https://bugzilla.kernel.org/show_bug.cgi?id=214375

Bug ID: 214375 Summary: 5.14 Regression: Null pointer dereference in radeon_agp_head_init Product: Drivers Version: 2.5 Kernel Version: 5.14.2 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: Video(DRI - non Intel) Assignee: drivers_video-dri@kernel-bugs.osdl.org Reporter: calvin.walton@kepstin.ca Regression: No

Created attachment 298753 --> https://bugzilla.kernel.org/attachment.cgi?id=298753&action=edit Complete kernel dmesg

I have an i586 system (ALi chipset, AMD CPU) running with a Radeon 9200 SE in an AGP slot. This system was working correctly with the 5.13 kernel series, but after switching to 5.14 I no longer have kms graphics output.

The radeon module fails to initialize with the following backtrace:

Sep 12 13:15:53 mai kernel: [drm] radeon kernel modesetting enabled. Sep 12 13:15:53 mai kernel: radeon 0000:01:00.0: vgaarb: deactivate vga console Sep 12 13:15:53 mai kernel: Console: switching to colour dummy device 80x25 Sep 12 13:15:53 mai kernel: BUG: kernel NULL pointer dereference, address: 00000008 Sep 12 13:15:53 mai kernel: #PF: supervisor read access in kernel mode Sep 12 13:15:53 mai kernel: #PF: error_code(0x0000) - not-present page Sep 12 13:15:53 mai kernel: *pde = 00000000 Sep 12 13:15:53 mai kernel: Oops: 0000 [#1] Sep 12 13:15:53 mai kernel: CPU: 0 PID: 288 Comm: systemd-udevd Tainted: G W 5.14.2 #2 Sep 12 13:15:53 mai kernel: Hardware name: American Megatrends Inc. Uknown /PT-2200 , BIOS 062710 Sep 12 13:15:53 mai kernel: EIP: radeon_agp_head_init+0xa/0xa0 [radeon] Sep 12 13:15:53 mai kernel: Code: 85 fb fe ff 74 d6 84 c9 74 d6 84 c9 ff ff e9 f7 ff ff e9 f7 90 66 90 66 90 66 90 66 55 ba c0 0d 55 ba c0 0d 56 53 8b 70 56 53 <8b> 70 6> Sep 12 13:15:53 mai kernel: EAX: 00000000 EBX: b3978c00 ECX: b3a21ce8 EDX: 00000dc0 Sep 12 13:15:53 mai kernel: ESI: b493e000 EDI: b1cad000 EBP: b3a21cf8 ESP: b3a21cf0 Sep 12 13:15:53 mai kernel: DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 EFLAGS: 00210202 Sep 12 13:15:53 mai kernel: CR0: 80050033 CR2: 00000008 CR3: 03f86000 CR4: 00000090 Sep 12 13:15:53 mai kernel: Call Trace: Sep 12 13:15:53 mai kernel: radeon_driver_load_kms+0x168/0x1a0 [radeon] Sep 12 13:15:53 mai kernel: drm_dev_register+0xb5/0x1a0 [drm] Sep 12 13:15:53 mai kernel: radeon_pci_probe+0xa1/0xe0 [radeon] Sep 12 13:15:53 mai kernel: pci_device_probe+0x88/0x100 Sep 12 13:15:53 mai kernel: really_probe.part.0+0x78/0x220 Sep 12 13:15:53 mai kernel: __driver_probe_device+0x7e/0x100 Sep 12 13:15:53 mai kernel: driver_probe_device+0x19/0xe0 Sep 12 13:15:53 mai kernel: __driver_attach+0x81/0x140 Sep 12 13:15:53 mai kernel: ? __device_attach_driver+0xe0/0xe0 Sep 12 13:15:53 mai kernel: bus_for_each_dev+0x47/0x80 Sep 12 13:15:53 mai kernel: driver_attach+0x17/0x20 Sep 12 13:15:53 mai kernel: ? __device_attach_driver+0xe0/0xe0 Sep 12 13:15:53 mai kernel: bus_add_driver+0xec/0x1a0 Sep 12 13:15:53 mai kernel: driver_register+0x74/0xc0 Sep 12 13:15:53 mai kernel: ? 