From nobody Thu Nov 28 08:34:41 2024 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 CD5851A2C05; Thu, 3 Oct 2024 15:18:49 +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=1727968732; cv=none; b=G1l4nigL8+3mqg9chPYfmZV5TDxBKqyOqknvKbzkKasAxi15gcJPQzKQ1Q/nbj6q2yO1vRwUV6XAuAHLj2vYPS7/NOGj54inSox8HAkAj/SY7jzU3rLD9dd2cRF96x2NxwRSf3K5SEg1Q/5K9mL09iuQ8Ol75CF3F3Dc97CwrJY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727968732; c=relaxed/simple; bh=mtMV15nwSgC24wpcl6rcJCStzDUXS/XjqRPiMOjRqhA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=LiEFbYfCFTMASBgvwkwxbDs7f8YI2+QZutwZtP1tJdYeVipW3Wtw7yzH/7/BUCQ+D0qvLqeo/HPe9Lwek9f6GzW00MNA/pfZ3H59XpZzvmussc4hvYgwdI6A+hbhAYeTsHaEp3koKR75ziz8U6237ymwGrnXOQNa8f/Tn/l/64k= 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=hbV7WCRK; 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="hbV7WCRK" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=efficios.com; s=smtpout1; t=1727968725; bh=mtMV15nwSgC24wpcl6rcJCStzDUXS/XjqRPiMOjRqhA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hbV7WCRKltuEdzVtpPFHreHAjf7XCF2DxigiVx4HVFO59+Xs8Po0FO+kKpPKC77PM CF8FV3qm6HiFOse7/ZJHzexYFCXYErjX/9MFVKwWFmCRMsRWrB0zjlcP7cmZycsz4z 2uOOe/pe5nwPcuMtDVq3KyAW7VFuad4m/W89czZTYjIGPtJY30jBHrCIOxYrnM0D8K pu6mMNdjuVkFl07TU6LQW0HZiywg3G+yCbXHDNmIiQNaWII1QvHLSfNzpzg0SzdOFT 0U43387P7QOocr3w586bS4vLBQbWgpJczOO8K5f5CJ+0p01dKDRxsbnOF33Ms87nfH VFVeKJN4TcsVA== 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 4XKFgn14Qkz640; Thu, 3 Oct 2024 11:18:45 -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 v1 6/8] tracing/ftrace: Add might_fault check to syscall probes Date: Thu, 3 Oct 2024 11:16:36 -0400 Message-Id: <20241003151638.1608537-7-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-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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 0228d9ed94a3..e0d4850b0d77 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(); \ guard(preempt_notrace)(); \ do_trace_event_raw_event_##call(__data, args); \ } diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index edcfa47446c7..89d7e4c57b5b 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)(); =20 syscall_nr =3D trace_get_syscall_nr(current, regs); @@ -348,6 +349,7 @@ static void ftrace_syscall_exit(void *data, struct pt_r= egs *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)(); =20 syscall_nr =3D trace_get_syscall_nr(current, regs); --=20 2.39.2