From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755279AbbI3JJb (ORCPT ); Wed, 30 Sep 2015 05:09:31 -0400 Received: from mail-wi0-f176.google.com ([209.85.212.176]:38406 "EHLO mail-wi0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752646AbbI3JJT (ORCPT ); Wed, 30 Sep 2015 05:09:19 -0400 From: Baptiste Reynal To: kvmarm@lists.cs.columbia.edu, iommu@lists.linux-foundation.org, alex.williamson@redhat.com, christoffer.dall@linaro.org, eric.auger@linaro.org Cc: tech@virtualopensystems.com, kvm@vger.kernel.org (open list:VFIO PLATFORM DRIVER), linux-kernel@vger.kernel.org (open list) Subject: [RFC PATCH v5 2/3] vfio: platform: access device property as a list of strings Date: Wed, 30 Sep 2015 11:09:06 +0200 Message-Id: <1443604149-3242-2-git-send-email-b.reynal@virtualopensystems.com> X-Mailer: git-send-email 2.6.0 In-Reply-To: <1443604149-3242-1-git-send-email-b.reynal@virtualopensystems.com> References: <1443604149-3242-1-git-send-email-b.reynal@virtualopensystems.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Antonios Motakis Certain device properties (e.g. the device node name, the compatible string), are available as a list of strings (separated by the null terminating character). Let the VFIO user query this type of properties. Signed-off-by: Antonios Motakis Signed-off-by: Baptiste Reynal --- v4 -> v5: - return ENOSPC when the buffer size is too small - remove strlen call v3 -> v4: - The list length is computed before strings copy. If the entire list doesn't fit, no strings are copied to the user. --- drivers/vfio/platform/properties.c | 43 +++++++++++++++++++++++++++++++++++++- 1 file changed, 42 insertions(+), 1 deletion(-) diff --git a/drivers/vfio/platform/properties.c b/drivers/vfio/platform/properties.c index 48c90c5..212755f 100644 --- a/drivers/vfio/platform/properties.c +++ b/drivers/vfio/platform/properties.c @@ -22,7 +22,48 @@ static int dev_property_get_strings(struct device *dev, char *name, unsigned *lenp, void __user *datap, unsigned long datasz) { - return -EINVAL; + const char **val; + int n, i, ret; + + if (lenp == NULL) + return -EFAULT; + + *lenp = 0; + + n = device_property_read_string_array(dev, name, NULL, 0); + if (n < 0) + return n; + + val = kcalloc(n, sizeof(char *), GFP_KERNEL); + if (!val) + return -ENOMEM; + + ret = device_property_read_string_array(dev, name, val, n); + if (ret < 0) + goto out; + + for (i = 0; i < n; i++) + *lenp += strlen(val[i]) + 1; + + if (datasz < *lenp) { + ret = -ENOSPC; + goto out; + } + + for (i = 0; i < n; i++) { + size_t len = strlen(val[i]) + 1; + + if (copy_to_user(datap, val[i], len)) { + ret = -EFAULT; + goto out; + } + + datap += len; + } + +out: + kfree(val); + return ret; } static int dev_property_get_uint(struct device *dev, -- 2.6.0