From patchwork Thu Jul 25 20:29:57 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josh Poimboeuf X-Patchwork-Id: 11059653 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B0FE2912 for ; Thu, 25 Jul 2019 20:30:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A120628817 for ; Thu, 25 Jul 2019 20:30:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 956EC288EF; Thu, 25 Jul 2019 20:30:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 4EF3928817 for ; Thu, 25 Jul 2019 20:30:51 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A2B686E82E; Thu, 25 Jul 2019 20:30:48 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by gabe.freedesktop.org (Postfix) with ESMTPS id CBDB36E82D; Thu, 25 Jul 2019 20:30:46 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2F47985539; Thu, 25 Jul 2019 20:30:46 +0000 (UTC) Received: from treble.redhat.com (ovpn-122-90.rdu2.redhat.com [10.10.122.90]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0FB6F5D772; Thu, 25 Jul 2019 20:30:44 +0000 (UTC) From: Josh Poimboeuf To: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Date: Thu, 25 Jul 2019 15:29:57 -0500 Message-Id: <51a4155c5bc2ca847a9cbe85c1c11918bb193141.1564086017.git.jpoimboe@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Thu, 25 Jul 2019 20:30:46 +0000 (UTC) Subject: [Intel-gfx] [PATCH] drm/i915: Remove redundant user_access_end() from __copy_from_user() error path X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Arnd Bergmann , Peter Zijlstra , Nick Desaulniers , linux-kernel@vger.kernel.org, Sedat Dilek , Thomas Gleixner , Linus Torvalds , Nathan Chancellor Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP Objtool reports: drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool: .altinstr_replacement+0x36: redundant UACCESS disable __copy_from_user() already does both STAC and CLAC, so the user_access_end() in its error path adds an extra unnecessary CLAC. Fixes: 0b2c8f8b6b0c ("i915: fix missing user_access_end() in page fault exception case") Reported-by: Thomas Gleixner Reported-by: Sedat Dilek Acked-by: Peter Zijlstra (Intel) Tested-by: Nick Desaulniers Tested-by: Sedat Dilek Link: https://github.com/ClangBuiltLinux/linux/issues/617 Signed-off-by: Josh Poimboeuf Reviewed-by: Thomas Gleixner Acked-by: Chris Wilson --- .../gpu/drm/i915/gem/i915_gem_execbuffer.c | 20 +++++++++---------- 1 file changed, 9 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c index 5fae0e50aad0..41dab9ea33cd 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c @@ -1628,6 +1628,7 @@ static int check_relocations(const struct drm_i915_gem_exec_object2 *entry) static int eb_copy_relocations(const struct i915_execbuffer *eb) { + struct drm_i915_gem_relocation_entry *relocs; const unsigned int count = eb->buffer_count; unsigned int i; int err; @@ -1635,7 +1636,6 @@ static int eb_copy_relocations(const struct i915_execbuffer *eb) for (i = 0; i < count; i++) { const unsigned int nreloc = eb->exec[i].relocation_count; struct drm_i915_gem_relocation_entry __user *urelocs; - struct drm_i915_gem_relocation_entry *relocs; unsigned long size; unsigned long copied; @@ -1663,14 +1663,8 @@ static int eb_copy_relocations(const struct i915_execbuffer *eb) if (__copy_from_user((char *)relocs + copied, (char __user *)urelocs + copied, - len)) { -end_user: - user_access_end(); -end: - kvfree(relocs); - err = -EFAULT; - goto err; - } + len)) + goto end; copied += len; } while (copied < size); @@ -1699,10 +1693,14 @@ static int eb_copy_relocations(const struct i915_execbuffer *eb) return 0; +end_user: + user_access_end(); +end: + kvfree(relocs); + err = -EFAULT; err: while (i--) { - struct drm_i915_gem_relocation_entry *relocs = - u64_to_ptr(typeof(*relocs), eb->exec[i].relocs_ptr); + relocs = u64_to_ptr(typeof(*relocs), eb->exec[i].relocs_ptr); if (eb->exec[i].relocation_count) kvfree(relocs); }