From e034b8a18d4badceecb672c58b488bad1e901d95 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Wed, 22 Feb 2023 13:37:12 +0100 Subject: [PATCH 1/3] drm/msm: Fix possible uninitialized access in fbdev Do not run drm_fb_helper_unprepare() if fbdev allocation fails. Avoids access to an uninitialized pointer. Original bug report is at [1]. Reported-by: kernel test robot Signed-off-by: Thomas Zimmermann Fixes: 3fb1f62f80a1 ("drm/fb-helper: Remove drm_fb_helper_unprepare() from drm_fb_helper_fini()") Link: https://lore.kernel.org/oe-kbuild-all/202302220810.9dymwCQ8-lkp@intel.com/ # 1 Reviewed-by: Dmitry Baryshkov Link: https://patchwork.freedesktop.org/patch/msgid/20230222123712.5049-1-tzimmermann@suse.de --- drivers/gpu/drm/msm/msm_fbdev.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/msm/msm_fbdev.c b/drivers/gpu/drm/msm/msm_fbdev.c index c804e5ba682af..d26aa52217ce1 100644 --- a/drivers/gpu/drm/msm/msm_fbdev.c +++ b/drivers/gpu/drm/msm/msm_fbdev.c @@ -136,13 +136,13 @@ static const struct drm_fb_helper_funcs msm_fb_helper_funcs = { struct drm_fb_helper *msm_fbdev_init(struct drm_device *dev) { struct msm_drm_private *priv = dev->dev_private; - struct msm_fbdev *fbdev = NULL; + struct msm_fbdev *fbdev; struct drm_fb_helper *helper; int ret; fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL); if (!fbdev) - goto fail; + return NULL; helper = &fbdev->base; From c176060a4c76ed0043cb9c10435af04ed1ad0560 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Fri, 24 Feb 2023 10:25:12 -0700 Subject: [PATCH 2/3] drm: omapdrm: Do not use helper unininitialized in omap_fbdev_init() Clang warns (or errors with CONFIG_WERROR): ../drivers/gpu/drm/omapdrm/omap_fbdev.c:235:6: error: variable 'helper' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized] if (!fbdev) ^~~~~~ ../drivers/gpu/drm/omapdrm/omap_fbdev.c:259:26: note: uninitialized use occurs here drm_fb_helper_unprepare(helper); ^~~~~~ ../drivers/gpu/drm/omapdrm/omap_fbdev.c:235:2: note: remove the 'if' if its condition is always false if (!fbdev) ^~~~~~~~~~~ ../drivers/gpu/drm/omapdrm/omap_fbdev.c:228:30: note: initialize the variable 'helper' to silence this warning struct drm_fb_helper *helper; ^ = NULL 1 error generated. Return early, as there is nothing for the function to do if memory cannot be allocated. There is no point in adding another label to just emit the warning at the end of the function in this case, as memory allocation failures are already logged. Fixes: 3fb1f62f80a1 ("drm/fb-helper: Remove drm_fb_helper_unprepare() from drm_fb_helper_fini()") Link: https://github.com/ClangBuiltLinux/linux/issues/1809 Link: https://lore.kernel.org/oe-kbuild-all/202302250058.fYTe9aTP-lkp@intel.com/ Reported-by: kernel test robot Signed-off-by: Nathan Chancellor Signed-off-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20230224-omapdrm-wsometimes-uninitialized-v1-1-3fec8906ee3a@kernel.org --- drivers/gpu/drm/omapdrm/omap_fbdev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/omapdrm/omap_fbdev.c b/drivers/gpu/drm/omapdrm/omap_fbdev.c index 84429728347f7..a6c8542087ecf 100644 --- a/drivers/gpu/drm/omapdrm/omap_fbdev.c +++ b/drivers/gpu/drm/omapdrm/omap_fbdev.c @@ -233,7 +233,7 @@ void omap_fbdev_init(struct drm_device *dev) fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL); if (!fbdev) - goto fail; + return; INIT_WORK(&fbdev->work, pan_worker); From 047a754558d640eaa080fce3b22ca9f3d4e04626 Mon Sep 17 00:00:00 2001 From: Asahi Lina Date: Mon, 27 Feb 2023 18:04:21 +0900 Subject: [PATCH 3/3] drm/shmem-helper: Revert accidental non-GPL export The referenced commit added a wrapper for drm_gem_shmem_get_pages_sgt(), but in the process it accidentally changed the export type from GPL to non-GPL. Switch it back to GPL. Reported-by: Dmitry Osipenko Fixes: ddddedaa0db9 ("drm/shmem-helper: Fix locking for drm_gem_shmem_get_pages_sgt()") Signed-off-by: Asahi Lina Signed-off-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20230227-shmem-export-fix-v1-1-8880b2c25e81@asahilina.net --- drivers/gpu/drm/drm_gem_shmem_helper.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index 259176d78f3b9..b05dc62418f7d 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -744,7 +744,7 @@ struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem) return sgt; } -EXPORT_SYMBOL(drm_gem_shmem_get_pages_sgt); +EXPORT_SYMBOL_GPL(drm_gem_shmem_get_pages_sgt); /** * drm_gem_shmem_prime_import_sg_table - Produce a shmem GEM object from