ perf_trace_##call(void *__data, proto) \ u64 __count __attribute__((unused)); \ struct task_struct *__task __attribute__((unused)); \ \ + might_fault(); \ guard(preempt_notrace)(); \ do_perf_trace_##call(__data, args); \ } diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 0430890cbb42..53faa791c735 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -600,6 +600,7 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) * Syscall probe called with preemption enabled, but the ring * buffer and per-cpu data require preemption to be disabled. */ + might_fault(); guard(preempt_notrace)(); syscall_nr = trace_get_syscall_nr(current, regs); @@ -706,6 +707,7 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) * Syscall probe called with preemption enabled, but the ring * buffer and per-cpu data require preemption to be disabled. */ + might_fault(); guard(preempt_notrace)(); syscall_nr = trace_get_syscall_nr(current, regs);