From patchwork Wed Dec 29 13:10:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: SeongJae Park X-Patchwork-Id: 12700879 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5179EC4332F for ; Wed, 29 Dec 2021 13:10:37 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id BA4756B0074; Wed, 29 Dec 2021 08:10:35 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id AFE616B007D; Wed, 29 Dec 2021 08:10:35 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 905B66B007B; Wed, 29 Dec 2021 08:10:35 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0159.hostedemail.com [216.40.44.159]) by kanga.kvack.org (Postfix) with ESMTP id 768EE6B0074 for ; Wed, 29 Dec 2021 08:10:35 -0500 (EST) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 2B3758249980 for ; Wed, 29 Dec 2021 13:10:35 +0000 (UTC) X-FDA: 78970866030.21.6BE3CA1 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf07.hostedemail.com (Postfix) with ESMTP id AB75040007 for ; Wed, 29 Dec 2021 13:10:34 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 90198B81905; Wed, 29 Dec 2021 13:10:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC33AC36AE7; Wed, 29 Dec 2021 13:10:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1640783433; bh=VQ2B0wuDXmafjk9e5koIOksR1NIA/USY11VBWynEVR8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ISW9lcpSNaDv/3bwMyPO1VeTwaF+UMTxb6hwMRvRmELcy4CerL62kExmERH12vaP1 m1IxgP3ZCiLxmQ3DLNRhYe3Dtf4pQcZhS2boyvENsX2Xr+2dDaMiRbzwtaUZ38BhdM gBiJ/FjQ4/CoME6iX5CU7zVg2PeYNCig3CnNfJ7k1tFBMp7D9iMl+e5SA2fzeBJeOE MnW7XzTwQU2nTv40sAIQtSlmG9BzzS0y9jTF/WxkbdEKvMp9wjGD2i2yXqflZMt33H wMhHs77LYPeVx4ONh2pwINhUJ+34FPaSws6noxeeM6V4nYvw3WXDZFEzXCoNwxx4K0 fwThJsPGpMW2g== From: SeongJae Park To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, SeongJae Park Subject: [PATCH 4/4] mm/damon: Hide kernel pointer from tracepoint event Date: Wed, 29 Dec 2021 13:10:16 +0000 Message-Id: <20211229131016.23641-5-sj@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20211229131016.23641-1-sj@kernel.org> References: <20211229131016.23641-1-sj@kernel.org> Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=ISW9lcpS; spf=pass (imf07.hostedemail.com: domain of sj@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=sj@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: AB75040007 X-Stat-Signature: 61ym1p9cqxxhe6cw4rc5x7kexfm4yd9o X-HE-Tag: 1640783434-81346 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: DAMON's virtual address spaces monitoring primitive uses 'struct pid *' of the target process as its monitoring target id. The kernel address is exposed as-is to the user space via the DAMON tracepoint, 'damon_aggregated'. Though primarily only privileged users are allowed to access that, it would be better to avoid unnecessarily exposing kernel pointers so. Because the trace result is only required to be able to distinguish each target, we aren't need to use the pointer as-is. This commit makes the tracepoint to use the index of the target in the context's targets list as its id in the tracepoint, to hide the kernel space address. Signed-off-by: SeongJae Park --- include/trace/events/damon.h | 8 ++++---- mm/damon/core.c | 4 +++- 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/include/trace/events/damon.h b/include/trace/events/damon.h index 99ffa601e351..c79f1d4c39af 100644 --- a/include/trace/events/damon.h +++ b/include/trace/events/damon.h @@ -11,10 +11,10 @@ TRACE_EVENT(damon_aggregated, - TP_PROTO(struct damon_target *t, struct damon_region *r, - unsigned int nr_regions), + TP_PROTO(struct damon_target *t, unsigned int target_id, + struct damon_region *r, unsigned int nr_regions), - TP_ARGS(t, r, nr_regions), + TP_ARGS(t, target_id, r, nr_regions), TP_STRUCT__entry( __field(unsigned long, target_id) @@ -26,7 +26,7 @@ TRACE_EVENT(damon_aggregated, ), TP_fast_assign( - __entry->target_id = t->id; + __entry->target_id = target_id; __entry->nr_regions = nr_regions; __entry->start = r->ar.start; __entry->end = r->ar.end; diff --git a/mm/damon/core.c b/mm/damon/core.c index 6482d510dcbe..1dd153c31c9e 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -514,15 +514,17 @@ static bool kdamond_aggregate_interval_passed(struct damon_ctx *ctx) static void kdamond_reset_aggregated(struct damon_ctx *c) { struct damon_target *t; + unsigned int ti = 0; /* target's index */ damon_for_each_target(t, c) { struct damon_region *r; damon_for_each_region(r, t) { - trace_damon_aggregated(t, r, damon_nr_regions(t)); + trace_damon_aggregated(t, ti, r, damon_nr_regions(t)); r->last_nr_accesses = r->nr_accesses; r->nr_accesses = 0; } + ti++; } }