From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753177AbcIAWlP (ORCPT ); Thu, 1 Sep 2016 18:41:15 -0400 Received: from mail-it0-f42.google.com ([209.85.214.42]:34742 "EHLO mail-it0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752500AbcIAWk6 (ORCPT ); Thu, 1 Sep 2016 18:40:58 -0400 From: Laura Abbott To: Sumit Semwal , John Stultz , =?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= , Riley Andrews Cc: Laura Abbott , Daniel Vetter , linaro-mm-sig@lists.linaro.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, Eun Taik Lee , Liviu Dudau , Jon Medhurst , Mitchel Humpherys , Jeremy Gebben , Bryan Huntsman , Greg Kroah-Hartman , Android Kernel Team , Chen Feng , Brian Starkey Subject: [PATCHv2 3/4] staging: android: ion: Add an ioctl for ABI checking Date: Thu, 1 Sep 2016 15:40:43 -0700 Message-Id: <1472769644-11039-4-git-send-email-labbott@redhat.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1472769644-11039-1-git-send-email-labbott@redhat.com> References: <1472769644-11039-1-git-send-email-labbott@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The current Ion ioctls lack a good way to tell what ioctls are available. Introduce an ioctl to give an ABI version. This way when the ABI inevitably gets screwed up userspace will have a way to tell what version of the screw up is available. Signed-off-by: Laura Abbott --- drivers/staging/android/ion/ion-ioctl.c | 53 ++++++++++++++++++++++++++------- drivers/staging/android/uapi/ion.h | 22 ++++++++++++++ 2 files changed, 65 insertions(+), 10 deletions(-) diff --git a/drivers/staging/android/ion/ion-ioctl.c b/drivers/staging/android/ion/ion-ioctl.c index 341ba7d..53b9520 100644 --- a/drivers/staging/android/ion/ion-ioctl.c +++ b/drivers/staging/android/ion/ion-ioctl.c @@ -22,6 +22,29 @@ #include "ion_priv.h" #include "compat_ion.h" +union ion_ioctl_arg { + struct ion_fd_data fd; + struct ion_allocation_data allocation; + struct ion_handle_data handle; + struct ion_custom_data custom; + struct ion_abi_version abi_version; +}; + +static int validate_ioctl_arg(unsigned int cmd, union ion_ioctl_arg *arg) +{ + int ret = 0; + + switch (cmd) { + case ION_IOC_ABI_VERSION: + ret = arg->abi_version.reserved != 0; + break; + default: + break; + } + + return ret ? -EINVAL : 0; +} + /* fix up the cases where the ioctl direction bits are incorrect */ static unsigned int ion_ioctl_dir(unsigned int cmd) { @@ -42,22 +65,27 @@ long ion_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) struct ion_handle *cleanup_handle = NULL; int ret = 0; unsigned int dir; - - union { - struct ion_fd_data fd; - struct ion_allocation_data allocation; - struct ion_handle_data handle; - struct ion_custom_data custom; - } data; + union ion_ioctl_arg data; dir = ion_ioctl_dir(cmd); if (_IOC_SIZE(cmd) > sizeof(data)) return -EINVAL; - if (dir & _IOC_WRITE) - if (copy_from_user(&data, (void __user *)arg, _IOC_SIZE(cmd))) - return -EFAULT; + /* + * The copy_from_user is unconditional here for both read and write + * to do the validate. If there is no write for the ioctl, the + * buffer is cleared + */ + if (copy_from_user(&data, (void __user *)arg, _IOC_SIZE(cmd))) + return -EFAULT; + + ret = validate_ioctl_arg(cmd, &data); + if (WARN_ON_ONCE(ret)) + return ret; + + if (!(dir & _IOC_WRITE)) + memset(&data, 0, sizeof(data)); switch (cmd) { case ION_IOC_ALLOC: @@ -129,6 +157,11 @@ long ion_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) data.custom.arg); break; } + case ION_IOC_ABI_VERSION: + { + data.abi_version.abi_version = ION_ABI_VERSION; + break; + } default: return -ENOTTY; } diff --git a/drivers/staging/android/uapi/ion.h b/drivers/staging/android/uapi/ion.h index a9c4e8b..7ca4e8b 100644 --- a/drivers/staging/android/uapi/ion.h +++ b/drivers/staging/android/uapi/ion.h @@ -19,6 +19,7 @@ #include #include +#include typedef int ion_user_handle_t; @@ -128,6 +129,19 @@ struct ion_custom_data { unsigned long arg; }; +/** + * struct ion_abi_version + * + * @version - current ABI version + */ + +#define ION_ABI_VERSION KERNEL_VERSION(0, 1, 0) + +struct ion_abi_version { + __u32 abi_version; + __u32 reserved; +}; + #define ION_IOC_MAGIC 'I' /** @@ -194,4 +208,12 @@ struct ion_custom_data { */ #define ION_IOC_CUSTOM _IOWR(ION_IOC_MAGIC, 6, struct ion_custom_data) +/** + * DOC: ION_IOC_ABI_VERSION - return ABI version + * + * Returns the ABI version of this driver. + */ +#define ION_IOC_ABI_VERSION _IOR(ION_IOC_MAGIC, 8, \ + struct ion_abi_version) + #endif /* _UAPI_LINUX_ION_H */ -- 2.7.4