From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?utf-8?q?Noralf=20Tr=C3=B8nnes?= Date: Tue, 22 Nov 2022 21:58:40 +0100 Subject: [PATCH 2/6] drm/gud: Fix UBSAN warning MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="utf-8" Message-Id: <20221122-gud-shadow-plane-v1-2-9de3afa3383e@tronnes.org> References: <20221122-gud-shadow-plane-v1-0-9de3afa3383e@tronnes.org> In-Reply-To: <20221122-gud-shadow-plane-v1-0-9de3afa3383e@tronnes.org> To: Thomas Zimmermann , stable@vger.kernel.org, Dave Airlie , dri-devel@lists.freedesktop.org, Hans de Goede , Noralf Trønnes , Maxime Ripard , Javier Martinez Canillas X-Mailer: b4 0.10.1 X-Developer-Signature: v=1; a=ed25519-sha256; t=1669150743; l=3198; i=noralf@tronnes.org; s=20221122; h=from:subject:message-id; bh=ogMSE9EsFPrqPZEUwysXH8lyHyy6tDQqqNui2sxir30=; b=sDJN+srNmYtspJkZWFj6PEgW4229F2NCN9iGDnbPOYeOByMep7wr3ivfINEEM1pOnTM2pPn4nXMf p0jdQ7xzAAiUOCw1dLGEq+zwwmuVJBdb5yHrye32YbplHZn8wel/ X-Developer-Key: i=noralf@tronnes.org; a=ed25519; pk=0o9is4iddvvlrY3yON5SVtAbgPnVs0LfQsjfqR2Hvz8= X-Endpoint-Received: by B4 Submission Endpoint for noralf@tronnes.org/20221122 with auth_id=8 List-Id: B4 Web Endpoint Patches UBSAN complains about invalid value for bool: [ 101.165172] [drm] Initialized gud 1.0.0 20200422 for 2-3.2:1.0 on minor 1 [ 101.213360] gud 2-3.2:1.0: [drm] fb1: guddrmfb frame buffer device [ 101.213426] usbcore: registered new interface driver gud [ 101.989431] ================================================================================ [ 101.989441] UBSAN: invalid-load in /home/pi/linux/include/linux/iosys-map.h:253:9 [ 101.989447] load of value 121 is not a valid value for type '_Bool' [ 101.989451] CPU: 1 PID: 455 Comm: kworker/1:6 Not tainted 5.18.0-rc5-gud-5.18-rc5 #3 [ 101.989456] Hardware name: Hewlett-Packard HP EliteBook 820 G1/1991, BIOS L71 Ver. 01.44 04/12/2018 [ 101.989459] Workqueue: events_long gud_flush_work [gud] [ 101.989471] Call Trace: [ 101.989474] [ 101.989479] dump_stack_lvl+0x49/0x5f [ 101.989488] dump_stack+0x10/0x12 [ 101.989493] ubsan_epilogue+0x9/0x3b [ 101.989498] __ubsan_handle_load_invalid_value.cold+0x44/0x49 [ 101.989504] dma_buf_vmap.cold+0x38/0x3d [ 101.989511] ? find_busiest_group+0x48/0x300 [ 101.989520] drm_gem_shmem_vmap+0x76/0x1b0 [drm_shmem_helper] [ 101.989528] drm_gem_shmem_object_vmap+0x9/0xb [drm_shmem_helper] [ 101.989535] drm_gem_vmap+0x26/0x60 [drm] [ 101.989594] drm_gem_fb_vmap+0x47/0x150 [drm_kms_helper] [ 101.989630] gud_prep_flush+0xc1/0x710 [gud] [ 101.989639] ? _raw_spin_lock+0x17/0x40 [ 101.989648] gud_flush_work+0x1e0/0x430 [gud] [ 101.989653] ? __switch_to+0x11d/0x470 [ 101.989664] process_one_work+0x21f/0x3f0 [ 101.989673] worker_thread+0x200/0x3e0 [ 101.989679] ? rescuer_thread+0x390/0x390 [ 101.989684] kthread+0xfd/0x130 [ 101.989690] ? kthread_complete_and_exit+0x20/0x20 [ 101.989696] ret_from_fork+0x22/0x30 [ 101.989706] [ 101.989708] ================================================================================ The source of this warning is in iosys_map_clear() called from dma_buf_vmap(). It conditionally sets values based on map->is_iomem. The iosys_map variables are allocated uninitialized on the stack leading to ->is_iomem having all kinds of values and not only 0/1. Fix this by zeroing the iosys_map variables. Fixes: 40e1a70b4aed ("drm: Add GUD USB Display driver") Cc: # v5.18+ Signed-off-by: Noralf Trønnes --- drivers/gpu/drm/gud/gud_pipe.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/gud/gud_pipe.c b/drivers/gpu/drm/gud/gud_pipe.c index 7c6dc2bcd14a..61f4abaf1811 100644 --- a/drivers/gpu/drm/gud/gud_pipe.c +++ b/drivers/gpu/drm/gud/gud_pipe.c @@ -157,8 +157,8 @@ static int gud_prep_flush(struct gud_device *gdrm, struct drm_framebuffer *fb, { struct dma_buf_attachment *import_attach = fb->obj[0]->import_attach; u8 compression = gdrm->compression; - struct iosys_map map[DRM_FORMAT_MAX_PLANES]; - struct iosys_map map_data[DRM_FORMAT_MAX_PLANES]; + struct iosys_map map[DRM_FORMAT_MAX_PLANES] = { }; + struct iosys_map map_data[DRM_FORMAT_MAX_PLANES] = { }; struct iosys_map dst; void *vaddr, *buf; size_t pitch, len; -- b4 0.10.1