From 68d890a3cca5a96a5443972922c84df89f6301e6 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Micha=C5=82=20Miros=C5=82aw?= Date: Mon, 14 Aug 2017 23:53:45 +0200 Subject: [PATCH] drm/tegra: Fix NULL deref in debugfs/iova MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When IOMMU is off, ->mm_lock is not initialized and ->mm is NULL. Signed-off-by: Michał Mirosław Signed-off-by: Thierry Reding --- drivers/gpu/drm/tegra/drm.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c index eddea778290f..86b3e1ce0b65 100644 --- a/drivers/gpu/drm/tegra/drm.c +++ b/drivers/gpu/drm/tegra/drm.c @@ -1033,9 +1033,11 @@ static int tegra_debugfs_iova(struct seq_file *s, void *data) struct tegra_drm *tegra = drm->dev_private; struct drm_printer p = drm_seq_file_printer(s); - mutex_lock(&tegra->mm_lock); - drm_mm_print(&tegra->mm, &p); - mutex_unlock(&tegra->mm_lock); + if (tegra->domain) { + mutex_lock(&tegra->mm_lock); + drm_mm_print(&tegra->mm, &p); + mutex_unlock(&tegra->mm_lock); + } return 0; } -- 2.30.2