0xf0e5f000 Sep 12 13:15:53 mai kernel: __pci_register_driver+0x37/0x40 Sep 12 13:15:53 mai kernel: radeon_module_init+0x65/0x1000 [radeon] Sep 12 13:15:53 mai kernel: do_one_initcall+0x33/0x120 Sep 12 13:15:53 mai kernel: ? kfree+0x151/0x160 Sep 12 13:15:53 mai kernel: ? __vunmap+0x1d5/0x260 Sep 12 13:15:53 mai kernel: ? kmem_cache_alloc+0x10a/0x160 Sep 12 13:15:53 mai kernel: do_init_module+0x45/0x240 Sep 12 13:15:53 mai kernel: load_module+0x1cc3/0x2020 Sep 12 13:15:53 mai kernel: ? 0xf0e5f000 Sep 12 13:15:53 mai kernel: __ia32_sys_finit_module+0x89/0xc0 Sep 12 13:15:53 mai kernel: do_int80_syscall_32+0x2e/0x80 Sep 12 13:15:53 mai kernel: entry_INT80_32+0x109/0x109 Sep 12 13:15:53 mai kernel: EIP: 0xa7b66332 Sep 12 13:15:53 mai kernel: Code: 90 66 90 66 90 66 90 90 55 57 56 53 8b 6c 24 2c 8b 7c 24 28 8b 74 24 24 8b 54 24 20 8b 4c 24 1c 8b 5c 24 18 8b 44 24 14 cd 80 <5b> 5e 5> Sep 12 13:15:53 mai kernel: EAX: ffffffda EBX: 00000016 ECX: a7cbfb05 EDX: 00000000 Sep 12 13:15:53 mai kernel: ESI: 02068a50 EDI: 020677c0 EBP: ffffffff ESP: affc0fcc Sep 12 13:15:53 mai kernel: DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b EFLAGS: 00200292 Sep 12 13:15:53 mai kernel: Modules linked in: r8169 radeon(+) realtek mdio_devres libphy snd_emu10k1 snd_ac97_codec ac97_bus snd_util_mem i2c_algo_bit snd_hwdep drm_ttm> Sep 12 13:15:53 mai kernel: CR2: 0000000000000008 Sep 12 13:15:53 mai kernel: ---[ end trace d1e7fe80690cc5a8 ]--- Sep 12 13:15:53 mai kernel: EIP: radeon_agp_head_init+0xa/0xa0 [radeon] Sep 12 13:15:53 mai kernel: Code: 85 fb fe ff 74 d6 84 c9 74 d6 84 c9 ff ff e9 f7 ff ff e9 f7 90 66 90 66 90 66 90 66 55 ba c0 0d 55 ba c0 0d 56 53 8b 70 56 53 <8b> 70 6> Sep 12 13:15:53 mai kernel: EAX: 00000000 EBX: b3978c00 ECX: b3a21ce8 EDX: 00000dc0 Sep 12 13:15:53 mai kernel: ESI: b493e000 EDI: b1cad000 EBP: b3a21cf8 ESP: b3a21cf0 Sep 12 13:15:53 mai kernel: DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 EFLAGS: 00210202 Sep 12 13:15:53 mai kernel: CR0: 80050033 CR2: 00000008 CR3: 03f86000 CR4: 00000090

It looks like this issue should be easy to bisect, but the system is pretty slow, so that will take a while. Please let me know if there are any other logs or debug options that you would like me to try. I've attached the full kernel boot log from the boot that this backtrace was taken from.

Note that although I'm running Gentoo, I am using an unpatched upstream kernel.