From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9DEC16453 for ; Tue, 22 Mar 2022 21:39:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 67512C340EE; Tue, 22 Mar 2022 21:39:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1647985166; bh=xC2cZqPNFzyjybznmsAmzD/7GWHjCHD+MjNDI4Fd8cE=; h=Date:To:From:In-Reply-To:Subject:From; b=g9SB1ZKKafzmjd4WG2tsKL9guNHYWxfWhn6RLlRFzmYeJ5+jnqZJENe/6LnbCYhLE 1Ruzkr9m3mLSFR3PXIt736hGVGUcjQEeVQwVZA3jyCANUhqSQJNfMLfzcoQApSbE2V sW9OvG6EYdVAluL4N4jckJfiqzZi2cJ80yVwNQmA= Date: Tue, 22 Mar 2022 14:39:25 -0700 To: songmuchun@bytedance.com,linmiaohe@huawei.com,akpm@linux-foundation.org,patches@lists.linux.dev,linux-mm@kvack.org,mm-commits@vger.kernel.org,torvalds@linux-foundation.org,akpm@linux-foundation.org From: Andrew Morton In-Reply-To: <20220322143803.04a5e59a07e48284f196a2f9@linux-foundation.org> Subject: [patch 018/227] mm/memremap: avoid calling kasan_remove_zero_shadow() for device private memory Message-Id: <20220322213926.67512C340EE@smtp.kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: From: Miaohe Lin Subject: mm/memremap: avoid calling kasan_remove_zero_shadow() for device private memory For device private memory, we do not create a linear mapping for the memory because the device memory is un-accessible. Thus we do not add kasan zero shadow for it. So it's unnecessary to do kasan_remove_zero_shadow() for it. Link: https://lkml.kernel.org/r/20220126092602.1425-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Reviewed-by: Muchun Song Signed-off-by: Andrew Morton --- mm/memremap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/mm/memremap.c~mm-memremap-avoid-calling-kasan_remove_zero_shadow-for-device-private-memory +++ a/mm/memremap.c @@ -282,7 +282,8 @@ static int pagemap_range(struct dev_page return 0; err_add_memory: - kasan_remove_zero_shadow(__va(range->start), range_len(range)); + if (!is_private) + kasan_remove_zero_shadow(__va(range->start), range_len(range)); err_kasan: untrack_pfn(NULL, PHYS_PFN(range->start), range_len(range)); err_pfn_remap: _