From patchwork Thu Jun 16 17:03:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cristian Marussi X-Patchwork-Id: 12884616 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 DE670C433EF for ; Thu, 16 Jun 2022 17:05:24 +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: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:In-Reply-To:References: List-Owner; bh=oMAHk0bcprh70vGfhcagezPikj4FqKp64zi93jOwAuM=; b=xUAf+ro4o/bLjE kzF9EGzlFoUo+vbtcLtqTK60uA3KtHmITQ9Sr8/xZ5s+jFPKo0gUsgSrYz+nIv8Pw0XadOWpa18aV 1ahC6l7nO8xLCfd/6x5ujiI/N2p1rvcKx6NTb+br0+jc/HJml+xhhO6KzUb78El6RWCZZ8ODwn//g w+ugYI6CqSQo7odEhQ5tf9dIJEWB6fC/azXYINa2uorb+cTr+GxdM4dFFm3VsShWZmS3tsbh3xy5t n9ssy0inwNYC2pw6PNCEkRdZ8v/vhUq8aa/3KVbWqOA62KOmvL5e1Ut5rXVEpU6Al/qlWehvRcokj ODOm83T5Ahr7NaA48Gwg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o1sum-003aTP-EQ; Thu, 16 Jun 2022 17:04:16 +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 1o1suh-003aON-GI for linux-arm-kernel@lists.infradead.org; Thu, 16 Jun 2022 17:04:13 +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 EFD3511FB; Thu, 16 Jun 2022 10:04:02 -0700 (PDT) Received: from e120937-lin.home (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B76BC3F73B; Thu, 16 Jun 2022 10:04:01 -0700 (PDT) From: Cristian Marussi To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: sudeep.holla@arm.com, robin.murphy@arm.com, nicola.mazzucato@arm.com, vincent.guittot@linaro.org, f.fainelli@gmail.com, Cristian Marussi Subject: [PATCH] firmware: arm_scmi: Relax CLOCK_DESCRIBE_RATES out-of-spec checks Date: Thu, 16 Jun 2022 18:03:47 +0100 Message-Id: <20220616170347.2800771-1-cristian.marussi@arm.com> X-Mailer: git-send-email 2.32.0 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220616_100411_673353_4A48AE5B X-CRM114-Status: GOOD ( 16.84 ) 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 A reply to CLOCK_DESCRIBE_RATES issued against a non rate-discrete clock should be composed of a triplet of rates descriptors (min/max/step) returned all in one reply message. This is not always the case when dealing with some SCMI server deployed in the wild: relax such constraint while maintaining memory safety by checking carefully the returned payload size. While at that cleanup a stale debug printout. Fixes: 7bc7caafe6b1 ("firmware: arm_scmi: Use common iterators in the clock protocol") Signed-off-by: Cristian Marussi Tested-by: Robin Murphy --- drivers/firmware/arm_scmi/clock.c | 26 +++++++++++++++++++++++++- drivers/firmware/arm_scmi/driver.c | 1 + drivers/firmware/arm_scmi/protocols.h | 3 +++ 3 files changed, 29 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c index c7a83f6e38e5..3ed7ae0d6781 100644 --- a/drivers/firmware/arm_scmi/clock.c +++ b/drivers/firmware/arm_scmi/clock.c @@ -194,6 +194,7 @@ static int rate_cmp_func(const void *_r1, const void *_r2) } struct scmi_clk_ipriv { + struct device *dev; u32 clk_id; struct scmi_clock_info *clk; }; @@ -223,6 +224,29 @@ iter_clk_describe_update_state(struct scmi_iterator_state *st, st->num_returned = NUM_RETURNED(flags); p->clk->rate_discrete = RATE_DISCRETE(flags); + /* Warn about out of spec replies ... */ + if (!p->clk->rate_discrete && + (st->num_returned != 3 || st->num_remaining != 0)) { + dev_warn(p->dev, + "Out-of-spec CLOCK_DESCRIBE_RATES reply for %s - returned:%d remaining:%d rx_len:%zd\n", + p->clk->name, st->num_returned, st->num_remaining, + st->rx_len); + + /* + * A known quirk: a triplet is returned but num_returned != 3 + * Check for a safe payload size and fix. + */ + if (st->num_returned != 3 && st->num_remaining == 0 && + st->rx_len == sizeof(*r) + sizeof(__le32) * 2 * 3) { + st->num_returned = 3; + st->num_remaining = 0; + } else { + dev_err(p->dev, + "Cannot fix out-of-spec reply !\n"); + return -EPROTO; + } + } + return 0; } @@ -255,7 +279,6 @@ iter_clk_describe_process_response(const struct scmi_protocol_handle *ph, *rate = RATE_TO_U64(r->rate[st->loop_idx]); p->clk->list.num_rates++; - //XXX dev_dbg(ph->dev, "Rate %llu Hz\n", *rate); } return ret; @@ -275,6 +298,7 @@ scmi_clock_describe_rates_get(const struct scmi_protocol_handle *ph, u32 clk_id, struct scmi_clk_ipriv cpriv = { .clk_id = clk_id, .clk = clk, + .dev = ph->dev, }; iter = ph->hops->iter_response_init(ph, &ops, SCMI_MAX_NUM_RATES, diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index c1922bd650ae..8b7ac6663d57 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -1223,6 +1223,7 @@ static int scmi_iterator_run(void *iter) if (ret) break; + st->rx_len = i->t->rx.len; ret = iops->update_state(st, i->resp, i->priv); if (ret) break; diff --git a/drivers/firmware/arm_scmi/protocols.h b/drivers/firmware/arm_scmi/protocols.h index c679f3fb8718..51c31379f9b3 100644 --- a/drivers/firmware/arm_scmi/protocols.h +++ b/drivers/firmware/arm_scmi/protocols.h @@ -179,6 +179,8 @@ struct scmi_protocol_handle { * @max_resources: Maximum acceptable number of items, configured by the caller * depending on the underlying resources that it is querying. * @loop_idx: The iterator loop index in the current multi-part reply. + * @rx_len: Size in bytes of the currenly processed message; it can be used by + * the user of the iterator to verify a reply size. * @priv: Optional pointer to some additional state-related private data setup * by the caller during the iterations. */ @@ -188,6 +190,7 @@ struct scmi_iterator_state { unsigned int num_remaining; unsigned int max_resources; unsigned int loop_idx; + size_t rx_len; void *priv; };