From nobody Mon Feb 9 17:35:48 2026 Received: from mail-wm1-f73.google.com (mail-wm1-f73.google.com [209.85.128.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6EE3632D452 for ; Mon, 26 Jan 2026 10:44:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.73 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769424286; cv=none; b=kWolh0V4vp7yZgU/Njrojcidx6Vd0uV134B6CXgMyL8U+Z+vSXV8y63DjLbjoEukhr+mfRlSjQJznYVLsqq66spa3hUlHNckbx01DOtGXuIAx/84bBD33xLFei0Slm/DIOM8wo55nb4/duSn4imxp3//7D9XP4rcnsrm8DzxOtU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769424286; c=relaxed/simple; bh=+E83IqF+W5HGdaZV8YeGmeArEiV/GcB4OlenBzDOJBU=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Z3WkoIJaSlU1rVPj1ZN70nzA6SDxbuicen7nsFKksU2zxnsBQYeGm+UHf1qdBKbuioJ4TAGblSUpYTu4Tb0esLvDZcdii0k9w2mWJafpcgSaekHXcOI5ztSyQdJXAJwd2vDJSk2kUfN1Qf3nt+ny6PcYtQ+K45Z6ulDcCo1AFcc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=wlD6eP8C; arc=none smtp.client-ip=209.85.128.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="wlD6eP8C" Received: by mail-wm1-f73.google.com with SMTP id 5b1f17b1804b1-47ee8808ffbso32712835e9.2 for ; Mon, 26 Jan 2026 02:44:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1769424282; x=1770029082; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=YywhJHdQmzvLYqPf/VNWfmyvJv23Am2v8tnakAtmlS0=; b=wlD6eP8Cy5H9w/NYjunLT0egu+r60RIhx8pFPhL8jXDb1hXA9pCj0U4+PtsmEpAcR4 8wCYX0ObA1dwZ8mSORYRDP4FGo7Zs8nJj3Qx9iL7dSrUmb5MVu+ej/2ibkVE9uEebAqB Uf/Zquzkkk2szkm/3AaBvkd3UWczEjJpkoOnWzveLZD8tK0GMfWn/bFtDN35Zbk0i2zE ahefMVgKQVZ1HhSiCF5urT1H1238vley0YRge5PhZIqDZjbotmfZQe7+4N3fdltcLsn4 GFjxj7FH0FqFpz6kKaSNiMFdKEOfx1hruBsnjOMOsqqc87n7iZV+B8TnGofejV+hNuYE PM9g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769424282; x=1770029082; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=YywhJHdQmzvLYqPf/VNWfmyvJv23Am2v8tnakAtmlS0=; b=p6K0aA5LulCit5JDO2/0Qa3iYBOdF+5B0r9Q7Acp4wBBseBOmzr9+dY3U/4NLWt+xn 3tY6/PvY6E/bpXgEWdj48yfytZCVDoTKc9wlXKvXpGa+CkeKw3wqT6VkVa5aMACYPstz SLYV5/ASnp/RkQrmrx+LXPFRK91gmyMI9SdCrjkStE7hT22IQAirbrsHf5A3ytxX/1FJ G7sQCHIfoYugdVWQJak8L7rKyk6qQklO7cld1Cz0a27YF6JpfC49u3zkyirwOsVkS8mH 9moE7Ln+o6O70IuHFj/uhUYq997S/LRoz8J3mxa9omSPTenyrLmZk5aZh+IPSFO3rij/ q0IQ== X-Forwarded-Encrypted: i=1; AJvYcCXC9+V+89jg/iB3SF6fmuIdO6e5sm8U/ZaZWdOPdOnpSRqyrdxNzCKWsoojMYYwnonTid7pP1B7AApjsuA=@vger.kernel.org X-Gm-Message-State: AOJu0YxLj9xUf2Do0dv2znKpLu0LpIprFMRrS3zDVNeUPXh9FfxwIVKO 8XRs8bs8lVqQBRln70pGh3Dg1sHk1Xvlt9bVOr4mKj57Ugm/lk5A578FwLvexPSGSN9LcFisC8o odfhNcYMPXmyRS6syvOa5cQ== X-Received: from wmkg7.prod.google.com ([2002:a7b:c4c7:0:b0:477:5a4b:d57f]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:5395:b0:47e:e20e:bb9c with SMTP id 5b1f17b1804b1-4805cd40991mr56788285e9.8.1769424282193; Mon, 26 Jan 2026 02:44:42 -0800 (PST) Date: Mon, 26 Jan 2026 10:44:07 +0000 In-Reply-To: <20260126104419.1649811-1-vdonnefort@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260126104419.1649811-1-vdonnefort@google.com> X-Mailer: git-send-email 2.52.0.457.g6b5491de43-goog Message-ID: <20260126104419.1649811-19-vdonnefort@google.com> Subject: [PATCH v10 18/30] tracing: Check for undefined symbols in simple_ring_buffer From: Vincent Donnefort To: rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, linux-trace-kernel@vger.kernel.org, maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, jstultz@google.com, qperret@google.com, will@kernel.org, aneesh.kumar@kernel.org, kernel-team@android.com, linux-kernel@vger.kernel.org, Vincent Donnefort Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The simple_ring_buffer implementation must remain simple enough to be used by the pKVM hypervisor. Prevent the object build if unresolved symbols are found. Signed-off-by: Vincent Donnefort diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 9e86c43bf320..9f675d5d27c7 100644 Reviewed-by: Steven Rostedt (Google) --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -131,4 +131,20 @@ obj-$(CONFIG_TRACE_REMOTE) +=3D trace_remote.o obj-$(CONFIG_SIMPLE_RING_BUFFER) +=3D simple_ring_buffer.o obj-$(CONFIG_TRACE_REMOTE_TEST) +=3D remote_test.o =20 +# +# simple_ring_buffer is used by the pKVM hypervisor which does not have ac= cess +# to all kernel symbols. Fail the build if forbidden symbols are found. +# +UNDEFINED_ALLOWLIST :=3D memset alt_cb_patch_nops __x86 __ubsan __asan __k= asan __gcov __aeabi_unwind +UNDEFINED_ALLOWLIST +=3D __stack_chk_fail stackleak_track_stack __ref_stac= k __sanitizer +UNDEFINED_ALLOWLIST :=3D $(addprefix -e , $(UNDEFINED_ALLOWLIST)) + +quiet_cmd_check_undefined =3D NM $< + cmd_check_undefined =3D test -z "`$(NM) -u $< | grep -v $(UNDEFINED_= ALLOWLIST)`" + +$(obj)/%.o.checked: $(obj)/%.o FORCE + $(call if_changed,check_undefined) + +always-$(CONFIG_SIMPLE_RING_BUFFER) +=3D simple_ring_buffer.o.checked + libftrace-y :=3D ftrace.o --=20 2.52.0.457.g6b5491de43-goog