From nobody Sat Apr 11 13:57:28 2026 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) (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 2E4C13BE148 for ; Fri, 6 Mar 2026 14:36:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772807774; cv=none; b=pxsHes3cz0g653Jf81R/RYHrEMORVGMOuPcpSgOJk57JLFK571TDA/AdSDSFKLn9aStOAUs+qtshllX+floq5LYrFnf0rxQ7znQ/im+dmKuj+0gU6cOBQzCDyLbTZgH6VyMr7lznRt3bL1WyM+EdW6I7DmYk6OXaGdCCcaZSPeA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772807774; c=relaxed/simple; bh=nvJVMgivk0n7tnxwYIskJ85licES15A0ESfOQLBBACk=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Ovrnf/OgVuunsMZoSpwqvA+/ohwDkE/5FQaP0Tws+eoOAuLv2Ysgt0ZTQ69VIWKVjYNaJK4Orup4Pu95HQAipCgTZxCW5XLxOtzq9bkc17hkoZ9szDlZYFDA9tMX5pbAOWPS9vHSk1taHKx7gXYyjhscPsGSofOZqMp1A4tKTrE= 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=2LhAlu1/; arc=none smtp.client-ip=209.85.128.74 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="2LhAlu1/" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-48069a43217so97677515e9.1 for ; Fri, 06 Mar 2026 06:36:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1772807771; x=1773412571; 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=ISTtnZxQZml/VUbaQMgN/rAKYfhBuJPSGaUgT7FyeoU=; b=2LhAlu1/5hgEy78QDmfqwTRIoP+cRlXaips4nkNgzEqaEF6B/9Ymj35VV8CN21JeAJ 0zV955lcz1O/gI7h0Kio30v2iwoxb9XIUtMyZute+kc6nmcNNGqmlaSWGyGnIGu2uhQJ 2A4FjQqNsgIW5soPxOzDBuUnQYMXUjANztEn6bdCZOD0AGLPGDEH0I9ximzlxBqwOtR+ 2efgCZyjI3hndl+78Hkw6esH4K4WUweCC1AwzPAbK2Jss+BTURoCfPg0TREHAwmL/iij l4YeNrxgV/JYvz9KfI2r2Qt/a8v9XGn/qdocdoNmEXhbA/Uw3QNMt7qZtoNxWQveLZNI 3OVw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772807771; x=1773412571; 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=ISTtnZxQZml/VUbaQMgN/rAKYfhBuJPSGaUgT7FyeoU=; b=lCuWjZf+E+swcw1562uVYETCzuL2jy315dKvh7WZbM+tMpbzsWor7j1daG4E4kHYQ5 EJ9qgz1f3nktAd84wohr2cstz57u38wS7mqAFcMuEYfaSCesqF3rXDkXDsRnXDBkTlYJ sWRfMi1KkgmNeCOcR4YsPWsxahBepxLInqZuWcNafsa9ew7XRymgfIkPI6C/gowXWV2V VQk7/QWyWz5u56KmvxUgMunXas+BNUTXENmWa19gn62PF4i0uVTeOPpKblPDdMRnhX4T /d1+k/XhGZS9zdE41IVBVbU/8K6RRfDtd/LIK6sImIAC1FuRWDYaU9HrvlVoMxy2ULmD LLoA== X-Forwarded-Encrypted: i=1; AJvYcCXp57K2yU5Ex6BFXs6H0iKVI9amqlBVprt0Fng4WEvwJEnl3QN6Qlb24csB1kGyiFoqrvv/LZaY2hHqoFA=@vger.kernel.org X-Gm-Message-State: AOJu0Yz5j+fkHotFUXK9ahg09nOQOt0VYdBAl47Vago9oy7aE0mBtBWy yJoakiLBezHce9owMH+GPpVkV3tGcWSS55Cd5F7KCAXJyKnamudHfP9IP2cgO+ZiHBXsmraW2ph eDG05XxbF/Z2wVx6WBvbt+A== X-Received: from wmbfl21.prod.google.com ([2002:a05:600c:b95:b0:483:6ff0:11a0]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:1e88:b0:483:1403:c47f with SMTP id 5b1f17b1804b1-485269182b5mr44060185e9.6.1772807770415; Fri, 06 Mar 2026 06:36:10 -0800 (PST) Date: Fri, 6 Mar 2026 14:35:22 +0000 In-Reply-To: <20260306143536.339777-1-vdonnefort@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260306143536.339777-1-vdonnefort@google.com> X-Mailer: git-send-email 2.53.0.473.g4a7958ca14-goog Message-ID: <20260306143536.339777-19-vdonnefort@google.com> Subject: [PATCH v13 18/32] 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. Reviewed-by: Steven Rostedt (Google) Signed-off-by: Vincent Donnefort diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index d106beca8d7f..3182e1bc1cf7 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -132,4 +132,20 @@ 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 2.53.0.473.g4a7958ca14-goog