On Wed, Oct 21, 2020 at 08:13:43PM -0700, Randy Dunlap wrote: > Hi, > > With linux-next 20201021, when booting up, I am seeing this: > > [ 0.560896] UBSAN: signed-integer-overflow in ../drivers/gpu/drm/drm_modes.c:765:20 > [ 0.560903] 2376000 * 1000 cannot be represented in type 'int' Dang. Didn't realize these new crazy >8k modes have dotclocks reaching almost 6 GHz, which would overflow even u32. I guess we'll switch to 64bit maths. Now I wonder how many other places can hit this overflow in practice... > [ 0.560909] CPU: 3 PID: 7 Comm: kworker/u16:0 Not tainted 5.9.0-next-20201021 #2 > [ 0.560914] Hardware name: TOSHIBA PORTEGE R835/Portable PC, BIOS Version 4.10 01/08/2013 > [ 0.560924] Workqueue: events_unbound async_run_entry_fn > > [ 0.560930] Call Trace: > [ 0.560938] dump_stack+0x5e/0x74 > [ 0.560943] ubsan_epilogue+0x9/0x45 > [ 0.560948] handle_overflow+0x8b/0x98 > [ 0.560953] ? set_track+0x3f/0xad > [ 0.560958] __ubsan_handle_mul_overflow+0xe/0x10 > [ 0.560964] drm_mode_vrefresh+0x4a/0xbc > [ 0.560970] initcall i915_init+0x0/0x6a returned 0 after 116076 usecs > [ 0.560974] calling cn_proc_init+0x0/0x36 @ 1 > [ 0.560978] cea_mode_alternate_clock+0x11/0x62 > [ 0.560985] drm_match_cea_mode+0xc7/0x1e7 > [ 0.560987] initcall cn_proc_init+0x0/0x36 returned 0 after 3 usecs > [ 0.560990] calling topology_sysfs_init+0x0/0x2d @ 1 > [ 0.561000] drm_mode_validate_ycbcr420+0xd/0x48 > [ 0.561005] drm_helper_probe_single_connector_modes+0x6db/0x7da > [ 0.561012] drm_client_modeset_probe+0x225/0x143f > [ 0.561018] ? bitmap_fold+0x8a/0x8a > [ 0.561023] ? update_cfs_rq_load_avg+0x192/0x1a2 > [ 0.561029] __drm_fb_helper_initial_config_and_unlock+0x3f/0x5b7 > [ 0.561035] ? get_sd_balance_interval+0x1c/0x40 > [ 0.561040] drm_fb_helper_initial_config+0x48/0x4f > [ 0.561047] intel_fbdev_initial_config+0x13/0x23 > [ 0.561052] async_run_entry_fn+0x89/0x15c > [ 0.561058] process_one_work+0x15c/0x1f3 > [ 0.561064] worker_thread+0x1ac/0x25d > [ 0.561069] ? process_scheduled_works+0x2e/0x2e > [ 0.561074] kthread+0x10e/0x116 > [ 0.561078] ? kthread_parkme+0x1c/0x1c > [ 0.561083] ret_from_fork+0x22/0x30 > [ 0.561087] ================================================================================ > > -- > ~Randy > Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Ville Syrjälä Intel _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
