From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794225932; b=bSIxDpptJ/HXGERPZSxYhJvOFwuS5rcseSQ47QxZ8qN6VuUsSf8Opii9V3jw8qTQgXpu PR1xh0GRMWn/qNyHPPkjSdg1Fq3NeUV5HqFficzxOLguz2mCd8ilLKQDwQmzIr5IBiOzl N4re4OB5t+P70x6mW0esNtVGPXd3bBc/Tnxu1VVTvHrHwKewHo7SYP0HQdIaYdbRt2pqr 3qQUlwYO3KbRYlG+qgIEShgbYWv6Q2Hkn5MSqGY0tgvVXQ9lCF8d5VlRINuXjoX0LZB+T irvcshmM+KMUIZzGah1Fk35lR3wONqA7+lToT0hrEcVE7kMpySJ8rw9KgT1N8iir7kg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794225932; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=6LYzOqgVWc34uRY6ovO7R7m1hhJFjX7us7aa10zp4XA=; b=ze5ONbXCF55JBlvAtS2VYW97+OPaNRWMT1gDGbJifqw5/ztMRlc56mDKoZQWPSCF8CLT iUCPYieDGKIQUVqjBlDh2lHuGq1IPlYJn1oAdZlnYdkqY9lFetjVnUWQrk6RPo7+NpEBb PE1adb5H9dbKgkcW7CZTFIDlUwrFNH/Ga5aLdqciezOT46Xq4JRi5d5oeF0fpKHQmULID yMp0zoKWTC1s7XpSbD504J/Dh2eEiwzTiXpFFUTFKuGKJIvXbTV3LP+7IWs0ev5/BcfGJ scTpUwdmrTPEjTFlSrU36seq+/kNvx9GC+Rc4wimh/xFZXhsuCyfDkpAELJus0xQyWQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ifqPUIQb; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 78540606A31C for ; Mon, 9 Nov 2026 12:05:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ifqPUIQb Received: by smtp.kernel.org (Postfix) with ESMTPSA id EDEAA1F0089F; Mon, 9 Nov 2026 12:05:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794225932; bh=6LYzOqgVWc34uRY6ovO7R7m1hhJFjX7us7aa10zp4XA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ifqPUIQb4197CXOoo3zkk/P+62IWE3W6hw3VXHH7BmaZDJzTj/sylmfjzUn/heM/o Dy3qocNvWVFwIqtPRM05SK7rH7jllGShFdSL1cRyz7QQ/mkOqRGeBPNiZRUO8mrxRm FIachU3c43wQuZXo5Uct+uIktJlmVTYkENycEl9wY+AjWuGD9c6TxAz1oGp/9/UG2+ XGuWNxEDTKXdIbIkn+pWSeDgW1jw3znXhbtuXBKg7H3oAZHzcnibIYvO90zTJhWf1j 3bP/GAN+qstiydBQLS9s63mMSLiQr3I7JY3AW6z//o+NeybqI0nzbTP8tHEzysVNuR YHkTNUk0CoDNQ== From: Jisheng Zhang To: Catalin Marinas , Will Deacon , Mark Rutland , Andrey Ryabinin , Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , Tejun Heo , Dennis Zhou , Christoph Lameter Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org Subject: [PATCH v2 5/6] arm64: lib: Disable branch profiling for architecture library code Date: Mon, 9 Nov 2026 19:44:58 +0800 Message-ID: <20261109114500.20298-6-jszhang@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20261109114500.20298-1-jszhang@kernel.org> References: <20261109114500.20298-1-jszhang@kernel.org> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit arch/arm64/Kbuild disables branch profiling through subdir-ccflags-y. However, arch/arm64/lib/ is built separately through libs-y and does not inherit that flag. Consequently, CONFIG_TRACE_BRANCH_PROFILING can introduce explicit profiling instrumentation into library code, including helpers used while applying alternatives. noinstr does not suppress instrumentation inserted by the branch-profiling macros. Disable branch profiling in arch/arm64/lib/Makefile to extend the existing arm64 policy to this directory Signed-off-by: Jisheng Zhang Assisted-by: LLM --- arch/arm64/lib/Makefile | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile index 38ffd359123c..59d714865c00 100644 --- a/arch/arm64/lib/Makefile +++ b/arch/arm64/lib/Makefile @@ -1,5 +1,9 @@ # SPDX-License-Identifier: GPL-2.0 +# Built via libs-y, so the flags in arch/arm64/Kbuild do not reach here. +# Branch profiling isn't noinstr-safe. +ccflags-$(CONFIG_TRACE_BRANCH_PROFILING) += -DDISABLE_BRANCH_PROFILING + # KCSAN uses udelay for introducing watchpoint delay; avoid recursion. KCSAN_SANITIZE_delay.o := n -- 2.55.0