From mboxrd@z Thu Jan 1 00:00:00 1970 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 B6C842C9D for ; Tue, 30 Nov 2021 11:45:19 +0000 (UTC) Received: by mail-wm1-f73.google.com with SMTP id n16-20020a05600c3b9000b003331973fdbbso12722660wms.0 for ; Tue, 30 Nov 2021 03:45:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=K7olqGN/TGjGn55ZVkEX4B3oA8fATuBzpoXYDPWo+s8=; b=clBdSB1KsdaD9LhF3VuIZRE5qDbZm9VUy7Jmjj5Uln7EAmbx9/EVEhCZVIjKZMPCK+ qVPPdLDGmjPahXUB+7UHlvMJZMoPvtMBSVaYAWCfkloYps+FrLrtPD/MSZq6V5qCVz9F HLMEG9qAzvEkT52Tvk9GFZWjZEpBWUwzTzdkavD1KWL9RmtktroFJZ7Egs8clPbPBHwn wN7uOQ716yPwwUBgmjReM4uHwoUeb55jkQFwgYZRDRcrW/uO9L1BglBLfcp2U6lDrDpx FloEFIIraKR1zTwfjZbLjFAUKKD+8XROZdOh1bjkVCNAV7lpb1p+AtLZAWaWo2nZkkq5 egZA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=K7olqGN/TGjGn55ZVkEX4B3oA8fATuBzpoXYDPWo+s8=; b=ZGwhBGoMLwJdcdW5CHUDDp1Afc+62jNkQpo4UV9MflJSvgWgvZLp+tHcUfFLPyePYf fAzL/4HLlZ4PMmv3Bbh/j8VcFHrdZKuRW4hATncfoAFHiHxSeQoOYG7wngLXs6E4rteC QB6lnfqzAEX1Lx9uAnuzF6+U1EmDq1EC0Y5ZBnD+ltv9n5nTCboDBUNoPcjswDhvtNjk 8K49nhrGD0iDV4TEA3KxOGeLBqfqidgJz3eBmIcUG/DM1N9FydXC1UWogJpQjzVeZBSt 1wz/Vb4xFcng3n5U8daY7s4i3oE7aKp7DW4xbf7rUa3Y8ZNVAXqSaxOoCxPgy0aIWrnj N/mQ== X-Gm-Message-State: AOAM533uKkaylgwEoFN961tQR9i5LtplOU+/y2X7H+zmGEDHHOVENzcv sSJnRhLAoQ4yWry6ouYcw9uvAhu8sg== X-Google-Smtp-Source: ABdhPJwldFqpTbfajaFXWNrJX3ZXShEvmpEyVyn9WWq1XUdWN/HHO/Y9FjyIOfXlhbvUoQlQcowRnYznoQ== X-Received: from elver.muc.corp.google.com ([2a00:79e0:15:13:86b7:11e9:7797:99f0]) (user=elver job=sendgmr) by 2002:a05:600c:4f0b:: with SMTP id l11mr625490wmq.0.1638272717644; Tue, 30 Nov 2021 03:45:17 -0800 (PST) Date: Tue, 30 Nov 2021 12:44:14 +0100 In-Reply-To: <20211130114433.2580590-1-elver@google.com> Message-Id: <20211130114433.2580590-7-elver@google.com> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20211130114433.2580590-1-elver@google.com> X-Mailer: git-send-email 2.34.0.rc2.393.gf8c9666880-goog Subject: [PATCH v3 06/25] kcsan, kbuild: Add option for barrier instrumentation only From: Marco Elver To: elver@google.com, "Paul E. McKenney" Cc: Alexander Potapenko , Boqun Feng , Borislav Petkov , Dmitry Vyukov , Ingo Molnar , Mark Rutland , Peter Zijlstra , Thomas Gleixner , Waiman Long , Will Deacon , kasan-dev@googlegroups.com, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, llvm@lists.linux.dev, x86@kernel.org Content-Type: text/plain; charset="UTF-8" Source files that disable KCSAN via KCSAN_SANITIZE := n, remove all instrumentation, including explicit barrier instrumentation. With instrumentation for memory barriers, in few places it is required to enable just the explicit instrumentation for memory barriers to avoid false positives. Providing the Makefile variable KCSAN_INSTRUMENT_BARRIERS_obj.o or KCSAN_INSTRUMENT_BARRIERS (for all files) set to 'y' only enables the explicit barrier instrumentation. Signed-off-by: Marco Elver --- scripts/Makefile.lib | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index d1f865b8c0cb..ab17f7b2e33c 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -182,6 +182,11 @@ ifeq ($(CONFIG_KCSAN),y) _c_flags += $(if $(patsubst n%,, \ $(KCSAN_SANITIZE_$(basetarget).o)$(KCSAN_SANITIZE)y), \ $(CFLAGS_KCSAN)) +# Some uninstrumented files provide implied barriers required to avoid false +# positives: set KCSAN_INSTRUMENT_BARRIERS for barrier instrumentation only. +_c_flags += $(if $(patsubst n%,, \ + $(KCSAN_INSTRUMENT_BARRIERS_$(basetarget).o)$(KCSAN_INSTRUMENT_BARRIERS)n), \ + -D__KCSAN_INSTRUMENT_BARRIERS__) endif # $(srctree)/$(src) for including checkin headers from generated source files -- 2.34.0.rc2.393.gf8c9666880-goog