From patchwork Wed Oct 9 01:07:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mathieu Desnoyers X-Patchwork-Id: 13827317 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 33139224DC; Wed, 9 Oct 2024 01:09:29 +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=1728436170; cv=none; b=i+B+Ku/jAo5iRDb8lxWsAv0JcbzZjThDBOQWSBj1ikMxLiWuY5XUFrtjyOcKUoPtFcpPRwApbLhIuX2KKriIpUsPvikmHnZsynPNSqx/1xIxh6ANd0kilE7jarP0wYbzY31BtrIfX+LgUNbtVmBsNVHukGFHn/7PAMzLITdvfS0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728436170; c=relaxed/simple; bh=d+E75dmXX/WxB9LGBzxMHqJhTyc8uayrKteU/ba9CsQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=txhr5bf9A3OQkZau+jfnnPd3dUmqtHdodwynWwlnE2MIb30ZuhlVGBaU1hed3PQ3RpwSFhmaNMw+16pcszhPaFgblhca1xU5uI0Myt858kKu/1JGsoHAiZms/3RiqCnttJW6KvSItxapdKxsyLUtzHsdNLN+p7vDo/oWMdB3J6s= 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=US+G2mAI; 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="US+G2mAI" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=efficios.com; s=smtpout1; t=1728436167; bh=d+E75dmXX/WxB9LGBzxMHqJhTyc8uayrKteU/ba9CsQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=US+G2mAIXkiGzwvNPpoa+mTC2hQR6elldpNVtCS0H0I8LaGHygDXdBQ/RiB2UmfIG HXI2KBdNIC1kb/szfMmIq7I25kBfewAzj+crAi/oiM7pqrSscjAilOnNCFhvuHi9A2 yQMGqNZV5tZVASPphYlgIdarl9SG/MNfu84wrASFasZhH12XEohowZ3tvyJJAhWiPR kn6pkZ5ut+z6wy0ZVnB+H9ZbcPkg7L/sXvc9CQ9PUChR70LsvQCHKATAiwL/7L3OAf wdv21S00ORp7vYmRv+liEHgrTbJJeWPPvzJOIm0FwSfurIr1Me5MOhfEbWA2Tg+WJU v3LvTHB+a5M4w== Received: from thinkos.internal.efficios.com (unknown [IPv6:2606:6d00:100:4000:cacb:9855:de1f:ded2]) by smtpout.efficios.com (Postfix) with ESMTPSA id 4XNZY34X9ZzS0S; Tue, 8 Oct 2024 21:09:27 -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 v4 6/8] tracing/ftrace: Add might_fault check to syscall probes Date: Tue, 8 Oct 2024 21:07:16 -0400 Message-Id: <20241009010718.2050182-7-mathieu.desnoyers@efficios.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20241009010718.2050182-1-mathieu.desnoyers@efficios.com> References: <20241009010718.2050182-1-mathieu.desnoyers@efficios.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Add a might_fault() check to validate that the ftrace sys_enter/sys_exit probe callbacks are indeed called from a context where page faults can be handled. Signed-off-by: Mathieu Desnoyers Acked-by: Masami Hiramatsu (Google) 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/trace_events.h | 1 + kernel/trace/trace_syscalls.c | 2 ++ 2 files changed, 3 insertions(+) diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h index 63071aa5923d..4f22136fd465 100644 --- a/include/trace/trace_events.h +++ b/include/trace/trace_events.h @@ -446,6 +446,7 @@ __DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \ static notrace void \ trace_event_raw_event_##call(void *__data, proto) \ { \ + might_fault(); \ preempt_disable_notrace(); \ do_trace_event_raw_event_##call(__data, args); \ preempt_enable_notrace(); \ diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index b1cc19806f3d..6d6bbd56ed92 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -303,6 +303,7 @@ static void ftrace_syscall_enter(void *data, 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); @@ -348,6 +349,7 @@ static void ftrace_syscall_exit(void *data, 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);