From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F20E9C3601A for ; Thu, 3 Apr 2025 14:27:40 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 666E610E9FB; Thu, 3 Apr 2025 14:27:40 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=collabora.com header.i=dmitry.osipenko@collabora.com header.b="hElxKqev"; dkim-atps=neutral Received: from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com [136.143.188.112]) by gabe.freedesktop.org (Postfix) with ESMTPS id 357DF10E9FB for ; Thu, 3 Apr 2025 14:27:39 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; t=1743690443; cv=none; d=zohomail.com; s=zohoarc; b=K3Nb25MxH7+0OhMRLOA9J8O+lKajw4+NwyzfBzURx/xSAlKkILvGWBPFklyrDj2FBW492riINvSHw5I8gpeaK1+lS6ZchP5gPRkUD10udY84rk+fxgA606gtbEt28zR+AVLTVj3kJ/W1svCdzeXCgMIhQU+RgqiMYqVQr4pti9g= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1743690443; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:MIME-Version:Message-ID:Subject:Subject:To:To:Message-Id:Reply-To; bh=oirO8kcN/r9uSBJ+v9FYpxLcssDHYsJBhsQlC7HHKrc=; b=EK5s6x9g9Dvc7ua2PLaP4NpXKj7AZdaGosdqE3MCurx3GNIBFsirfGKDOAcPDEkKzc24QDFRqJcK8E+NzW0E7lcg/+mvyPyJjx2MvTKVu5YYXth8bdMBmIx/SRYoP2BYjiOgJGafRn/IlcZl6357hC3Q7WV7nHKrI/mKdWx6SaA= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=dmitry.osipenko@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1743690443; s=zohomail; d=collabora.com; i=dmitry.osipenko@collabora.com; h=From:From:To:To:Cc:Cc:Subject:Subject:Date:Date:Message-ID:MIME-Version:Content-Transfer-Encoding:Message-Id:Reply-To; bh=oirO8kcN/r9uSBJ+v9FYpxLcssDHYsJBhsQlC7HHKrc=; b=hElxKqevrUCM0CvLsy7NDdP7+0ZbxCIQFqO7uT1VPB+nX9nw5W1mfGzsvsW//TLo u0IctGTqk1X2xHGBTeOvoDO/3Y91EzocXrbSgThWkkpgpuMd0/giHK2ERM05Kc8EZ2n bl9XFfmRZ3Qeg5PvdpS4PnOdQ4De5jBtVy/RVL5U= Received: by mx.zohomail.com with SMTPS id 1743690441799662.414689971647; Thu, 3 Apr 2025 07:27:21 -0700 (PDT) From: Dmitry Osipenko To: Thomas Zimmermann , Lucas De Marchi , Boris Brezillon Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, kernel@collabora.com Subject: [PATCH v1] drm/shmem-helper: Fix unsetting shmem vaddr while vmap refcount > 0 Date: Thu, 3 Apr 2025 17:26:33 +0300 Message-ID: <20250403142633.484660-1-dmitry.osipenko@collabora.com> X-Mailer: git-send-email 2.49.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-ZohoMailClient: External X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" We switched to use refcount_t for vmaps and missed to change the vunmap code to properly unset the vmap pointer, which is now cleared while vmap's refcount > 0. Clear the cached vmap pointer only when refcounting drops to zero to fix the bug. Fixes: e1fc39a92332 ("drm/shmem-helper: Use refcount_t for vmap_use_count") Reported-by: Lucas De Marchi Closes: https://lore.kernel.org/dri-devel/20250403105053.788b0f6e@collabora.com/T/#m3dca6d81bedc8d6146a56b82694624fbc6fa4c96 Signed-off-by: Dmitry Osipenko --- drivers/gpu/drm/drm_gem_shmem_helper.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index 2d924d547a51..aa43265f4f4f 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -415,11 +415,11 @@ void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem, if (refcount_dec_and_test(&shmem->vmap_use_count)) { vunmap(shmem->vaddr); + shmem->vaddr = NULL; + drm_gem_shmem_unpin_locked(shmem); } } - - shmem->vaddr = NULL; } EXPORT_SYMBOL_GPL(drm_gem_shmem_vunmap_locked); -- 2.49.0