From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 0013039D3F1 for ; Mon, 1 Jun 2026 10:08:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780308500; cv=none; b=uTZzIzG/CP85g+1FYpCC4NcOFFiUOvnEYHidRd0YJOxsxRU3RTxuKvpGAUUjD1tkCIRzyo932fYVvkPIgASo+NALMDzEj6/PEkagBwtYwok5XWB/pbhlF4+n40pMgdYkXjcaKCQaEwamLwOMFhQaYbr4Nm4vsCjPDbE9aqyLbIY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780308500; c=relaxed/simple; bh=hV53Qdv1PgmYKFUIbcP2hKzzjioGX7FNtwUP59NL6Fo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=G18s/8cMGpLtelWCe6zUaspCvSs1xEafdnyJLl8KUMp1iFxkP3BhtpzlTLMNtfk7oJ+/whqNpjIc2SPaCYA5qmJtApyEMeDL6sJZSifS5HjmxbrenkxAHx0d0ZFJZWgvXbv55tA5N/XPnHqc2icmZSbiB47bVbv4bC3trAO21W0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=gULyG36L; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="gULyG36L" 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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3155a54e-f0df-49d7-9cf7-6f1c0f826f31@arm.com> > 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