From patchwork Fri Dec 3 11:44:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 12694677 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4634BC433F5 for ; Fri, 3 Dec 2021 11:51:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Sj0AvNPgDfPXRTf1Z1qKLY4/nmDv4IU2Z+bDgEx+mvE=; b=z/3ylOMNGgUE2t dmP4A7xKw3mswPACz2nHA1/Dhr/LBqrpqRVWdij3TMXb239NJHmzqKGP1t8AEfISnLNa5IUhUfcLP 3tML4QDolskwKHm6IGzSJ6XeexdG6fjk7YHRH6R8uk4nSCBrFC2EyTfJSBtWhqR3voXU0f2QAsQ09 qdWt/Sx7zvzD5fMDuC4inZwjXJWbbXj9x2qc/UMD9JQSxn+KGu3TYTXXZ2vVS9mrN4rRknEPrC1wb rdlvWS+aqZFE/Y0UDhtYFn6doEXICFSQg1dsWe3inTSSkKU2qA4+VuutQUYEQPJTgwv26333MUtoU M/EOPoZvFieBUN50MV1w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mt72r-00FThx-4Z; Fri, 03 Dec 2021 11:48:05 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mt70C-00FSTz-J4 for linux-arm-kernel@lists.infradead.org; Fri, 03 Dec 2021 11:45:22 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A9DE715A1; Fri, 3 Dec 2021 03:45:19 -0800 (PST) Received: from e121345-lin.cambridge.arm.com (e121345-lin.cambridge.arm.com [10.1.196.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 204693F5A1; Fri, 3 Dec 2021 03:45:19 -0800 (PST) From: Robin Murphy To: will@kernel.org Cc: mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org Subject: [PATCH 09/14] perf/arm-cmn: Move group validation data off-stack Date: Fri, 3 Dec 2021 11:44:58 +0000 Message-Id: <0cabff2e5839ddc0979e757c55515966f65359e4.1638530442.git.robin.murphy@arm.com> X-Mailer: git-send-email 2.28.0.dirty In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211203_034520_730940_A9085D64 X-CRM114-Status: GOOD ( 12.70 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org With the value of CMN_MAX_DTMS increasing significantly, our validation data structure is set to get quite big. Technically we could pack it at least twice as densely, since we only need around 19 bits of information per DTM, but that makes the code even more mind-bogglingly impenetrable, and even half of "quite big" may still be uncomfortably large for a stack frame (~1KB). Just move it to an off-stack allocation instead. Signed-off-by: Robin Murphy --- drivers/perf/arm-cmn.c | 43 ++++++++++++++++++++++++------------------ 1 file changed, 25 insertions(+), 18 deletions(-) diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c index acff8683af2c..d2dd02f040b8 100644 --- a/drivers/perf/arm-cmn.c +++ b/drivers/perf/arm-cmn.c @@ -876,8 +876,8 @@ static int arm_cmn_validate_group(struct perf_event *event) struct arm_cmn_node *dn; struct perf_event *sibling, *leader = event->group_leader; enum cmn_node_type type; - struct arm_cmn_val val; - int i; + struct arm_cmn_val *val; + int i, ret = -EINVAL; u8 occupid; if (leader == event) @@ -886,18 +886,22 @@ static int arm_cmn_validate_group(struct perf_event *event) if (event->pmu != leader->pmu && !is_software_event(leader)) return -EINVAL; - memset(&val, 0, sizeof(val)); + val = kzalloc(sizeof(*val), GFP_KERNEL); + if (!val) + return -ENOMEM; - arm_cmn_val_add_event(&val, leader); + arm_cmn_val_add_event(val, leader); for_each_sibling_event(sibling, leader) - arm_cmn_val_add_event(&val, sibling); + arm_cmn_val_add_event(val, sibling); type = CMN_EVENT_TYPE(event); - if (type == CMN_TYPE_DTC) - return val.cycles ? -EINVAL : 0; + if (type == CMN_TYPE_DTC) { + ret = val->cycles ? -EINVAL : 0; + goto done; + } - if (val.dtc_count == CMN_DT_NUM_COUNTERS) - return -EINVAL; + if (val->dtc_count == CMN_DT_NUM_COUNTERS) + goto done; if (arm_cmn_is_occup_event(type, CMN_EVENT_EVENTID(event))) occupid = CMN_EVENT_OCCUPID(event) + 1; @@ -907,25 +911,28 @@ static int arm_cmn_validate_group(struct perf_event *event) for_each_hw_dn(hw, dn, i) { int wp_idx, wp_cmb, dtm = dn->dtm; - if (val.dtm_count[dtm] == CMN_DTM_NUM_COUNTERS) - return -EINVAL; + if (val->dtm_count[dtm] == CMN_DTM_NUM_COUNTERS) + goto done; - if (occupid && val.occupid[dtm] && occupid != val.occupid[dtm]) - return -EINVAL; + if (occupid && val->occupid[dtm] && occupid != val->occupid[dtm]) + goto done; if (type != CMN_TYPE_WP) continue; wp_idx = arm_cmn_wp_idx(event); - if (val.wp[dtm][wp_idx]) - return -EINVAL; + if (val->wp[dtm][wp_idx]) + goto done; - wp_cmb = val.wp[dtm][wp_idx ^ 1]; + wp_cmb = val->wp[dtm][wp_idx ^ 1]; if (wp_cmb && wp_cmb != CMN_EVENT_WP_COMBINE(event) + 1) - return -EINVAL; + goto done; } - return 0; + ret = 0; +done: + kfree(val); + return ret; } static int arm_cmn_event_init(struct perf_event *event)