Got UBSAN warning from Dell D600 running 5.0.0-rc4-00218-g12491ed354d2.
The warning did not happen on bootup but during xfce session start or console
switch.
[ 15.323113] radeon 0000:01:00.0: putting AGP V2 device into 4x mode
[ 15.323134] radeon 0000:01:00.0: GTT: 128M 0xE0000000 - 0xE7FFFFFF
[ 15.323142] radeon 0000:01:00.0: VRAM: 128M 0x00000000E8000000 -
0x00000000EFFFFFFF (32M used)
[ 15.323459] [drm] Detected VRAM RAM=128M, BAR=128M
[ 15.323463] [drm] RAM width 64bits DDR
[ 15.323566] [TTM] Zone kernel: Available graphics memory: 412446 kiB
[ 15.323567] [TTM] Initializing pool allocator
[ 15.323580] [TTM] Initializing DMA pool allocator
[ 15.323609] [drm] radeon: 32M of VRAM memory ready
[ 15.323611] [drm] radeon: 128M of GTT memory ready.
[ 15.323621] [drm] radeon: power management initialized
[ 15.331289] radeon 0000:01:00.0: WB disabled
[ 15.331296] radeon 0000:01:00.0: fence driver on ring 0 use gpu addr
0x00000000e0000000 and cpu addr 0x712386dd
[ 15.331299] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[ 15.331300] [drm] Driver supports precise vblank timestamp query.
[ 15.331315] [drm] radeon: irq initialized.
[ 15.331317] [drm] Loading R200 Microcode
[...]
[ 15.795041] [drm] radeon: ring at 0x00000000E0001000
[ 15.795073] [drm] ring test succeeded in 1 usecs
[ 15.795316] [drm] ib test succeeded in 0 usecs
[ 15.801857] [drm] Panel ID String: 2K077141X13
[ 15.801861] [drm] Panel Size 1024x768
[ 15.801938] [drm] No TV DAC info found in BIOS
[ 15.802012] [drm] Radeon Display Connectors
[ 15.802015] [drm] Connector 0:
[ 15.802017] [drm] VGA-1
[ 15.802023] [drm] DDC: 0x60 0x60 0x60 0x60 0x60 0x60 0x60 0x60
[ 15.802024] [drm] Encoders:
[ 15.802027] [drm] CRT1: INTERNAL_DAC1
[ 15.802030] [drm] Connector 1:
[ 15.802031] [drm] DVI-D-1
[ 15.802033] [drm] HPD1
[ 15.802038] [drm] DDC: 0x64 0x64 0x64 0x64 0x64 0x64 0x64 0x64
[ 15.802040] [drm] Encoders:
[ 15.802042] [drm] DFP1: INTERNAL_TMDS1
[ 15.802044] [drm] Connector 2:
[ 15.802046] [drm] LVDS-1
[ 15.802047] [drm] Encoders:
[ 15.802049] [drm] LCD1: INTERNAL_LVDS
[ 15.802051] [drm] Connector 3:
[ 15.802053] [drm] SVIDEO-1
[ 15.802054] [drm] Encoders:
[ 15.802056] [drm] TV1: INTERNAL_DAC2
[ 15.845987] [drm] fb mappable at 0xE8040000
[ 15.845988] [drm] vram apper at 0xE8000000
[ 15.845989] [drm] size 1572864
[ 15.845990] [drm] fb depth is 16
[ 15.845990] [drm] pitch is 2048
[ 15.848183] fbcon: radeondrmfb (fb0) is primary device
[ 15.892233] Console: switching to colour frame buffer device 128x48
[ 15.901408] radeon 0000:01:00.0: fb0: radeondrmfb frame buffer device
[ 15.905786] [drm] Initialized radeon 2.50.0 20080528 for 0000:01:00.0 on
minor 0
[...]
[ 447.146334]
================================================================================
[ 447.146347] UBSAN: Undefined behaviour in
drivers/gpu/drm/radeon/r200.c:480:34
[ 447.146351] shift exponent 4096 is too large for 32-bit type 'int'
[ 447.146357] CPU: 0 PID: 386 Comm: Xorg Not tainted
5.0.0-rc4-00218-g12491ed354d2 #7
[ 447.146358] Hardware name: Dell Computer Corporation Latitude D600
/0X2034, BIOS A16 06/29/2005
[ 447.146359] Call Trace:
[ 447.146375] dump_stack+0x16/0x19
[ 447.146379] ubsan_epilogue+0xb/0x29
[ 447.146381] __ubsan_handle_shift_out_of_bounds.cold.14+0x26/0x80
[ 447.146486] ? radeon_cs_packet_next_reloc+0x3c/0x150 [radeon]
[ 447.146521] ? r100_reloc_pitch_offset+0x27/0x150 [radeon]
[ 447.146551] r200_packet0_check.cold.0+0xf/0x45 [radeon]
[ 447.146592] ? r200_copy_dma+0x430/0x430 [radeon]
[ 447.146626] r100_cs_parse_packet0+0x53/0xe0 [radeon]
[ 447.146661] r100_cs_parse+0x12e/0x440 [radeon]
[ 447.146700] ? r200_copy_dma+0x430/0x430 [radeon]
[ 447.146734] radeon_cs_ioctl+0x256/0x890 [radeon]
[ 447.146743] ? ttm_bo_init_reserved+0x338/0x390 [ttm]
[ 447.146779] ? radeon_cs_parser_init+0x550/0x550 [radeon]
[ 447.146804] drm_ioctl_kernel+0x96/0xe0 [drm]
[ 447.146816] drm_ioctl+0x25f/0x530 [drm]
[ 447.146850] ? radeon_cs_parser_init+0x550/0x550 [radeon]
[ 447.146855] ? ktime_get_mono_fast_ns+0xb6/0x1f0
[ 447.146880] radeon_drm_ioctl+0x40/0x80 [radeon]
[ 447.146905] ? radeon_pci_shutdown+0x30/0x30 [radeon]
[ 447.146909] do_vfs_ioctl+0x90/0x6c0
[ 447.146913] ? handle_mm_fault+0xa48/0xfe0
[ 447.146918] ? vm_mmap_pgoff+0x88/0xd0
[ 447.146923] ? ktime_get_ts64+0x5f/0x1e0
[ 447.146925] ksys_ioctl+0x39/0x70
[ 447.146927] sys_ioctl+0x11/0x13
[ 447.146930] do_fast_syscall_32+0x95/0x1d0
[ 447.146934] entry_SYSENTER_32+0x6b/0xbd
[ 447.146936] EIP: 0xb7f937cd
[ 447.146939] Code: 54 cd ff ff 85 d2 8b 98 58 cd ff ff 89 c8 74 02 89 0a 5b 5d c3
8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90
90 90 90 8d 76 00 58 b8 77 00 00 00 cd 80 90 8d 76
[ 447.146941] EAX: ffffffda EBX: 0000000e ECX: c0206466 EDX: 02311c40
[ 447.146943] ESI: 02311a00 EDI: c0206466 EBP: 0000000e ESP: bff73058
[ 447.146945] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b EFLAGS: 00203292
[ 447.146947]
================================================================================
