On Wednesday 22 March 2023 14:36:23 Jon Hunter wrote: > On 21/03/2023 18:44, Jon Hunter wrote: > > > > On 20/03/2023 20:59, Pali Rohár wrote: > > > Hello! > > > > > > On Monday 20 March 2023 20:26:05 Jon Hunter wrote: > > > > Hi Pali, > > > > > > > > After this change was made we are seeing the following bug > > > > report on a Tegra234 Jetson Orin board ... > > > > > > > > [ 17.172346] tegra194-pcie 141a0000.pcie: host bridge > > > > /pcie@141a0000 ranges: > > > > [ 17.172470] tegra194-pcie 141a0000.pcie: MEM > > > > 0x2800000000..0x2b27ffffff -> 0x2800000000 > > > > [ 17.172519] tegra194-pcie 141a0000.pcie: MEM > > > > 0x2b28000000..0x2b2fffffff -> 0x0040000000 > > > > [ 17.172548] tegra194-pcie 141a0000.pcie: IO > > > > 0x003a100000..0x003a1fffff -> 0x003a100000 > > > > [ 17.173449] tegra194-pcie 141a0000.pcie: iATU: unroll T, 8 > > > > ob, 2 ib, align 64K, limit 32G > > > > [ 18.279048] tegra194-pcie 141a0000.pcie: Phy link never came up > > > > [ 19.279285] tegra194-pcie 141a0000.pcie: Phy link never came up > > > > [ 19.279599] tegra194-pcie 141a0000.pcie: PCI host bridge to > > > > bus 0005:00 > > > > [ 19.279613] pci_bus 0005:00: root bus resource [bus 00-ff] > > > > [ 19.279622] pci_bus 0005:00: root bus resource [mem > > > > 0x2800000000-0x2b27ffffff pref] > > > > [ 19.279631] pci_bus 0005:00: root bus resource [mem > > > > 0x2b28000000-0x2b2fffffff] (bus address [0x40000000-0x47ffffff]) > > > > [ 19.279639] pci_bus 0005:00: root bus resource [io > > > > 0x200000-0x2fffff] (bus address [0x3a100000-0x3a1fffff]) > > > > [ 19.279687] pci 0005:00:00.0: [10de:229a] type 01 class 0x060400 > > > > [ 19.279886] pci 0005:00:00.0: PME# supported from D0 D3hot > > > > [ 19.283256] pci 0005:00:00.0: PCI bridge to [bus 01-ff] > > > > [ 19.283590] pcieport 0005:00:00.0: Adding to iommu group 26 > > > > [ 19.283991] pcieport 0005:00:00.0: PME: Signaling with IRQ 174 > > > > [ 19.284429] pcieport 0005:00:00.0: AER: enabled with IRQ 174 > > > > [ 19.285003] pci_bus 0005:01: busn_res: [bus 01-ff] is released > > > > [ 19.285591] pci 0005:00:00.0: Removing from iommu group 26 > > > > [ 19.285751] pci_bus 0005:00: busn_res: [bus 00-ff] is released > > > > [ 19.285870] > > > > ================================================================== > > > > [ 19.293351] BUG: KFENCE: use-after-free read in > > > > pci_bus_release_domain_nr+0x10/0x70 > > > > > > > > [ 19.302817] Use-after-free read at 0x000000007f3b80eb (in > > > > kfence-#115): > > > > [ 19.309677] pci_bus_release_domain_nr+0x10/0x70 > > > > [ 19.309691] dw_pcie_host_deinit+0x28/0x78 > > > > [ 19.309702] tegra_pcie_deinit_controller+0x1c/0x38 [pcie_tegra194] > > > > [ 19.309734] tegra_pcie_dw_probe+0x648/0xb28 [pcie_tegra194] > > > > [ 19.309752] platform_probe+0x90/0xd8 > > > > [ 19.309764] really_probe+0xb8/0x298 > > > > [ 19.309777] __driver_probe_device+0x78/0xd8 > > > > [ 19.309788] driver_probe_device+0x38/0x120 > > > > [ 19.309799] __device_attach_driver+0x94/0xe0 > > > > [ 19.309812] bus_for_each_drv+0x70/0xc8 > > > > [ 19.309822] __device_attach+0xfc/0x188 > > > > [ 19.309833] device_initial_probe+0x10/0x18 > > > > [ 19.309844] bus_probe_device+0x94/0xa0 > > > > [ 19.309854] deferred_probe_work_func+0x80/0xb8 > > > > [ 19.309864] process_one_work+0x1e0/0x348 > > > > [ 19.309882] worker_thread+0x48/0x410 > > > > [ 19.309891] kthread+0xf4/0x110 > > > > [ 19.309904] ret_from_fork+0x10/0x20 > > > > > > > > [ 19.311457] kfence-#115: > > > > 0x00000000063a155a-0x00000000ba698da8, size=1072, > > > > cache=kmalloc-2k > > > > > > > > [ 19.311469] allocated by task 96 on cpu 10 at 19.279323s: > > > > [ 19.311562] __kmem_cache_alloc_node+0x260/0x278 > > > > [ 19.311571] kmalloc_trace+0x24/0x30 > > > > [ 19.311580] pci_alloc_bus+0x24/0xa0 > > > > [ 19.311590] pci_register_host_bridge+0x48/0x4b8 > > > > [ 19.311601] pci_scan_root_bus_bridge+0xc0/0xe8 > > > > [ 19.311613] pci_host_probe+0x18/0xc0 > > > > [ 19.311623] dw_pcie_host_init+0x2c0/0x568 > > > > [ 19.311630] tegra_pcie_dw_probe+0x610/0xb28 [pcie_tegra194] > > > > [ 19.311647] platform_probe+0x90/0xd8 > > > > [ 19.311653] really_probe+0xb8/0x298 > > > > [ 19.311663] __driver_probe_device+0x78/0xd8 > > > > [ 19.311672] driver_probe_device+0x38/0x120 > > > > [ 19.311682] __device_attach_driver+0x94/0xe0 > > > > [ 19.311694] bus_for_each_drv+0x70/0xc8 > > > > [ 19.311702] __device_attach+0xfc/0x188 > > > > [ 19.311713] device_initial_probe+0x10/0x18 > > > > [ 19.311724] bus_probe_device+0x94/0xa0 > > > > [ 19.311733] deferred_probe_work_func+0x80/0xb8 > > > > [ 19.311743] process_one_work+0x1e0/0x348 > > > > [ 19.311753] worker_thread+0x48/0x410 > > > > [ 19.311763] kthread+0xf4/0x110 > > > > [ 19.311771] ret_from_fork+0x10/0x20 > > > > > > > > [ 19.311782] freed by task 96 on cpu 10 at 19.285833s: > > > > [ 19.311799] release_pcibus_dev+0x30/0x40 > > > > [ 19.311808] device_release+0x30/0x90 > > > > [ 19.311814] kobject_put+0xa8/0x120 > > > > [ 19.311832] device_unregister+0x20/0x30 > > > > [ 19.311839] pci_remove_bus+0x78/0x88 > > > > [ 19.311850] pci_remove_root_bus+0x5c/0x98 > > > > [ 19.311860] dw_pcie_host_deinit+0x28/0x78 > > > > [ 19.311866] tegra_pcie_deinit_controller+0x1c/0x38 [pcie_tegra194] > > > > [ 19.311883] tegra_pcie_dw_probe+0x648/0xb28 [pcie_tegra194] > > > > [ 19.311900] platform_probe+0x90/0xd8 > > > > [ 19.311906] really_probe+0xb8/0x298 > > > > [ 19.311916] __driver_probe_device+0x78/0xd8 > > > > [ 19.311926] driver_probe_device+0x38/0x120 > > > > [ 19.311936] __device_attach_driver+0x94/0xe0 > > > > [ 19.311947] bus_for_each_drv+0x70/0xc8 > > > > [ 19.311956] __device_attach+0xfc/0x188 > > > > [ 19.311966] device_initial_probe+0x10/0x18 > > > > [ 19.311976] bus_probe_device+0x94/0xa0 > > > > [ 19.311985] deferred_probe_work_func+0x80/0xb8 > > > > [ 19.311995] process_one_work+0x1e0/0x348 > > > > [ 19.312005] worker_thread+0x48/0x410 > > > > [ 19.312014] kthread+0xf4/0x110 > > > > [ 19.312022] ret_from_fork+0x10/0x20 > > > > > > Based on the above trace it looks like a double free of "pp->bridge" > > > structure. > > > > > > Also, which kernel version are you using? Because from above third > > > trace it looks like that dw_pcie_host_deinit() calls first > > > pci_remove_root_bus() function and then (from first strace) it also > > > calls pci_bus_release_domain_nr() function. > > > > > > I have definitely seen this with v6.2. I was doing some more testing and > > now it appears that the issue is somewhat intermittent. So now I am no > > longer confident that reverting this change does fix it. The backtrace > > made it seem like this is a likely candidate, but I need to do more > > testing. > > > OK, so I have done some more testing. I found that if I build the Tegra194 > PCIe driver into the kernel, then I can reproduce the above 100%. I guess by > loading early there is more chance of a probe deferral. With that I verified > that the issue is seen on v6.2 (as I previously observed) and on v6.3-rc3. > Reverting this commit on top of v6.3-rc3 fixes this and I no longer see the > problem. > > Let me know if you have any thoughts on how to fix this. > > Thanks > Jon > > -- > nvpublic Sorry, but I'm not going to investigate another issue in this area. I spent too much time in debugging issues, prepared fixes and the only result was simple silence, rejection and proposal to resend emails. The only thing which I receive are bug reports from the users and I really do not want to repeat reply, hey patch for this was sent to mailing list... So I do not see reason why I should look at this issue as with high probability result would be same... for which I'm not interested.
