Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934939Ab3FSRMv (ORCPT ); Wed, 19 Jun 2013 13:12:51 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:65291 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934924Ab3FSRMt (ORCPT ); Wed, 19 Jun 2013 13:12:49 -0400 From: Serban Constantinescu To: linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, kernel-team@android.com, arve@android.com, john.stultz@linaro.org, Dave.Butcher@arm.com Cc: Serban Constantinescu Subject: [PATCH v5 4/6] staging: android: binder: fix alignment issues Date: Wed, 19 Jun 2013 18:12:34 +0100 Message-Id: <1371661956-10894-5-git-send-email-serban.constantinescu@arm.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1371661956-10894-1-git-send-email-serban.constantinescu@arm.com> References: <1371661956-10894-1-git-send-email-serban.constantinescu@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2069 Lines: 49 The Android userspace aligns the data written to the binder buffers to 4bytes. Thus for 32bit platforms or 64bit platforms running an 32bit Android userspace we can have a buffer looking like this: platform buffer(binder_cmd pointer) size 32/32 32b 32b 8B 64/32 32b 64b 12B 64/64 32b 64b 12B Thus the kernel needs to check that the buffer size is aligned to 4bytes not to (void *) that will be 8bytes on 64bit machines. The change does not affect existing 32bit ABI. Signed-off-by: Serban Constantinescu --- drivers/staging/android/binder.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c index ce70909..7450d56 100644 --- a/drivers/staging/android/binder.c +++ b/drivers/staging/android/binder.c @@ -1247,7 +1247,7 @@ static void binder_transaction_buffer_release(struct binder_proc *proc, struct flat_binder_object *fp; if (*offp > buffer->data_size - sizeof(*fp) || buffer->data_size < sizeof(*fp) || - !IS_ALIGNED(*offp, sizeof(void *))) { + !IS_ALIGNED(*offp, sizeof(u32))) { pr_err("transaction release %d bad offset %zd, size %zd\n", debug_id, *offp, buffer->data_size); continue; @@ -1496,7 +1496,7 @@ static void binder_transaction(struct binder_proc *proc, struct flat_binder_object *fp; if (*offp > t->buffer->data_size - sizeof(*fp) || t->buffer->data_size < sizeof(*fp) || - !IS_ALIGNED(*offp, sizeof(void *))) { + !IS_ALIGNED(*offp, sizeof(u32))) { binder_user_error("%d:%d got transaction with invalid offset, %zd\n", proc->pid, thread->pid, *offp); return_error = BR_FAILED_REPLY; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/