From mboxrd@z Thu Jan 1 00:00:00 1970 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 134FCCD6E61 for ; Mon, 1 Jun 2026 10:08:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=rajaosXHuJHIaYK3T3csqioDStDpmpeCVfagtDiv81I=; b=IYLaNzisSSK1q63sbqUqK+Pn0F 053r+27pgmBUym43vFRUJ03aWeZJWXK7XRMDPUT6QYs1EP2s3O937Dy00HG0IoqkvGBx/K5XF7zrN eAT5U+ITPadKXRRkfA6pB29OScSfmyc6DXD4AhGuprADzAptiGLtlYU+7FjF03ch714mv8d7xQqB0 tYLVHJscoqvR0XyRjAh5ZayQ30GaxQkM2mVCxyhxRs6NRfMa2SaaOn7YrpUNG2ekkG8Si95dQjZwu siaVAiWIYHwaKByuVKJAQILX/9SPsuaDnrNwFnDCZULn5S0IQaVpginCb4P51bEu0dTpq/Vj2KK3Y /CjyRqsw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wTzZC-0000000AaCM-1DnQ; Mon, 01 Jun 2026 10:08:18 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wTzZB-0000000AaCD-1R65 for linux-arm-kernel@bombadil.infradead.org; Mon, 01 Jun 2026 10:08:17 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=rajaosXHuJHIaYK3T3csqioDStDpmpeCVfagtDiv81I=; b=A8Q7YXLPOSR8WyHXKJWypjFMHk iaCp/5NxuEqWM2MuxsMcQP9R/Mf/Pq3iZwSLGCMkHAlO8qhiOM/0fKuSJUX42YY7cw4HKeM6K7kJR 5+9GWN/TCZUSmb+pt5RcoDzJZOoSYT+m1ZY50xn2zs2wGqMj4LhRC5C2LxM0+Xszb0nG7BbApTD2r y0JsZ7TjX+4ymzdedh4o2sc+KyX0BaVOIZjWBtmziouAXJySH/i3oblegu28Nq9NBHlrxFcP3rHjF irR2csmqS5Gelu07R2IDhTxv3U5tYR9RVV6SfwlhphtLnIEtbqZmFhP88EgeeMa3/LOsn2r+xOYjU 9ljcJ5DQ==; Received: from foss.arm.com ([217.140.110.172]) by desiato.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wTzZ7-00000006Kv7-2hhn for linux-arm-kernel@lists.infradead.org; Mon, 01 Jun 2026 10:08:16 +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 327F51E8D; Mon, 1 Jun 2026 03:08:07 -0700 (PDT) Received: from e129823.arm.com (e129823.arm.com [10.1.197.6]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C138E3F905; Mon, 1 Jun 2026 03:08:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1780308492; bh=hV53Qdv1PgmYKFUIbcP2hKzzjioGX7FNtwUP59NL6Fo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=gULyG36LVZfyyA7V7yPtUPaKe33/BGwN9mrHMgaYh/EXweaKU9Je1zzvpopajG7QA nwdzvEWQsiidFuJzkT1gFyVrzVNlUiLyX3XgncquqexY8f8IMLuG65XXqoOIoiiXTR aquEUe98PTF9FKm5gPbFv+AxV69vDr37M+kU7Zhk= Date: Mon, 1 Jun 2026 11:08:08 +0100 From: Yeoreum Yun To: Suzuki K Poulose Cc: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, mike.leach@arm.com, james.clark@linaro.org, alexander.shishkin@linux.intel.com, leo.yan@arm.com, jie.gan@oss.qualcomm.com Subject: Re: [PATCH v7 02/13] coresight: etm4x: fix underflow for nrseqstate Message-ID: References: <20260519154812.254884-1-yeoreum.yun@arm.com> <20260519154812.254884-3-yeoreum.yun@arm.com> <3155a54e-f0df-49d7-9cf7-6f1c0f826f31@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3155a54e-f0df-49d7-9cf7-6f1c0f826f31@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260601_110814_307655_41D17713 X-CRM114-Status: GOOD ( 20.62 ) 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 > On 19/05/2026 16:48, Yeoreum Yun wrote: > > TCRSEQEVR is implemented only when TCRIDR5.NUMSEQSTATE is 0b100, > > in which case n ranges from 0 to 2; otherwise, TCRIDR5.NUMSEQSTATE is 0b000. > > > > Therefore, drvdata->nrseqstate should be checked before entering the loop. > > for (i = 0; i < drvdata->nrseqstate - 1; i++) > > Wouldn't that check cover the case ? (provided i is signed int ?) > > Suzuki Unfortunately, the drvdata->nrseqstate is u8 but i is signed int. I think in this case it would iterate 255 times (0xff). > > > > > Link: https://developer.arm.com/documentation/ihi0064/latest/ [0] > > Fixes: 2e1cdfe184b5 ("coresight-etm4x: Adding CoreSight ETM4x driver") > > Reviewed-by: Leo Yan > > Signed-off-by: Yeoreum Yun > > --- > > .../hwtracing/coresight/coresight-etm4x-core.c | 18 ++++++++++-------- > > .../coresight/coresight-etm4x-sysfs.c | 2 ++ > > 2 files changed, 12 insertions(+), 8 deletions(-) > > > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c > > index 1e3b0344dc00..94b9385e964a 100644 > > --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c > > +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c > > @@ -542,9 +542,11 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata) > > etm4x_relaxed_write32(csa, config->vissctlr, TRCVISSCTLR); > > if (drvdata->nr_pe_cmp) > > etm4x_relaxed_write32(csa, config->vipcssctlr, TRCVIPCSSCTLR); > > - for (i = 0; i < drvdata->nrseqstate - 1; i++) > > - etm4x_relaxed_write32(csa, config->seq_ctrl[i], TRCSEQEVRn(i)); > > + > > if (drvdata->nrseqstate) { > > + for (i = 0; i < drvdata->nrseqstate - 1; i++) > > + etm4x_relaxed_write32(csa, config->seq_ctrl[i], TRCSEQEVRn(i)); > > + > > etm4x_relaxed_write32(csa, config->seq_rst, TRCSEQRSTEVR); > > etm4x_relaxed_write32(csa, config->seq_state, TRCSEQSTR); > > } > > @@ -1896,10 +1898,10 @@ static int etm4_cpu_save(struct coresight_device *csdev) > > if (drvdata->nr_pe_cmp) > > state->trcvipcssctlr = etm4x_read32(csa, TRCVIPCSSCTLR); > > - for (i = 0; i < drvdata->nrseqstate - 1; i++) > > - state->trcseqevr[i] = etm4x_read32(csa, TRCSEQEVRn(i)); > > - > > if (drvdata->nrseqstate) { > > + for (i = 0; i < drvdata->nrseqstate - 1; i++) > > + state->trcseqevr[i] = etm4x_read32(csa, TRCSEQEVRn(i)); > > + > > state->trcseqrstevr = etm4x_read32(csa, TRCSEQRSTEVR); > > state->trcseqstr = etm4x_read32(csa, TRCSEQSTR); > > } > > @@ -2009,10 +2011,10 @@ static void etm4_cpu_restore(struct coresight_device *csdev) > > if (drvdata->nr_pe_cmp) > > etm4x_relaxed_write32(csa, state->trcvipcssctlr, TRCVIPCSSCTLR); > > - for (i = 0; i < drvdata->nrseqstate - 1; i++) > > - etm4x_relaxed_write32(csa, state->trcseqevr[i], TRCSEQEVRn(i)); > > - > > if (drvdata->nrseqstate) { > > + for (i = 0; i < drvdata->nrseqstate - 1; i++) > > + etm4x_relaxed_write32(csa, state->trcseqevr[i], TRCSEQEVRn(i)); > > + > > etm4x_relaxed_write32(csa, state->trcseqrstevr, TRCSEQRSTEVR); > > etm4x_relaxed_write32(csa, state->trcseqstr, TRCSEQSTR); > > } > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c > > index e9eeea6240d5..0e1ad175aa1e 100644 > > --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c > > +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c > > @@ -1395,6 +1395,8 @@ static ssize_t seq_idx_store(struct device *dev, > > struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent); > > struct etmv4_config *config = &drvdata->config; > > + if (!drvdata->nrseqstate) > > + return -ENOTSUPP; > > if (kstrtoul(buf, 16, &val)) > > return -EINVAL; > > if (val >= drvdata->nrseqstate - 1) > -- Sincerely, Yeoreum Yun