From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.web.de (mout.web.de [212.227.17.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3yG57q037TzDrFy for ; Tue, 17 Oct 2017 04:35:34 +1100 (AEDT) Subject: [PATCH 4/4] char/tpm: Less checks in tpm_ibmvtpm_probe() after error detection From: SF Markus Elfring To: linux-integrity@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Andy Shevchenko , Benjamin Herrenschmidt , Corentin Labbe , Jarkko Sakkinen , Jason Gunthorpe , Jerry Snitselaar , Kenneth Goldman , Michael Ellerman , Nayna Jain , Paul Mackerras , =?UTF-8?Q?Peter_H=c3=bcwe?= , Stefan Berger Cc: LKML , kernel-janitors@vger.kernel.org References: <1d3516a2-a8e6-9e95-d438-f115fac84c7f@users.sourceforge.net> Message-ID: <09a2c3a1-1b10-507d-a866-258b570f6da1@users.sourceforge.net> Date: Mon, 16 Oct 2017 19:34:56 +0200 MIME-Version: 1.0 In-Reply-To: <1d3516a2-a8e6-9e95-d438-f115fac84c7f@users.sourceforge.net> Content-Type: text/plain; charset=utf-8 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Markus Elfring Date: Mon, 16 Oct 2017 19:00:34 +0200 Two pointer checks could be repeated by the tpm_ibmvtpm_probe() function during error handling even if the relevant properties can be determined for the involved variables before by source code analysis. * Return directly after a call of the function "kzalloc" failed at the beginning. * Adjust jump targets so that extra checks can be omitted at the end. Signed-off-by: Markus Elfring --- drivers/char/tpm/tpm_ibmvtpm.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c index a4b462a77b99..b8dda7546f64 100644 --- a/drivers/char/tpm/tpm_ibmvtpm.c +++ b/drivers/char/tpm/tpm_ibmvtpm.c @@ -610,7 +610,7 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, ibmvtpm = kzalloc(sizeof(*ibmvtpm), GFP_KERNEL); if (!ibmvtpm) - goto cleanup; + return -ENOMEM; ibmvtpm->dev = dev; ibmvtpm->vdev = vio_dev; @@ -619,7 +619,7 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, crq_q->crq_addr = (struct ibmvtpm_crq *)get_zeroed_page(GFP_KERNEL); if (!crq_q->crq_addr) { dev_err(dev, "Unable to allocate memory for crq_addr\n"); - goto cleanup; + goto free_tpm; } crq_q->num_entry = CRQ_RES_BUF_SIZE / sizeof(*crq_q->crq_addr); @@ -629,7 +629,7 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, if (dma_mapping_error(dev, ibmvtpm->crq_dma_handle)) { dev_err(dev, "dma mapping failed\n"); - goto cleanup; + goto free_page; } rc = plpar_hcall_norets(H_REG_CRQ, vio_dev->unit_address, @@ -683,13 +683,10 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, reg_crq_cleanup: dma_unmap_single(dev, ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE, DMA_BIDIRECTIONAL); -cleanup: - if (ibmvtpm) { - if (crq_q->crq_addr) - free_page((unsigned long)crq_q->crq_addr); - kfree(ibmvtpm); - } - +free_page: + free_page((unsigned long)crq_q->crq_addr); +free_tpm: + kfree(ibmvtpm); return rc; } -- 2.14.2