From patchwork Sun Oct 4 19:21:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rob Clark X-Patchwork-Id: 11815919 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0997792C for ; Sun, 4 Oct 2020 19:21:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DC16020637 for ; Sun, 4 Oct 2020 19:21:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ofZAEfvf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726754AbgJDTVo (ORCPT ); Sun, 4 Oct 2020 15:21:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60514 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726713AbgJDTVf (ORCPT ); Sun, 4 Oct 2020 15:21:35 -0400 Received: from mail-pg1-x542.google.com (mail-pg1-x542.google.com [IPv6:2607:f8b0:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3DE7EC0613CE; Sun, 4 Oct 2020 12:21:35 -0700 (PDT) Received: by mail-pg1-x542.google.com with SMTP id m34so4330936pgl.9; Sun, 04 Oct 2020 12:21:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=bvgK4u82bAyvmLcb1xV4zW9ZRosaPzo7Ro9rB88uZpw=; b=ofZAEfvfh8t1vznoy1eMEzfJNtT51uN1eqHEdUNZZF2XCyOISMqnMSt9iGAymBkYJ6 OReDh6nmpyaSeoep3kHHJHmvTuVVu/cT4A/Ig81/FTn9aY78ns7Af8iuMfQkvopF0Wsg dYzRG8fNOWbOQQoURIBzhVdMhp+ur3eGpbwlqgIRW1EesJz90TDCM8cwpoZ/KKyFmxPi DJnTQ+qRG0DpWj5DXS1YLfXmWxGMyB2JDh0G9ca3MCooBUBbLA5JcpQKp88956t44m6a M7xuso8lV3k2U61P0RypNKvWj7ihmkcIB/dLvASEkMl/axDNPx4heJF53YNzhyygy/mk qcvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=bvgK4u82bAyvmLcb1xV4zW9ZRosaPzo7Ro9rB88uZpw=; b=De7f6ox4fLbqmsBLlZE6c0/oyKgYfBIeqBxupAw9be5pMp+30fBzAi3qguaLSKdtBE ltDRmqbX6QlayUJGssvp+35byj04Z9P716E+rvP08XaGBkJVcQcfnCACkObPLVOsLR1X ZY8pGb/BEFZBk285sHvuBFuEmdf01Xxo4CuAVzjp3rBZEG7SCYlaokKIc19fwvEMPZOc v7VmXj9zCfLNZtn+Yzjh65jSby62qGbCUdbLuJ3Wu9p5pj+k6vCZiI2pHkKF8Zhzae6W gsy7JH7XQ3z0XEPpEtSTIbuPyHwAqVwdVr9SwL4VOR7dex4UXNBHmGWytbDolL/ZU5yR 0mEQ== X-Gm-Message-State: AOAM533hV0NZw1rararqL0Ey1jokqU0iC9lvRuBbRXB4Dgo2fAHXjEaU JQLSYi5aNf9sAOD5b9LXago= X-Google-Smtp-Source: ABdhPJz09/i+2Wvqqf8XiOcUyAb17zQupk0PEwwUc6Pj2OeVvWLdUTNDay5FX1WDau4Gd0Ws7QGjBA== X-Received: by 2002:a63:d242:: with SMTP id t2mr11411995pgi.47.1601839294703; Sun, 04 Oct 2020 12:21:34 -0700 (PDT) Received: from localhost (c-73-25-156-94.hsd1.or.comcast.net. [73.25.156.94]) by smtp.gmail.com with ESMTPSA id ie13sm8103444pjb.5.2020.10.04.12.21.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 04 Oct 2020 12:21:33 -0700 (PDT) From: Rob Clark To: dri-devel@lists.freedesktop.org Cc: Rob Clark , Rob Clark , Sean Paul , David Airlie , Daniel Vetter , Sumit Semwal , =?utf-8?q?Christian_K=C3=B6nig?= , linux-arm-msm@vger.kernel.org (open list:DRM DRIVER FOR MSM ADRENO GPU), freedreno@lists.freedesktop.org (open list:DRM DRIVER FOR MSM ADRENO GPU), linux-kernel@vger.kernel.org (open list), linux-media@vger.kernel.org (open list:DMA BUFFER SHARING FRAMEWORK), linaro-mm-sig@lists.linaro.org (moderated list:DMA BUFFER SHARING FRAMEWORK) Subject: [PATCH 12/14] drm/msm: drop struct_mutex in madvise path Date: Sun, 4 Oct 2020 12:21:44 -0700 Message-Id: <20201004192152.3298573-13-robdclark@gmail.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201004192152.3298573-1-robdclark@gmail.com> References: <20201004192152.3298573-1-robdclark@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org From: Rob Clark The obj->lock is sufficient for what we need. This *does* have the implication that userspace can try to shoot themselves in the foot by racing madvise(DONTNEED) with submit. But the result will be about the same if they did madvise(DONTNEED) before the submit ioctl, ie. they might not get want they want if they race with shrinker. But iova fault handling is robust enough, and userspace is only shooting it's own foot. Signed-off-by: Rob Clark --- drivers/gpu/drm/msm/msm_drv.c | 11 ++------ drivers/gpu/drm/msm/msm_gem.c | 6 ++-- drivers/gpu/drm/msm/msm_gem.h | 38 ++++++++++++++++++-------- drivers/gpu/drm/msm/msm_gem_shrinker.c | 4 +-- 4 files changed, 32 insertions(+), 27 deletions(-) diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c index e766c1f45045..d2488816ce48 100644 --- a/drivers/gpu/drm/msm/msm_drv.c +++ b/drivers/gpu/drm/msm/msm_drv.c @@ -906,14 +906,9 @@ static int msm_ioctl_gem_madvise(struct drm_device *dev, void *data, return -EINVAL; } - ret = mutex_lock_interruptible(&dev->struct_mutex); - if (ret) - return ret; - obj = drm_gem_object_lookup(file, args->handle); if (!obj) { - ret = -ENOENT; - goto unlock; + return -ENOENT; } ret = msm_gem_madvise(obj, args->madv); @@ -922,10 +917,8 @@ static int msm_ioctl_gem_madvise(struct drm_device *dev, void *data, ret = 0; } - drm_gem_object_put_locked(obj); + drm_gem_object_put(obj); -unlock: - mutex_unlock(&dev->struct_mutex); return ret; } diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c index 5e75d644ce41..9cdac4f7228c 100644 --- a/drivers/gpu/drm/msm/msm_gem.c +++ b/drivers/gpu/drm/msm/msm_gem.c @@ -639,8 +639,6 @@ int msm_gem_madvise(struct drm_gem_object *obj, unsigned madv) mutex_lock(&msm_obj->lock); - WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex)); - if (msm_obj->madv != __MSM_MADV_PURGED) msm_obj->madv = madv; @@ -657,7 +655,7 @@ void msm_gem_purge(struct drm_gem_object *obj, enum msm_gem_lock subclass) struct msm_gem_object *msm_obj = to_msm_bo(obj); WARN_ON(!mutex_is_locked(&dev->struct_mutex)); - WARN_ON(!is_purgeable(msm_obj)); + WARN_ON(!is_purgeable(msm_obj, subclass)); WARN_ON(obj->import_attach); mutex_lock_nested(&msm_obj->lock, subclass); @@ -749,7 +747,7 @@ void msm_gem_active_get(struct drm_gem_object *obj, struct msm_gpu *gpu) struct msm_drm_private *priv = obj->dev->dev_private; might_sleep(); - WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED); + WARN_ON(msm_gem_madv(msm_obj, OBJ_LOCK_NORMAL) != MSM_MADV_WILLNEED); if (!atomic_fetch_inc(&msm_obj->active_count)) { mutex_lock(&priv->mm_lock); diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h index e98a8004813b..bb8aa6b1b254 100644 --- a/drivers/gpu/drm/msm/msm_gem.h +++ b/drivers/gpu/drm/msm/msm_gem.h @@ -97,18 +97,6 @@ static inline bool is_active(struct msm_gem_object *msm_obj) return atomic_read(&msm_obj->active_count); } -static inline bool is_purgeable(struct msm_gem_object *msm_obj) -{ - WARN_ON(!mutex_is_locked(&msm_obj->base.dev->struct_mutex)); - return (msm_obj->madv == MSM_MADV_DONTNEED) && msm_obj->sgt && - !msm_obj->base.dma_buf && !msm_obj->base.import_attach; -} - -static inline bool is_vunmapable(struct msm_gem_object *msm_obj) -{ - return (msm_obj->vmap_count == 0) && msm_obj->vaddr; -} - /* The shrinker can be triggered while we hold objA->lock, and need * to grab objB->lock to purge it. Lockdep just sees these as a single * class of lock, so we use subclasses to teach it the difference. @@ -125,6 +113,32 @@ enum msm_gem_lock { OBJ_LOCK_SHRINKER, }; +/* Use this helper to read msm_obj->madv when msm_obj->lock not held: */ +static inline unsigned +msm_gem_madv(struct msm_gem_object *msm_obj, enum msm_gem_lock subclass) +{ + unsigned madv; + + mutex_lock_nested(&msm_obj->lock, subclass); + madv = msm_obj->madv; + mutex_unlock(&msm_obj->lock); + + return madv; +} + +static inline bool +is_purgeable(struct msm_gem_object *msm_obj, enum msm_gem_lock subclass) +{ + return (msm_gem_madv(msm_obj, subclass) == MSM_MADV_DONTNEED) && + msm_obj->sgt && !msm_obj->base.dma_buf && + !msm_obj->base.import_attach; +} + +static inline bool is_vunmapable(struct msm_gem_object *msm_obj) +{ + return (msm_obj->vmap_count == 0) && msm_obj->vaddr; +} + void msm_gem_purge(struct drm_gem_object *obj, enum msm_gem_lock subclass); void msm_gem_vunmap(struct drm_gem_object *obj, enum msm_gem_lock subclass); diff --git a/drivers/gpu/drm/msm/msm_gem_shrinker.c b/drivers/gpu/drm/msm/msm_gem_shrinker.c index c41b84a3a484..39a1b5327267 100644 --- a/drivers/gpu/drm/msm/msm_gem_shrinker.c +++ b/drivers/gpu/drm/msm/msm_gem_shrinker.c @@ -54,7 +54,7 @@ msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc) mutex_lock(&priv->mm_lock); list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) { - if (is_purgeable(msm_obj)) + if (is_purgeable(msm_obj, OBJ_LOCK_SHRINKER)) count += msm_obj->base.size >> PAGE_SHIFT; } @@ -84,7 +84,7 @@ msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc) list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) { if (freed >= sc->nr_to_scan) break; - if (is_purgeable(msm_obj)) { + if (is_purgeable(msm_obj, OBJ_LOCK_SHRINKER)) { msm_gem_purge(&msm_obj->base, OBJ_LOCK_SHRINKER); freed += msm_obj->base.size >> PAGE_SHIFT; }