From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: [PATCH v2 20/40] metag: fix put_user sparse errors Date: Tue, 6 Jan 2015 17:44:38 +0200 Message-ID: <1420558883-10131-21-git-send-email-mst@redhat.com> References: <1420558883-10131-1-git-send-email-mst@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mx1.redhat.com ([209.132.183.28]:50935 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755871AbbAFPot (ORCPT ); Tue, 6 Jan 2015 10:44:49 -0500 Content-Disposition: inline In-Reply-To: <1420558883-10131-1-git-send-email-mst@redhat.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-kernel@vger.kernel.org Cc: Arnd Bergmann , linux-arch@vger.kernel.org, James Hogan , linux-metag@vger.kernel.org virtio wants to write bitwise types to userspace using put_user. At the moment this triggers sparse errors, since the value is passed through an integer. For example: __le32 __user *p; __le32 x; put_user(x, p); is safe, but currently triggers a sparse warning. Fix that up using __force. This also fixes warnings due to writing a pointer out to userland. Note: this does not suppress any useful sparse checks since callers do a cast (__typeof__(*(ptr))) (x) which in turn forces all the necessary type checks. Suggested-by: James Hogan Signed-off-by: Michael S. Tsirkin --- arch/metag/include/asm/uaccess.h | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/arch/metag/include/asm/uaccess.h b/arch/metag/include/asm/uaccess.h index c314b45..9627c19 100644 --- a/arch/metag/include/asm/uaccess.h +++ b/arch/metag/include/asm/uaccess.h @@ -107,18 +107,23 @@ extern long __put_user_asm_w(unsigned int x, void __user *addr); extern long __put_user_asm_d(unsigned int x, void __user *addr); extern long __put_user_asm_l(unsigned long long x, void __user *addr); -#define __put_user_size(x, ptr, size, retval) \ -do { \ - retval = 0; \ - switch (size) { \ +#define __put_user_size(x, ptr, size, retval) \ +do { \ + retval = 0; \ + switch (size) { \ case 1: \ - retval = __put_user_asm_b((unsigned int)x, ptr); break; \ + retval = __put_user_asm_b((__force unsigned int)x, ptr);\ + break; \ case 2: \ - retval = __put_user_asm_w((unsigned int)x, ptr); break; \ + retval = __put_user_asm_w((__force unsigned int)x, ptr);\ + break; \ case 4: \ - retval = __put_user_asm_d((unsigned int)x, ptr); break; \ + retval = __put_user_asm_d((__force unsigned int)x, ptr);\ + break; \ case 8: \ - retval = __put_user_asm_l((unsigned long long)x, ptr); break; \ + retval = __put_user_asm_l((__force unsigned long long)x,\ + ptr); \ + break; \ default: \ __put_user_bad(); \ } \ -- MST