From nobody Mon Feb 9 08:28:46 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 B3163357704 for ; Sat, 31 Jan 2026 13:29:39 +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=1769866182; cv=none; b=fMcP3g8lu/h9jcCqrdWXeRyCD9R6Cq5+ybKVEVT8THtm77XwkB7WCyqBuw07Qp42dBkcT5/6oMNhlmw3uE+gCW7H4wVENeEUZcTw3hWAkO1QcHiHQF3jpx4SNYzwY80O+lk0xyCtHHHCZsPmhhranvSkyWVxaZaL8gV1pqo2u2I= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769866182; c=relaxed/simple; bh=GbGuivigEnOxXZ6AzKbFEuI6H/bL1pwWbx0et86tPxQ=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=pLmlBZ2qMgeFMVZap+iSErfHRZsEQ0u+nd8Pf+jiUxWDDRzyxs2bojkwImqphDOwsnIlKg6n/5RRnyqmNgY9m4IESgWrai0ND4do/yi2lzy4QuQEVjg7UnNqQLTF4yIBsndMMKW9ajKx6lyA9eN5dj7G1VFoPq8zThpSJPfmGTg= 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=NGs8el4u; 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="NGs8el4u" Received: by mail-wm1-f73.google.com with SMTP id 5b1f17b1804b1-477c49f273fso27863475e9.3 for ; Sat, 31 Jan 2026 05:29:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1769866178; x=1770470978; 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=TvedzD7+kJrfpkXnSgvR+lwDnj1DXH1BG+s75ebhGeM=; b=NGs8el4u5nUTFHUFMD1//Sa6CNGSNfuiqFxSWU3K5O0Ky3YONwrnZigs4+uSG923kY 4zu0XYXB90l7/6NPARA1II0fWOfVtZw2kkz9bsP8DzRSxif7hA3K68qhWK+kfLp9SO3Q Qo3Vstn3NPUu2o0mT6+zJYAu19JaNPuFaBjGd/3VyjTrf9nYz0SCvTlFVD/LNiNCremQ O8sK00Lk3gH9lk/6EIbq3Ky1/1EP8lzrkfWxxHzRcfVZj9g6nMtz7uwUU1r6CmvWL0vl +LsBpsemF/O+SJao6TofugDyxDep8wlAso871+Ezvo1GVHi/JhCD93xH4uPXW3xuLSc9 9HnQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769866178; x=1770470978; 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=TvedzD7+kJrfpkXnSgvR+lwDnj1DXH1BG+s75ebhGeM=; b=jYDEOVM0e90YcBpgNUYAIdOHoqV+pj+A5ZbMrzGSqc1/A6ExitmsqduOKqrLwdsW/u UI25DoHJMvIrXAJRJvMvVm3+4aH8pbCj14kNrXVD4YtfmBiyJ1ttsLzeCU8yA9baJ+yN /zEXunFWWfOMrKsPRPJ6A69E8T5YcwXVVgoag0Sw0c6ex6neCoVfuQ6Ix8afRDFWbzYd v4RmLE0pHP8X3MqNl2D+WigcniZkGkucEIGoS5qMhGeC44nqF4pR3XwE97Fni7zItcan /gtffBrZLQgGWua6Lm3+Cbq9rXRqVsjLy/mcX6+C1wqwCFxVPHvJzD7jhh4l+zjP4cPU Lr0Q== X-Forwarded-Encrypted: i=1; AJvYcCWS3CK+q/oejOwnB3F+V4NttElskcopvIosQyOg0HLBYq3qVFZPW8T5F9wPKz9hnN4Dno4+0FyY3/G1EEg=@vger.kernel.org X-Gm-Message-State: AOJu0YyCXOBoXECX47SdJ0P6qB6KKS417OcmJMEXphUhs30OivX9ewWG Qr6BQJ8AVLwTHU+iU+gAHYV5IDnTAzRpGaxWMErz8Plpxl79jxfQoBbjaKuujma7iEYRcQSg7Ce zo0q/OsCKo/B3QcnLq/9EbA== X-Received: from wmpc35.prod.google.com ([2002:a05:600c:4a23:b0:47e:dc0c:276f]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:8289:b0:480:32da:f338 with SMTP id 5b1f17b1804b1-482db45cb90mr66590785e9.14.1769866178166; Sat, 31 Jan 2026 05:29:38 -0800 (PST) Date: Sat, 31 Jan 2026 13:28:36 +0000 In-Reply-To: <20260131132848.254084-1-vdonnefort@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260131132848.254084-1-vdonnefort@google.com> X-Mailer: git-send-email 2.53.0.rc1.225.gd81095ad13-goog Message-ID: <20260131132848.254084-19-vdonnefort@google.com> Subject: [PATCH v11 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. Reviewed-by: Steven Rostedt (Google) Signed-off-by: Vincent Donnefort diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 9e86c43bf320..9f675d5d27c7 100644 --- 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 2.53.0.rc1.225.gd81095ad13-goog